Geology of Cuba (AAPG Studies in Geology 58)

Overview

Pardo, G., 2009, Overview, in G. Pardo, The geology of Cuba: AAPG Studies in Geology Series, no. 58, p. 1 – 47.

INTRODUCTION

the Instituto Cubano del Petroleo (ICP) and Cubapetroleo (CUPET). After the revolution, Cuba joined the Committee for Mutual Economic Assistance (COMECON), formed by the former Soviet Union and associated countries, and received considerable assistance from Soviet, Polish, Bulgarian, Czechoslovakian, and Romanian earth scientists and technicians. Exploration and drilling became the responsibility of the Instituto Cubano de Recursos Minerales (ICRM), and later of the Empressa de Perforacion y Extraccion de Petroleo (EPEP). These agencies were under the control of the Ministerio de Industrias Basica (MINBAS). A large number of deep wells (3000–5000 m [10,000– 16,400 ft] deep) were drilled in central and western Cuba, many of them (Pozos Parametricos) only for stratigraphic and structural information. Non-Soviet and non-COMECON foreign work began again in 1988, resulting in an increase in exploration and development activity (mostly seismic surveying and drilling). So far, major international oil companies and United States-based companies have not participated. There has been an ongoing program of mapping the entire island conducted under the direction of the Cuban Academy of Science, Institute of Geology and Paleontology, with, formerly, the assistance of the former Soviet Union’s Academy of Science. This program has yielded several publications, mostly in Spanish, but some in English. It also resulted in a 1:500,000 geologic map in 1985 (Cuba, 1985a), an excellent 1:250,000 geologic map in 1988 (Pushcharovsky et al., 1988), a good 1:500,000 tectonic map in 1989 (Pushcharovsky et al., 1989), and a 1:500,000 nonmetallic mineral and combustible deposits and indication map in 1988 (Cuba, 1988). Unfortunately, the Cuban Academy of Science and the Cuban government agencies responsible for petroleum exploration and production do not appear to work together; matters related to petroleum are considered confidential.

The geology of Cuba has been a challenge to geologists because of features such as the presence of well-preserved Jurassic ammonites, the rich Tertiary foraminiferal faunas (including remarkable Paleogene orbitoids), the gigantic Upper Cretaceous rudistids, the spectacular limestone Mogotes of Pinar del Rio, the extensive outcrops of ultrabasic igneous rocks, the chromite and manganese deposits, and the extraordinary structural complexity. In addition to these features, the numerous petroleum seeps, many of them coming out of basic igneous rock, have attracted much attention. It is interesting to read early papers by reputable geologists such as E. DeGoyler (1918), J. W. Lewis (1932), or R. H. Palmer (1945), and to realize how little was known or understood about the geology of the southern portion of the North American continent in the early part of the 20th century. Much early understanding of the geology of Cuba resulted from a series of studies conducted between 1936 and 1946 by the University of Utrecht, Holland, under the direction of L. M. R. Rutten. Some resultant publications are Rutten (1936), MacGillavry (1937), Thiadens (1937a, b), Vermut (1937), van Wessen (1943), Keijzer (1945), Hermes (1945), and De Vletter (1946). These authors outlined the components of a classic geosyncline. Between the late 1930s and late 1950s, Cuban geologists and paleontologists, such as P. R. Ortega y Ros, J. Broderman, P. Bermudez, and J. F. Albear, published several articles about the island’s geology. The search for oil has contributed significantly to the present understanding of the island’s geology. Prior to the 1959 revolution, hydrocarbon exploration was mostly undertaken by international oil companies such as Atlantic Refining, Esso Standard, Gulf Oil, Shell Oil, and the California Oil Company. Late in 1959, the oil company files were copied and confiscated. In 1960, the oil companies were expropriated, and the search for oil became the responsibility of

Copyright n2009 by The American Association of Petroleum Geologists. DOI:10.1306/13141059St583328

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FIGURE 1. Cuba: old provinces.

FIGURE 2. Cuba: new (1976) provinces.

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FIGURE 3. Regional setting.

In 1967, Khudoley (at that time with the former Soviet Union’s Academy of Sciences) published, through AAPG, his concepts and interpretation of Cuban geology. In 1971, Khudoley and Meyerhoff presented their conflicting concepts in a joint article in a Geological Society of America memoir. Contacts between Cuban, American, and international earth scientists have now revived. An example is International Union of Geological Sciences – United Nations Educational, Scientific, and Cultural Organization International Geological Correlation Programme (IGCP) Project 364 and ongoing Project 433 on Caribbean geology. Manuel Iturralde-Vinent, from Havana’s Museo Nacional de Historia Natural, has made significant contributions to the understanding of the island’s geology; not only has he authored papers on several aspects of Cuban geology, but he has written and cooperated on projects by a number of international organizations (Iturralde-Vinent, 1969, 1970, 1972, 1975a, b, 1981, 1985, 1988, 1996, 1998; Iturralde-Vinent and de la Torre, 1990; Iturralde-Vinent et al., 2006), thus dis-

seminating information that was previously restricted to Cuba and eastern European Countries. Until recently, very little has been published in English describing Cuban geology. This is unfortunate because a better understanding of Cuban geology might lead others to become aware of processes not recognized elsewhere. The interpretations presented here are based on models derived from areas such as the Alps or the Pacific. This report presents as much factual material as possible in addition to an interpretation of the data. Cuba is, geographically and geologically, a part of the Caribbean. English-language reviews of Caribbean geology such as those found in Nairn and Stehli (1975) and Dengo and Case (1990) are useful for understanding Cuban geology. Recently, Pindell et al. (2006, p. 304) suggested that much of the Caribbean geology is well understood, and that new evaluations, ‘‘may also partly reflect the involvement of new or younger workers who were not actively involved in much of the older work.’’ Unfortunately, Cuban geology has been an inadequately known

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FIGURE 4. Cuba generalized geologic map. part of Caribbean geology. I hope this book helps improve knowledge of Cuban geology and will stimulate further work by both younger and older workers. The work done by Gulf Oil Corporation (Gulf ) in the early 1950s has never been published in its entirety. This publication an attempt to present it in the framework of Cuban geological studies done since and new general geological concepts. It must be stressed that the only way to properly describe this work is by defining and using the original stratigraphic nomenclature. Unfortunately, many of the names used have found their way into the official Cuban nomenclature, commonly with a different meaning than the original intent. Therefore, in this book, when a name used by Gulf is used in its original meaning, an asterisk follows (Santa Teresa*), thus differentiating it from any other usage. This in no way suggests changes to the present nomenclature. This book is divided into two sections. The first section, Overview, is printed herein and presents a broad description of Cuba’s geology and provides an interpretation of the geological events leading to the for-

mation of the island. The second section, Data, is on the accompanying CD-ROM in the back of this publication and provides a detailed description of Cuban stratigraphy, geophysics, and structures. Because hydrocarbons have been a significant driver for much of the study of Cuban geology, Chapter 6 in this publication entitled Hydrocarbons, gives a historical overview of work on petroleum occurrences.

POLITICAL SUBDIVISIONS Before 1976, Cuba was subdivided into seven provinces (Figure 1). In 1976, the island was subdivided into 14 provinces plus a district for the city of La Habana (Figure 2). The change postdates the acquisition of much of the precise information in this publication. To avoid errors converting from the old to the new provinces, the pre-1976 provincial nomenclature is used here. It should be noted that the Isla de Pinos is now Isla de la Juventud. The province of Matanzas has been

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FIGURE 5. Cuba generalized structure.

FIGURE 6. Cuba generalized cross sections.

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FIGURE 7. Cuba’s geologic provinces. extended to the south coast and includes part of the old Las Villas (Santa Clara) province. The remaining part of the old Las Villas province has been approximately subdivided into the Villa Clara, Cienfuegos,

FIGURE 8. Lithologic symbols used in sections.

and Sancti Spiritus provinces. The ‘‘Camaguey’’ province remains, but the boundaries have been changed; its western portion has been named ‘‘Ciego de Avila,’’ and its eastern part has been named ‘‘Las Tunas.’’ The

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FIGURE 9. Sedimentary terranes generalized geologic map.

old Oriente Province has been approximately subdivided into Holguin, Granma, Santiago de Cuba, and Guantanamo provinces. Pinar del Rio and La Habana have remained essentially unchanged except that the boundary between the two has moved some 30 km (18 mi) westward.

REGIONAL SETTING Cuba is the largest of the Caribbean islands and has an arclike shape, concave to the south (Figure 3). This shape has tempted some authors to call Cuba an ‘‘island arc.’’ The truth is much more complex. The

FIGURE 10. Eastern Cuba: sedimentary terranes generalized geologic map.

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FIGURE 11. North-central terrane sections. See Figure 8 for definitions of lithologic symbols. broad and deep Straits of Florida separate Cuba from Florida, and the narrow, and relatively shallow, Nicholas and Old Bahamas channels separate Cuba from the Bahamas. To the northwest, Cuba adjoins the Gulf of Mexico and is separated from the Yucatan Platform by the narrow but deep Yucatan Channel. To the south, the Yucatan Basin appears to be enclosed between Cuba to the north and the Cayman Ridge, which is the westward continuation of the Sierra Madre in the southern Oriente province. Cuba, the Cayman Basin, and the Cayman Ridge appear to constitute a physiographic province between the stable margin of the North American craton and the highly mobile Caribbean Basin. This province is separated from the Chortis-Nicaraguan rise block, including Jamaica and Hispaniola, by the east – west pull-apart basin of the Cayman trough, whose spreading center has been recording the eastward migration of the Caribbean plate since the late Eocene.

Over most of its length, the northern coast of Cuba is the dividing line between stable conditions (at least since the Middle Jurassic) to the north and west and very complex ones to the south. Figure 4 shows a generalized geologic map of Cuba. Although it is geologically deformed, the part of the northern coast of Cuba extending from eastern Matanzas to western Oriente belongs to the Florida-Bahamas carbonatebank province. To the south, in part under an upper Eocene or younger cover, is a relatively narrow belt, 45 –160 km (28–99 mi) wide, of intensely folded and faulted Middle Jurassic to middle Eocene rocks consisting, from north to south, of: 

the north-central sedimentary terranes, characterized by very thick platform carbonates and evaporites on the north and a relatively thin section of platform to pelagic carbonates and cherts on the south

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FIGURE 12. Western Cuba: southwestern terrane generalized geologic map. 



the ophiolitic basic igneous-volcanic (called igneous-volcanic because of being a mixture of intrusive and volcanic rocks with a general predominance of volcanic rocks) terranes, with ultrabasic intrusive rocks, many types and great thicknesses of basic, basaltic to andesitic volcanic rocks, volcanic-derived sediments, and granodioritic intrusives the southwestern sedimentary terranes, with primarily thin stratigraphic sections of platform to pelagic carbonates and cherts but locally with great thicknesses of older, continental-derived sandstones and shales showing various degrees of metamorphism

The most striking feature about the geology of the island is the great disparity between the ophiolitevolcanic sequence of the basic igneous-volcanic terranes and the sedimentary sequences of the northcentral and southwestern sedimentary terranes. Except for a few notable cases, essentially no relationship exists between these sedimentary and igneous terranes. There has been much argument about how the terranes

came into contact and became structurally mixed, but it is generally accepted today that the ophiolitevolcanic sequence is totally allochthonous. Figure 5 shows a map of Cuba’s major structural features and terrane distribution, and Figure 6 shows, in cross section, the structural relations between the various terranes. Nearly all major structural features formed after the early Maastrichtian and prior to the late Eocene. Quiet, continuous uplift has predominated in Cuba since the late Eocene. The island rose almost entirely above sea level during the Miocene and, except in the Escambray and the Sierra Maestra, Cuba today has a generally low elevation, although many areas have rugged topography. Cuba has had no volcanism since the middle Eocene and, with the exception of southern Oriente, has been seismically inactive in historical times. Despite its general low elevation, Cuba is an example of a Cretaceous – Paleogene Alpine orogenic feature in which thrust sheets moved northward over the craton. The ophiolites and volcanics are essentially unmetamorphosed, which is uncommon for an

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FIGURE 13. Southwestern terrane sections: Guaniguanico See Figure 8 for definitions of lithologic symbols. Alpine orogenic feature. In the northern Caribbean (with the possible exception of southeastern Belize), only in Cuba are shelfal deposits juxtaposed against ophiolites and deep-water volcanics and clastics. The other Greater Antilles Islands show intense deformation, but any former relationship to a continent is missing or has been obscured by strong transcurrent motion. The northern Venezuela Caribbean Mountains and their borderlands are structurally and timewise, but not stratigraphically, a mirror image of Cuba. This is the only other place in the Caribbean where thrust sheets of ophiolites, volcanics, and sediments moved over a craton (in this case, southward) during the early to middle Eocene. The associated metamorphism is much more extensive and intensive than in Cuba. Between these two orogenic belts with opposing vergence are the essentially undisturbed Late Cretaceous to Holocene Colombian and Venezuelan basins.

These basins are limited on the north and south by the trenches of the Muertos trough and the southern Caribbean (Curazao Ridge) deformed belt. The trenches, related to, respectively, north- and south-dipping subduction zones, are essentially inactive today. Separating Cuba from the Yucatan Basin is the Camaguey Trench, a northeast-dipping, apparently inactive trench under the Jardines de la Reina Cays. Although Cuba is now part of the North American continent, it is a remnant of a Cretaceous to early Tertiary orogenic belt that has been preserved because of the local configurations of the North American and Caribbean plates. As a consequence, Cuba exposes sequences of Upper Jurassic and Cretaceous nonvolcanic pelagic sediments that are rare, if not unique, in the Caribbean as well as in North, Central, and South America. However, Cuba has facies and faunal similarities with equivalent strata of the Tethys region, specifically the Alps and Italian Apennines.

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FIGURE 14. Southwestern terrane sections: Guaniguanico. See Figure 8 for definitions of lithologic symbols. Similarities and differences exist between the Jurassic–Cretaceous sedimentary sections of Cuba and other areas in the region. Nannoconus biomicrites containing aptychi, identical with the Neocomian of Cuba (and the Alps), are present in southern Belize, south of the Maya Mountains (Flores, 1952; Schafhauser et al., 2003); in Mexico, in the Lower Cretaceous of the Sierra Madre Oriental; and in the coreholes of Deep Sea Drilling Project Leg 77 in the southeastern Gulf of Mexico (this type of Cretaceous sediment is widespread in the deep Atlantic Ocean). In the Maya Block of the Yucatan Peninsula (and northern Belize, north and west of the Maya Mountains), all the reported carbonates belong to the Cretaceous Coban and Campur formations. They are similar to the bank carbonates of the Bahamas Platform and, therefore, are similar to the bank carbonates of north-central Cuba. The Coban Formation

grades northward into a thick evaporite section, which overlies the dominantly red clastics of the Todos los Santos Formation, that has been compared to the San Cayetano Formation of Cuba’s Pinar del Rio. Carbonates exist in the highly deformed Motagua fault zone, in central Guatemala, but similarity to carbonates found in Cuba is uncertain. The clastic El Plan Formation in the Chortis block of Central America in Honduras has been compared to the San Cayetano Formation. It shows lithologic and paleoenvironmental similarities. However, its Triassic to Middle Jurassic age, although somewhat in doubt, makes it older than the San Cayetano. El Plan Formation is a very controversial unit because all the contacts with other units are tectonic. Present in much of Central America is a Cretaceous carbonate section unlike the Cuban carbonates of the same age. It consists of Neocomian to Cenomanian, mostly shallow-water Yojoa Group limestone underlain

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FIGURE 15. Southwestern terrane sections: metamorphics. See Figure 8 for definitions of lithologic symbols. by Upper Jurassic to Lower Cretaceous clastics of the Honduras Group and overlain by the Upper Cretaceous Valle de los Angeles Group that consists mostly of red beds. Similar to the northeastern Cuban evaporites are Upper Jurassic(?) to Lower Cretaceous Maraval evaporites in the Paria Peninsula and Gulf of Paria, in the southern Caribbean between Venezuela and Trinidad. The metamorphosed clastics and marbles of the Jurassic to Lower Cretaceous Caracas series in northern Venezuela have some similarities to Cuba’s southern metamorphic massifs. In addition, the thick section of Upper Jurassic clastics of the Cosina Group (overlain by fossiliferous Neocomian carbonates of the Kesima, Palare, Moina, and Yaruma formations) in the Guajira Peninsula have similarities to the San Cayetano of Cuba’s Pinar del Rio. Some similarity exists between the Orbitolina-bearing reef carbonates of Cuba, Venezuela’s Lower Cretaceous Cogollo Group

and Cantil Formation, and contemporaneous facies of the Florida-Bahamas Platform. Close similarities exist between the Mesozoic igneous intrusive and associated volcanic rocks of Cuba and those of the Caribbean. Ophiolites are common throughout the Caribbean and extend from the Motagua fault zone, between the Maya and Chortis block, to Puerto Rico. They also form the floor of the Cayman Trench. These rocks are also common along the northern coast of South America from Tobago to the Guajira Peninsula, although they are not as intensely serpentinized as in the northern Caribbean. Cuba’s outcrops of ultrabasic rocks are the most extensive in the region. Similarities exist between the Caribbean and the Cuban Upper Cretaceous volcanic and associated intrusive rocks. The Cuban Upper Cretaceous granodioritic intrusion has counterparts outcropping in Hispaniola, Jamaica, and Puerto Rico in the north (where

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FIGURE 16. Central Cuba: basic igneous-volcanic terrane generalized geologic map. the intrusive’s ages range into the early Tertiary) and in Aruba, the Venezuelan Antilles, and the Aves Ridge in the south. Volcanics containing a characteristic fauna of Acteonella, large rudists (Hippurites), and orbitoids are present in Cuba, Jamaica, Hispaniola, Puerto Rico, the Dutch West Indies, and northern Venezuela, suggesting a connection between the various parts of the volcanic province. Other than the Yucatan Basin, Cuba is probably the only place in the Caribbean with complete sections representative of the early Caribbean region after the separation of North and South America and before the formation of the present Caribbean plate in the Tertiary.

STRATIGRAPHIC AND STRUCTURAL HISTORY The geological history of Cuba is part of the history of the Caribbean and, consequently, the history of the relative motions between the North and South American continents. As a result, as a background for the history of Cuba, some of the salient features of Caribbean history are included here. A more indepth look at Caribbean geology is presented in Dengo and Case (1990). Details of the stratigraphy and structure of Cuba are given in the Data section of this book located on the CD-ROM in the back of this publication.

To assist in the understanding of Cuba’s geologic history, a number of simplified geologic maps (locations shown on Figure 7) and accompanying stratigraphic sections will be presented. Triangles on the maps show the location of the stratigraphic sections, and Figure 8 shows the lithologic symbols used in the sections. Limited stratigraphic names are shown in the columnar sections for easy reference to the Data section of this publication. Stratigraphic unit names followed by an asterisk (i.e., Capitolio*) were originally named by Gulf’s geologists and might, or might not, be used today in the same context. Central and western Cuba are the only areas where the exposures of sedimentary terranes show sufficient facies relationships to permit meaningful, paleogeographic reconstructions of the early stages of the opening of the Caribbean. Central and eastern Cuba better represent the paleogeography of the rims of the later volcanic Caribbean plate. In this publication, the term ‘‘belt’’ is used. A belt in Cuba was originally defined by G. Pardo in 1953 and later published (Pardo, 1975, p. 561) as follows: ‘‘The central part of Cuba can be divided into a series of narrow linear and roughly parallel belts that extend along the north-central part of the island in a northwest–southeast direction. Each one of these is

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FIGURE 17. Central Cuba: basic igneous-volcanic terrane sections. See Figure 8 for definition of lithologic symbols. characterized by a diagnostic stratigraphy and structural style. These belts. . .’’ The definition of ‘‘belt’’ as applied in Cuba is discussed in detail in the Data section of this publication under Chapter 1, The Belt Nomenclature Problem. The use of belt was extended to western Cuba by Truitt (1956a, b) and, later, by other authors. It is still used in the Cuban literature. Belts are discreet, separate stratigraphic features, structurally brought into contact, and superimposed. The fundamental structural-stratigraphic model proposed here for Cuba is that of an Alpine orogeny along the continental margin of North America. It consists of shelfal carbonates paired with deep-water sediments, volcanics, and ophiolites thrust northward toward the craton. The model assumes the involvement of plate-tectonic processes and includes a proposal for Cuba (and other, geologically similar, areas) of a mechanism explaining the obduction of oceanic

crust over continental margins. Superimposed on this basic structure are other structural elements such as possible rifting and wrenching, which have contributed to confusion about, for example, the origin and mode of emplacement of the ophiolites. Walter Bu ¨ cher (1954, personal communication), Hatten et al. (1958), Rigassi-Studer (1963), Hatten (1967), Meyerhoff et al. (1969), Knipper and Cabrera (1974), Iturralde-Vinent (1977, 1981, 1996), Pszczo´lkowski (1999), Cobiella-Reguera (2005), and others have accepted variations on an Alpine orogenic model, but the nature and degree of acceptance varies. Meyerhoff et al. (1969) rejected the involvement of plate tectonics. Hess (1938) once used Cuba as the type symmetrical ‘‘Tectogene’’ (he changed his interpretation in later years). Flint et al. (1948) interpreted some of the major thrusting as being directed from north to south. Ducloz and Vuagnat (1962) postulated that many of the structures of central Cuba were caused

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FIGURE 18. Eastern-central Cuba: basic igneous-volcanic terrane sections. See Figure 8 for definition of lithologic symbols.

by deep-seated wrench faulting without major overthrusting and denied the existence of windows and klippen. Interpretations from the era of the former Soviet Union and Cuban cooperation are divided between thin-skinned and basement tectonics. It should be mentioned that Bohor and Seitz (1990) suggested that Cuba’s complex geology was caused by a meteorite impact in the Isla de la Juventud vicinity. This suggestion was not seriously followed, but mounting evidence shows that the Chicxulub K-T boundary meteorite impact had some effect on Cuba (see Officer et al., 1992). Pszczo´lkowski (1986b, 1999) proposed that the Cacarajicara Formation (and its correlative, the Amaro) was caused by such an event. Mounting evidence shows that the detritals of the Cacarajicara, Pen ˜alver, and the Amaro formations were caused by the Chicxulub tidal wave (Takayama et al., 2000; Kiyokawa et al., 2002), but carbonate turbidite deposits are

very common through the entire Cuban Cretaceous and lower–middle Eocene. The Lutgarta Formation contains many turbidites, interbedded with biomicrites and radiolarian cherts, which accumulated from the Santonian through the Maastrichtian. Furthermore, the most impressive carbonate breccia, the Sagua* Formation, reaches unquestionably into the lower to middle Eocene.

Restoration of Cuban Geology Structural complexities have shuffled the various components of Cuban stratigraphy. The present relative position of the outcrops is quite different from their position at the time of deposition or formation. Any palynspastic restoration will depend, therefore, on the assumed direction of thrusting. In this publication, all the major displacements are considered as having been from south-southwest to north-northeast.

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FIGURE 19. Western Cuba: basic igneous-volcanics terrane generalized geologic map.

North-Central Sedimentary Terranes Figures 9 and 10 are maps of central and eastern Cuba showing the distribution of the sedimentary belts separated by folded and faulted major thrusts. They also show the southwestern sedimentary terranes, Escambray and Asuncion, as windows through the basic igneous-volcanic terranes. This is the conventional interpretation and was Gulf’s interpretation in the late 1950s. It is also the interpretation of Hatten et al. (1958), Meyerhoff and Hatten (1968), Pardo (1975), and Hatten et al. (1988). This reconstruction is supported by: the presence of Jaguita* and Ronda* unmetamorphosed carbonate outcrops, along the Tuinicu fault, south of the basic igneous-volcanic terranes; the total lack of volcanic and ultrabasic components associated with the sedimentary terranes; and the fact that the basic igneousvolcanic terranes completely surround (in fault contact) the Escambray and Asuncion massifs. Figure 11 shows, from north to south, the thick Jurassic and Cretaceous carbonate and evaporite bank sections of the Punta Alegre* (PA) and Yaguajay* (Y)

belts, followed by the transitional Jatibonico* (J) belt and the Las Villas* belt. The type locality of the Las Villas* Belt at Quemado de Guines (QG) exposes a relatively thick section of Upper Jurassic bank carbonates of the Trocha* Group, which grade into the uppermost Jurassic deep-water limestones of the Caguaguas* Formation. The Jurassic is overlain by Lower Cretaceous, thin, deep-water, nannoplankton carbonates of the Capitolio* Formation. The Upper Cretaceous is mostly pelagic and distal carbonate bank turbidites, with radiolarian cherts, of the Calabazar* and Carmita* formations. Of note are the carbonate conglomerates of the Sabanilla* Formation, definitely derived from the south. The Upper Cretaceous is very thin and in places not represented by sediments. To the south, the Placetas* (P) and Cifuentes* belts, representing the higher thrusts, do not show any appreciable thickness of Jurassic sediments. In the southernmost Cifuentes* belt of Las Villas province at La Rana (LR), Jarahueca, and Rancho Veloz, the pelagic limestones of the Lower Cretaceous Ronda* Formation and the Jobosi* conglomerate rest on weathered,

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FIGURE 20. Northern Cuba: basic igneous-volcanic terrane generalized geologic map. strongly deformed, and allochthonous granodioritic basement. This basement must have formed a paleoridge (Meyerhoff’s ‘‘Median Welt’’) called here ‘‘La Rana’’; its original location is presently unknown. In the Sierra de Camajan window of the Camaguey province, the Lower Cretaceous Veloz (Ronda*) Formation rests upon the Tithonian Nueva Maria Formation that interfingers with tholeitic basalts. Present in the Cifuentes* belt is a widespread quartz-muscovite sandy limestone of Aptian–Albian age, the Constancia* Formation. The presence of abundant muscovite is surprising because the basement exposures are poor in micas. In the Yaguajay*, Sagua*, Jatibonico*, and Las Villas* belts, varied thicknesses of basic igneous detritus of the lower–middle Eocene Vega* Formation are invariably present underlying the Rosas* orogenic megabreccia. Basic igneous detrital clasts are present in the south in the Maastrichtian Miguel* Formation, as well as in the Rodrigo*, indicating that the basic igneousvolcanic terrane began to move in the Maastrichtian,

with deformation culminating in the early middle Eocene.

Southwestern Sedimentary Terranes The southwestern sedimentary terranes are characterized by the presence of a thick section of continentally derived clastics of mostly Middle Jurassic age. The Upper Jurassic and Cretaceous part of the section is very similar to the Las Villas* to Cifuentes* belts of the north-central sedimentary terranes. With one notable exception, the Cretaceous carbonate bank facies is absent. The southwestern sedimentary terranes show various degrees of metamorphism, principally in the Isla de la Juventud and the Escambray massifs. Figure 12 is a geologic map of western Cuba, including the Isla de la Juventud. Here, the exposures of Jurassic to middle Eocene sedimentary rocks form a group of low-elevation hills called the Sierra de Guaniguanico. In contrast with the tightly faulted and imbricated stack of south-dipping plates of central Cuba, the belts are less intensely tectonized, north-dipping,

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FIGURE 21. Western and northern Cuba: basic igneous-volcanic terrane sections. See Figure 8 for definition of lithologic symbols.

superimposed thrust sheets. Each belt consists of a stack of several sheets showing great similarity to each other. The present order of the belts is reversed from their original position. The significance of the larger number of imbrications in the Sierra de Guaniguanico (±30) than in central Cuba (7) is not clear. The larger number may be partly, but not entirely, caused by the quality of exposure; perhaps the more numerous imbrications are a result of greater horizontal displacement. Figure 13 shows sections on the eastern part of the Sierra de Guaniguanico, with the belts in their assumed original position. The Sierra de los Organos belt (PG, SG), like the Las Villas* belt, exhibits a fairly thick Upper Jurassic section of shallow-water carbonates, the Mogotesforming Guasasa Formation. It is transitionally underlain by the Jagua as well as the San Cayetano continentally derived clastics of Middle to Late Jurassic

age. The thickness of the San Cayetano varies from possibly very thin to nonexistent in the north to possibly very thick (more than 10,000 ft [3000 m]) in the south. Simultaneously, in the southern Rosario belt (CP), the Guasasa grades into the thinner, deeper water, thin-bedded carbonate facies of the Artemisa Formation. These carbonates are similar to and partly coeval with the Caguaguas*, Capitolio*, and Ronda* formations of the Las Villas*, Placetas*, and Cifuentes* belts. Farther south, in the northern Rosario belt (N), the Artemisa overlies and partially interfingers with the tholeitic basalts of El Sabalo Formation. This situation is identical with the one found in Loma Camajan in the Camaguey province. The Cretaceous section is generally thin and accumulated in deep water. The highest thrust sheet of the Sierra de Guaniguanico, Guajaibon–Sierra Azul (GSA), is highly unusual and difficult to explain. It consists mostly of

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FIGURE 22. Eastern Cuba: basic igneous-volcanic terrane generalized geologic map. massive bank carbonates with a facies (and microfacies) identical with the carbonate banks of the Yaguajay* belt of north-central Cuba. Being the highest thrust sheet under the basic igneous-volcanic terranes suggests a position south of much deeper water facies and no connection to the Bahamas banks. These rocks may have been deposited over the westward continuation of the southern La Rana granodioritic ridge exposed in the southernmost sheets of the Cifuentes* belt. Figure 14 shows sections on the western part of the Sierra de Guaniguanico. They differ from the eastern sections in having a greater thickness of San Cayetano clastics-Loma del Muerto (LM), and Pizarras del Sur (PDS) by an indication that the Guasasa Formation carbonates at EPEP Pinar-1 might not have been underlain by thick San Cayetano clastics (total depth of the well was near seismic-refraction basement) and by considerable quartz-sand development in the Cretaceous of the Esperanza (E) belt. Although these sands might have come from the Yucatan (Pszczo´lkowski, 1999), they are consistent with the southern granodiorite high and might correlate with the Cifuentes* and Placetas* belts’ Constancia* Formation of Early Cretaceous age. The Santa Teresa* Formation cherts, characteristic of the Cifuentes* belt, are well represented in the southern Rosario (LM, LP) and La Esperanza (E) belts. Although the Cacarajicara detrital limestone represents a remarkable distal turbidite, it is similar to the Carmita*, Amaro*, Lutgarta*, and Sagua* of north-

central Cuba. These turbidites were deposited throughout the Cretaceous and the early–middle Eocene. In the Sierra de Guaniguanico, variable thicknesses of Paleocene to lower–middle Eocene Manacas (similar to Vega*) basic igneous-derived detrital rocks, overlain by the Vieja (similar to Rosas*) orogenic megabreccia, are present above most thrust slices. Figure 15 shows sections of the metamorphosed massifs of Escambray and Isla de la Juventud. Because of the structural complexities in both massifs, the indicated thicknesses are questionable. The slightly metamorphosed Cangre belt–Pino Solo (PS) unit on the southern border of the Sierra de Guaniguanico is also shown. The Isla de la Juventud and Escambray massifs, although not studied to the extent of other areas in Cuba, have sections dominated by Middle Jurassic clastics (La Llamagua, Loma la Gloria, Can ˜ada, Agua Santa) equivalent to the San Cayetano Formation. The Upper Jurassic–Lower Cretaceous carbonates (Sauco, Cobrito, Mayari, and Collantes) seem to have accumulated in deep water, akin to the Artemisa Formation. In both massifs, as well as in the Cangre belt, the metamorphism appears reversed. The upper units are more metamorphosed than the core of the structures. For example, the upper Pino Solo unit has a higher metamorphic grade than the lower Mestanza unit. The age of metamorphism of the Cangre belt is Paleocene–early Eocene (Pszczo´lkowski, 1985). It is also very significant that the median radiometric

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FIGURE 23. Eastern Cuba: basic igneous-volcanic terrane sections. See Figure 8 for definition of lithologic symbols. age of metamorphism in Escambray and Isla de la Juventud is 66 m.y. or Paleocene (Iturralde-Vinent, 1996). This, together with the sedimentary evidence of the timing of thrusting, suggests that the reverse metamorphism was caused by the slab of basic igneousvolcanic terranes riding over the sedimentary terranes and not by the island arc thermal activity.

Basic Igneous-Volcanic Terranes Central Cuba Figure 16 is a map showing the distribution of the general types of igneous and volcanic rocks (including volcaniclastic) in central Cuba. Generally speaking, the basic igneous-volcanic terranes occur in a complexly folded and faulted synclinorium, which is separated from the underlying sedimentary terranes by the Domingo* fault. Above the fault and at the base of the volcanic section are various-sized bodies of

ultrabasics (serpentine, gabbro) to the north and metamorphosed ultrabasics (amphibolite) to the south. Highly sheared serpentine forms the base of the section and contains large blocks of exotic metamorphics. The trough of the synclinorium consists of oceanic volcanics overlain by arc volcanics and associated sediments. Several granodiorite bodies intruded the volcanic section from the central to the southern parts of the synclinorium and extend from the Escambray massif to eastern Camaguey. Figures 17 and 18 are representative columnar sections of the basic igneous-volcanic terranes in central Cuba. It should be noted that the sections of Santa Clara (SC), Santo Domingo (SD), and Camajan (C) show the best and most complete exposures of probable oceanic crust (Domingo* belt) and, possibly, upper mantle. The most complete and least deformed volcanic (Cabaiguan* belt) sections are exposed on the north and south flanks of the Seibabo syncline

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FIGURE 24. Palynspastic base.

FIGURE 25. 163 Ma: Callovian. PC = Precambrian; PZ = Paleozoic.

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FIGURE 26. 144 Ma: early Tithonian.

(SNF, SSF), and they provide the best basis for interpreting the origin of the volcanic rocks. The Lower Cretaceous in the Seibabo syncline consists mostly of basalts and basic volcaniclastics. Part of the Cenomanian – Turonian section contains no volcanics. This section comprises the Gomez* and Huevero* dark-gray shale and black nodular limestones and the Cristobal* and Casanova* detrital, fine- to medium-grained limestones containing Upper Jurassic detrital oolites and other fragments. This volcanic-free section represents a period of volcanic quiescence following the formation of the new Upper Jurassic–Cretaceous oceanic basement and preceding the development of an Upper Cretaceous volcanic arc. Of the above units, the Gomez* Formation is the most characteristic and can be recognized in many localities. It must be noted that in the Las Villas province, most of the exposed volcanics are Early Cretaceous or older in age, whereas in Camaguey, they are middle to Late Cretaceous in age. Contrary to the interpretation of Iturralde-Vinent (1996) and others, volcanism was active during the Maastrichtian as shown by outcrops of the Las Villas province (Hilario*, Cotorro*, and Carlota*) (see Data section on the CD-ROM in the back of this publica-

tion). Piggyback basins characterize the Paleocene and lower–middle Eocene. They contain volcanic-derived sediments, marls, and limestones. The Taguasco* Formation, consisting of conglomerates containing large spherical granite boulders, and its equivalents are found at the base of the section.

Northern and Western Cuba Figures 19 and 20 are maps showing the distribution of the basic igneous-volcanic terranes in western and northern Cuba. Here, the Sierra de Guaniguanico occupies a structural position equivalent to the Escambray massif; it is a window of sediments cut by the Pinar fault to the south. An outlier of unmetamorphosed arc volcanics exists on the north of the Isla de la Juventud, the Teneme Formation. The most complete sections of basic intrusive and volcanic rocks occur north of the Sierra de Guaniguanico in the Bahia Honda (BH) and Felicidades (F) belts. Figure 21 shows several sections of this terrane. The most complete section of oceanic crust is found at the base of the Bahia Honda (BH) belt and is very similar to the section present in central Cuba. The Lower Cretaceous is not as well developed as in central Cuba and

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FIGURE 27. 132 Ma: Valanginian.

has not been studied in detail, but the middle to Upper Cretaceous Quio ˜ nes Formation in the Felicidades (F) belt shows some affinities with the Gomez* and Huevero* formations of central Cuba. However, Upper Cretaceous, Paleocene, and lower–middle Eocene outcrops are widespread and, being near Havana, have been studied in detail for many years. These lower Tertiary deposits form well-developed piggyback basins that were transported northward by the advancing ophiolite sheet, with no indication of nearby volcanic activity.

Eastern Cuba Figure 22 is a map of eastern Cuba showing the various provinces. Eastern Cuba is characterized by a strongly tectonized, steeply southward-dipping, basic igneous-volcanic section (Kozary, 1968, referred to it as the collapsed Aura trench); a nearly horizontal, allochthonous, ultrabasic sheet overriding the volcanics in the Mayari and Baracoa massifs; the metamorphosed volcanics of the El Purial massif; and a thick lower– middle Eocene section of the El Cobre arc volcanics. Figure 23 shows several stratigraphic sections through eastern Cuba. The thicknesses are questionable in

most areas, but especially in northern Oriente (NO) and southeastern Oriente Purial massif (PM). However, there is no question that the lower – middle Eocene Cobre Formation is very thick. It contains the only lower Tertiary volcanic rocks in Cuba. The Purial massif is the only place in Cuba where the volcanic section exhibits regional metamorphism; these volcanic rocks are under a nearly horizontal imbrication of an ultrabasic sheet. A small window of slightly metamorphosed southwestern terranes sediments is present at La Asuncion. Figure 24 is a palynspastic base showing the approximate relative positions of the different belts at the time of their deposition. It also shows the equivalence of the belts between the different areas of Cuba. The Domingo-Cabaiguan belt could have originated farther to the southwest in the middle Cretaceous.

HISTORY OF CUBA The summary here of the geological history of Cuba has been strongly influenced by the geology of central Cuba. However, the timing of the events was not isochronous along the whole length of the orogen.

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FIGURE 28. 110 Ma: Aptian. Paleogeographic maps (Figures 25 – 34) illustrate the possible past distribution of the most characteristic stratigraphic units. These maps are on a continental drift base modified from the Ocean Drilling Stratigraphic Network (ODSN) created in 2005 by the University of Bremen, with Florida occupying a fixed position. In all maps, Cuba is shown in its present position relative to Florida, although different parts of the island came from various places. The first map of the sequence, 163 Ma (Callovian), shows the position of the African and South American cratons. In these maps, ‘‘autochthonous nappes,’’ ‘‘allochthonous nappes,’’ and ‘‘subduction’’ will be used to describe, respectively, the thrusting toward the continent of the sediments, the basic igneous-volcanic rocks, and the subduction. Supported by observations in Cuba and elsewhere, these maps (as well as cross sections discussed later) show subduction as the main cause of the uplift of a convergent continental margin or ocean floor, whereas the nappes are the result of sedimentary or volcanic cover sliding away, under the force of gravity, from the area uplifted by subduction.

Burke (1988), Pindell and Barrett (1990), IturraldeVinent (1996), Cobiella-Reguera (2005), Garcı´a-Casco et al. (2006), Giunta et al. (2006), and Pindell et al. (2006), have interpreted the Cretaceous Cuban subduction as northeast dipping and reversing polarity to the southwest during the Upper Cretaceous. Cuba’s geology suggests that the subduction was continuously north dipping, and this concept is discussed in more detail below. The paleogeographic history presented here is in general agreement with that of Pszczo´lkowski (1999). Differences are, for example, the position of the Guajaibon–Sierra Azul belt, the origin of the middle Cretaceous quartzose clastics, and the dip of the subduction zone.

Early(?)–Middle Jurassic Very little is known about the pre-Late Jurassic history of the island except that the lower part of the San Cayetano clastics might be Lower Jurassic (163 Ma; see Figure 25). The San Cayetano must have been deposited over an initially rifting basement that probably included fragments of continental crust as well as

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FIGURE 29. 94 Ma: Cenomanian.

basaltic flows. This is supported by the pre-Neocomian granodioritic klippen of La Rana, Tre´s Guanos, and Rancho Veloz and the occurrences of the El Sabalo and Nueva Maria tholeitic basalts underlying the sedimentary section of the northern Rosario belt and Cifuentes* belt of the Sierra de Camajan. It can also be assumed that, prior to the deposition of the Upper Jurassic rocks, a large area of basement was exposed to the northwest, extending from Florida’s Sarasota arch to the Maya Mountains. The nature of this basement is generally unknown, but it must have been of granitic to granodioritic composition as indicated by the arkosic nature of the San Cayetano Formation. In south Florida, several wells have penetrated an undifferentiated Jurassic–Triassic volcanic section and Paleozoic granite. The basement must also have included Paleozoic sediments known to outcrop in the Maya Mountains, present as fragments in San Cayetano conglomerates, and, perhaps, as exotics in the Cayo Coco Formation. The bulk of the San Cayetano Formation accumulated south of this basement high. The San Cayetano clastics could have originated from the Gulf of Mexico, as well as nearby South

America. As already mentioned, some studies indicate that the southwestern part of the San Cayetano originated from the southwest, and the northeastern part originated from the northeast. Structural complexity makes source direction hard to evaluate. Toward the northeast, pre-Upper Jurassic sediments have not been observed in situ, but the Cunagua salt suggests the presence of an evaporite basin correlating with the Louann Salt and Maraval evaporites and, possibly, as suggested by the San Adrian Formation, interfingering with the San Cayetano. As rifting continued, new oceanic crust formed with outpouring of basalts (El Sabalo) and serpentinization of the upper mantle.

Tithonian In the Tithonian (144 Ma; see Figure 26) section, sediments vary from the shallow-water, carbonate, and evaporite deposits of Wood River, Punta Alegre*, and Guani* in the north, toward Florida and the Bahamas, to shallow-water, normal marine limestones of the Trocha* Group to the south in the Las Villas* belt. Toward Pinar del Rio, thick, massive, shallow-water

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FIGURE 30. 80 Ma: Santonian. limestone of the Guasasa Formation accumulated over a northward-thinning wedge of San Cayetano, Jagua, and possibly, basement. Farther south, the thinbedded limestones of Cobrito, Sauco, and Isla de la Juventud marbles were deposited over the lower Oxfordian thin, quartzose sandstones of La Llamagua, Loma la Gloria, and Agua Santa formations. The outpouring of basalt continued forming the slightly younger Nueva Maria Formation in the southern Loma Camajan. Farther south, rifting produced ultrabasic oceanic crust.

Neocomian Shallow-water platform carbonates, with some evaporites, continued to accumulate in the north (coastal area, Yaguajay* belt). Elsewhere in central and western Cuba (Las Villas*, southern Rosario belts), the water was markedly deeper as indicated by the deposition of the Capitolio* and Artemisa formations containing abundant nannoplankton (commonly rock forming) and other pelagic forms. Some tectonic activity extended into the Neocomian (132 Ma; see Figure 27), possibly associated with

the rifting, and uplifted blocks south of the Yaguajay* belt. The result was denudation of previously deposited sediments as indicated by northward shedding of carbonate clastics (Sabanilla* Formation), a southward increase in basement exposures (La Rana, Tre´s Guanos, Rancho Veloz), and deposition of the Jobosi* arkosic conglomerate. This basement could have been derived from a continental block, here named the La Rana block (after the best exposures) and similar to the Maya or Chortis blocks, that was overridden by later nappes. In central Cuba, the Upper Jurassic and Neocomian beds were only partially eroded. In western Cuba, shallow-bank carbonates, similar to those of the Vinas* Group, accumulated atop the La Rana granodiorite horst and formed the Guajaibon – Sierra Azul belt. South of the La Rana basement horst, deep-water limestones of the Mayari, Collantes, and Cobrito formations were deposited and preserved. Farther south, rifting continued, accompanied by outpouring of tholeites and other basic to ultrabasic material forming a layered oceanic basement consisting of peridotite, gabbro, sheeted dikes, pillow basalts (old volcanics of the Domingo* sequence), and

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FIGURE 31. 67 Ma: Maastrichtian. associated sediments. Although some genetic relationship exists between the Domingo* sequence and the El Sabalo – Nueva Maria lithologies, these belong to two entirely different provinces. El Sabalo and the Nueva Maria formations, like the granodiorites, belong to the autochthonous nappes and were at the continental margin, whereas the Domingo* sequence forms the base of the allochthonous nappe and is entirely oceanic.

Barremian During the Barremian, deposition of platform carbonates continued in the north, grading from shallowwater algal types, with fewer evaporites, to breccias. South, west, and possibly east of the Bahamas Platform, deep-water sedimentation of pelagic (nannoplankton) carbonates continued. However, because of the late Neocomian tectonic activity, conglomerates, derived from the previously deposited limestones in the Las Villas* belt and from the exposed granitic basement in the Cifuentes* belt to the south, became common. No Barremian sediments were deposited in some of the southern areas. However, the basaltic to intermediate

flows possibly continued to accumulate over the southern part of the basic igneous basement.

Aptian During the Aptian (110 Ma; see Figure 28), deposition continued to be shallow-water marine along the north coast (Yaguajay* belt) with, farther to the north (Cayo Coco area) and as far as Oriente (Gibara area), some pelagic influence (Casablanca Group). Toward central and western Cuba, conditions continued to be pelagic. The pelagic and shallow-water conditions were separated by a conglomeratic breccia zone (Sagua la Chica* belt) representing a forereef facies, although reefs themselves are not common in outcrops. There was an influx of quartz- and mica-rich turbiditic detritus, possibly from the erosion of the previously formed basement high, which formed the La Esperanza, Polier, and Constancia* formations. A southern Guajaibon–Sierra Azul carbonate bank may have been deposited. Toward the south, the close of the Early Cretaceous was characterized by a great outpouring of basaltic flows (Matagua´* Formation) over rifted basement.

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FIGURE 32. 50 Ma: top lower Eocene.

This activity was accompanied toward the north and west (Cifuentes*, southern Rosario, northern Rosario, and La Esperanza belts) by abundant and extensive chert deposits (Calabazar*, Carmita*, and Santa Teresa* formations).

Albian–Cenomanian Except for the Yaguajay* belt along the north coast where platform carbonates accumulated, deep-water pelagic deposition continued during the Albian to Cenomanian (93 Ma; see Figure 29). In the south, volcanic activity contributed silica to the seawater, which led to the deposition of primary radiolarian cherts (Calabazar*, Carmita, and Santa Teresa) below the carbonate compensation depth. Whereas noncalcareous detritus was absent over most of the northern area, volcanic-derived clays became increasingly abundant toward the south (Santa Teresa* Formation). The Rana granodiorite high was still active, providing material for the Chaco Azul Formation. The position

of the Vin ˜as* type carbonates of the Guajaibon–Sierra Azul belt is problematic. To the north, as during the Aptian –Albian, the shallow carbonate banks continued to be separated from the pelagic, deep-water sediments to the south by a zone of carbonate-derived clastics, which shifted progressively southward; carbonate turbidites became increasingly abundant (Calabazar* and Mata* formations). In the Florida Straits, carbonate deposition did not keep up with subsidence as indicated by the increase in pelagic deposits, including chert (upper Casablanca Group). Toward the south, the volcanic activity that formed the lower Cabaiguan* sequence decreased markedly, and argillaceous, calcareous sedimentation became predominant, whereas conditions remained pelagic. The detrital limestones in the southernmost outcrops of the volcanic sequence (Cristobal* Formation) that contain abundant Upper Jurassic reworked carbonates (including oolites) indicate an unknown southern source, possibly the Yucatan Platform.

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FIGURE 33. 40 Ma: base upper Eocene.

With the exception of the thick carbonate banks, the Cenomanian sediments are mostly uniformly thin.

Turonian–Campanian Turonian and Coniacian sediments are not common across most of the nonvolcanic area (80 Ma; see Figure 30). They are present to the north in the Cayo Coco area, to the south in the Seibabo area in central Cuba, and in a few units of the southern and northern Rosario belts in western Cuba. The strata above and below the missing interval all have deep-water characteristics, and no evidence of subaerial erosion exists to explain the lack of the Turonian and Coniacian sediments across such a large area. Either there was no deposition, or the section was eroded because of changes in current patterns or submarine slides. Local erosion is unlikely because a hiatus of the same age has been found in many of the holes drilled by the DSDP in the southern Gulf of Mexico and the western Atlantic. Toward the north, in the platform

to deep water province, whatever sediments remain show that sedimentation continued under pelagic conditions and was essentially calcareous, with subordinate cherts. Toward the south in the basic igneous-volcanic province, conditions were also dominantly pelagic. Sedimentation was accompanied by a renewal of volcanism, with an outpouring of flows and other ejecta of a more rhyolitic composition (Pastora* Group). Evidence of subaerial volcanism (such as glass bombs and ash beds) exists. Shallow-water reefs with rudists, corals, and large foraminifera are commonly associated with the volcanics and volcaniclastics. This was the period of major arc volcanism associated with subduction. It was also the time of intrusion of the Manicaragua granodiorite into the central Cuba volcanics.

Campanian–Maastrichtian After the period of the disconformity, pelagic conditions characterized the platform to deep-water province, which received massive, dominantly carbonate

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FIGURE 34. Present.

turbidite flows from the north (Lutgarda* Formation) and from the south (Amaro* and Cacarajı´cara formations) (67 Ma; see Figure 31). Over the basic igneousvolcanic province, local provenance resulted in an abundance of fragmental rocks; that is, limestones toward the north (Pen ˜alver Formation) and volcanics toward the south. In the south, sedimentation was accompanied during the Maastrichtian by an outpouring of late orogenic basaltic flows and flow breccias (the Maastrichtian age of these flows disagrees with the current interpretation of most Cuban geologists, including Iturralde-Vinent, 1996). Toward the north, along the present outer line of clays, deposition of coarse Maastrichtian limestone conglomerate (Mayajigua* Formation) graded into fine-grained pelagic rocks. The basic igneous-volcanic province began its initial northward movement as indicated by serpentine detritus in the turbidites, by basic intrusivederived clastics (Miguel Formation) associated with the Domingo* thrust, as well as by the presence of

large Maastrichtian thrust sheets of ultrabasics in Oriente. Thrusting (and metamorphism) of ultrabasics began in the Escambray, and thrust sheets began to stack into the former basin that is today represented by the Guaniguanico Mountains. Northward-dipping subduction to the south produced uplift of the convergent margins. The northward-moving thrust sheets or nappes formed as the result of the sedimentary or volcanic cover sliding away from the uplifted areas.

Paleocene (Danian) The Paleocene is very poorly represented in Cuba for reasons that are not entirely clear. Fossils this age have been found only in Cabaiguan* sequence rocks in Habana, Las Villas, and western Camaguey provinces, but the paucity of the Paleocene is probably not just a paleontological artifact. Strata above and below contain rich lower Eocene and Maastrichtian faunas, respectively. Where present, the Maastrichtian

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FIGURE 35. Obduction 1. See Figure 8 for definition of lithologic symbols.

was deposited in deep waters and so was the lower– middle Eocene flysch. No indication of subaerial erosion or unconformity exists.

Early to Middle Eocene The early to middle Eocene was characterized by intense orogenic activity (50 Ma; see Figure 32). Early in the Eocene, the large-scale low-angle thrust sheets, or gravity nappes, that first moved in the Maastrichtian began to move at a greater rate. The volcanic section, along with the oceanic basement, rode over the platform to deep water province, probably along the line separating the basic igneous-volcanic province from the platform to deep basin province. As thrusting proceeded, additional thrusts formed within the carbonate section in front of and north of the basic

igneous-volcanic front. As a result, the thrust sheets were generally arranged from older and more southerly sourced at the top of the stack to younger and more northerly sourced at the base. A large trough-shaped basin formed in front of the thrust sheets, deeper near the thrust front and shallower northward. Lower to middle Eocene flysch deposition in the trough began with sediments derived from limestones, such as the Sagua* and San Martin* formations, followed by an increase in volcanic and intrusive-derived detritus, such as the lower Vega* and lower Manacas (Pica Pica) formations, and finally, capped by the intrusive and volcanic-derived coarse conglomerates and wildflysch of the upper Vega* (Rosas*) and upper Manacas (Vieja) formations. In central Cuba, the rocks of the deep-water Vega* Formation became coarser grained through time. In

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FIGURE 36. Obduction 2. See Figure 8 for definition of lithologic symbols.

western Cuba, the fine-grained clastics and other pelagic sediments of the Manacas Formation changed abruptly to the coarse breccias of the Vieja Member. The breccia clasts reflect the lithology of the associated fault blocks. This suggests some subaerial erosion in central Cuba, whereas western Cuba was largely submarine. South of the front of the advancing volcanic and basic intrusive-rock thrust plate, a second series of basins developed parallel to the northern trough. Within these basins, which were carried piggyback by the thrust plate, lower Eocene igneous-derived sediments accumulated, but under quieter tectonic conditions (the Taguasco*, Bijabo*, Santa Clara*, Alkazar, Bacunayagua, Capdevila, and Universidad formations, for example). As the thrust sheets advanced, they overrode the lower to middle Eocene flysch, which had accumu-

lated in front of them, and the flysch served as a lubricating medium for further thrusting. The subduction responsible for the uplift driving the thrusting ceased progressively from west to east, and volcanic activity continued in Oriente until the middle Eocene. Along what appears to be a north-dipping subduction zone and south of the Jardines de la Reina Cays (Camaguey trench) is a filled trench, which is a remnant of an accretionary prism. This trench could be related to the exposures in Haiti’s southern peninsula and the Muertos Trench. In central and eastern Cuba, the thrust front advanced until the volcanic and basic intrusive rocks covered extensive areas of the massive shallow-water carbonates of the northern coast of the island (Yaguajay* belt, coastal and Gibara areas). After the front stopped advancing, compression from the south continued, tightly folding and then reverse faulting the

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FIGURE 37. Scotia Sea bathymetry. Modified after the National Oceanic and Atmospheric Administration Satellite and Information Service.

FIGURE 38. Scotia Sea structural interpretation. PZ = Paleozoic.

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FIGURE 39. Scotia Sea structural interpretation on bathymetry. Modified after the National Oceanic and Atmospheric Administration Satellite and Information Service. FZ = fault zone; PZ = Paleozoic. succession of thrust plates. The result was the late Eocene structures shown in Figure 33. As compression continued, the folds became sharper, and the faults

FIGURE 40. Caribbean topography.

began lateral motion, probably because the northward compression was not directed perpendicular to the front of the carbonate banks. It is possible

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FIGURE 41. Caribbean free air gravity. Modified after Sandwell and Smith (1997). that a deep-seated, crustal transcurrent fault was also involved. In western Cuba, the northward-moving stack of thrust sheets did not reach the buttress of the Bahamas Platform, and the nappes came to rest on the sea floor toward the southern Gulf of Mexico. As a result, they are less deformed than they are to the east. It is possible that a large number of the present-day high-angle faults, some with reverse thrusting (Seibabo syncline), formed during the last phase of the orogeny. The intense orogenic activity ceased toward the close of the middle Eocene or early late Eocene, and the uplifted, faulted, and folded orogenic complex was subsequently eroded and peneplained.

Late Eocene to Present Shallow-marine conditions prevailed during most of this time interval, and mostly limestones, marls, and shales accumulated, accompanied by some coarse clastic sediment (present; see Figure 34). There was very little tectonic activity. In the northern basins, a strong angular unconformity separates the upper Eocene strata from the older rocks. In the southern basins, sedimentation was essentially continuous from the Cretaceous through the Tertiary, with no major

unconformity. Some local basins may have formed as gentle deformation of the old orogenic belt occurred. This deformation consisted mostly of large-scale folds (Habana-Matanzas) and high-angle faults (Pinar). This type of deformation is still active today and is largely responsible for Cuba’s present physiography. Cuba is an example of subduction generating an orogenic belt. The subduction progressed from an oceanic environment through a region of relatively recent oceanic crust between North and South America and, finally, became inactive at the southern margin of the North American continent. The main difference relative to most of the well-known marginal orogenic belts is that the thrust sheets that accompanied the subduction rode onto and over a much depressed and fragmented continental margin (with fragments now in the Bahamas Basin, Gulf of Mexico, Yucatan) relatively far away from a fully continental craton. The orogeny was characterized by a scarcity of detrital sediments on its continental side and by the rapidity of the entire orogenic process that started during the Late Cretaceous and culminated within the early to middle Eocene. It also shows clearly that when the thrusting occurred, the continental margin was not contiguous with the subduction, but was separated from it by an arch, which mostly exposed

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FIGURE 42. Caribbean structural interpretation. PC = Precambrian; PZ = Paleozoic. See Figure 8 for definition of lithologic symbols.

granodioritic basement rocks. The Alps show similar geology. The northward displacement of the visible thrusting was on the order of several hundred kilometers.

CUBA’S CONTRIBUTION TO THE UNDERSTANDING OF OBDUCTION A great contribution of Cuba to our knowledge of orogeny is that it provides evidence that obduction must not be the converse of subduction. That is to say, the obduction in Cuba did not result from the pushing of oceanic crust over the top of a subducting plate. The evidence from Cuba indicates a different process, which could have much more general application than just in Cuba. This process was referred to above, will be explained further below, and is diagrammatically shown in Figures 35 and 36.

The Domingo* belt shows a characteristic cross section of oceanic crust (>4000 m; >13,100 ft), with serpentine at the base. The serpentine very probably formed during oceanic rifting when seawater came near, or in contact with, the upper mantle. As the serpentine became buried under layers of basalt and associated volcaniclastic, its low permeability did not allow the water to escape at a rate directly related to the weight of accumulating overburden. The water bore much of the overburden load, which generated near geostatic pore-fluid pressure. The resultant decrease in shear strength would have produced a definite low-velocity Moho discontinuity. The decrease in shear strength created unstable oceanic crust, similar to the overpressured shales at the base of normally compacted deltaic sedimentary sections. For Cuba, north-dipping subduction of oceanic crust under the newly rifted oceanic crust raised the newly formed oceanic crust. It broke up and, under

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FIGURE 43. Structural interpretation on topography. Modified after the National Oceanic and Atmospheric Administration Satellite and Information Service. PC = Precambrian; PZ = Paleozoic. See Figure 8 for definition of lithologic symbols.

the force of gravity, detached along the overpressured serpentine and slid downhill toward the foreland basin and away from the subduction zone. This Cuban scenario is supported by the presence of metamorphic exotics in the serpentine; by the absence or the relatively low-grade reverse metamorphism of the sediments underlying the serpentine; by the total lack of metamorphism of the volcanics overlying the oceanic crust; by the diapirism and evidence of flowage exhibited by many serpentine bodies and contained exotics; and by the definite evidence of stacked oceanic thrust sheets in the Santa Clara–Placetas area, as well as in the Mayari and Baracoa massifs in eastern Cuba. As the subduction of oceanic crust under oceanic crust migrated, the uplifted and now-detached allochthonous fragment of newly formed oceanic crust kept sliding northward away from the subduction zone until it overrode (was obducted over) the continental margin, capturing and dragging, in its base, fragments of that margin, and eventually riding over a bed of detritus derived from its own basic igneous rocks (the Vega and Vieja formations). This obducted, allochthonous sheet carried, piggyback, the arc volcanics and volcanoclastic basins. The continental margin deep-

water carbonates and cherts also became involved in the slide and were pushed in thrust sheets in front of the advancing oceanic crustal sheet. Away from its front edge, the warm slab of sliding oceanic crust caused reverse metamorphism (Maastrichtian –early Eocene) in the Trinidad and Isla de la Juventud massifs and Pinar del Rio’s Cangre belt. The granodiorite associated with the arc volcanism was intruded during the Late Cretaceous and, thus, preceded the metamorphism. The Cuba subduction was part of the Caribbean oceanic crust subduction extending from the Yucatan to the Saba Bank. A continuous series of oceanic crustal blocks became detached and began sliding northward from late Maastrichtian near Yucatan to early Eocene toward Hispaniola. To the west, the sliding was over the oceanic crust of the Yucatan oceanic basin (Pinar del Rio). In central Cuba, the sheet of oceanic crust slid (was obducted) onto the southward-projecting Florida-Bahamas continental margin. Exposed farther to the east, in Hispaniola and Puerto Rico, is the Caribbean oceanic crust subducted under the Atlantic oceanic crust (Haiti southern peninsula, Muertos Trench), where it is possible that the Caribbean oceanic crust

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FIGURE 44. 162 Ma: Callovian. A = Africa; FL = Florida; NA = North America; SA = South America. was also obducted by sliding over the Atlantic oceanic crust. Obduction appears to accompany subduction only in cases of subduction of oceanic crust under oceanic crust and, as in Cuba, northern Venezuela, and the Alpine ranges, on thinned continental margins adjacent to spreading the Caribbean- and Mediterraneantype oceans. In Cuba, the obducted sea floor is the sea floor that was originally on the upside of the subduction; therefore, the obduction moved in the same direction as the dip of the subduction. In other words, the evidence from Cuba indicates that the continental plate was not subducted under the oceanic plate. It is very possible that this Cuban obduction process may be the most common form of obduction.

CUBA’S CONTRIBUTION TO THE HISTORY OF THE CARIBBEAN North America began separating from Africa during the Triassic, approximately 200 Ma, and paleogeographic reconstructions prior to 150 Ma are uncertain. Pindell and Barrett (1990) present what may

be the tightest fit, but at the expense of moving parts of Mexico out of the way through the Mojave-Sonora megashear and rotating and sliding crustal blocks such as the Yucatan and southern Florida. Salvador and Green (1980) give an interesting reconstruction of the early stages of separation in the Late Triassic (200 Ma). They postulate that the Yucatan block was farther north in the Gulf of Mexico, but otherwise, Florida, the Bahamas, and Cuba were as they are today, except that the entire area was much closer to South America. This reconstruction has the advantages of being simple and based on regional geology and is adopted, in part, here. Also assumed here is that since the Triassic period, the South American continent has included the Cordillera Central and the Santa Marta massif in Colombia, and that the Bocono fault in Venezuela has been of minor importance. Many problems concerning the history of the Caribbean exist that the geology of Cuba cannot resolve. An example is accounting for the postulated 1100 km (683 mi) of left-lateral displacement of the Cayman rift and the introduction of the NicaraguaJamaica rise since the upper Eocene, although the relative positions of North and South America remained

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FIGURE 45. 144 Ma: early Tithonian. A = Africa; FL = Florida; NA = North America; SA = South America.

essentially unchanged during that time. It is almost impossible to locate a right-lateral displacement of the same magnitude (even with multiple smaller faults) along the north coast of Venezuela. Another example is whether the circum-Caribbean orogenies originated with a Great Arc (Pindell and Barrett, 1990), spreading from the Pacific Ocean, or whether there were multiple arcs. A third example is the polarity of the subduction. James (2006) proposed an in-situ origin based on similarities to areas such as the Scotia Sea and Banda arc. The gross morphological similarities between the Caribbean and the Scotia Sea are obvious. Both appear to be eastward oceanic incursions between two continental masses: North and South America, and South America and Antarctica. Both are limited to the east by an active volcanic arc resulting from westwarddipping oceanic – oceanic subduction, and in both cases, the western margins of the westward-drifting continents are bounded by eastward-dipping continental and oceanic subduction. In both cases, it appears as if the oceanic floor is moving eastward in relation to the continents.

Some important differences exist. The Scotia Sea shows a definite oceanic basement, with a presently active east-northeast-spreading axis, interrupted by several west-southwest transverse faults (Figures 37–39). This oceanic basement seems to be continuous with the Pacific, although separated by the Shackleton fracture zone. Each spreading strip between transforms seems to end in subduction, either under the South American or the Antarctic continent. The oceanic crust is being generated in situ and does not come from the Pacific. The major Caribbean basins (Yucatan, Colombian, and Venezuelan), however, do not have presently spreading oceanic crust; only one short, active, north– south-spreading axis exists in the center of the Cayman trough (Figures 40–43). These basins are not considered typically oceanic, and only weak magnetic anomalies indicate a spreading center in the Venezuelan Basin, which has remained inactive for the last 127 m.y. (since the Hauterivian). This is puzzling because the distance between North and South America increased continuously from the Triassic until the Campanian (80 Ma). In addition, in the Caribbean,

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FIGURE 46. 132 Ma: Valanginian. A = Africa; FL = Florida; NA = North America; SA = South America.

undisturbed Upper Cretaceous (Turonian) and younger pelagic sediments overlie older volcanics (such as basalts, dolerites, and tuffs). The South American continent south of the Cerros de la Ventana (correlated to the Africa’s Cape Mountains) is covered by a large expanse of Jurassic volcanics (Serie Tobifera), which forms the basement. Protruding out of this basement are the Paleozoic Falkland (Maldives) Islands. Precambrian rocks have been cored on the Falkland plateau. The Tierra del Fuego Andes and the Antarctica Peninsula have a Paleozoic core. The Scotia Sea appears, therefore, to have opened across a Paleozoic to Precambrian continental mass (Dalziel, 1974). Unlike the Scotia Sea, very confusing evidence of what happened at the end of the Paleozoic in the Caribbean area exists. The Ouachitas do not appear to be a simple continuation of the Appalachians. Drilling south of the Ouachitas shows thick, slightly metamorphosed(?), and relatively undisturbed Cambrian– Ordovician Ellenburger carbonates. No known volcanic or igneous equivalent exists, unless it runs under the Gulf of Mexico or farther south. The Andes of to-

day resulted from the superposition of orogenic deformation that started in the Paleozoic. The Cambrian of Colombia is characterized by Atlantic province trilobites and not Pacific. How the Appalachian orogenic belt (or the Hercynian Atlas) connected with Colombia is unknown, but it must have gone through the Caribbean region prior to the opening of the Caribbean. Fragmental outcrops of Precambrian to upper Paleozoic rocks are present in Mexico, from the Cabo de las Corrientes through Oaxaca, in the Maya Mountains, and in north-central Nicaragua (Dengo, 1975). In central Florida, drilling has penetrated Paleozoic granites and metamorphic rocks below a Triassic to Lower Jurassic volcanic complex. Allochthonous basement blocks in Cuba range in age from Precambrian to at least Late Jurassic. The evidence suggests that the early Caribbean basement also consisted of metamorphics and plutons reflecting the Appalachian or Hercynian orogeny. Perhaps the Scotia Sea is an analog of the early stage of the opening of the Caribbean. That would suggest that the Caribbean oceanic crust formed in situ and was not of Pacific origin. Assuming that this is true,

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FIGURE 47. 110 Ma: Aptian. A = Africa; FL = Florida; NA = North America; SA = South America. both the Scotia Sea and the Caribbean would have similar relations between spreading axis and oceanunder-continent subduction on one side and oceanunder-ocean on the other. The Caribbean continental basement blocks, named here Chortis, Acapulco, Maya, La Rana, and South Florida, were surely part of Gondwana and were fragmented by the opening of the North Atlantic when North America started rifting from Gondwana. Figures 44 – 52 show the stages of Cuban evolution described above relative to a possible plate-tectonic reconstruction of the Caribbean. The continental positions in these reconstructions are based on the reconstructions of the ODSN. The position of the Caribbean is shown in relation to Africa. Cuba is placed in its present position relative to Florida, although different parts of the island come from different places. The reconstruction shown by Figures 44–52 can explain several observations, but cannot be proven by present evidence.

Callovian The Callovian is an early stage of the opening of the Caribbean (162 Ma; see Figure 44). Spreading oc-

curred through Florida and the Gulf of Mexico, with fragmentation of the Paleozoic basement and southward motion of the resulting Chortis, Acapulco, Maya, La Rana, and South Florida blocks. The Louann and Cunagua Salt, as well as the Maraval evaporite basins, formed. This was the time of major continentalderived clastic sedimentation in the opening Caribbean, with the deposition of the Todos los Santos and the San Cayetano (and equivalent schists and quartzites of the Isle of Pines and Escambray massifs). The east-dipping Andes subduction zone is assumed to have separated the Americas from the Pacific Ocean. Cuba could have been located over one of the numerous transforms offsetting the spreading axis. Such transforms might have become later transcurrent faults, thus explaining the so-called ‘‘crustal discontinuity’’ running parallel to and north of the axis of the island.

Early Tithonian The opening between North and South America continued with a strong left-lateral component, but the spreading axis jumps south of the Paleozoic blocks (144 Ma; see Figure 45). From then on, the southern

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FIGURE 48. 94 Ma: Cenomanian. A = Africa; FL = Florida; NA = North America; SA = South America. margin of the North American continent and northern Cuba became fixed relative to each other, and the entire north coast of Cuba, from Matanzas to Oriente, became part of the North American plate. Shallowwater conditions covered much of Cuba, the Bahamas, Florida, La Rana, and Maya, and the deposition of the Florida-Bahamas-Yucatan banks began. Some of the Cayo Coco and Maraval evaporites were still being deposited. This was the time of the formation and deepening of the early Caribbean. The Maya MountainsSarasota arch, the remnant of a late Paleozoic mountain range, was an effective dam holding back the sediments derived from North America. The major marine opening was toward the Atlantic, resulting in a strong influx of Tethys faunas.

Valanginian The lower Cabaiguan* section indicates that the Caribbean continued to expand with the generation of new crust (132 Ma; see Figure 46). The rest of Cuba showed a marked increase in water depth with accumulation of calcareous nannoplankton. In southern Belize, the ‘‘Aptychus’’ limestone accumulated

in a facies identical with that of Cuba’s Capitolio*. The La Rana block appears to have remained positive with deposition of bank limestone of the Vinas* Group.

Aptian South America began to separate from Africa, and the Caribbean continued to open (110 Ma; see Figure 47). The Maya Mountains-Sarasota arch continued to prevent the Gulf of Mexico clastics from reaching the Caribbean. The shallow-water Cogollo-Chimana reef limestones of Venezuela accumulated in a facies similar to that of the Coban, Marquesas, and Cayo Coco to the north. Strong submarine (oceanic) volcanism continued as indicated by the pillow basalts of the lower Cabaiguan sequence and by the Curac¸ao lava as well as the pre-Horizon B volcanics of the Venezuelan and Colombian basins.

Albian–Cenomanian–Turonian Oceanic spreading was mostly in the North and South Atlantic (94 Ma; see Figure 48). The motion in

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FIGURE 49. 80 Ma: Santonian. A = Africa; FL = Florida; NA = North America; SA = South America.

the Caribbean was mostly transcurrent, with increasing separation between North and South America. In Cuba, this is reflected by a marked decrease in volcanic material at the base of the Cabaiguan* sequence. The Cenomanian – Turonian was characterized by decreasing volcanic flows in the Gomez* Formation (Cabaiguan* sequence), which were, however, still in proximity to basic submarine volcanism. The Gomez*, characterized by black shale and thin nodular black limestone beds, is reminiscent of the La Luna and Querecual in Venezuela and the Eagle Ford in the Gulf states. It correlates, in part, with the extensive Santa Teresa cherts and clays that are similar to the San Antonio in Venezuela and the Mowry in the Rocky Mountains. A major regional if not worldwide marine transgression was accompanied by extensive submarine volcanic activity. Perhaps the silica was contributed by volcanism along the mid-Atlantic rift.

Coniacian–Santonian–Campanian The transcurrent motion between Cuba and South America decreased from the Albian to the Maastrich-

tian, whereas the separation between North and South America increased (80 Ma; see Figure 49). During the Coniacian, a new spreading axis formed (perhaps coinciding with today’s Cayman trough and under the Curac¸ao Ridge), and subduction intensified along the boundaries facing North and South America. The subduction generated a new arclike, more acidic, volcanic sequence (Pastora* Group in Cuba, and KnipVilla de Cura in Venezuela). Pindell et al. (2006) considers that this volcanic sequence indicates the insertion of a Pacific oceanic plate (the present Caribbean) between both continents. It could as well have been generated in situ, which would agree better with the geology of Cuba.

Maastrichtian The Maastrichtian saw the initiation of the northward gravity slide of the basic igneous-volcanic terranes in western Cuba and the clockwise rotation of the Villa de Cura (Tiara volcanics) in Venezuela (67 Ma; see Figure 50). Volcanism ceased in western Cuba and greatly diminished in central Cuba. It persisted during the middle and lower Eocene in eastern

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FIGURE 50. 67 Ma: Maastrichtian. A = Africa; FL = Florida; NA = North America; SA = South America.

Cuba, Hispaniola, and Puerto Rico. The lack of metamorphism of the Cuban basic igneous-volcanic terranes was caused by their detachment from their roots and their continuous slide away from the active subduction area and toward the Florida-Bahamas Banks.

Paleocene–Middle Eocene Around the Caribbean, including Cuba, compression, gravity sliding, and other orogenic activity culminated in the early to middle Eocene (50 Ma; see Figure 51). In Cuba, the Vega*, Rosas*, and Vieja orogenic sediments accumulated at the same time as the Venezuelan Guarico Formation, Matatere flysch, and the Barquisimeto olistostrome. The synchroneity and symmetry of deformation resulted from the two bounding subduction zones that responded to similar spreading and faced opposing continents and oceans. The Lesser Antillean arc became active, and Puerto Rico trench formed as a consequence of ocean-ocean subduction. The Barbados deep-water fan, derived from the Guyana shield, was deposited and began to be overridden by the Lesser Antilles accretionary wedge. The

Curac¸ao Ridge became detached and slid northward into the Venezuelan basin.

Early Late Eocene The northern and southern parts of the Caribbean began to look as they do today, and the circumCaribbean orogeny ended (see Figure 52; 40 Ma). The Caribbean became isolated from the Pacific by the north-dipping ocean – ocean Central American subduction zone and from the Atlantic by the westdipping ocean – ocean subduction of the Lesser Antilles arc. The Chortis block moved to its present position in Central America, and the Cayman Trench pull-apart rift began. All significant tectonic activity in Cuba ended.

CONCLUSIONS Cuba rests on the site of oceanic crust that formed as North America first began to separate from the rest of Pangea in the Late Triassic to Early Jurassic. It shows the most complete assemblage of intrusive,

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FIGURE 51. 50 Ma: lower Eocene. A = Africa; FL = Florida; NA = North America; SA = South America. volcanic, and sedimentary rocks in the Caribbean region. During and after the separation of South America from Pangea in the Early Cretaceous, spreading continued in the Caribbean as well as the Atlantic and Pacific oceans. Oceanic plates were subducting under North and South America. As a result of the Caribbean rifting, a pair of opposing orogenic belts developed. Along strike, the northern subduction changed from oceanic crust under continental crust (with obduction) in Cuba to oceanic under oceanic in Hispaniola and Puerto Rico. Figure 53 shows, diagrammatically (transforms have been omitted), the possible connection between Cuba and other Greater Antilles deformation. On the south side of the Caribbean, continental and oceanic subduction (with obduction) occurred in Venezuela, and oceanic – oceanic subduction occurred in Panama (the Panama segment may have

reversed polarity during the Tertiary). Both subduction zones operated simultaneously, and analogous to the present-day Scotia Sea, there must have been a spreading axis between them. Later processes, such as those that formed the Cayman trough, probably obscured the location of the spreading axis. It is particularly interesting that the entire orogenic activity shown by the rocks of Cuba (with the exception of some subaerial volcanism) appears to have occurred below sea level. The introduction of the Chortis block, as well as the relationship with older Hercynian and Appalachian deformed belts, remains poorly understood. The end of significant tectonic activity in Cuba in the late Eocene means that the island’s geology gives no indication about the nature of the Cayman trough’s left-lateral motion nor about the apparent right-lateral transcurrent motion in northern South America.

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FIGURE 52. 40 m.y.: base upper Eocene. A = Africa; FL = Florida; NA = North America; SA = South America.

ACKNOWLEDGMENTS Gulf Oil Corporation, which was very active in Cuba in the late 1940s and 1950s, was acquired by Chevron in 1984. Gulf donated, with Chevron’s authorization, all its Cuban files and material available in the United States to the Institute of Geophysics, University of Texas, Austin. These data are now in the public domain and are available at the University of Texas. It must be mentioned that Gulf’s original reports (like those of other foreign companies), were nationalized in 1959 by the revolutionary government. Unless lost, the reports are supposedly available to the public at the Fondo Geologico, La Habana. Much of Gulf’s information was based on a field mapping campaign conducted under my direction from 1952 to 1955. Paul B. Truitt and Harry Wassall were responsible for most of the fieldwork and general stratigraphic and structural studies. Much credit is also due to P. Bro ¨ nnimann, who was in charge of the stratigraphic laboratory in La Habana, and was

assisted by N. K. Brown in paleontology and K. K. Dickson in petrography. Bro ¨ nnimann discovered the abundant presence, in Cuban strata, of Alpine nannoplankton, leading to the unraveling of much of Cuban stratigraphy (Bro ¨ nnimann, 1955a, b). M. T. Kozary, at the time a graduate student at Columbia University, was closely associated with the project. In 1990, Harry Wassall, then at Petroconsultants, requested that I write a report on the Geology and Oil Prospects of Cuba. This report, issued in 1993, was, in large part, based on the writer’s own experience, the Gulf reports at the University of Texas, and the extensive literature available at the University of Texas. Wassall and G. Winston, Geological Consultant, provided much assistance and information. After Wassall’s death, IHS Energy Group, which had acquired Petroconsultants, relinquished all rights to this material. This publication is a much revised version of the Petroconsultants report. I also thank Amos Salvador and E. Rosencrantz of the University of Texas for making the data at the Institute of Geophysics easily available, giving valuable

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FIGURE 53. Obduction over Cuba and Hispaniola.

suggestions, and participating in important discussions. The author is grateful to M. Iturralde-Vinent of Havana’s Museo Nacional de Historia Natural for providing much assistance and recent information. I am also greatly indebted to T. Anderson for many suggestions concerning the interpretation of the data and

editing parts of the manuscript. Lastly, I am terribly grateful to Andrzej Pszczo´lkowski from the Polish Academy of Sciences and author of many recent studies of Cuban geology, who reviewed the manuscript and made many suggestions for improvements, as well as providing up-to-date information.

References Cited Ball, M. M., R. G. Martin, and W. D. Bock, 1981, Multichannel measurements over a possible gas-bearing structure near Cay Sal, Bahamas: AAPG Bulletin, v. 65, no. 5, p. 894. Ball, M. M., R. G. Martin, W. D. Bock, R. E. Sylwester, R. M. Bowles, D. Taylor, E. L. Coward, J. E. Dodd, and L. Gilbert, 1985, Seismic structure and stratigraphy of northern edge of Bahaman–Cuban collision zone: AAPG Bulletin, v. 69, p. 1275 – 1294. Bazhenov, M. L., A. Pszczo´lkowski, and S. V. Shipunov, 1996, Reconnaissance paleomagnetic results from western Cuba: Tectonophysics, v. 253, p. 65– 81. Bermudez, P. J., 1950, Contribicion al estudio del Conozoico Cubano, Universidad de la Habana (in Spanish): Memoria de la sociedad Cubana de historia natural, v. 19, no. 3, p. 205–375. Bermudez, P. J., 1961, Las formaciones geologicas de Cuba: La Habana, Ministerio de Industrias, Instituto Cubano de Recursos Minerales, Geologia Cubana, no. 1, 177 p. Bermudez, P. J., and R. Hoffsteller, 1959, Lexique Stratigraphique International. Amerique Latine, Cuba, v. 5, 140 p. Bohor, B. F., and R. Seitz, 1990, Cuban K/T Catastrophe: Nature, v. 344, p. 593. Boiteau, A., and M. Campos, 1974, Data preliminares sobre la geologia de la parte sur de la Sierra del Purial (Preliminary data on the geology of the southern part of La Sierra del Purial) (Spanish): Cuba, University de Oriente. Bovenko, V. G., B. Y. Scherbakova, and G. Hernandez, 1981, Topography of the Mohorovicic discontinuity beneath eastern Cuba (in English): Transactions of the U.S.S.R. Academy of Sciences, Earth Science Sections, v. 256, p. 8 – 12. Bovenko, V. G., B. Y. Scherbakova, and G. Hernandez, 1982, New geophysical data on the deep structure of eastern Cuba: International Geology Review, v. 24, p. 1155 – 1162. Brito Rojas, A., 1983, New aspects of the subdivision of the Cobre Formation, in E. Nagy et al., eds., Contribucion a la Geologia de Cuba Oriental: Editorial CientificoTecnica, Ministerio de Cultura, Ciudad de la Habana, p. 86 – 89. *Bro¨nnimann, P., 1953a, Laboratory Memorandum PB-14: Progress biostratigraphic chart, northern Las Villas Province, Cuba, Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas.

Albear Franquiz, J. F. de, and M. A. Iturralde-Vinent, 1985a, Estratigrafia de las provincias de la Habana, in M. A. Iturralde-Vinent, ed., Contribucion a la geologia de las provincias de la Habana y ciudad de la Habana: Ciudad de la Habana, Editorial Cientifico-Tecnica, Ministerio de Cultura, p. 12 – 54. Albear Franquiz, J. F. de, and M. A. Iturralde-Vinent, 1985b, Pisos estructurales en el territorio de las provincias de la Habana, in M. A. Iturralde-Vinent, ed., Contribucion a la geologia de Cuba Oriental: Ciudad de la Habana, Editorial Cientifico-Tecnica, Ministerio de Cultura, p. 77 – 86. Albear Franquiz, J. F. de, and M. A. Iturralde-Vinent, 1985c, Posicion tectonica del complejo gabro-peridotitico de las provincias de La Habana, in M. A. Iturralde-Vinent, ed., Contribucion a la geologia de las provincias de la Habana y ciudad de la Habana: Ciudad de la Habana, Editorial Cientifico-Tecnica, Ministerio de Cultura, p. 87 – 93. Albear Franquiz, J. F. de, J. Sanchez Arango, and M. A. Iturralde-Vinent, 1985, Formacion Rosario: Redescripcion y estudio micropaleontologico, in M. A. IturraldeVinent, ed., Contribucion a la geologia de las provincias de la Habana y ciudad de la Habana: Ciudad de la Habana, Editorial Cientifico-Tecnica, Ministerio de Cultura, p. 59– 76. Alegret, L., I. Arenillas, J. A. Arz, C. Dı´az, J. M. GrajalesNishimura, A. Mele´ndez, E. Molina, R. Rojas, and A. R. Soria, 2005, Cretaceous–Paleogene boundary deposits at Loma Capiro, central Cuba: Evidence for the Chicxulub impact, Geology, v. 33, no. 9, p. 721–724. Alva-Valdivia, L. M., A. Goguitchaichvili, J. CobiellaReguera, J. Urrutia-Fucugauchi, M. Fundora-Granda, J. M. Grajales-Nishimura, and C. Rosales, 2001, Palaeomagnetism of the Guaniguanico Cordillera, western Cuba: A pilot study: Cretaceous Research, v. 22, p. 705– 718. Ando´, J., S. Harangi, B. Szakma´ny, and L. Doszta´ly, 1996, Petrologia de la Asociacion Ofiolitica de Holguin, in M. A. Iturralde-Vinent, ed., 1996, Ofiolitas y Arcos Volcanicos de Cuba (Cuban Ophiolites and Volcanic Arcs) (Spanish): International Union of Geological Sciences —United Nations Educational, Scientific and Cultural Organization, International Geological Correlation Programme, Contribution No. 1, Project 364 (Geological Correlation of Ophiolites and Volcanic Arc Terrane in the CircumCaribbean Realm), p. 154 – 175.

*All italicized references in this References Cited Section are unpublished reports donated by Gulf/Chevron to The University of Texas — Institute for Geophysics, and can be found listed in the UTIG Plates Project Bibliography of Caribbean Geology and Geophysics located at http://www.ig.utexas.edu/research/projects /plates/biblio/carib/carib.htm (accessed December 15, 2008).

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50 / Pardo *Bro¨nnimann, P., 1953b, Laboratory Memorandum PB-28: Progress biostratigraphic chart, northern Las Villas Province, Cuba, Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. *Bro¨nnimann, P., 1954, Paleontological Report 456: Annotations to the correlation chart and catalogue of formations, Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. Bro ¨ nnimann, P., 1955a, Microfossils incertae sedis from the Upper Jurassic and Lower Cretaceous of Cuba: Micropaleontology, v. 1, p. 28 – 49. *Bro¨nnimann, P., 1955b, Paleontological Report 754: Annotation to the correlation chart of the Fomento-Jatibonico area and catalogue of formations, Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. *Bro¨nnimann, P., 1956, Paleontological Report 1148: Annotations to the correlation chart of northern Las Villas Province, Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. Bro ¨ nnimann, P., and D. Rigassi, 1963, Contribution to the geology and paleontology of the area of the city of La Habana, Cuba, and its surroundings: Eclogae Geologicae Helvetiae, v. 56, p. 1–480. Burke, K., 1988, Tectonic evolution of the Caribbean: Annual Review of Earth and Planetary Sciences, v. 16, p. 201 – 230. Bush, V. A., and I. N. Shcherbakova, 1986, New data on the deep tectonics of Cuba: Geotectonics, v. 20, no. 3, p. 192 – 203. *Butticaz, P., 1952, Gas seepages in the Keys east of the Isle of Pines, Cuba, Standard Cuban Oil Company, La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. *Calvache, G., 1958, Final report on Collazo 1 well, Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. Cerma´k, V., M. Kresl, J. Safanda, M. Na´poles-Pruna, R. TenreyroPerez, L. M. Torres-Paz, and J. J. Valdes, 1984, First heat flow density assessments in Cuba: Tectonophysics, v. 103, p. 283 – 296. Cerma´k, V., M. Kresl, J. Safanda, L. Bodri, M. Na´poles-Pruna, and R. Tenreyro-Perez, 1991, Terrestrial heat flow in Cuba: Physics of the Earth and Planetary Interiors, v. 65, p. 207 – 209. Chauvin, A., M. L. Bazhenov, and T. Beaudouin, 1994, A reconnaissance paleomagnetic study of cretaceous rocks from central Cuba: Geophysical Research Letters, v. 21, no. 16, p. 1691 – 1694. Childs, O. E., G. Steele, and A. Salvador, eds., 1988, Correlation of stratigraphic units of North America (COSUNA) Project, Gulf Coast Region, AAPG, Tulsa, Oklahoma, 1 sheet. Cobiella, J. L., 1974, Los macizos serpentiniticos de Saba-

nilla Mayari Arriba (Serpentine Massifs of Sabanilla, Mayari Arriba) (Spanish): Revista Tecnologica, v. 12, no. 4, p. 41–50. Cobiella, J., F. Quintas, M. Campos, and M. M. Hernandez, 1984, Geology of the central and southeast region of Guantanamo province: Santiago de Cuba, Editorial Oriente, 125 p. Cobiella-Reguera, J. L., 2005, Emplacement of Cuban ophiolites: Geologica Acta, v. 3, no. 3, p. 273 – 294. Coutı´n-Correa, D., and A. Brito-Rojas, 1976, Caracteristicas de la Zeolitizacio´n de las rocas Sedimentarias de origen volcanico de Cuba oriental (Characteristics of the Zeolitization of the Sedimentary Rocks of Volcanic Origin of Eastern Cuba): Transactions of the Caribbean Geological Conference, Flushing, NY, Queens College Press, p. 293–297. Cuba, 1985a, Mapa Geologica de la Republica de Cuba: Ministerio de la Industria Basica, Centro de Investigaciones Geologicas, scale 1:500,000, 5 sheets. Cuba, 1985b, Mapa Tectonico de Cuba: Ministerio de la Industria Basica, Centro de Investigaciones Geologicas, scale 1:500,000, 4 sheets. Cuba, 1988, Mapa de Yacimientos y Manifestaciones Minerales no Metalicos y Combustibles de la Republica de Cuba: Academy of Sciences of Cuba and USSR, scale 1:500,000, 5 sheets. Cuevas Ojeda, J. L., L. A. Dı´az Larrinaga, and B. P. Gonza´lez, 2003, Mapas generalizados de las anomalias gravimetricas del Caribe Occidental y America Central, 1:2,000,000: Tectonic of Caribbean plates, International Geological Correlation Programme – United Nations Educational, Scientific, and Cultural Organization Project 433, Memorias GEOMIN (Geologia y Mineria) (Spanish): La Habana, 9 p. Dalziel, I. W. D., 1974, Evolution of the margins of the Scotia Sea, in C. H. Burk and C. L. Drake, eds., The geology of continental margins: New York, Springer Verlag, p. 567– 579. Darton, N. H., 1926, Geology of Guantanomo Basin, Cuba: Journal of the Washington Academy of Science, v. 16, p. 324 – 333. DeGolyer, E., 1918, The geology of Cuban petroleum deposits: AAPG Bulletin, v. 2, p. 133 – 167. Dengo, G., 1975, Paleozoic and Mesozoic tectonic belts in Mexico and Central America, in A. E. Nairn and F. G. Stehli, eds., The ocean basins and margins: The Gulf of Mexico and the Caribbean: New York, Plenum Press, v. 3, p. 283 – 323. Dengo, G., and J. E. Case, eds., 1990, The Caribbean region, decade of North American geology (DNAG), The Geology of North America, V.H.: Geological Society of America, 528 p. De Vletter, D. R., 1946, Geology of the western part of the Middle Oriente, Cuba: Doctoral thesis, Kemink, University of Utrecht, Netherlands, 106 p.

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References / 51 Dilla, M., and L. Garcı´a, 1984, Stratigraphy and sedimentogenesis of the superpositioned basins of central Cuba (in Spanish): Serie Geologica, Instituto de Geologia y Paleontologia Academia de Ciencias de Cuba, p. 101 – 154. Dilla, M., and L. Garcia, 1985, New data on the stratigraphy of the provinces of Cienfuegos, Villa Clara and SanctiSpiritus (in Spanish): Serie Geologica, Instituto de Geologia y Paleotologia Academia de Ciencias de Cuba, p. 53 – 77. Ducloz, C., 1960, Apuntes sobre el yeso del Valle de Yamuri, Matanzas (Notes on the gypsum of Valle de Yamuri, Matanzas) (Spanish): Sociedad Cubana de Historia Natural, Memorias, v. 28, no. 1, p. 1–9. Ducloz, C., 1963, Geomorphic study of the region of Matanzas, Cuba: Archives tes Sciences, Societe de Physique et Histoire Naturelle, v. 16, p. 351 – 402. Ducloz, C., and M. Vaugnat, 1962, On the age of serpentines of Cuba: Archives tes Sciences, Societe de Physique et Histoire Naturelle, v. 15, p. 310 –331. Echevarria-Rodriguez, G., G. Hernandez-Perez, J. O. Lopez Quintero, J. G. Lopez-Rivera, R. Rodriguez-Hernandez, J. R. Sanchez-Arango, R. Socorro-Trujillo, R. TenreyroPerez, and J. L. Yparraguirre-Pena, 1991, Oil and gas exploration in Cuba (in Spanish): Journal of Petroleum Geology, v. 14, p. 259 – 274. Fernandez, G., J. Fernandez, and S. Blanco-Bustamante, 1987, Estudio biostratigrafico y ambientes de sedimentacion del pozo Candelaria 1 de la provincia de Pinar del Rio, in Memorias del III Encuentro Cientifico-Tecnico de Geologia, P. del Rio, October 24, 1987: p. 32– 39. Flint, D. E., J. F. Albear, and P. W. Guild, 1948, Geology of chromite deposits of the Camaguey district, Camaguey Province, Cuba: U.S. Geological Survey Bulletin, v. 954, p. 39 – 63. *Flores, G., 1949, Western Matanzas Province, 20, Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. Flores, G., 1952, Geology of northern British Honduras: AAPG Bulletin, v. 36, p. 404 – 413. Franco, G. L., 1983a, Considerations about the OligoMiocene deposits of Guantanamo, in E. Nagy et al., eds., Contributions on the geology of eastern Cuba (in Spanish): La Habana, Editorial Cientifico-Tecnica, p. 138 – 143. Franco, G. L., 1983b, Geologic column of the Tertiary of the Golfo de Guacanayabo (in Spanish), in E. Nagy et al., eds., Contribucion a la geologia de Cuba Oriental: Ciudad de la Habana, Editorial Cientifico-Tecnica, p. 127–133. Franco, G. L., 1985, Tectono-environmental classification of Neogene deposits in eastern Cuba: Ciencias de la Terra y del Espacio, no. 10, p. 57–67. Franco, G. L., 1986, Scheme of the history of sedimentation during the Neogene in eastern Cuba: Ciencias de la Terra y del Espacio, no. 11, p. 81 – 91.

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52 / Pardo Haczewski, G., 1987, Reconocimiento sedimentologico de la Formacion San Cayetano: Un margen continental acumulativo en el Jurasico de Cuba occidental, in A. Pszczo´lkowski et al., eds., Contribucion a la geologia de la provincia de Pinar del Rio: Ciudad de La Habana, Ministerio de Cultura, Editorial Cientifico-Tecnica, p. 228 – 247. Hatten, C. W., 1957, Geology of the Central Sierra de los Organos, Pinar Del Rio Province, Cuba, Report found at the Library of the Institute for Geophysics, University of Texas, Austin, Texas, 48 p. Hatten, C. W., 1967, Principal features of Cuban geology: Discussion: AAPG Bulletin, v. 51, p. 780 – 789. *Hatten, C. W., D. E. Schooler, N. Giedt, and A. A. Meyerhoff, 1958, Geology of central Cuba, eastern Las Villas and western Camaguey Provinces, Cuba: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas, 174 p. Hatten, C. W., M. Somin, G. Millan, P. Renne, R. W. Kistler, and J. M. Mattinson, 1988, Tectonostratigraphic units of central Cuba, in L. Barker, ed., Transactions of the 11th Caribbean Geological Conference, Barbados, 1986: p. 35.1– 35.13. Hedberg, H. D., ed., 1976, International Stratigraphic Guide, John Wiley & Sons, New York, New York, 200 p. Hermes, J. J., 1945, Geology and paleontology of East Camaguey and West Oriente: Geographische en Geologische Mededeelingen, Physiographisch-Geologische Reeks, Series 7: Utrecht, Holland, Instituut der Rijksuniversiteit, 75 p. Hernandez Perez, G., and J. F. Blickwede, 2000, Cuba deepwater exploration opportunities described in southeastern Gulf of Mexico: Oil & Gas Journal, v. 98, no. 50, p. 42 – 48, 46 – 48. Herrera, N., 1961, Contribution to the Stratigraphy of the Pinar del Rio Province (in Spanish): Revista Sociedad Cuban Ingenieria, v. 61, no. 1-2, p. 2 – 24. Hess, H. H., 1938, Gravity anomalies and island arc structure with particular reference to the West Indies: Proceedings of the American Philosophical Society, v. 79, no. 1, Symposium on the Geophysical Exploration of the Ocean Bottom, arranged by the American Geophysical Union, April 21, 1938, p. 71 – 96. Holcombe, T. L., J. W. Ladd, G. Westbrook, N. Terrence Edgar, and C. L. Bowland, 1990, Caribbean marine geology, ridges and basins of the plate interior, in G. Dengo and J. E. Case, eds., The geology of North America, v. H: The Caribbean region: Geological Society of America, p. 231 – 260. Imlay, R. W., 1942, Late Jurassic fossils from Cuba and their economic significance: Geological Society of America Bulletin, v. 53, p. 1417 – 1477. Ipatenko, S., and I. N. Sashina, 1971, Sobre el levantamiento gravimetrico en Cuba: Ministerio de Minas, La Habana, Cuba (in Spanish), 14 p. Ipatenko, S., M. Kopnin, and S. Shijov, 1971, Using gravi-

metric exploration to study the crustal structure of the island of Cuba and adjacent territory (in Spanish): Revolucion Tecnologica, v. 9, no. 2, p. 40 – 46. Iturralde-Vinent, M., 1988, Naturaleza Geologica de Cuba: Editorial Cientifico-Technica, La Habana, 246 p. Iturralde-Vinent, M., et al., 1981, Geologica del territorio de Ciego-Camaguey-Las Tunas: Resultados de las investigaciones cientificas y del levantamiento geolo´gico escala 1:250,000: Academias de ciencias de Cuba y Bulgaria, 940 p. Iturralde-Vinent, M. A., 1969, Neogene stratigraphy in western Cuba: New data: AAPG Bulletin, v. 54, p. 1938 – 1955. Iturralde-Vinent, M. A., 1970, Principal characteristics of Cuban Neogene stratigraphy: AAPG Bulletin, v. 53, p. 658– 661. Iturralde-Vinent, M. A., 1972, Principal characteristics of the Oligocene and Lower Miocene stratigraphy of Cuba (in Spanish): Revolucion Tecnologica, v. 10, no. 3 – 4, p. 24 – 35. Iturralde-Vinent, M. A., 1975a, Problems in the application of modern tectonic hypotheses to Cuba and the Caribbean region: AAPG Bulletin, v. 59, p. 838 – 855. Iturralde-Vinent, M. A., 1975b, Problems with the application of modern hypotheses to Cuba and the Caribbean region: Revolucion Tecnologica, v. 13, no. 1, p. 46 – 63. Iturralde-Vinent, M. A., 1977, The tectonic movements during the platform development stage in Cuba (in Spanish): Informe Cientifico-Tecnico, v. 20, p. 1 – 24. Iturralde-Vinent, M. A., 1981, New interpretative model of the geological evolution of Cuba (in Spanish): Ciencias de la Tierra y del Espacio, v. 3, p. 51 – 89. Iturralde-Vinent, M. A., 1985, Historia geologica del Mesozoico de las provincias de La Habana, in M. A. IturraldeVinent, ed., Contribucion a la geologia de las provincias de la Habana y ciudad de La Habana: Ciudad de la Habana, Editorial Cientifico-Tecnica, Ministerio de Cultura, p. 94–99. Iturralde-Vinent, M. A., 1994, Cuban geology: A new plate tectonic synthesis: Journal of Petroleum Geology, v. 17, no. 1, p. 39 – 70. Iturralde-Vinent, M. A., ed., 1996, Ofiolitas y arcos volcanicos de Cuba (Cuban ophiolites and volcanic arcs), in International Union of Geological Sciences – United Nations Educational, Scientific, and Cultural Organization International Geological Correlation Programe, Contribution 1, Project 364, (Geological Correlation of Ophiolites and Volcanic Arc Terrane in the CircumCarribean Realm), 254 p. Iturralde-Vinent, M. A., 1998, Sinopsis de la constitucio´n geolo´gica de Cuba: Acta Geologica Hispanica, v. 33, no. 1 – 4, p. 9 – 56. Iturralde-Vinent, M. A., and A. C. de la Torre, 1990, Posicion estratigrafica de los rudistas de Camaguey, Cuba, in D. K. Larne and G. Draper, eds., Transactions, 12th

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ternational Union of Geological Sciences-United Nations Educational, Scientific and Cultural Organization (Geological Correlation of Ophiolites and Volcanic Arc Terrane in the Circum-Caribbean Realm): International Geological Correlation Programme, Contribution No. 1, Project 364, 254 p. *Kozary, M., 1955a, Geology of the Campo Florida section of the Habana-Matanzas anticline (Geological Memorandum MK-3), Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. *Kozary, M., 1955b, Geology of the Ciego de Avila-Tamarindo area, Camaguey (Geological Memorandum MK-4), Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. Kozary, M. T., 1968, Ultramafic rocks in thrust zones of northwestern Oriente province, Cuba: AAPG Bulletin, v. 52, p. 2298 – 2317. Kuznetsov, V. I., J. R. Sanchez, G. Furrazola, and R. Garcia, 1985, New data on the thrust sheets of the north coast of Cuba (in Spanish): Serie Geologica, Instituto Geologia y Paleontologia Academia de Ciencias de Cuba, p. 106 – 118. Lewis, J. M., 1932, Geology of Cuba: AAPG Bulletin, v. 16, no. 6, p. 533-555. *Littlefield, M., 1952, Summary report: Cuban Gulf Oil Co. Blanquizal 111 #1, Cuban Gulf Oil Co., La Habana: Report, Library of the Institute for Geophysics, University of Texas, Austin, Texas. Lopez-Rivera, J. G., J. O. Lopez Quintero, J. Fernandez Carmona, and G. Fernandez Rodriguez, 1987, Analisis geologica del corte del pozo Parametrico Pinar 1: In Memorias del III Encuentro Cientifico-Tecnico de Geologia, P. Del Rio, October 24, 1987, p. 40– 45. MacGillarry, H. J., 1937, Geology of the province of Camaguey, Cuba, with revisional studies in rudist paleontology: Geographische en Geologische Mededeelingen. Physiographisch-Geologische Reeks, Series 14: Utrecht, Holland, Instituut der Rijksuniversiteit, 169 p. Meyerhoff, A. A., and C. W. Hatten, 1968, Diapiric structures in central Cuba, in J. Braunstein and G. D. O’Brien, eds., Diairism and diapirs: AAPG Memoir 8, p. 315 – 357. Meyerhoff, A. A., M. M. Khudoley, and C. W. Hatten, 1969, Geologic significance of radiometric dates from Cuba: AAPG Bulletin, v. 53, p. 2494 – 2500. Milla´n, G., 1981, Geology of the metamorphic massif of the Isla de la Juventud Ciencias de la Tierra y del Espacio, no. 3, p. 3 – 22. Milla´n G., 1992, Analisis comparativo entre los macizos metamorficos de Isla de la Juventud y Escambray (Comparative analysis between the Metamorphic Massifs of Isla de la Juventud and Escambray): Programa y resu´menes 13va Conferencia Geolo´gica del Caribe, Pinar del Rio, Cuba, p. 53 – 54. Milla´n, G., and R. Myczynski, 1979, Jurassic ammonite

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Adamovich, A. F., and V. Chejovich, 1964, Principal characteristics of the geology and the useful minerals of the northeast region of Oriente Province: Revistas Tecnologica (Spanish), v. 2, no. 1, p. 14 – 20. Bandy, O., 1964, Foraminiferal biofacies in sediments of the Gulf of Batabano, Cuba, and their geologic significance: AAPG Bulletin, v. 48, p. 1666 – 1679. Bresznyanszky, K., and M. A. Iturralde-Vinent, 1983, Paleogeografia del Paleogeno de Cuba Oriental, in E. Nagy et al., eds., Contribucion a la Geologia de Cuba Oriental: Ciudad de la Habana, Editorial Cientifico-Tecnica, Ministerio de Cultura (Spanish), p. 115 – 126. Bresznyanszky, K., and M. A. Iturralde-Vinent, 1985, Paleogeografia del Paleogeno de las provincias de La Habana, in M. A. Iturralde-Vinent, ed., Contribucion a la Geologia de Las Provincias de La Habana y Ciudad de La Habana: Ciudad de la Habana, Editorial CientificoTecnica, Ministerio de Cultura (Spanish), p. 100 – 115. Campos, M., and M. Hernandez, 1990, Correlacion de las Metavulcanitas de la Sierra del Purial (Cuba Oriental) con las Rocas de la Asociacion Ofiolitica, in D. K. Larue and G. Draper, eds., Transactions of the 12th Caribbean Geological Conference, St. Croix, U. S. Virgin Islands, 1989: Miami, Florida, Miami Geological Society (Spanish), p. 95 – 98. Cruz Ferra´n, C., 2000, Paleomagnetic studies of Jurassic to Tertiary rocks in Jamaica and Cuba (abs.): Licentiate thesis, Samha¨llsbyggnadsteknik/Tilla¨mpad geofysik, Sweden: http://epubl.luth.se/1402-1757/2000/59/index.html (accessed October 15, 2008). Diaz de Villalvilla, L., 1985, Proposal for a division of the socalled Tobas Formation (Cienfuegos, Villa Clara and Sancti Spiritus Provinces): Serie Geologica 1, Instituto de Geologia y Paleontologia, Academia de Ciencias de Cuba (Spanish), p. 133 – 154. Donnelly, T. W., G. S. Horne, R. C. Finch, and E. Lo´pezRamos, 1990, Northern Central America, the Maya and Chortis Block, in G. Dengo, ed., The geology of North America vol. H, The Caribbean region: The Geological Society of America, p. 37 – 76. Echevarria, H., N. V. Shablinskya, and V. I. Shatsilov, 1974, New data on the crustal structure of western Cuba (English, translation of Russian article): International Geological Review, v. 16, p. 59 – 61. Fonseca, E., F. Castillo, A. Uhanov, M. Navarette, and G. Correa, 1990, Geoquimica de la Asociacion Ofiolitica de Cuba, in D. K. Larue and G. Draper, eds., 12th Caribbean Geological Conference, St. Croix, U. S. Virgin

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60 / Pardo Lopez Ramos, E., 1975, Geological summary of the Yucatan Peninsula, in A. E. Nairn and F. G. Stehli, eds., The ocean basins and margins, vol. 3: The Gulf of Mexico and the Caribbean: New York, Plenum Press, p. 257 – 282. Malinovski, Y. M., R. Segura Soto, E. Fonseca, N. Garcia, and L. Antonenko, 1974, New data on the lithology and stratigraphy of Mesozoic and Cenozoic deposits of the north coast of Cuba (Habana-Matanzas): Revista Tecnologica (Spanish), v. 2, p. 36 – 42. Nagy, E., and D. P. Coutin, 1980, Formal and informal lithostratigraphic subdivisions in the former province of Oriente: Informe Cientifico-Tecnico 109, Academia de Ciencias de Cuba (Spanish), 7 p. Pardo, M., V. Bello, H. Amador, S. Taba, O. Sousin, I. Matamoros, and I. de Moya, 1990, Interpretacion de los Datos Geofisicos con Fines de la Cartografia GeologoEstructural de la Republica de Cuba, in D. K. Larue and G. Draper, eds., Transactions of the 12th Caribbean Geological Conference, August 7–11, 1989: Miami, Florida, Miami Geological Society (Spanish), p. 43–50. Pe´rez Estrada, L. M., J. Ferna´ndez Carmona, J. Herna´ndez, C. Perera, M. Ronda, and C. Lariot, 2001, Analisis biofacial de la Formacio´n Vega Alta sello regional de la franja de crudos pesados de la costa norte de Cuba, in Geologı´a y Minerı´a, La Habana, 19 – 23 de Marzo (Geologı´a del petroleo): GeoMin 2001, La Habana, Cuba (CD-ROM, Spanish). Perez-Parcareu, L. J., 1977, Geologic-geophysic considerations on northern Pinar Del Rio: Ciencias Tecnicas: Library of Institute for Geophysics, University of Texas, Austin (Spanish), p. 117 – 131. Piotrowska, K., 1987, Interrelationship of terranes in western and central Cuba: Tectonophysics, v. 220, p. 1 – 10. Piotrowski, J., 1986, The nappe units in the Yumuri and Caunavaco valleys: Bulletin of the Polish Academy of Sciences, Earth Sciences (Spanish), v. 34, p. 29 – 36. Piotrowski, J., 1987a, La actividad volcanica en el Mesozoico y el Paleogeno (?) de la provincia de Pinar Del Rio, in A. Pszczolkowski et al., eds., Contribucion a La Geologia de La Provincia de Pinar Del Rio: Ciudad de La Habana, Editorial Cientifico-Tecnica, Ministerio de Cultura (Spanish), p. 157 – 162. Piotrowski, J., 1987b, Nuevos datos sobre los sedimentos de Cretacico Superior Tardio y el Paleogeno en la zona estructuro-facial de San Diego de los Banos, in A. Pszczolkowski et al., eds., Contribucion a La Geologia de La Provincia de Pinar Del Rio: Ciudad de La Habana, Editorial Cientifico-Tecnica, Ministerio de Cultura (Spanish), p. 185 – 196. Piotrowski, J., and R. Myczynski, 1986, The volcanogenicsedimentary deposits of the Zaza Zone in Matanzas Province: Bulletin of the Polish Academy of Sciences, Earth Sciences (Spanish), v. 34, p. 50 – 66. Pszczo´lkowski, A., 2000, New data on late Albian and late Cenomanian nannoconid assemblages from Cuba: Bulletin of the Polish Academy of Sciences, Earth Sciences, v. 48, no. 2, p. 135 – 149.

Pugaczewska, H., 1978, Jurassic pelecypods from Cuba: Acta Palaeontologica Polonica, v. 23, p. 163 – 186. Pushcharovsky, Y., A. L. Vtulochkin, A. A. Mossakovskiy, G. Y. Nekrasov, and S. D. Sokolov, 1987, Crustal structure and types of Cuba: Transactions of the USSR Academy of Science, Earth Science Sections (English, translation of Russian article), v. 294, p. 47 – 50. Renne, P. R., 1991, Appendix: 40AR/39AR data and thermochronologic implications for a block from the Jagua Clara melange of the Rio San Juan Complex in Hispaniola, in P. Mann, G. Draper, and J. Lewis, eds., Geologic and tectonic development of the North America-Caribbean plate boundary: Geological Society of America Special Paper 295, p. 91 – 95. Rojas-Agramonte, Y., F. Neubauer, A. V. Bojar, E. Hejl, R. Handler, and D. E. Garcia-Delgado, 2005, Geology, age and tectonic evolution of the Sierra Maestra Mountains, southeastern Cuba: Geologica Acta, v. 4, no. 1 – 2, p. 123– 150. Schneider, J., D. Bosch, P. Monie´, S. Guillot, A. Garcı´a-Casco, J. M. Lardeaux, R. Luı´s Torres-Rolda´n, and G. Milla´n Trujillo, 2004, Origin and evolution of the Escambray Massif (central Cuba): An example of HP/LT rocks exhumed during intraoceanic subduction: Journal of Metamorphic Geology, v. 22, p. 227. Segura-Soto, R., et al., 1985, Lithological complexes on the northwestern end of Cuba and their stratigraphic implications as per data obtained in deep bore holes: Revista Tecnologica (Spanish), v. 15, no. 1, p. 32 – 35. Shein, V. S., R. Tenreyro-Perez, and E. Garcia-Alvarez, 1985, Model of the deep geologic structure of Cuba: Serie Geologica 1, Instituto de Geologia y Paleontologia, Academia de Ciencias de Cuba (Spanish), p. 78– 88. Sigurdsson, H., S. Kelley, R. M. Leckie, S. Carey, T. Bralower, and J. King, 2000, History of circum-Caribbean explosive volcanism: 40Ar/39Ar dating of tephra layers: Proceedings of the Ocean Drilling Program, scientific results, Leg 165: College Station, Texas, Texas A & M University, v. 165, p. 299 – 314. Solsona, J. B., and C. M. Khudoley, 1964, Tectonic sketch of the history of the geologic evolution of Cuba: Revista Tecnologica (Spanish), v. 2, no. 1, p. 4 – 13. Talavera-Coronel, F., B. Echevarria, D. Tchounev, S. Ivanev, and T. Tzankov, 1986, General characteristics of volcanism in the region Ciego de Avila-Camaguey-Las Tunas (Cuba): Ciencias de la Tienra y del Espacio (Spanish), no. 11, p. 15 – 24. Tenreyro-Perez, R., R. Otero, and G. Barcelo, 1986, Complex interpretation of geophysical data in the north of Cuba: Serie Geologica 3, Instituto de Geologia y Paleontologia, Academia de Ciencias de Cuba (Spanish), p. 73 – 87. Terence, E. N., W. P. Dillon, C. Jacobs, L. M. Parson, K. M. Scanion, and T. L. Holcombe, 1990, Structure and spreading history of the central Cayman Trough, in D. K. Larue and G. Draper, eds., 12th Caribbean Geological Conference, St. Croix, U. S. Virgin Islands, 1989: Miami, Florida, Miami Geological Society, p. 33–42.

Catalog of Stratigraphic Units CUBAN GULF VERSUS 1988 CUBAN GEOLOGIC MAP (PUSHCHAROVSKY ET AL., 1988) TERMINOLOGY

Contrabando Formation = Incl. in Guaney Formation Mayajigua Formation = not recognized Jaula Formation = Venero Formation (in part) Turiguano´ = Venero Formation (in part)

1988 Cuban geologic map (Pushcharovsky et al., 1988) terminology is underlined; areas are in italics. Incl. = included.

SAGUA LA CHICA BELT = INCL. IN CAMAJUANI ZONE Sagua Formation = Vega Formation-Breccia Sagua (in part)

YAGUAJAY BELT = REMEDIOS ZONE Las Villas Vin ˜as Group = Remedios Group Guani Formation = not recognized Bartolome´ Formation = not recognized Puntilla Formation = not recognized Palenque Formation = not recognized Camaco Formation = Incl. in Remedios Group Palone Formation = Incl. in Remedios Group Mayajigua Formation = Incl. in Remedios Group Remedios Formation = Incl. in Remedios Group Grande Formation = Incl. in Remedios Group Sagua Formation = Grande Formation (in part) San Martin Formation = Caibarien Formation (in part?) Vega Formation = not recognized Lower Vega Member = not recognized Upper Vega Member-Rosas = not recognized Caibarien Formation = Caibarien Formation (in part)

JATIBONICO BELT = INCL. IN REMEDIOS ZONE Guani Formation = Incl. in Remedios Group Mabuya Formation = Incl. in Remedios Group Florencia Formation = Incl. in Remedios Group Mayajigua Formation = Incl. in Remedios Group Sagua Formation = Embarcadero Formation (in part) San Martin Formation = Embarcadero Formation (in part) LAS VILLAS BELT = CAMAJUANI ZONE La Trocha Group = La Trocha Formation Hollo Colorado Formation = Incl. in La Trocha Formation Jaguita Formation = Incl. in La Trocha Formation Caguaguas Formation = Incl. in La Trocha Formation Penton Group Capitolio Formation = Margarita Formation, Paraiso Formation (in part) Remblazo Formation = Paraiso Formation (in part) Sabanilla Formation = not recognized (incl. in Margarita? and Paraiso ?) Malpaez Group Calabazar Formation = Incl. in Mata Formation Mata Formation = Incl. in Mata Formation Lutgarda Formation = Lutgarda Formation Sagua Formation = Incl. in Vega Formation-Breccia Sagua Camajuani Formation = Incl. in Vega FormationBreccia Sagua San Martin Formation = Incl. in Vega FormationBreccia Sagua Vega Formation = Incl. in Vega Formation-Breccia Sagua

YAGUAJAY BELT = REMEDIOS ZONE Camaguey (Sierra de Cubitas) Vin ˜as Group = Remedios Group Sagua Formation = Embarcadero Formation (in part) San Martin Formation = Embarcadero Formation (in part) Vega Formation Lower Vega Member = not recognized Upper Vega Member-Rosas = Senado Formation Caibarien Formation = Lesca Formation COASTAL REGION = CAYO COCO? Punta Alegre Formation = Punta Alegre Formation Cayo Coco Formation = ? Guillermo Formation = Incl. in Guaney Formation Romano Formation = Incl. in Guaney Formation 61

62 / Catalog of Stratigraphic Units

Lower Vega Member = Incl. in Vega FormationBreccia Sagua Upper Vega Member-Rosas = Incl. in Vega Formation-Breccia Sagua PLACETAS BELT = PLACETAS BELT (in part) Ronda Formation = Veloz Formation Constancia Formation = Constancia Formation (in part) Carmita Formation = Carmita Formation Encrucijada Member = not recognized Bermejal Member = not recognized Corona Formation = Amaro Formation CIFUENTES BELT = PLACETAS BELT (in part) Jobosi Formation = Constancia Formation (in part) Ronda Formation = Veloz Formation Constancia Formation = Constancia Formation (in part) Carmita Formation = Carmita Formation Encrucijada Member = not recognized Santa Teresa Formation = Santa Teresa Formation Amaro (incl. Macagua) Formation = Incl. in Amaro Formation Rodrigo Formation = Incl. in Amaro Formation DOMINGO SEQUENCE = ZAZA ZONE (in part) Venega Formation = not recognized (mapped as igneous) Andre´s Formation = not recognized (mapped as igneous) Cumbre Formation = Zurrapandilla Formation (in part) Miguel Formation = Incl. in Vega Alta Formation Note: The 1988 geologic map shows an extensive development of the Vega Alta Formation of middle– lower Eocene described as an olistostrome. Gulf considered it a tectonic mixture of Cifuentes, Domingo, and Cabaiguan (including Miguel, ophicalcite, and rubble zones) belts; not a true sediment. CABAIGUAN SEQUENCE = ZAZA ZONE (in part) North Seibabo´ syncline ‘‘Old Volcanics’’ = Matagua´ Formation (in part), Los Pasos Formation Obregon Formation = Incl. in Matagua´ Formation Barro Formation = Incl. in Matagua´ Formation Huevero Formation = not recognized Gomez Formation = Gomez Member of the Provincial Formation Bruja Formation = Bruja Formation (in part)

Felipe Formation = Felipe Formation of the Tassajera Group Cotorro Formation = Cotorro Formation of the Tassajera Group Curamaguey Formation = Incl. in Tassajera Group Yaya Formation = Incl. in Tassajera Group Algarrobos Formation = Incl. in Tassajera Group Bernia Formation = Santa Clara Formation (in part) South Seibabo´ syncline ‘‘Old Volcanics’’ = Matagua´ Formation (in part), Los Pasos Formation Relampago Formation = Incl. in Matagua´ Formation Matagua´ Formation = Incl. in Matagua´ Formation Cristobal Formation = Incl. in Provincial Formation Casanova Formation = Incl. in Provincial Formation Seibabo´ Formation = Seibabo´ Formation Pastora Group = Bruja Formation Bruja Formation = Incl. in Bruja Formation Pastora Formation = Incl. in Bruja Formation Agabama Formation = Incl. in Bruja Formation Escambray Formation = Incl. in Bruja Formation Salvador Formation = Incl. in Tassajera Group Palmarito Member = Palmarito Formation of the Tassajera Group Maguey Member = Maguey Formation of the Tassajera Group Cotorro Formation = not recognized Hilario Formation = Hilario Formation of the Tassajera Group Tamarindo-Camajuani area ‘‘Old Volcanics’’ = Zurrapandilla Formation (in part) Gomez Formation = not recognized Cotorro Formation = not recognized Hilario Formation = not recognized Carlota Formation = Incl. in Carlota Formation Flow Breccia Member = not recognized Porphyry Member = not recognized Rana Member = not recognized Turino Formation = Incl. in Carlota Formation Jiquimas Formation = Incl. in Carlota Formation Taguasco Formation Fomento-Taguasco area (Taguasco vicinity) ‘‘Old Volcanics’’ = Incl. in Matagua´ Formation Viajaca Formation = not recognized Potrerillos Formation = not recognized Satasa Formation = not recognized Undifferentiated tectonized Cretaceous Volcanics Taguasco Formation = Taguasco Formation

Pardo / 63

Lucia Formation = Incl. in Bijabo Formation Bijabo Formation = Incl. in Bijabo Formation Siguaney Formation = Incl. in Siguaney Formation (Loma Iguara) Rubio Formation = Incl. in Siguaney Formation Fomento-Taguasco area (Fomento vicinity) ‘‘Old Volcanics’’ = Incl. in Matagua´ Formation Jucillo Formation (Upper Cretaceous) = Jucillo Formation (lower Eocene) Isabel Formation = Incl. in Perseverancia Formation Fomento Formation = Incl. in Bijabo Formation Santo Domingo-Santa Clara area ‘‘Old Volcanics’’ = Incl. in Matagua´ Formation Corojo Formation = Incl. in Matagua´ Formation? Hatillo Formation = Incl. in Matagua´ Formation

Diego Formation = Albian –Cenomanian(?) Bruja Formation = not recognized Bayate (Bruja) Formation = not recognized Felipe Formation = Incl. in Tassajera Group Lower Member = Incl. in Tassajera Group Middle Member (Roble) = Incl. in Tassajera Group Upper Member = Incl. in Tassajera Group Cotorro Formation = not recognized Belico Formation = not recognized Bernia (Santa Clara?) Formation = Santa Clara Formation? Santa Clara Formation = Santa Clara Formation Lower – Middle Eocene Units = Ochoa Formation Vega Formation = Incl. in Ochoa Formation Vicente Formation = Incl. in Ochoa Formation Falcon Formation = Incl. in Ochoa Formation

Formation Index Anco´n Formation, 153 – 165, 171 Andre´s* Formation, 62, 150, 199 Apolo, 233 Apolo Formation, 233 Arroyo Cangre Formation, 180 Artemisa (La Trocha* Group) Formation, 117, 336 Artemisa Formation, 18, 19, 26, 123, 150, 151, 157, 164, 174 Bacunayagua Formation, 32 Bacuranao Member, 242 Bahia conglomerate, 242 Barraderas Member, 256 Barrancas Formation, 261, 262 Barro* Formation, 62, 206, 213 Bartolome´* Formation, 61, 95, 96, 108, 111, 119, 145 Basement, 15, 17, 19, 26, 40, 41, 133, 150, 183 Bayamo Formation, 287, 289 Bayate* Formation, 63, 219 Belico* Formation, 63, 209, 221, 227 Bermejal* Member, 62, 129 Bernia *Formation, 63, 209 Bernia* Formation, 63, 209 Bijabo* Formation, 32, 63, 218, 219 Bitirı´ Formation, 288 Blanco* Formation, 284, 285 Boquero´n Formation, 189 Boquerones Formation, 189 Bruja Oriental Formation, 259 Bruja* Formation, 62, 63, 207, 212, 219 Bucuey (Santo Domingo, Teneme) Formation, 256 Buenavista Group, 152, 157, 165, 166, 181 Cabacu´ Formation, 291 Cabaiguan* belt intrusives, 139 Cabo Cruz Formation, 288 Cacarajı´cara Formation, 15, 30, 124, 145, 147, 152, 154, 157, 238, 243 Caguaguas* Formation, 16, 61, 114, 119, 120, 138, 139, 151 Caibarien* Formation, 61, 96, 99, 106 Calabazar* Formation, 16, 28, 61, 105, 113, 114, 119– 121, 123, 124, 138 Camaco* Formation, 61, 95, 112, 145 Camajuani* Formation, 61, 121, 123

Capitolio* –Gulf Name ‘‘Cunagua Salt’’ –Informal Name Vin ˜ales –Published Name ‘‘Asiento Viejo Marbles’’, 186 ‘‘Casa-escuela Conglomerate’’, 242 ‘‘Colombo Marbles’’, 187 ‘‘Cunagua salt’’, 25, 41, 91, 92, 103 ‘‘Daguilla amphibolite’’, 187 ‘‘Ferrer Group’’, 285 ‘‘Isla de la Juventud marbles’’, 26 ‘‘Jibacoa olistostrome’’, 242 ‘‘Jojo sequence’’, 265, 266 ‘‘La Reforma calci-siliceous rock’’, 187 ‘‘Las Casas marble’’, 187 ‘‘Loma Quivican sequence’’, 265 ‘‘Los Mangos flysch’’, 242, 243 ‘‘Mal Nombre sequence’’, 265, 266 ‘‘Manacal*’’, 284 ‘‘Mango*’’, 284 ‘‘Marly Micritic Limestone’’ Member, 171 ‘‘Old Volcanics’’*, 26, 62, 63, 217 ‘‘Perdomo*’’, 284 ‘‘Playa Bibijagua marble’’, 186, 187 ‘‘Pre-Camufiro beds’’, 222 ‘‘Purial complex’’, 263, 265, 268 ‘‘Rio Baracoa sequence’’, 263, 266 ‘‘Rio Piedras conglomerate’’, 242 ‘‘Seibabo upper units’’, 209 ‘‘sheeted dikes’’, 26 ‘‘Sierra Chiquita marble’’, 187 ‘‘Sierra de Caballos marbles’’, 187 ‘‘Urria beds’’, 245 ‘‘Via Mulata sequence’’, 263, 265 ‘‘Via Tu´nel conglomerate’’, 242 Agabama* Formation, 62, 212 Agua Santa Formation, 26, 185 Algarrobo crystalline schists, 191 Algarrobos* Formation, 62, 209, 227 Alkazar, 32 Alkazar Formation, 32, 233 Amaro* Formation, 15, 30, 62, 123, 124, 132, 135 Ana* Formation, 139, 182, 233 Ancon Formation, 153 – 165, 171

65

66 / Pardo

Camarones Formation, 289 Camaza´n Formation, 288, 289 Camufiro Formation, 222 Can ˜ada Formation, 185 Can ˜as Formation, 265 Caney Member, 262 Cangrejeras Formation, 283, 284 Cantabria Formation, 208, 213 Capdevila Formation, 32, 233, 235, 236, 237 Capiro Formation, 291 Capitolio Formation, 16, 26, 61, 114, 119, 120, 139, 151, 152, 174 Carlota* Formation, 62, 214, 215, 227 Carmita Formation, 135, 141, 152, 165 Carmita* Formation, 16, 28, 62, 123, 129, 131, 132, 137, 139, 152 Casablanca Group, 27, 28, 101, 105, 106, 111, 112, 120 Casanova* Formation, 62, 211, 219 Castillo de los Indios Formation, 101 Cayo Coco* Formation, 25, 61, 92, 103, 104, 107, 108, 111, 114, 118, 119, 160 Cepeda* Formation, 285 Chafarina Formation, 194, 195 Chambas* Formation, 106 Charcas*Formation, 286 Charco Azul Formation, 191 Charco Redondo Formation, 253, 254, 258 Chirino Formation, 232, 240 Cilindro Formation, 290 Coabilla Formation, 224, 225 Cobre Formation, 23 Cobrito Formation, 26, 189, 191, 193 Cojimar Formation, 280, 283, 284 Collantes Formation, 26, 191 Constancia* Formation, 17, 19, 62, 124, 128, 129, 131, 132, 134, 161, 183 Contrabando* Formation, 61, 105 Corea Formation, 255 Corojo* Formation, 63, 219 Corona*, 62, 123, 129, 130, 132, 133, 136, 202, 203 Corona* Formation, 62, 123, 129, 130, 132, 133, 136, 202, 203 Cotorro* Formation, 62, 63, 208, 212, 213 Cristobal* Formation, 28, 62, 210 Cuabitas Formation, 261 Cumbre Formation, 62, 204, 219, 251 Cumbre* Formation(?), 62, 251 Curamaguey* Formation, 62, 209 Diego* Formation, 63, 211, 212 dikes, 27 Dura´n Formation, 224, 225, 227

El Americano Member, 170 El Jobal Formation, 101 El Sabalo Formation, 18, 150, 164, 181 El Sabalo Formation(?), 18, 150, 160 El Tambor Formation, 191, 193 Embarcadero (Embarcadero Oriental) Formation, 101 Embarcadero Formation, 61, 99, 112, 253 Encanto Formation, 282 Encrucijada Formation, 232 Encrucijada* Member, 62, 129, 131, 132 Escambray* Formation, 62, 212 Falcon* Formation, 63, 221 Farallon Grande Formation, 262 Felicidad greenschists, 192 Felipe* Formation, 62, 208, 213, 219, 227 Ferrer* Formation, 62, 63 Florencia* Formation, 61, 113, 114, 122 Florida Formation, 124 flow breccia member, 62, 215 Fomento* Formation, 63, 217, 219 Francisco Formation, 123, 139, 164, 170, 181 gabbro, 20, 27, 138, 158, 179, 200, 201 gabbros, 125, 160, 175, 200, 205 gabbros G&BW*, 204, 205 Gibara Formation, 100 Gomez* Formation, 22, 43, 62, 132, 207, 213, 219, 225, 227 Gran Tierra Formation, 257, 258 Grande* Formation, 61, 96 granitoids, 164, 175, 200 Guajaibo´n Formation, 143, 145 Guanajay Formation, 281 – 283 Guani* Formation, 61, 95, 102, 114, 118, 119 Guasasa Formation, 18, 19, 126, 150, 161, 173 Guasasa Formation(?)– Pinar-1 deep-water carbonate, 173 Guasasa Formation(?) – Pinar-1 shallow-water carbonate, 173 Guayos* Formation, 218 Guillermo* Formation, 61, 96, 104, 105 Guines Formation, 246 Gu ¨ines Formation, 107 Gu ¨ira de Jauco Formation, 195 Haticos Formation, 252, 253, 257 Hatillo* Formation, 63, 219 Herradura Formation, 189 Hilario* Formation, 62, 208, 213, 227 Hongolosongo Formation, 261 Hoyo Colorado* Formation, 117, 119, 139 Huevero* Formation, 23, 62, 132, 206, 207, 213, 219, 225

Formation Index / 67

Husillo Formation, 282, 283, 284 Iberia Formation, 251 – 254, 256 Infierno Member, 170, 181 intermediate igneous, 199, 201, 204, 205 Isabel* Formation, 63, 218, 227 Jabaco Formation, 281, 282 Jagua Formation, 150, 151, 164, 168, 174, 179 Jagua Vieja Member, 174 Jagu ¨ eyes Formation, 288 Jaguita* Formation, 61, 114, 117, 118 –120, 132, 138 –140 Jaruco Formation, 283 Jatibonico* Formation, 286 Jaula* Formation, 61, 106 Jia Formation, 284 Jicotea Formation, 284 Jimaguayu Formation, 224 Jiquimas* Formation, 62, 215, 224, 227 Jobosi* Formation, 62, 128, 129, 134, 138, 200, 205 Ju´caro Formation, 288 Jucillo* Formation, 63, 218 La Chispa Formation, 192 La Cruz Formation, 291 La Esperanza Formation (Santa Lucı´a Formation), 27, 151, 160 La Farola Formation, 256, 257 La Guira Member, 171 La Jiquima Member, 252, 254 La Legua Member, 171 La Llamagua Formation, 26, 192 La Morena Member, 252, 256 La Sabina Formation, 191 La Sierra Formation, 223 La Trampa Group, 241, 247 La Zarza Member, 149, 150, 151, 161, 164, 165 Lara* Formation, 286 Lesca Formation, 61, 99 Limones Formation, 263 Lindero Member, 282 Llorente* Formation, 285 Loma Blanca Formation, 252 Loma la Gloria Formation, 26, 190 Loma Quivican Formation, 191 Loma Yucatan Member, 223 Los Cayos Member, 153 Lucas Formation, 124, 150 Lucia* Formation, 63, 217, 218 Lutgarda* Formation, 30, 61, 113, 114, 121, 123, 124, 130, 132, 133 Mabujina amphibolite, 188, 190, 193, 204, 266, 267, 327 Mabuya* Formation, 61, 114, 119

Macagua* Formation, 62, 132 Madruga, 233 Madruga Formation, 233 Maguey* Member, 62, 212 Malpaez* Group, 61, 120, 121, 171 Manacas Formation, 31, 32, 102, 125, 138, 141, 146, 157 Manacas Formation, 31, 32, 102, 125, 138, 141, 146, 161, 183 Manzanillo Formation, 263 Maquey Formation, 208 Maraguan Formation, 224 Marti Formation, 223 Martin Mesa Group, 156, 157 Mata* Formation, 28, 62, 120, 123, 129, 171 Matagua´* Formation, 27, 62, 63, 204, 206, 219 Mayajigua* Formation, 30, 61, 95, 96, 101, 102, 105, 106, 111, 112, 114, 115, 121 Mayari Formation, 26, 192 Mercedes, 233 Mercedes Formation, 233 metamorphic exotics, 37, 203 Mı´cara Member, 257 Miguel* Formation, 17, 30, 62, 130, 135, 202 Miranda Formation, 101 Moncada Formation, 171, 175 Monte Alto Formation, 287 Moreno Formation, 152, 153, 165 Naranjo ‘‘Group’’, 192 Narciso Formation, 192 Nazareno Group, 245, 246 Nueva Maria Formation, 17, 26, 27, 135, 150 Obregon* Formation, 206, 213, 214 Orozco Formation, 232 Palenque* Formation, 114 Palma Mocha Member, 261, 263 Palmarito* Member, 212 Palone* Formation, 112, 121 Pan de Azucar Member, 168, 169 Paso Real Formation, 281 Pastora* Group, 208, 212 Pedernales Formation, 288 Pen ˜alver Formation, 153, 232 Pen ˜as Formation, 171, 174 Penton* Group, 119 Perazo* Formation, 285, 286 peridotite, harzburgite (serpentine), 203 Pica Pica, 125, 146, 153, 193 Pica Pica Member, 125, 138, 155, 156 Picota Formation, 257, 258 Piedras* Formation, 277, 278 Pilo´n Member, 262, 263

68 / Pardo

Pimienta Member, 151, 152, 169 Pinalilla Formation, 152 Piragua Formation, 222, 224 Playuela* Formation, 286 Polier (Constancia*) Formation, 124 Polier Formation, 150, 151, 157, 160, 176, 182 Pons Formation, 150, 152, 170, 171, 174 Porphyritic Serpentine, 203 Porphyry Member, 215 Potrerillos*Formation, 217 Principe Member, 245 Provincial Formation, 208, 212 Puerto Boniato Formation, 254, 258 Punta Alegre* Formation, 140 Punta Brava Formation, 245 –247, 249 Puntilla* Formation, 95, 97 Purio Formation, 95, 98 Quin ˜ones Formation, 146, 153, 231, 232 Ramblazo* Formation, 119, 120, 123, 139 Rana* Member, 215 Rancho Bravo Formation, 278 Relampago* Formation, 62, 210 Remedios* Formation, 61, 93, 95, 96, 111, 112, 121, 145 Remedios* Formation(?), 61, 93, 95, 96, 111, 112, 121, 145 reticulate serpentine, 203 Roble Member, 63, 151, 157 Roble* Formation, 221, 227 Rodrigo Formation, 62, 132, 133, 136, 183 Rodrigo* Formation, 62, 132, 133, 136, 183, 202, 227 Rollete* Formation, 285 Romano* Formation, 61, 105 Ronda*, 16, 62, 135, 130 Ronda* Formation, 16, 18, 62, 127, 129, 130, 132 – 136, 174, 196 Rosario Formation, 283 Rosas* Formation, 31, 112, 114, 122, 125, 141 Rosas* Formation, 31, 112, 114, 122, 125, 141 Rubio* Formation, 63, 218 Sabanilla* Formation, 16, 26, 61, 119 – 123, 125, 128 Sagua de Tanamo Formation, 290 Sagua* Formation, 15, 61, 96, 99, 101, 106, 112, 113, 115, 121, 123, 141, 171 Salvador* Formation, 62, 208, 212, 227 San Adrian Formation, 25, 92, 95, 104, 118, 140 San Cayetano Formation, 11, 19, 25, 92, 103, 142, 161, 167, 179, 181, 185 San Francisco Member, 223 San Ignacio Formation, 290 San Juan Group, 191

San Juan y Martinez Formation, 232 San Luis Formation, 278, 288, 289, 290 San Martin* Formation, 31, 61, 96, 99, 101, 113 – 115, 121 – 123, 234 San Pedro Formation, 208, 213 San Vicente Member, 150, 161, 164, 182 Sancti Spiritus granodiorite, 226, 327, 329 Santa Clara* Formation, 32, 63, 209 Santa Teresa Formation, 129, 135, 141, 160, 174 Santa Teresa Formation (Panchita Formation), 160 Santa Teresa*, 4, 28, 44, 62, 139 Santa Teresa* Formation, 19, 28, 62, 132, 136 Santo Domingo Formation, 256 Saramaguacan Formation, 224 Satasa* Formation, 62, 217 Sauco Formation, 192 Seibabo* Formation, 62, 207, 212 Senado Formation, 61, 99, 112, 122 Serpentine, 20, 92, 99, 101, 125, 133, 134, 135, 138, 139, 148, 154, 155, 175, 203, 205 Sevilla Formation, 287 sheeted dikes, 26 Sierra de Rompe sequence, 222 Sierra Verde Formation, 194, 195 Siguaney* Formation, 62, 218, 221 Suceso* Formation, 285 Sumidero (Capitolio*) Formation, 123 Sumidero Member, 150, 151, 161, 165 Taguasco* Formation, 22, 32, 62, 133, 217 Teguaro Formation, 284 Tejas Formation, 259 Teneme Formation, 22, 185 The Guanı´* Formation, 114, 118, 119 Tinajita Member, 252 – 254 Tinguaro Formation, 246 Toledo Member, 245 Tomas* Formation, 286 Trocha* Group, 16, 25, 114, 117 Tumbadero Member, 151, 170 Tumbitas Member, 151, 171 Turiguano* Formation, 106 Turino* Formation, 62, 215, 227 ultrabasic complex, 256 ultrabasics, 30, 251, 253 –259 Universidad Formation, 32, 236, 237, 243 – 246 Vaqueria Formation, 208, 213 Varga* Formation, 285 Vasquez Formation, 280 Vega, 37, 61, 112 Vega Alta Formation, 113, 135, 202 Vega* Formation, 17, 31, 61, 83, 96, 99, 101, 102, 113, 114, 122, 125, 135, 138 – 140, 147, 156, 157

Formation Index / 69

Veloz (Ronda*) Formation, 62, 127, 129, 135 Venega* Formation, 61, 62, 200, 203 Vertientes Formation, 224 Via Blanca Formation, 139, 157, 231, 232, 274 Via Crucis, 243 Via Crucis Formation, 243, 244 Viajaca* Formation, 62, 217 Vibora Group, 233 Vicente* Formation, 63, 229 Vieja Member, 32, 125, 138, 146, 155, 158, 160, 161, 231 Vigia (Vigia Oriental) Formation, 101 Vigia* Formation, 101, 112

Vilato´ Formation, 96 Vin ˜ales Group, 150, 169, 181 Vin ˜as* Group, 26, 42, 61, 94, 95, 97, 98, 101, 104 waxy serpentine, 203, 204 Yaguanabo Formation, 191, 193 Yaguaneque Formation, 256 Yateras Formation, 290 Yaya* Formation, 62, 209, 227 Yayabo Formation, 189 Yayabo* Formation, 286 Yayal Formation, 288, 289 Zacarı´as Member, 169 Zaza* Formation, 218

Localities 1988 GEOLOGIC MAP (PUSHCHAROVSKY ET AL., 1988) GRID LOCATION OF LOCALITIES MENTIONED IN THE TEXT

Coralillo [12-34-54] Cristal, Sierra de Cristales oil field [21-24-72] Cruz Verde oil field [3-36-38] Cubitas, Sierra de [2-21-82] Cumanayagua [12-25-58] Cunagua, Cierra de Judas de la [13-25-76] Cunagua, Loma [13-25-76] Dimas [9-29-16] Escambray massif [20-24-58] [20-22-64] Esmeralda [21-22-79] Florida [21-19-78] Fomento area [12-25-63] Fomento-Taguasco area [12-25-63] [13-24-68] Gibara [23-26-57] Gibara, Silla [23-26-56] Golfo de las Corrientes [17-22-12] Guaimaro [22-14-88] Guaimaro-Las Tunas area [22-14-88] [30-25-49] Guanabacoa [3-36-36] Guanabo oil field [3-37-38] Guanacayabo, Gulf of [30-19-42] Guanajay [10-34-32] Guaney Beach [13-24-80] Guaniguanico, Sierra de [9-26-17] [10-33-29] Guantanamo, Bay [31-15-67] Guasima oil field [3-37-46] Guayabo anticlinorium [12-31-60] Holguin [31-25-56] Iguara´ [13-26-68] Isle of the Pines [18-21-30] Jarahueca [13-25-67] Jarahueca Fenster[13-25-66] [13-26-68] Jardines de la Reina [29-25-25] [29-30-34] Jatibonico [21-23-69] Jatibonico oil field [21-24-69] Jatibonico, Sierra de [13-26-71] La Gabriela [22-20-65] La Habana [3-37-36] Las Mercedes [22-19-84] Las Tunas [30-25-49] Loma de Yeso [13-28-72] Los Barriles [13-25-71] Los Organos, Sierra de [9-27-18] [10-30-24]

Amancio Rodriguez [30-24-42] Ana Maria, Gulf of [21-19-73] Ariguanabo 202 Arroyo Blanco [13-24-69] Asuncion [32-17-77] Bacuranao oil field [3-36-38] Bahia Honda [10-34-27] Baracoa [32-18-74] Batabano [11-32-37] Bauta [10-35-34] Bayamo [30-19-52] Blanquizal [4-36-55] Boca de Jaruco [3-37-39] Boca de Jaruco oil field [3-37-39] Bolivia [13-25-77] Bonachea, Loma [12-29-61] Brisas [3-37-38] Cabaiguan [12-25-65] Cabeza de Horacio [9-28-17] Cajalbana, Sierra de [10-33-24] Calabazar de Sagua [12-31-61] Camaco River [12-29-64] Camaguey [22-17-81] Camajan, Sierra [22-19-84] Camajuani [12-29-63] Camajuani River [12-30-62] Camarioca [3-35-46] Candelaria [22-17-21] Cantel oil field [3-36-46] Cardenas [3-35-47] Cardenas, Bay [3-36-48] Catalina oil field [21-22-68] Cauto [30-21-49] Cayo Coco-Punta Alegre area [13-29-75] [13-27-72] Cayo Frances [13-31-68] Central Depression [21-32-69] Chambas [13-26-71] Chapelin oil field [3-37-47] Ciego de Avila [21-22-73] Cifuentes [12-31-60]

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Los Palacios [10-30-26] Lugaren ˜o [22-19-86] Mamonal oil field [21-23-71] Manati, Bay of [22-16-92] Manicaragua [12-25-60] Mantua [9-27-16] Marbella oil field [3-37-47] Mariel [2-35-31] Martin Mesa Window [10-34-32-] [10-35-33] Mata [12-31-60] Matanzas [3-35-44] Meneses, Sierra de [13-27-68] Mir [30-23-52] Morena, Sierra [12-33-54] Moron [13-25-74] Motembo oil field [12-34-53] Nipe Bay [31-23-61] Nueva Maria quarry [22-19-84] Nuevas Grandes [22-18-91] Nuevitas [22-19-88] Ojo de Agua [21-23-79] Pan de Guajaibo´n [10-23-25] Pen ˜as Altas [3-36-38] Perea-Mayajigua road [13-26-69] Placetas [12-27-63] Placetas [12-27-63] Pons [10-30-20] Pons Valley [10-30-20] Puerto Padre [22-16-95] Punta Alegre [13-28-72] Purial, Sierra del [32-17-72] Quemado de Gu ¨ ines anticlinorium [12-33-57] Rancho Veloz [12-33-56] Ranchuelo [12-28-58] Reforma [21-24-70] Remedios [12-29-64] Rosario, Sierra del [10-32-26] [10-32-29] Sagua la Chica River [12-30-62]

Sagua la Grande [12-33-59] Sagua la Grande River [12-32-59] San Adrian [3-46-32] San Antonio de las Vueltas [12-29-63] San Diego de los Ban ˜os [10-31-25] San German [31-21-58] San Juan de Sagua [10-33-25] Sancti Spiritus [21-23-66] Sancti Spiritus, Alturas de [20-22-64] Santa Clara [12-28-60] Santa Clara, Bahia de [12-34-56] Santa Maria del Mar oil field [3-37-38] Santo Domingo [12-31-57] Santo Domingo-Santa Clara area [12-30-59] [12-28-62] Seibabo syncline, north [12-28-59] [12-27-67] Seibabo syncline, south [12-27-59] [12-26-52] Sierra Madre [30-15-35] [31-15-58] Sitiecito [12-32-29] Taguasco [13-24-67] Tamarindo [13-25-71] Tamarindo-Camajuani area [12-30-62] [13-25-68] Tiguani [31-19-54] Trinidad, Sierra de [20-23-59] Tuinicu fault [12-24-63] Turiguano, Isla de [13-27-74] Varadero [3-36-47] Varadero oil field [3-36-48] Vega [12-30-62] Vega Alta [12-30-62] Vertientes [21-16-79] Via Blanca [3-36-37] Vin ˜as [12-28-65] Vin ˜as River [12-29-65] Yaguayay [13-28-68] Yumuri [3-36-42] Zaza del Medio [21-24-67] Zulueta [12-20-64]

Glossary accumulate in the front of thrusts and become incorporated into the melange. Miogeosyncline The part of a geosyncline devoid of volcanic activity. The sediments can have a continental or pelagic oceanic source. Molasse Sediments derived from the erosion and peneplanation of an inactive orogenic belt. They commonly grade upward from coarse to fine. Nappe A large-amplitude thrust block commonly beginning as a recumbent anticline. The reverse limb is commonly considerably thinned, and sometimes missing, through stretching. It is commonly the result of gravity sliding. Obduction The process by which a slab of oceanic crust rides over the margin of a continental plate. The results of obduction are commonly observed in orogenies, but the mechanism remains obscure. Olistolith Blocks within an olistostrome. Olistostrome Large-scale rock slide consisting of a fine-grained, commonly argillaceous, matrix in which large blocks (from boulder size up to several kilometers) of coherent lithologic units are imbedded. These slides, which are commonly submarine and gravity driven, are normally the result of orogenic uplift. They are sedimentary bodies, but are related to nappes. Orthogeosyncline A broad term that includes the large-scale, linear, sedimentary, and tectonic features characteristic of tectonically and magmatically active continental margins. Subduction The process by which an oceanic plate plunges under a continental or another oceanic plate. A subduction zone Term coined by Bally to describe the leading edge of an orogenic thrust front in which the thrusts are directed toward the continent. B subduction zone Term also coined by Bally to describe the area where subduction of an oceanic plate under a continental plate is occurring; B stands for Benioff. Wildflysch The coarsest conglomeratic upper part of a flysch deposit. Related to and sometimes difficult to differentiate from olistostrome.

Allochthonous Rocks that have been tectonically displaced from their original location of formation. Autochthonous Rocks that have not been tectonically displaced from their original location of formation. Boudinage The stretching process which gives the bedding a link sausage aspect (from ‘‘boudin’’ in French); common in the underside of nappes. CCD Carbonate compensation depth; water depth at which the shells of calcareous planktonic foraminifera are dissolved. Normally 5– 5.5 km (3.1 – 3.4 mi), although a shallower figure is possible because of upwelling. Below this depth, the sediments commonly consist of clays and radiolarian oozes. Eugeosyncline The part of an orthogeosyncline characterized by volcanic activity, generally its oceanic side. Exogeosyncline The continental side of an orthogeosyncline; commonly a basin receiving sediments from both the continent and an active orogeny away from the continent. Flysch Sediments produced by the erosion of an active orogeny where the structural uplift is the continuing source of sediments. A flysch commonly grades upward from fine to coarse. Fragmental Any rock consisting of rock fragments, i.e., fragmental tuff (tuff breccia), fragmental limestone (detrital limestone, limestone breccia), etc. This term has been used frequently in Cuba, and it is commonly difficult to translate written descriptions in more modern terminology such as grainstone, packstone, etc. Geosyncline Any large-scale depression or gradient of the Earth’s crust where sediments tend to accumulate, such as passive continental margins, rifts (taphrogeosynclines), continental interior basins (autogeosynclines), orogenic continental margins (orthogeosynclines), etc. Melange Tectonic mixture of disparate lithologies resulting from the process of subduction or obduction and commonly occurs at great subsurface depth. Strictly tectonic in origin, it can be difficult to differentiate from olistostromes, which commonly

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Pardo, G., 2009, Structural and stratigraphic elements, in G. Pardo, The geology of Cuba: AAPG Studies in Geology Series, no. 58, p. 77 – 83.

Structural and Stratigraphic Elements The generalized geologic map of Cuba (Figure 54) shows that the island is segmented into eight general areas of pre-upper Eocene outcrops surrounded by relatively undisturbed later Tertiary sediments. Although there are similarities between them, each area has its own stratigraphic and structural characteristics. From northeast to southwest, these areas can generally be grouped as follows: (1) north-central sedimentary terranes: from northern Las Villas to northern Oriente; (2) basic igneous-volcanic terranes: from northern Pinar del Rio to eastern Oriente; and (c) southwestern sedimentary terranes: from Pinar del Rio and Isla de la Juventud to southeastern Oriente. These areas are complexly deformed structurally and are present-day topographic highs. They are surrounded by a relatively thin and much less disturbed cover of sediments ranging in age from late lower Eocene to Pleistocene. These areas are large-scale, mostly post-Eocene, uplifts.

middle Eocene are present in a stack of folded and faulted thrusts sheets (nappes) dipping generally to the north. The direction of thrusting is believed to be northward. Along the north coast, near Bahia Honda, ultrabasics and Cretaceous volcanics are present. The general strike is northeast. This area extends into the western Habana Province. 2) Isla de la Juventud area. This consists mostly of a core of relatively low grade, but intensely deformed metamorphics of Middle to Upper Jurassic and possible Cretaceous age, similar to the older part of the section in Pinar Del Rio. This core has the general structure of a dome with the lower metamorphic grades in the center. In contact with the metamorphics, unmetamorphosed Cretaceous volcanics outcrop in the northwestern part of the island.

PRE-UPPER EOCENE

1) Habana-Matanzas area. This consists of Cretaceous volcanics and volcanic-derived sediments, as well as sediments as young as lower–middle Eocene, outcropping in an extremely deformed series of fault blocks. Scattered bodies of ultrabasic rock and some rare outcrops of unmetamorphosed Lower Cretaceous limestones exist. Dips are extremely variable, from horizontal to vertical, and the surface expression of the faults is nearly vertical. However, deep drilling along the north coast has proven that these rocks are structurally underlain by Jurassic and Cretaceous carbonates unrelated to the volcanics. The general strike is west-northwest. 2) Las Villas–northwestern Camaguey area. This area is similar to the Pinar Del Rio area in the sense that

Central Cuba

As already mentioned in the Overview section of this publication under the Regional Setting subsection, in Cuba, essentially, no stratigraphic mixing exists between the continental margin and deep-water marine (miogeosyncline) sediments and the volcanics and volcaniclastics (eugeosycline). In other words, with a few exceptions, all the mixing is of structural origin. Eight major outcrop areas exist as follows.

Western Cuba 1) Pinar Del Rio area. Sediments ranging in age from possibly older than Middle Jurassic to lower –

Copyright n2009 by The American Association of Petroleum Geologists. DOI:10.1306/13141059St583328

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FIGURE 54. Cuba, generalized geologic map. numerous facies of Upper Jurassic to lower–middle Eocene sediments are present. However, although the area is highly fragmented by vertical faults and is complexly folded, the general appearance is that of several long (more than 100 km [62 mi]) southdipping belts. The carbonate sediments are generally found to the northeast, the ultrabasic igneous in the middle, and the Cretaceous volcanics and volcaniclastics in the southwest. The northernmost exposed belt, the Yaguajay belt, shows massive carbonates similar to, and of the same order of thickness, as the Florida – Bahamas banks. The degree of deformation is most intense in the middle, mostly ultrabasic, area, between the carbonates to the north and the volcanics to the south. The general strike is northwest. Near the south coast of Cuba is the massif of Escambray, which consists of an igneous complex and variously metamorphosed, generally low-grade, Jurassic and Cretaceous sediments very similar to the Pinar Del

Rio section. The Escambray massif consists of two nearly circular domes and, as in the Isle of Pines, the metamorphic grade is lowest in their cores. The Las Villas–northwestern Camaguey area has the most complete sequences of sedimentary, volcanic, and igneous rocks occurring in the greatest variety of observable relationships on the island. For this reason, it is used here as a type geologic province and is the basis for many interpretations that will be extended to other parts of the island. 3) Central Camaguey area. This area is similar to the Las Villas – northwestern Camaguey area; however, with the exception of the extensive Cretaceous massive carbonate exposures of the Sierra de Cubitas and a few scattered outcrops of sedimentary facies, most of it is covered by ultrabasic and other igneous and Cretaceous volcanics intruded by large bodies of granodiorite. A steep southwestern dip exists, and the general strike is northwest.

Structural and Stratigraphic Elements / 79

Eastern Cuba 1) Northern Oriente area. This is very similar to the central Camaguey area and consists mostly of ultrabasics and Cretaceous volcanics, with the exception of an area of massive carbonate exposures north and west of Gibara. The dips are very steep toward the south, and the structures trend in a northwest–southeast direction in the west. Toward the east, the strike swings to an east-northeast direction where the sedimentary and volcanic facies, as well as the ultrabasic bodies, strike out to sea between Gibara and the Nipe Bay. Note that the massive carbonate outcrops of Yaguajay in Las Villas, Cubitas in Camaguey, and Gibara in northern Oriente appear to be three large, northwest– southeast en echelon structural highs partially surrounded by and apparently emerging out of an igneous and volcanic terrane. 2) Southeastern Oriente area. This is located south of Nipe Bay and northeast of the Guantanamo depression. Ultrabasic and other igneous rocks as well as Cretaceous to lower Eocene volcanics make up most of the outcrops. In general, they appear less disturbed than in other parts of Cuba; however, in the Sierra del Purial, nearly horizontal thrust sheets of ultrabasics lie on top of Upper Cretaceous volcanics. In Asuncion, in easternmost Cuba, low-grade metamorphics of Jurassic and Cretaceous age outcrop. Again, as with the previously mentioned metamorphics, they exhibit a strong similarity to part of the sedimentary section of Pinar Del Rio. 3) Southwestern Oriente area. Formed by the Sierra Maestra and located south of the Cauto depression, it consists almost entirely of Paleocene and lower – middle Eocene volcanics and volcaniclastics, with associated intrusives and a few Upper Cretaceous volcanics. The pre-upper Eocene rocks will generally be described from north to south and west to east, and the most complete sections will be described first. All the sedimentary sections (miogeosynclinal rocks) will be described together and separately from the basic igneous-volcanic sections (eugeosynclinal rocks).

POST-UPPER EOCENE The eight areas described above emerge topographically from a relatively undeformed late lower Eocene or younger cover that, in places, can reach a thick-

ness of several thousand feet. The areas of younger cover are 1) The northern coast of Habana, Matanzas, Las Villas, and Camaguey 2) Southern Pinar Del Rio, Habana and Matanzas, and the Gulf of Batabano 3) Southeastern Las Villas Central Depression and the Gulf of Ana Maria 4) The Cauto depression and the Gulf of Guacanayabo 5) The Nipe Bay 6) The Guantanamo depression These basins definitely are folded and faulted, but to a much lesser extent than in the pre-upper Eocene rocks. The post-middle Eocene Tertiary sediments will be described according to their geographic areas. In general, the sections consist of classical epiorogenic sediments, although possible time differences exist in the change from flysch to molasse sedimentation between northern and southern Cuba.

DEVELOPMENT OF THE CUBAN STRUCTURAL AND/OR STRATIGRAPHIC NOMENCLATURE The overall regional-stratigraphic history and the structural evolution of Cuba are relatively simple and not unique in the evolution of orogenies and continental margins. However, the position of Cuba on the southern border of the North American continent has been responsible for a complex tectonic history. The Cuban area was successively (1) part of the African and North American craton, (2) a passive margin north of a spreading center with strong left-lateral component, (3) a foreland of what appears to be a subduction zone (with ophiolite obduction in between), and finally, (4) subjected to strong left-lateral shear. This series of events has tectonized the geologic evidence to such an extent that few interpretations are incontrovertible. From 1958 to 1985, there was very little communication between Cuba and the West. However, some of the published information that filtered out in the last 30 yr is of outstanding quality, such as the works by Milla´n and Somin (1975, 1976, 1981, 1985a, b) on the metamorphics, those by Piotrowska (1986a, b, 1987a) and Pszczo´lkowski (1985, 1987) in Pinar Del Rio and Matanzas, and Iturralde-Vinent (1969, 1970, 1972, 1975a, b, 1977, 1981, 1985, 1996, 1998) in general geology. These authors have used western stratigraphic nomenclature and their work is easily interpretable.

80 / Pardo

Unfortunately, much other information follows Sovietera practice of naming rocks by age and interpretive basin classification, such as ‘‘Cretaceous parautochthonous miogeosynclinal,’’ which makes correlation with simple lithostratigraphic units difficult. In a few cases, the Cuban published information appears erroneous when compared to the solidly established pre-1960 data. Therefore, some of the recent information, when added to the natural geological complexities, increases the problems of interpretation. It has to be mentioned that the Mapa Geologico de la Republica de Cuba (Pushcharovsky et al., 1988), on data collected up to November 1, 1985, is the best overall published source of information available yet. Another excellent publication is the Mapa Tectonico de Cuba (Pushcharovsky et al., 1989).

Gulf’s Stratigraphic Nomenclature When Cuban Gulf Oil initiated systematic geologic mapping of central Cuba in 1951 at the scale of 1:40,000, the confusion over preexisting terminology was such that it was decided to establish a framework of stratigraphic units as if the geology of the island was totally unknown. Conventional rules of stratigraphic nomenclature were strictly adhered to; any association of rocks with characteristic and recognizable lithologic features were given a formation name. The age was determined through fossils or stratigraphic relationships and had no effect on the lithostratigraphic terminology. The number of formations thus described by the Cuban Gulf Oil was quite large, on the order of 125 for the pre-upper Eocene in central Cuba. With the extreme structural complexities, many groups of outcrops had recognizable characteristics, but were totally disconnected from each other, so that their relationships could not easily be determined in the field. In addition, to avoid misgrouping, it was deemed necessary to separate related lithologies that, under less extreme circumstances, might have been given a member rank and grouped under one formation name. In addition, the extreme structural shortening juxtaposes many lithologies that normally would be spread across a large area. It can be said that the large number of recognizable lithologic units across such a relatively small area is a measure of the magnitude of the telescoping of the basin. It should be emphasized that many of the stratigraphic units that have been published in the recent literature, notably in Pinar Del Rio and in the metamorphic massifs, are well defined and follow accepted international guide-

lines of stratigraphic nomenclature (Hedberg, 1976; Salvador, 1994).

The Belt Nomenclature Problem Several important related terms have been widely used in Cuba throughout the last 39 yr. These are belts, facies-structural zones, structurofacies zones, zones, tectonostratigraphic units, tectonic units, tecto-units, etc. The fact that in central Cuba, the names of these so-called units, zones, or belts have been freely interchanged by different authors increases the confusion considerably. For instance, the Las Villas unit of Hatten is approximately Pardo’s Cifuentes and Placetas belts, whereas Pardo’s Las Villas and Sagua la Chica belts are (more or less) Hatten’s Zulueta unit; Ducloz’s Remedios zone is Pardo’s Yaguajay, Jatibonico, and Cayo Coco belts or Hatten’s Remedios and Cayo Coco units; and so forth. Figure 55 is a chart showing the terms that have been most commonly used in central Cuba. What follows is an attempt to explain the origin and the reason for such terminology and the ensuing confusion. Although the complexity of the pre-Tertiary geology of Cuba has long been known (DeGolyer, 1918), Rutten, in 1936, recognized that, broadly speaking, the Las Villas Province could be divided into two terranes: limestone to the north and igneous-volcanic to the south. In 1937, a Cuban geologist, Ortega y Ros, properly identified, described, and named many of the Jurassic, Cretaceous, and Paleogene stratigraphic units of central Cuba. Unfortunately, his work appeared in an obscure publication and remained unnoticed until the middle 1950s. By the late 1940s, the two-terrane scheme had been further refined by various geologists, and the standard subdivisions of central Cuba became massive Remedios carbonates to the north, serpentine and Tuff series to the south, and the radiolarian-rich, thin-bedded, siliceous Aptychus Limestone in between. As Cuban Gulf Oil initiated the geologic mapping that began with the pre-upper Eocene of central Cuba, it became apparent that certain areas were characterized by successions and associations of lithologies quite different from those in adjoining areas, although the ages represented were similar. Because these areas tended to be elongated along the strike, they were named ‘‘belts.’’ They were strictly informal operational subdivisions. In 1953, Pardo (Cuban Gulf’s Memorandum 92, p. 4) wrote the following: Northern Las Villas and northwestern Camaguey can be subdivided in several parallel northwest,

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FIGURE 55. Central Cuba nomenclature.

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southeast trending belts. Each one of these is characterized by its structure and stratigraphy. . . In 1954, Pardo (p. 5) modified this definition as follows (the definition was published for the first time in Pardo, 1975, p. 561): The concept of belts exposed in G. Pardo memorandum no. 92 (1953) has remained essentially unchanged; however, due to the complexity of the tectonics, many of the belts cannot be geographically separated onto continuous areas. They are in many instances scattered in small patches following certain general trends. Therefore, for many of the belts, it is impossible to define them as a geographic unit such as the Yaguajay or Las Villas belts (which are continuous), and one has to recur to a stratigraphic definition of the belt; that is, a belt will be defined as an association of several lithologies that occur invariably together. This definition can be carried even further in a paleogeographic and paleotectonic sense: every part of a belt will have had an identical succession of tectonic, sedimentary and igneous events during geologic time. It turned out that some belts have characteristic internal structure. Lithologic associations are commonly bounded by faults, but they also grade into one another (or at least are not separated from each other by obvious major faults), making the assignment of lithologies to belts difficult (facies do eventually change). In Cuba, faults are everywhere, and they can be strongly deformed, so their importance is difficult to judge from field mapping alone. The disparity between two adjacent belts was used to determine the probable magnitude of a fault and not the magnitude of the fault to define the belt. In addition, the boundary faults are commonly imbricated with components of the two adjacent belts repeated several times. The California Company (Chevron) initiated reconnaissance work in 1951 and, in 1957, began their systematic mapping of central Cuba. Of course, they had no access to Gulf reports and, in 1957, formalized a classification scheme, like Gulf’s belts, called ‘‘tectounits,’’ but differing from Gulf’s by being slanted more heavily toward the present structure instead of stratigraphy. In 1957, in a private California Company report, Meyerhoff and Hatten wrote the following: A tecto-unit is defined as a large and essentially discrete structural unit, bounded on its two long

sides by a tectonic feature (such as a fault system), and characterized by unique petrology. A tectounit generally parallels regional stratigraphic strike. The characteristic of the petrology and stratigraphy in each tecto-unit are distinct. . . As can be seen, the differences between the Gulf and California Co. definitions are not major, but there were strong differences of opinion relative to the assignment of some rocks to equivalent belts (units). In 1960, the files of all foreign oil companies were confiscated by the revolutionary government, and the above concepts became public knowledge in the geologic circles of Cuba and of the assisting Soviet block countries; however, they remained virtually unknown in the west, where essentially nothing was published until the late 1960s to mid-1970s. Meanwhile, in Cuba, the application of these definitions, with varying degrees of understanding, resulted in confusion. For example, Dilla and Garcia (1984, 1985) reshuffled the existing terminology and split the existing zones, units, etc., between the Cretaceous and the Paleocene. They created two new zones (Sagua and Cabaiguan) that they thought contained only flysch sediments superimposed on the older rocks of all other zones. This reduced the usefulness of previously recognized zones, units, and belts, and using names that had been previously published added to the existing confusion. Besides, their assumption that flysch sedimentation always and only occurred from the Paleocene to the middle Eocene is surely not correct. In Pushcharovsky et al. (1988), these belts, units, zones, etc., are referred to as ‘‘zonas estructurofaciales’’ or structurofacies zones.

General Remarks The Gulf data set forms a coherent package, with well-established stratigraphic definitions now in the public domain, and its nomenclature is used as a backbone for this publication. A significant reason to do so is that the author of this publication knows precisely the meaning of the Gulf names whereas much of what has been published later has ambiguous definitions. As will be seen, many Gulf names have been incorporated in today’s official nomenclature or published literature, but are not so credited. In some cases, credit is given to the author of the Gulf name, i.e., Wassall, Truitt, etc., who were Gulf employees, but interestingly enough, Gulf is never recognized; nor is any other capitalist organization for that matter. As a result, it is not always known whether the presently

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used Gulf names are the result of a coincidence (i.e., same type locality), or whether they found their way into the terminology from Gulf’s early reports and were sometimes given a somewhat different connotation. This is also true of the work of other companies such as Chevron, Shell, etc. However, credit should be given to many Cuban and Eastern European workers who made definite efforts to identify the original author of many stratigraphic units. If the political situation had been different, much confusion would have been avoided. No attempt will be made to identify the author of Gulf’s terminology. It was a cooperative effort involving P. Bronnimann, G. Pardo, P. B. Truitt, and H. Wassall. Truitt and Wassall conducted most of the fieldwork and were the originators of much of the terminology (full references can be found in the University of Texas copies of Gulf’s reports). In some cases, Gulf used already existing names and applied a precise definition that might not have been followed by other authors. In this publication, all the names defined and used by Gulf will be followed by an asterisk (*), for example, to differentiate the Vega* Formation as defined by Gulf from the Vega Formation as used in Pushcharovsky et al. (1988), or Gulf’s Las Villas* belt from Hatten et al.’s Las Villas unit. It is hoped that in this manner, confusion will be avoided. At any rate, these homonyms will be clarified in the text. There certainly will be some departures from original definitions and interpretations because of new information such as age dating, published studies on the metamorphics, deep drilling, new geologic concepts, etc. Of course, in areas where other sources give more complete information, such as Pinar Del Rio, Cama-

guey, and Oriente, the published names will be used, and an attempt will be made to correlate them with Gulf’s data when pertinent. An attempt will be made to always give credit where it is due, but this sometimes will be impossible, considering the large volume of unpublished material that is being consulted (Gulf’s and others). However, the primary purpose of this chapter is to give information about Cuba and not to describe all the arguments that have ensued ever since the second geologist visited the island. The Geologic Map of Cuba, scale 1:250,000, (Pushcharovsky et al., 1988), and the Tectonic Map of Cuba, scale 1:500,000, (Pushcharovsky et al., 1989), published jointly by the Academy of Sciences of Cuba and the Academy of Sciences of the former Soviet Union will be extensively used to provide uniformity in discussing the entire island. To assist the reader, a table has been prepared (the Localities section of this publication) where the approximate location of geographic localities mentioned in the text is given, using the 10  10-km (6  6-mi) grid system on the 1988 geologic map (Pushcharovsky et al., 1988). This grid has an arbitrary origin west and south of Cuba, and the grid number refers to 10,000 m (33,000 ft); for instance, 33N means 330,000 m (1,082,677 ft) north of the origin. It should be noted that the southern part of Oriente has a different origin than most of the island (the usual problem of trying to fit a square grid over a sphere). In the Localities section of this publication, the southwestern corner of the quadrangle in which the locality is situated will be identified in the following manner: The locality name will be followed by [sheet number — grid north — grid east]. For instance: Quemado de Guines anticlinorium [12-33-37].

2

Pardo, G., 2009, Pre – Upper Eocene stratigraphy, in G. Pardo, The geology of Cuba: AAPG Studies in Geology Series, no. 58, p. 85 – 275.

Pre–Upper Eocene Stratigraphy INTRODUCTION

cross section across the former orthogeosyncline. By qualitative, I mean that the abundant evidence of large thrust and transcurrent displacements, which, together with the scarcity of facies changes along the strike of the belts, make the reconstruction of an accurate paleogeography difficult. Along much of the axis of the island, the structural complexities are extreme. For instance, in one of the less disturbed areas, a section being measured appeared to consist of an interbedding of more than half a dozen 1-ft (0.3-m) beds of manganese-stained limestone, consisting entirely of rudist fragments, and thin-bedded fine-grained limestones; very detailed mapping revealed that there was only one bed of rudist limestone repeated many times by isoclinal folding. Extreme boudinage is common. In one case, all the components of a Lower Cretaceous to lower–middle Eocene section, normally more than 4000 ft (1200 m) thick, were present in an outcrop not more than 300 ft (90 m) thick. In much of the outcrops, dip and strike mapping is totally meaningless because the different lithologic units are commonly present as isolated blocks. Blocks of similar lithologies, although disconnected, follow some general mappable trend, much as would be expected in landslides or olistostromes. Many of these areas, mapped by Gulf in detail, have been lumped by recent Cuban surveys into a stratigraphic unit called Vega Alta and defined as an olistostrome. Concerning well nomenclature, wells drilled prior to 1959 will be named by company name (i.e., Texaco, Gulf, etc.), lease name at the time of drilling (Cayo Coco, Blanquizal III, etc.), and well number. Later wells will be named by the organization responsible for the drilling (ICRM, EPEP, etc.) and the well name. In relation to well data, attention should be called to the fact that because of structural complications and the nature of the rocks (especially in the carbonate areas), the only way that sections can be accurately

In this section, only the stratigraphy of the rocks deposited before and during the violent events of the Cuban orogeny will be described. The deformation probably reached its peak during the early–middle Eocene. The reason for this rather indefinite time assignment is that no index faunas have been found to separate the middle from the lower Eocene in the synorogenic flysch sediments, much less in the wildflysch that characterizes the culmination of the orogeny. The only evidence that the orogeny is pre – upper Eocene is a widespread, well-defined unconformity below an upper Eocene orbitoid-rich limestone that, although occasionally deformed, was not involved in the strong orogenic tectonism. As will be seen later, the tectonic events that marked the end of the orogeny were not exactly synchronous all over Cuba. In the south, the orogenic deformation started in the late Maastrichtian to Paleocene, whereas in the north, the deformation started in the early Eocene. The molasse (or erosion of already inactive topography) cycle started in the south in the early Eocene while thrusting proceeded in the north in the middle Eocene with the production of associated flysch deposits (or erosion of an active orogenic front). The molasse was carried piggyback by the northward advancing thrusts while contemporaneous flysch was being generated in the north. Stratigraphy and structure are intimately intertwined in Cuba; the significance of structural features can be understood only through the knowledge of stratigraphy. Therefore, in this chapter, the stratigraphy will be described first to establish a plausible preorogenic paleogeography. As previously mentioned, many outcrops of related lithologies tend to be grouped in long, linear belts, permitting the reconstruction of a qualitative

Copyright n2009 by The American Association of Petroleum Geologists. DOI:10.1306/13141061St583328

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FIGURE 56. Lithologic symbols. identified and correlated in the subsurface is through continuous coring. Identification by cuttings is difficult and ambiguous because of the large amount of natural reworking in many of the sections, and geophysical logs do not differentiate the subtle differences between the many stratigraphic units that commonly can only be identified through microfacies analysis in thin sections. This is important because the lithologic data available today outside of Cuba consist mostly of cuttings. It is not known what kind of data forms the basis for most of the currently published identifications. The descriptions of fossiliferous stratigraphic units will contain a faunal list. Whenever possible, genera and species will be given. In many cases, the genus is followed by ‘‘sp.’’ or ‘‘spp.’’ Paul Bro ¨ nnimann had established an extensive type collection where, according to the common practice of many oil companies, numbers identified the species, such as, Dicyclina 2, Globotruncana 5, etc. These were cross-indexed to formal species names. Unfortunately, the type collection remained in Cuba, and as of this date, its fate is unknown. In many of the reports, only the informal species number is available. Because this number is of

no use to the readers of this study, it is replaced by ‘‘sp.’’ or ‘‘spp.’’ Even without species names, the faunal composition is of interest. The stratigraphic descriptions are accompanied by a graphic columnar section. In most cases, the thicknesses given in Gulf Oil (Gulf) data (formation name followed by an asterisk) were measured in the field or in wells. Where measurements were impossible because of structural complications, thickness estimates only will be given. When the thicknesses are from the literature, it is not always possible to know whether they are estimates or measurements. For convenience, the pre–upper Eocene graphic columnar sections will show a scale in meters and feet with the origin at the top of the Lower Cretaceous. The post–middle Eocene columnar sections show the measurements from the base of the upper Eocene. Figure 56 shows the lithologic symbols used throughout the study unless otherwise noted in the figures. Cuba can be subdivided into the following major geologic provinces: 1) The north-central terrane. It extends along the north coast from the subsurface between Habana and

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FIGURE 57. Central Cuba sedimentary terranes: generalized geologic map. Matanzas to Gibara in Oriente and is best developed in central Cuba. It consists of sediments deposited along the southern margin of the North American continent. This terrane can be further subdivided into a. Jurassic – Cretaceous carbonate platform b. Cretaceous carbonate slope or scarp c. Jurassic platform to Cretaceous deep-water limestone and chert basin These provinces have been further subdivided into belts. The structure varies from reverse faults and south-dipping monoclines to complexly folded and faulted, northward-directed thrust faults. 2) The southwestern terrane. It has been recognized from the subsurface of the Guanacahibes peninsula in Pinar del Rio to the Escambray massif. This terrane can be subdivided into an unmetamorphosed phase in the Guaniguanico Mountains, and a metamorphic phase extending from the Cangre through the Isla de la Juventud and the Escambray massif. In southeastern Oriente, in an area called Asuncion, are some metamorphosed sediments showing strong affinities with the La

Esperanza belt of Pinar del Rio, and the Cifuentes* belt of central Cuba. The oldest Jurassic consists of a thick quartzose terrigenous section overlain by Late Jurassic to Early Cretaceous bank carbonates that grade south and upward into a deep-water limestone and chert section similar to the north-central terrane deepwater facies. In the Guaniguanico Mountains, the structure consists of a succession of north-dipping thrust sheets. The Isla de la Juventud and the Escambray massif are domal structures showing stacks of thrust sheets. 3) The basic igneous-volcanic terrane. This terrane extends along the axis of the island and forms a complex syncline from Bahia Honda to Oriente that today separates the north-central terrane from the southwestern terrane. The contacts between the three terranes are always of a tectonic nature. This terrane can be subdivided into a lower basic igneous sequence and an upper volcanic arc sequence. The structure and stratigraphy of this terrane can be quite complex, showing stacks of folded thrust faults and a high variety of volcanic types.

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FIGURE 58. Eastern Cuba sedimentary terranes: generalized geologic map.

A lingering question has been whether the southwestern terrane was directly in contact with, and therefore part of, the deep-water part of the northcentral terrane, or if it was separated from it by the basic igneous-volcanic terrane. It must be emphasized that, with very few exceptions, rocks of the basic igneous-volcanic terrane are never found in normal sedimentary or intrusive contact with any of the components of the sedimentary provinces. Furthermore, no basic igneous and volcanic detritus is present in these sedimentary belts before the very Late Cretaceous or early Tertiary. This suggests that the basic igneous-volcanic terrane is completely exotic and was tectonically emplaced over the other two terranes. The stratigraphy of these provinces will be described from north to south and west to east. However, as will be seen later, the definition of belts (also referred to as Hatten-Meyerhoff units, Hatten et al., 1958) given in this chapter does not fit part of the carbonate platform, and to some extent, the entire basic igneousvolcanic terrane is a belt in itself. The major subdivisions of the Cuban geology given in this study will be flexible and will be named ‘‘belt’’ only when the definitions are satisfied. In the following discussion, the nomenclature of the major faults will follow the original nomenclature. Specifically, the faults are named for the belt of which they form the northern (upthrown) boundary. When consulting the literature, this can cause confusion because other authors have used the same names to designate other faults. For instance, the

Hatten et al. (1988) Las Villas fault is quite different from the Las Villas* fault used in this study.

NORTH-CENTRAL TERRANE LAS VILLAS: NORTHERN ORIENTE Under this section heading will be grouped all the sedimentary rocks (nonvolcanic) found outcropping and in the subsurface in central and northern Cuba that is extending from Habana to Gibara in northern Oriente. Figures 57 and 58 show the general distribution of the north-central and southwestern terranes and most of their subdivisions in central and eastern Cuba. Figure 59 is a general correlation chart for the northcentral terrane arranged according to belts and areas. As will be seen later, these outcrops can be restored to a normal succession of facies typical of a continental margin, going from shallow bank carbonates to a deep, pelagic oceanic environment.

Jurassic–Cretaceous Carbonate Platform The carbonate platform province was characterized by the deposition of thick platform carbonates and local evaporites during the Late Jurassic and Early Cretaceous. Locally, the carbonate bank sedimentation continued uninterruptedly through the Late Cretaceous and Cenozoic much as in the Bahamas Bank. This is generally known as the Remedios zone (Ducloz and Vaugnat, 1962). This name will not be used in this publication because (1) it includes the Sagua

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FIGURE 59. Correlation chart, north-central terrane, central and eastern Cuba.

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FIGURE 60. Central Cuba, basal section.

la Chica* and Jatibonico* belts that are not part of it and (2) it has been given different connotations by other authors. In Cuba, the most complete sections are known from the outcrops of the Yaguajay* belt. This is an uninterrupted south-dipping monocline with very good exposures and relatively little faulting. The Instituto Cubano de Recursos Minerales’ (ICRM) wells and Gulf Blanquizal III-1 have contributed additional but, unfortunately, incomplete knowledge of the area, and Shell Cayo Coco-2, although it provided excellent information, is representative of somewhat different conditions. Consequently, in this province, the description of the stratigraphy will not proceed from north to south, but from the Yaguajay* belt–type section north and south to other areas. The lower part of the section has never been observed in situ in surface exposures or in wells, but something can be inferred from the outcrops of three diapir complexes at Loma de Yeso, Isla de Turiguano, and San Adrian (the Loma Cunagua diapir shows only young Tertiary sediments on the surface). The drilling of Kewanee Collazo-1 in Loma de Yeso, Kewanee Tina-1 and Kewanee Tina-2 in Loma Cunagua, and geophysical data also contributed some information. As will be seen later, the fragmentary information on the lower

part of the section suggests that an older sequence could possibly underlie much of the carbonate platform province. It could also underlie, or at one time have underlain, other provinces or belts, as indicated by the San Adrian diapir, which is surrounded by rocks from the basic igneous-volcanic province. In view of its possible widespread occurrence, this basal section will be discussed first.

Basal Section A fundamental question revolves around the total thickness of sediments that can be expected under the carbonate platform. Gulf’s depth estimates to magnetic basement, made during the early 1950s, based on a survey by AeroService Corp. along the northeast coast of Cuba, Cay Sal, and southern Bahamas, range between 30,000 and 40,000 ft (9000 and 12,000 m). In the Cayo Coco area, the depth to magnetic basement is on the order of 30,000 ft (9000 m). Some old reflection seismic, by Shell in the Cayo Coco area, suggests a minimum depth of 20,000 ft (6000 m). Deep crustal seismic measurements by the Soviets have given 41,000 ft (12,500 m) in Cayo Fragoso and 36,000 ft (11,000 m) in Chambas (Scherbakova et al., 1978a). See Figure 60 for localities.

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The deepest wells drilled in the area are Tenneco Doubloon Saxon-1 to 21,740 ft (6628 m) and GulfCalifornia Cay Sal-1 to 18,906 ft (5764 m) in the Bahamas, 30 and 75 km (18 and 46 mi), respectively, north of the Cuban coast. In the north coast of Cuba, the deep wells drilled are ICRM Cayo Fragoso-1 to 16,450 ft (5014 m), ICRM Cayo Frances-5 to 14,885 ft (4537 m), ICRM Cayo Romano-1 to 13,317 ft (4060 m), Gulf Blanquizal III-1 to 11,218 ft (3419 m), and Shell Cayo Coco-2 to 10,563 ft (3220 m). None of them reached basement. At least 10,000 ft (3000 m) of unknown section obviously exist. An additional problem is that the deep structure of the coastal area is poorly known, and no data have been published by ICRM. For instance, some information (Shein et al., 1984; Petroconsultants, 1989, personal communication) suggests that much of the coastal area of Cuba, where the deep wells have been drilled, could be the upthrown block of a large reverse fault, or system of faults, approximately paralleling the coast. It could have as much as 10,000 ft (3000 m) of repeat. If this were the case, the unknown stratigraphic thickness could be less than 10,000 ft (3000 m). Based on the exposures in the diapirs and the drilling of Kewanee Collazo-1, Kewanee Tina-1, and Kewanee Tina-2, three lithostratigraphic units have been established: the informal Cunagua salt, the Punta Alegre* Formation, and the San Adrian Formation.

Cunagua Salt The name is derived from Loma Cunagua, where the well Kewanee Tina-1 drilled through a section of evaporites from 5508 to 10,526 ft (1679 to 3209 m). Halite forms as much as 70% of the section. It contains red and maroon shales, very finely crystalline white anhydrite, brown dolomite, white to orange limestone, and traces of red chert. No gypsum is present. In the Kewanee Collazo-1 well drilled in Loma de Yeso diapir, some halite was encountered at 1420 ft (433 m) and became a dominant component at 1700 ft (518 m). 1700 – 3100 ft (518 –945 m): The section consists of fairly massive and pure halite (in average more than 50%), containing many inclusions of anhydrite and dolomite. 3100–3963 ft (945–1208 m): The section consists of halite, possibly containing many inclusions of anhydrite, dolomite, and argillaceous silt. According to Calvache (1958), the salt has impurities fragments, pebbles, and masses of soft silt and

anhydrite, that in general have a tendency to be horizontally aligned. The salt crystals, where seen, are horizontal. On a core of silt, there are horizontal bands of pure salt. There is nothing in the salt suggestive of ‘‘Salt Dome Conditions’’ as vertical flowage, or vertical orientation of impurities, unless it represents an ‘‘overhang’’. The Cunagua salt is believed to stratigraphically underlie the Punta Alegre* Formation, although in Kewanee Collazo-1, the contact is structurally disturbed. No direct evidence of the age of the salt exists, but spores in the red shales included in the halite gave an age of middle Mesozoic, probably Middle Jurassic. It is considered equivalent to the Louann Salt by many authors. The geographic extent of the Cunagua salt is unknown. Salt water has been reported in wells drilled near the San Adrian diapirs in the Yumuri Valley in Matanzas. Other diapirs have been reported from seismic surveys in deep waters north of Cuba, but their composition is unknown.

Punta Alegre* Formation This unit, named by Truitt (1956b), has its type locality at the Loma de Yeso diapir and outcrops in the Isla de Turiguano diapir, both near the town of Punta Alegre. These diapirs are surrounded by younger Tertiary sediments and are located to the northeast of the carbonate platform outcrops of the Yaguajay* belt. This is different from Meyerhoff and Hatten’s (1968) Punta Alegre Formation. It must be emphasized that halite is not included in Truitt’s original definition of the Punta Alegre* Formation, which consists only of exotics (many of them from rocks never observed before) in a gypsum matrix. The formation name applies to a breccia of heterogeneous rock fragments in a gypsum matrix. The breccia has been subdivided into four types based on the number, size, and abundance of exotics and the red, blue, yellow, and brown color of the gypsum matrix. The exotics form most of the rock and vary in size from a few centimeters to more than 100 m (330 ft). They consist mostly of (1) blocks of black, dark-gray, and dark-red medium-grained limestone, sometimes oolitic; (2) dolomitized limestones and dolomites, (3) purple slate, (4) red shale, (5) argillite, (6) blue quartz sedimentary quartzite, (7) quartz sandstone, and (8) tuffs. The carbonates form most of the clasts. The age of the Punta Alegre* Formation is considered Tithonian or older based on abundant Favreina joukowskyi that is found in the dolomite exotics. Because of Favreina joukowskyi’s importance as an Upper Jurassic fossil (it is the only identifiable fossil

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found in the Punta Alegre Formation), it is worth mentioning the remarks of Bro ¨ nnimann (1956, p. 9), where he discusses its recorded worldwide occurrence. He concludes that From these records it appears that Favreina is a facies fossil of rather long range (Upper Jurassic to Tertiary). However, in Cuba and Trinidad, B.W.I., possibly also Mexico, it seems characteristic of a facies, which apparently is restricted to the Upper Jurassic (Oxfordian – Tithonian). . .. Faunistically therefore, the Upper Jurassic age of the Punta Alegre* Formation may still be questioned, but it is most probable that lithology and Favreina indicates here, as it does elsewhere in Cuba, an Upper Jurassic age. Kewanee Collazo-1 was spudded in the Loma de Yeso diapir 45 ft (13 m) above the Punta Alegre* Formation and encountered the following section: 45 – 630 ft (14 – 192 m): This consists of a mixture of gypsum, limestone, and dolomite, similar to the one in the outcrop. 630 – 1700 ft (192 – 518 m): The gypsum is increasingly replaced by anhydrite, and halite appears at 1420 ft (433 m). Below 1700 ft (518 m) to total depth at 13,032 ft (3972 m): Halite becomes common to dominant. Meyerhoff and Hatten (1968) proposed that the Kewanee Collazo-1 section, including the Cunagua salt, from 45 to 3963 ft (14 to 1208 m) be designated as the type section of the Punta Alegre Formation (for the first time in print). In view of the tectonic complications, the original Truitt definition will be maintained in this study. A question remains as to whether the gypsum at Punta Alegre and Isla de Turiguano has a cap rock origin by solution of halite (Meyerhoff and Hatten, 1968) or, as will be seen later, is derived from the anhydrite that is commonly interbedded with Lower Cretaceous and Upper Jurassic dolomites of the Cayo Coco* Formation. Halite is certainly overlain by gypsum at Loma de Yeso, but at Loma Cunagua, only halite containing some anhydrite, with no gypsum, is present. It is therefore possible that the Punta Alegre Formation of Meyerhoff and Hatten consists of a tectonic mixture of two or more stratigraphic units, the Punta Alegre* Formation, possibly equivalent to part of the Cayo Coco* Formation (that will be described later) and the Cunagua salt unit, which is dominant-

ly halite, with subordinate shale, siltstone, dolomite, and anhydrite. To consider the Punta Alegre and Isla de Turiguano diapirs similar to the Gulf Coast salt domes is misleading. They are associated with the upthrown limbs of large south-dipping Oligocene or later thrust faults.

San Adrian Formation This formation, initially described by Flores (1949) and formally named by Ducloz (1960), outcrops in a cluster of four fault-associated diapirs close to San Adrian, near the town of Matanzas. Compared to the diapirs near Punta Alegre, in the carbonate coastal province, these are surrounded by the basic igneousvolcanic province. As in Loma de Yeso, the formation name applies to a breccia of heterogeneous rock fragments in a gypsum matrix. The breccia contains abundant components up to 12 ft (4 m) in size. These components consist of (1) light- to dark-gray, silty and finely sandy, micaceous, slightly calcareous shales; (2) well-indurated medium-gray, coarse- to fine-grained, quartz sandstone with occasional feldspars and mica; (3) beige fine-grained limestone; (4) gray Nannoconus limestone; (5) fine-grained limestone with quartz grains; (6) dark-gray, fine-grained, thin-bedded radiolaria limestones; (7) dolomitic limestones; (8) marble; and (9) quartz mica schists. Sandstones and shales form most of the exotics, and a large inclusion of serpentine exists. Piotrowski and de Albear (1986) consider the major part of the diapirs to be a clastic-carbonate-evaporite sequence that has been fragmented by diapiric evaporite flowage. A minor part of the diapirs contains exotic blocks, from totally different environments, dragged from the overlying country rock such as the Neocomian Nannoconus limestones and serpentine. Furthermore, the clastic components are very similar to those outcropping 300–400 km (186–248 mi) to the west as part of the San Cayetano Formation that will be described below. Salt has not been observed in the area, but salt water has been reported in some of the water wells drilled in the vicinity. The age of the San Adrian Formation is considered Upper Jurassic (not later than Neocomian). It is believed to represent an evaporitic section, equivalent to the Punta Alegre* Formation, but with a much higher percentage of sandstones and shales. Here, like in the Punta Alegre area, the diapirs consist of material flowing along faults cutting a large variety of terranes.

Basal Section Discussion The above is definite evidence that a poorly known section at the base of the carbonate platform exists.

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FIGURE 61. Central Cuba, Yaguajay* belt. In the Punta Alegre area, the large percentage and types of carbonates compared to the clastics suggest a relationship between the evaporites and the bank carbonates. However, some clastics appear to be related to the San Cayetano. Other clastics are totally unrelated to anything known in Cuba and suggest the Permian micaceous black shales and blue quartzites of the Maya Mountains in Belize. By contrast, in San Adrian, the great abundance of the San Cayetano-like clastics suggests that here, the evaporites were mostly interbedded with them. Although some carbonates are present, many of the exotics appear to belong to belts that structurally overlie the evaporites (Las Villas*, Cifuentes*, etc.), and few of them suggest the platform carbonates. This, together with the fact that none of the wells drilled west of Gulf Blanquizal III-1 encountered the continuous platform facies, indicates that the edge of the platform must be somewhere between Gulf Blanquizal III-1 and Cardenas Bay. However, the evaporites must have existed, interbedded with the San Cayetano, under the Las Villas* belt. Other diapirs have been reported in deep waters north of Cuba, but none has been confirmed.

Yaguajay* Belt In 1975, Pardo extended the meaning of the Yaguajay* belt to all the carbonate platform outcrop areas, including the Sierra de Cubitas in northern Camaguey and the Gibara area in northern Oriente. See Figure 61 for locations in central Cuba.

This area is parallel to the coastal province and is limited to the south by a line running approximately through south of Sagua la Grande, San Antonio de las Vueltas, Vin ˜as, the southern part of the Sierra de Bamburanao and Sierra de Meneses, and northern the eastern end of the Sierra de Jatibonico. This belt is poorly exposed west of San Antonio de las Vueltas. This area is part of the Remedios (1) structurofacies zone of Pushcharovsky et al. (1988). This belt is approximately equivalent to the Remedios unit of Hatten et al. (1988), but not the original Remedios zone of Ducloz and Vaugnat (1962) that included the entire coastal area. In the geologic map of Cuba by Pushcharovsky et al. (1988), a Remedios ‘‘structurofacies zone’’ exists that, like that of Hatten et al., (1988) includes the Yaguajay* and the Jatibonico* belts of this study. Besides, the section exposed in this belt is still largely undivided officially and referred to as the Remedios Group in Pushcharovsky et al. (1988). This name is the extension of a Maastrichtian welldefined unit named Remedios Formation by Bermudez (1950). For this reason, the name Yaguajay* belt will be retained. In central Cuba, the Yaguajay* belt follows the original definition of belts, showing a characteristic sequence of lithologies, dipping 30 –608 south, and bounded to the north and south by major faults, the Yaguajay* and Las Villas* faults, respectively. On air photographs, it forms an easily mappable feature some 80 km (49 mi) long. To the southeast, it terminates at

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FIGURE 62. Stratigraphic section: Yaguajay* belt, Remedios to Sierra de Jatibonico area. the complex convergence of the two bounding faults, whereas to the northwest, it plunges under upper Eocene and later sediments.

Remedios to Sierra de Jatibonico Area The most complete sections are exposed to the northwest near the town of Remedios. The formations established in these sections will be described from oldest to youngest (see Figure 62). Vin ˜ as* Group. —This group includes several similar lithologies that are commonly found together. The essential types are dense, light-gray limestones grading laterally into light-gray pellet limestones and

brown, fine-crystalline dolomites and dolomite breccias. Many of the dolomites appear to be of the high saline type; they are brown, thin bedded, and microcrystalline. The breccias are of a very distinctive type. They are commonly found within sections of the abovementioned dolomites and consist exclusively of the high-saline microcrystalline dolomites in jumbled blocks with suture contacts. They strongly contrast with the numerous heterogeneous carbonate breccias found elsewhere in the section. They have been interpreted as the probable result of anhydrite solution (Littlefield, 1952). The bedding is medium to thick, and the whole sequence is free of terrigenous material.

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In the Vin ˜as River–type section, 10,300 ft (3140 m) have been measured. Its age ranges from the Upper Jurassic through the Cenomanian. This group has been subdivided into the Guani*, Bartolome´*, Puntilla*, and Palenque* formations. Guanı´* Formation. — The Guanı´* Formation consists of 4200 ft (1280 m) of thick-bedded brown, crystalline dolomite, with rare interbeds of limestone and dolomitized limestones. Some dolomite breccias, possibly caused by anhydrite solution, are present. Fossils are absent, but the age, based on the stratigraphic position, is considered Upper Jurassic. The nature of the upper contact with the Bartolome´* Formation is obscured by dolomitization. The upper Guanı´* could be dolomitized lower Bartolome´*. The base has not been observed, but it could be underlain by the Punta Alegre* or the San Adrian Formation. Bartolome´* Formation. — The Bartolome´* Formation consists of 2600 ft (793 m) in the Vin ˜ as River– type section (up to 5000 ft [1525 m] in other areas) of dense, medium- to thick-bedded, hard, light-brown limestone. Some beds are slightly dolomitized, and occasional interbedded dark-brown crystalline dolomites are present. Toward the base, oolitic limestones are present. In the lower part of the formation, the fauna includes Favreina, Dukhania, Valvulinella, and Clypeina, suggesting that the age extends from Upper Jurassic into the Lower Cretaceous. The upper contact with the Puntilla* Formation is conformable. Puntilla* Formation. — The Puntilla* Formation consists of 2200 ft (670 m) in the Camaco River-type section (3400 ft [1037 m] in other sections) of pure light-gray to blue, dense, thick- to medium-bedded miliolid limestones with interbeds of fine- to mediumcrystalline dolomite. At the base of the formation, an 800–1000-ft (245–300-m) dolomite is present. The Puntilla* Formation extends from the Aptian, as indicated by the Orbitolina cf. concava and Orbitolina cf. texana to probably the top of the Cenomanian. The contact with the overlying Camaco* formations is conformable. The Puntilla* Formation is a lateral equivalent of the Palenque* Formation. Palenque* Formation.— The Palenque* Formation (Hatten et al., 1958, described a Palenque Formation that appears to be synonymous with the entire Vin ˜as* Group) consists of 2200 ft (670 m) of massive dolomite breccias with heterogeneous dolomite components up to boulder size in a brown crystalline dolomite matrix. The breccias have interbedded dolomites

and limestones of the Puntilla* type. Anhydrite solution is believed to be the cause of brecciation. This unit is nonfossiliferous, but the age is considered Aptian to Cenomanian based on stratigraphic relationships. The Palenque* is a facies of the Puntilla* Formation and, in places, replaces the upper Puntilla*. It underlies conformably the Camaco* Formation. Hatten et al. (1958) described a Palenque Formation that appears to be synonymous with the entire Vin ˜as* Group. Camaco* Formation. —The Camaco* Formation consists of 2080 ft (635 m) of white to tan, porous algal limestone, thin to thick bedded, and occasionally thinly laminated. Algal remains and miliolids are very abundant. Rudist reefs are common near the base of the formation. In the Camaco River-type section, an 80-ft (25-m) interval of dolomitized limestone sharpstone conglomerate is present 1400 ft (427 m) from the top of the formation and is overlain by the Palone* Formation with apparent but questionable conformity. The Stensio¨ina sp., Cuneolina sp. assemblage indicates a Turonian to Santonian age. It appears to be equivalent to the Purio Formation of Hatten et al. (1958). Palone* Formation. — The Palone* Formation consists of 300 ft (91 m) of cream, organic, medium to fine calcarenite with rare secondary dolomitization. Most of the components are reworked foraminifera and abundant rudist fragments. Based on an Alveolina sp., Siderolites sp., Dicyclina sp., Cuneolina sp., and Coskinolina floridana assemblage, this formation is considered Campanian to early Maastrichtian in age. It is conformably overlain by the Remedios* Formation and is the lateral equivalent of the Mayajigua* Formation. Mayajigua* Formation. —This formation, besides being present in the Yaguajay* belt, is also present in the Cayo Coco–Punta Alegre area of the coastal province, as well as in the Jatibonico* belt. In the Perea-Mayajigua road-type section, it consists of 400 ft (122 m) of thick-bedded heterogeneous sharpstone conglomerate of cream and white, dense limestone and light-brown dolomitic limestone components in a translucent, finely crystalline, white organic limestone matrix. All the components originate from both older and contemporaneous units of the carbonate platform. This conglomerate is very well indurated, hard, and nonporous. The upper part of the formation is less conglomeratic and is made up mostly of medium beds of white, translucent, organic

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limestone similar to the matrix of the conglomerate. In Punta Alegre-1A, it is 640 ft (195 m) thick. Based on a rich Orbitoides sp., Pseudorbitoides sp., Lepidorbitoides sp., and Dicyclina sp. assemblage, the age is considered Maastrichtian. It is the southeastern lateral equivalent of the Palone* Formation and also is interbedded with the Remedios* Formation. It lies unconformably over the Bartolome´*, Florencia*, and Guillermo* formations. It is conformably overlain by the Remedios* Formation and in places unconformably by the lower– middle Eocene. Remedios* Formation. —This formation is best developed to the northwest of the belt and was named by P. Bermudez. It should not be confused with the Remedios Group of Pushcharovsky et al. (1988) that includes all Cretaceous and Jurassic carbonates in the Remedios structurofacies zone. The upper part of Hatten et al. (1958) Remedios Formation is certainly similar to Gulf’s; however, as the descriptions suggest, the lower part might be synonymous to the Mayajigua* and Palone* formations. Lower member. —It consists of 1550 ft (473 m) of brown, finely crystalline dolomite, and limy dolomite with occasional dolomitic limestone beds. The dolomite is massive, but near the top of the member, nearly 300 ft (91 m) of thinly laminated dolomite with laminations exist only a few millimeters apart. Upper member.— It consists of 850 ft (260 m) of dense, white, porcelaneous limestone. In places, the limestone is coarse to fine fragmental, light brown, and occasionally pseudo-oolitic. The beds are 2– 3 ft (60 –90 cm) thick. The thickness of this formation varies considerably, and it appears to lie with apparent conformity, but probable hiatus, under the lower–middle Eocene. The Remedios* Formation is richly fossiliferous and was considered upper Maastrichtian on the basis of a Borelis gunteri, Borelis floridanus, Cosinella sp., Siderolites sp., Rhapydiomina sp., and Gavelinella sp. assemblage. It correlates perfectly with the Cedar Keys of southern Florida. There has been some question as to whether this unit extends into the Paleocene because in Florida, the Cedar Keys is considered to be Paleocene. In view of recent claims of the discovery of Paleocene fossils in the Remedios* Formation, it is pertinent to quote Bro ¨ nnimann (1956, p. 5), who was fully aware of the Paleocene problem. In the writer’s opinion, the Danian is unquestionably a Tertiary stage and forms in the pres-

ent chart part of the Paleocene epoch. . . .Typically Danian faunas with Globigerina daubjergensis Bro ¨ nnimann have not been encountered as yet in Cuba, although such faunas are known from the Gulf Coast. However, assemblages with Globorotalia compressa Plummer, Globigerina pseudobulloides Plummer, and Globorotalia triloculinoides Plummer, and combined with the simultaneous absence of Truncorotalias, are suggestive of Danian or a younger Paleocene stage. Faunas of this composition have been found in Cuba only outside Las Villas province. Therefore, this remains an argument for paleontologists. At any rate, even if the Paleocene is present, it is not well represented. Grande* Formation. —The Grande* Formation consists of 80 ft (25 m) of white and gray, medium to coarse, heterogeneous calcarenite with some pebble conglomerates of white limestone fragments. This unit is very fossiliferous and contains a Tremastegina lopeztrigoi, Discocyclina sp., and Coskinolina sp. assemblage that indicates a lower–middle Eocene age. At this locality, it is conformably overlain by the Sagua* Formation. This unit occurs only at the type locality in the Sagua la Grande River and in the Sierra de Meneses. This name is not to be confused with the Grande Formation as used in Pushcharovsky et al. (1988) to designate limestone and carbonate breccias of Paleocene–Eocene age in the Remedios zone. Sagua* Formation.—This formation is a limestonedolomite conglomerate with angular components up to several feet in size. A fine matrix is very scarce compared to the number of larger blocks. In riverbank outcrops, polished by the stream, it looks like a mosaic of interlocking fragments, with clean suture contacts, smaller ones perfectly filling the space between larger ones. It is extremely hard, with no visible porosity and dogtooth weathering. The fragments consist of all older units of the Yaguajay* and Las Villas* belts. Fragments from the Yaguajay* belt are dominant, 70% or more. In its type locality, it ranges from Albian to lower–middle Eocene, but in the Yaguajay* belt, it is lower–middle Eocene. The lower – middle Eocene part of this formation is also present in the Sagua la Chica* and Las Villas* belts and the coastal province. It will be more fully described under the Sagua la Chica* belt section, below in this chapter, where it has its largest development. It outcrops all along the southern flank of the Yaguajay* belt, where it varies considerably in thickness; it is 80 ft (25 m) thick in the Sagua la Grande area, where it

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overlies the Grande* Formation with apparent conformity, whereas in the Camaco River; it is 690 ft (210 m) thick and rests with strong unconformity over the lower part of the Palone* Formation. In the Yaguajay* belt and coastal province, the Sagua* Formation lies with strong unconformity on older formations and contains a greater amount of components belonging to the older carbonate units. San Martin* Formation. —The San Martin* Formation is well represented in the Yaguajay* belt. In the Sagua la Grande River, 320 ft (97 m) of tan, fine to coarse calcarenites with abundant igneous grains exist, interbedded with pebble conglomerates containing abundant chert fragments and with dull light-gray argillaceous limestones typically shattered in splinters. It will be more fully described under the Las Villas* belt section, below in this chapter. The San Martin* Formation contains a rich foraminiferal fauna. Radiolaria are abundant, and coccolithophoridae and discoasteridae are rock forming. The age is lower –middle Eocene. In this belt, the San Martin* Formation represents the first influx of igneous detritus. This formation underlies conformably the terrigenous clastic Vega* Formation. The San Martin* Formation represents an upward transition from an exclusively carbonate to an exclusively terrigenous detrital regime. Vega* Formation. —The Vega* Formation, which is dominantly an igneous-derived unit, will be described in detail under the Las Villas* belt section. Part of the lower member of this formation, which consists of calcareous shales, igneous-derived sandstones, and occasional sandy limestones, occurs on the Yaguajay* belt. In the Sagua la Grande River where it shows affinities to the San Martin* Formation, the sandstones contain a large percentage of quartz grains. It also occurs in the Sierra de Meneses in a more or less distorted state all along the Las Villas* fault front. Caibarien* Formation. — In the type section, 300 ft (91 m) of Caibarien* Formation have been measured, but as much as 900 ft (275 m) are estimated. It consists of calcarenites and limestone conglomerates, with brown secondary chert, interbedded with chalky and marly limestones. The conglomerates are well and thin bedded, with constituents of nearly uniform size, seldom larger than 5 cm (2 in.). Iron oxide stains are common. In Pushcharovsky et al. (1988), a Caibarien Formation of lower–middle Eocene in the Remedios structurofacies zone described as limestones, marls and carbonate breccias is present; it is not believed to be the same as that of Gulf, although it is probably partly equivalent.

The fauna contains Asterocyclina sp. and Discocyclina sp. and indicates a lower – middle Eocene age. This unit is lithologically related to the San Martin* Formation and is also the lateral equivalent of the Lower Vega* Formation. Drilling.—Two wells were drilled in the Remedios– Sierra de Jatibonico area of the Yaguajay* belt: 1) Atlantic Puntilla-1 to a total depth of 4034 ft (1230 m). It was spudded in the Lower Cretaceous Puntilla* Formation. Orbitolina cf. texana was encountered at 1790 ft (545 m). It probably bottomed in the lower Puntilla* or Bartolome´* Formation. 2) Texaco Mayajigua-1 to a total depth of 10,005 ft (3050 m). It was spudded in the Lower Cretaceous, probably the Puntilla* or Palenque* Formation. At 2580 ft (785 m), the section became dominantly dolomite, possibly the lower Puntilla*, Palenque*, or Bartolome´*. Aptian–Albian was identified at 4850 ft (1480 m), and the section remained in the Lower Cretaceous to total depth. In view of the fact that dips ranged from 30 to 808, the total thickness penetrated was not more than 5740 ft (1750 m).

Sierra de Cubitas Area This area of exposures has the same trend as the Remedios –Sierra de Jatibonico area, but is offset approximately 90 km (56 mi) to the east. It is defined to the south by a line running from Ojo de Agua to Las Mercedes, north of which it terminates. This is the Remedios (2) zone of Pushcharovsky et al. (1988). Gulf did only reconnaissance in this area. The Sierra de Cubitas is a 75-km (46-mi)-long feature prominent in air photographs. It is bound to the south and east by what has been known as the Cubitas fault and disappears to the north and northwest under a Quaternary cover. To the southeast, it terminates against ultrabasics. Generally speaking, the dips are 30– 508 to the south, and the carbonates are cut by several faults parallel to the strike that repeat the section several times across the belt. The section, shown in Figure 63, is reported as follows. Vin ˜ as* Group Undifferentiated. —Formations of the Vin ˜as* Group, with a minimum thickness reported by Hatten et al. (1958) of 1890 ft (575 m), outcrops extensively in the area. This group must include the Palenque Formation, shown as Albian massive limestones by Iturralde-Vinent and de la Torre (1990). Vilato´ Formation.— It consists of an unknown thickness of calcarenites and calcirudites containing

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FIGURE 63. Stratigraphic section: Yaguajay* belt, Sierra de Cubitas area.

abundant rudist (Radiolites) fragments. It is considered of Cenomanian age. Purio Formation. — This name is used to identify an unknown thickness (perhaps in the hundreds of meters) of massive limestones of Turonian to Maastrichtian age. Unnamed Maastrichtian. — This unit is 460 ft (140 m) thick and consists of calcirudites containing the rudist Biradiolites mooretownensis. The following foraminifera have also been reported: Vaughanina cubensis, Vaughanina guatemaltensis, Pseudorbitoides spp., Sulcoperculina globosa, Chubbina cardenasensis,

Sidereolites skoirensis, Sidereolites vanbelleni, and Stomatorbina binkhorsti. Although no name has been given to this unit, it is considered distinctive and separated from the underlying section by Iturralde-Vinent and de la Torre (1990), who consider it the equivalent of the Camajan Formation of Loma Camajan. It is similar and is very probably the equivalent to the Remedios* and Mayajigua* formations. Hatten et al. (1958) reports that the Vin ˜as* Group is overlain by 7000 ft (2135 m) of Remedios Formation, which in this case appears to be synonymous with Vilato´, Purio, and the unnamed Maastrichtian (Remedios* and Mayajigua*) formations.

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FIGURE 64. Eastern Cuba, Yaguajay* belt. This thickness appears excessive, probably because of faulting. The 1988 geologic map (Pushcharovsky et al., 1988) shows that the thickness of the Remedios Group (including the Vin ˜as Group and Hatten’s Remedios Formation) is 2625 ft (800 m). Embarcadero Formation. — Described in Pushcharovsky et al. (1988) as lower–middle Eocene limestone with volcanic fragments and carbonate conglomerates, this description suggests the Sagua* and San Martin* formations. The thickness is given as 165 ft (50 m). In the northern Sierra de Cubitas, Hatten et al. (1958) report an interfingering of the Sagua* with the Jumagua (lower Vega*) Formation. Lesca Formation. —Described in Pushcharovsky et al. (1988) as middle Eocene conglomerates and limestones with chert, this description suggests the Caibarien* Formation. The thickness is given as 330 ft (100 m). Senado Formation.—This unit is described in Pushcharovsky et al. (1988) as olistostromes with blocks of limestone and serpentine, interbedded with sandstones and siltstones of middle Eocene age. As will be seen below, this is unquestionably the upper Vega* (Rosas*) Formation. The thickness is given as 660 ft (200 m).

Northern Oriente: Gibara Area In northern Oriente, only representatives of the carbonate platform and the basic igneous-volcanic provinces are present. The general structural style is a

continuation of that of central Cuba, but is apparently more compressed. The rocks of the carbonate platform form a generally south-dipping, folded and faulted, regional halfdome, bounded on the south by fairly continuous Paleocene –middle Eocene carbonate conglomerates and flysch. These outcrops with the Cubitas Range (in Camaguey) and the Yaguajay* belt (in Las Villas) form the three northwest – southeast-trending and southeast-plunging en echelon carbonate platform antiforms that define most of northern Cuba; these might have been originally separate carbonate banks. Here, the carbonates are present as a group of outcrops covering an area of 22  9 km (13  5.5 mi) west of, and including, the town of Gibara (see Figure 64). This is the easternmost occurrence of carbonate platform sediments in Cuba. Because the dolomitic continental margin carbonate complex is not present, G. Winston (1994, personal communication) considers these carbonates to be unrelated to the FloridaBahamas Platform. He believes them to have been deposited as a separate bank, such as the present-day eastern Bahamas. The limestone massif is surrounded and broken up by several faults. Of interest is that the fault that separates it from the basic igneous-volcanic province dips south and strikes northeast toward the sea, where it terminates offshore on the steep continental slope plunging to 1000 fathoms (1828 m). Although no information about the nature of the contact between

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FIGURE 65. Stratigraphic section: Gibara area, eastern Cuba – northern area.

Cuba and the Bahamas along this part of the Old Bahamas Channel is available (seismic profiles by the University of Texas do not get close enough to shore), it must certainly be a major fault. The section is as follows and shown in Figure 65. Gibara Formation. — The Gibara Formation consists of 2300–2600 ft (700–800 m) of limestones. Some estimates, including that of Pushcharovsky et al. (1988), of up to 20,000 ft (6000 m) exist, with no reference to their source. It would not be surprising if the total thickness of the carbonate platform is on this order

of magnitude, but it is doubtful that such a thickness is exposed in this area. The lower part of the formation consists of brownish white, compact, medium-bedded, crystalline limestones with intercalations of yellowish white, sometimes laminated, hard, microcrystalline limestones. It is separated by a slight angular discordance from an upper part, consisting of massive, crystalline, medium- to coarse-grained, yellowish gray limestones with abundant rudist remains. The uppermost part of the formation contains yellowish white, dense, microcrystalline, pelagic limestones.

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Beds of dolomite and dolomitic limestones are present; the most persistent has been named the Jobal Formation. The description suggests that one is dealing with at least two and possibly three units. The fauna of the lower part of the formation is characterized by Coskinolinoides cf. texanus, Dictyoconus cf. walnutensis, Orbitolina sp., Nommoloculina helmi, Milliolina sp., Planomalina buxtorfi, and Ticinella sp., indicating an Aptian–Albian age. The upper part contains Globotruncana arca, Globotruncana contusa, Globotruncana caliciformis, Globotruncana conica, Globotruncana fornicata, Globotruncana lapparenti bulloides, Globotruncana linneana, Globotruncana stuarti, Hedbergella sp., radiolaria, and rudistids. This latter assemblage is definitely Upper Cretaceous, possibly Turonian–Maastrichtian, and, except for the rudistids that are probably detritus, indicates pelagic depositional conditions similar to those of the Casablanca Group in the Cayo Coco – Punta Alegre and northwestern Cubitas of central Cuba; pelagic faunas are typically absent in the carbonate platform sediments. The mention of strong folding, observed in the upper part of the Gibara Formation, also suggests the thin-bedded marly limestones characteristic of the upper Casablanca Group. The lower part of the Gibara Formation is similar and correlative with the Puntillas* Formation of the Vin ˜as* Group. The upper part definitely suggests the Casablanca Group. El Jobal Formation.— El Jobal Formation consists of 230–330 ft (70–100 m) of gray to dark-brownish or pinkish gray, sugary, medium- to coarse-crystalline dolomites and dolomitic limestones. It is believed to be a facies of the upper part of the Gibara Formation. The dolomites are barren of fossils, but a limestone interbed has been found to contain Milliolina sp., Sulcoperculina sp., Vaughanina cubensis minor, Orbitoides murchissoni, Orbitoides tissoti, Pseudorbitoides sp., Sulcorbitoides sp., and rudist fragments, indicating an upper Campanian–lower Maastrichtian age. This unit is similar and equivalent to the Palone* Formation and is also equivalent to the Mayajigua* Formation. Embarcadero (Embarcadero Oriental) Formation. — This name has been used to designate the Sagua*-like conglomerate that outcrops in the Sierra de Cubitas in central Cuba. In Pushcharovsky et al., 1988, it is named Embarcadero Oriental. The formation consists of 150–1000 ft (50–300 m) of limestone and dolomite conglomeratic breccia made up of 95% of detritus, of which 90% consist of the various limestone types found in the older carbon-

ate platform, 6–8% of dolomites, and 2–4% of chert. The percentage of igneous components from the basic igneous-volcanics is very small. This conglomerate is identical with the Sagua* Formation of central Cuba, which ranges from the Aptian– Albian to the lower–middle Eocene, where it becomes geographically very extensive. No indigenous fauna has been found, and its age is based on components and because it underlies the upper Paleocene–middle Eocene Vigia Formation. The Vigia Formation correlates with the San Martin* and Vega* formations of central Cuba; therefore, whether the Sagua* or Embarcadero are Paleocene or lower–middle Eocene, they are coeval and reflect the same process. Vigia (Vigia Oriental) Formation.—The Vigia (Vigia Oriental) Formation (in Pushcharovsky et al., 1988, it is named Vigia Oriental) consists of up to 2300 ft (700 m) of mostly igneous-derived clastics, detrital limestones, and tuffs as follows: 1) The lower part of the formation consists of an interbedding of green to grayish green serpentine, limestone, and volcanic-derived graywacke sandstones and mudstones. They are well bedded, and their grain size varies from coarse to fine and sometimes contain large foraminifera. 2) The upper part consists of thin and well-bedded white to grayish white, calcareous, commonly silicified tuffs, and radiolaria-bearing marls, with bentonite. Rhyodacites and greenish gray, dense rhyodacitic tuffs are also present. The rhyodacites are white to grayish white and porphyritic, with phenocrysts of biotite, quartz, amphibole, and plagioclase up to 2 mm (0.08 in.) in diameter. The tuffs are commonly silicified or zeolitized. A rich, foraminiferal fauna contains Globorotalia (Acarinina) acarinata, Globorotalia (Acarinina) densa, Globorotalia (Acarinina) mckannai, Globorotalia (Acarinina) pentacamerata, Globorotalia (Acarinina) rugosoaculeata, Globorotalia (Acarinina) spinuloflata, Globorotalia (Acarinina) triplex, Amphistegina lopeztrigoi, Anomalina grosserugosa, Asterocyclina sp., Clavulina parisiensis, Cribohantkenina bermudezi, Dictyoconus americanus, Dictyoconus cookei, Discocyclina crassa, Discocyclina flintensis, Discocyclina pustulosa, Discocyclina vermunti, Ellipsoglandulina velascoensis, Ellipsonodosaria annulifera, Globigerina pseudoeocenica, Globigerinoides higginsi, etc. The age is considered upper Paleocene–middle Eocene. The Vigia Formation overlies unconformably the Embarcadero and the Gibara formations. It is equivalent to the Miranda and Castillo de los Indios formations of southeastern Oriente. The lower part of

102 / Pardo

FIGURE 66. Central Cuba, coastal areas.

this formation represents a flysch deposited in deep waters similar to, and coeval with, the Manacas Formation (Pica Pica Member) of western Cuba and the Vega* Formation of central Cuba. However, the upper part is of volcanic origin and of a volcanism synchronous to, and even postdating, the major thrusting episode of the orogeny.

Yaguajay* Belt Discussion This section exposes a minimum of ±8400 ft (±2550 m) of Tithonian and Lower Cretaceous massive, bank-type carbonates. Dolomite breccias are occasionally common, and evaporites are absent. The Upper Cretaceous (and possible Paleocene) is characterized by ±5600 ft (±1700 m) of occasionally richly fossiliferous limestones and occasional dolomites. It includes the regionally persistent, Campanian to lower Maastrichtian carbonate conglomerate of the Mayajigua* Formation, which is mainly derived from reef material. Finally, during the lower–middle Eocene, ±2200 ft (±700 m) were deposited, which are characterized by the coarse-grained Sagua* conglomerate followed by the San Martin* and younger detrital limestones and clastics where igneous fragments, derived from the orogenic front to the south, make their first appearance. The entire section was deposited

under shallow water, and although the evaporites are absent, it shows great affinity to the Bahamas section. The above thickness figures give a constant average rate of sedimentation (uncorrected for compaction) of 167 ft/Ma (51 m/Ma) from the middle Kimmeridgian through the middle Eocene or 114 Ma. However, the Upper Jurassic alone could show a higher rate of sedimentation depending on the age of the observed base of the Guani* Formation, which is unfossiliferous.

Coastal Region This region runs along the north coast. It is present north of a line as follows: It runs north of the Bahia de Cardenas, through Jumagua, Sagua la Grande, the confluence of the Camajuani and Sagua la Chica rivers, north of Remedios, along the north flank of the Sierra de Bamburanao, south of Yaguayay, Chambas, Moron, Loma Cunagua, Bolivia, along the north flank of the Sierra de Cubitas, La Gabriela, and goes to sea north of Nuevitas (see Figure 66). The original name, by Pardo (1953), was the Coastal Belt and was defined as the entire coastal area including the cays, with little or no pre–upper Eocene

Pre – Upper Eocene Stratigraphy / 103

outcrops, and where the sparse drilling (Gulf Blanquizal III-1, Shell Cayo Coco-2, Shell Punta Alegre-1A, Shell Punta Alegre-2) indicated a carbonate platform section with less structural complications than in the Yaguajay* belt, farther to the south. This was a departure from either the Pardo (1953, 1954) or HattenMeyerhoff (Hatten et al., 1958) definition of belts (units). In 1956b, Truitt restricted the coastal belt to a lithologic-type section as encountered in the well Shell Cayo Coco-2 (the stratigraphic definition of belt). The same area was named the Cayo Coco tectounit by Hatten et al. (1958) and the Cayo Coco belt by Pardo (1975). However, this restricted definition was difficult to extend outside the Cayo Coco–Punta Alegre area because of the lack of information, and Hatten et al. (1958) included in it the area north of the Sierra de Cubitas, although there was no information on the Lower Cretaceous–Upper Jurassic facies. Further drilling of the Kewanee Collazo-1 and Shell Manuy-1 wells and the scarce information available on the deep wells drilled by ICRM suggest facies changes within the coastal province and a much greater structural complexity, impossible to resolve with the information at hand. For this reason, it is suggested that the coastal areas of Las Villas and Camaguey, extending from Gulf Blanquizal III-1 to the town of Nuevitas, north of the Yaguajay* belt of carbonate platform outcrops, be named the coastal region, outside the belt (unit) classification scheme. For description purposes, this region will be subdivided into areas: the Cayo Coco–Punta Alegre (east) and the Blanquizal (west). In addition, a short description of the well Gulf-Chevron Cay Sal-1 as well as a discussion of the south Bahamas Platform will be provided under the Bahamas area.

Cayo Coco–Punta Alegre Area The section shown in Figure 67 is a composite section based on the Shell wells Cayo Coco-2, Punta Alegre-1A, and Punta Alegre-2. The sequence from older to younger is as follows: Cunagua Salt. — It is believed to be at the base of the section, although this unit has never been penetrated in this area in a normal stratigraphic position. Punta Alegre* Formation. — Although this unit has not been drilled in a normal position in this area, it is believed to be transitional between the evaporites and the Cayo Coco Formation. The breccia must be in part tectonic, but in part due to solution of the anhydrite. The abundance of components derived from a silicoclastic section suggests some relationship with the San Adrian and the San Cayetano Formations.

Cayo Coco* Formation.—In the Shell Cayo Coco-2 type section, it extends from 3998 ft (1218 m) to total depth at 10,563 ft (3220 m) for a total thickness, corrected for dip, of 5684 ft (1733 m). The dips average 308. 3998 – 7150 ft (1218 –2180 m). The upper 2728 ft (832 m) consists of massive to thick-bedded, brown to light-brown, micro- to medium-crystalline dolomites and minor dolomitized oolitic zones. Anhydrite occurs in minor amounts commonly as vug fillings. Many zones of healed, brecciated dolomite are present; Shell geologists called it the ‘‘upper (breccia) dolomite group.’’ Some clayshale laminae exist. 7144–10,563 ft (2178–3220 m). The lower 2956 ft (901 m) of the section consists of dolomites, calcarenites, and micritic limestones interbedded with characteristic, sometime massive, white to brown, micro- to fine-crystalline anhydrites. The dolomites are brown in color, micro- to coarse crystalline, with traces of anhydrite. The limestones are light brownish gray and contain microfossils, and the calcarenites are coarse grained and oolitic. A continuous limestone interval exists from 8982 to 9245 ft (2739 to 2819 m). G. Winston (1984, personal communication) considers the top of this lower section at 7144 ft (2178 m) correlative with the top lower Comanchean (middle Aptian), Punta Gorda Formation in Florida (COSUNA, 1988). Within the brown dolomites of this lower section are several zones of good intergranular to vugular porosity (up to 15%) from 8112 to 8350 and 8765 to 9000 ft (2473 to 2546 and 2672 to 2744 m). Tests indicated zones of reservoir-quality permeability. G. Winston (1984, personal communication) considers these two intervals of brown dolomite to be a section, repeated by a thrust fault at 8349 ft (2545 m), that correlates with the lower Able Member and upper Twelve Mile Member of the Lehigh Acres Formation of south Florida. However, either this lithology is younger in Florida, or unknown structural complications exist in Shell Cayo Coco-2. G. Winston (1984, personal communication) considers the Lehigh Acres Formation lower Comanchean (middle Aptian; Childs et al., 1988), whereas Upper Jurassic fossils have been identified at 9005 ft (2745 m) in Shell Cayo Coco-2. Asphalt stains are common throughout the entire section. Coskinolinoides cf. C. texanus, considered an Aptian– Albian index (lower Fredericksburg) in the Gulf Coast,

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FIGURE 67. Stratigraphic section: coastal province, Cayo Coco – Punta Alegre area.

was found at 6667 ft (2032 m). Saccocoma sp., Cuneolina sp., and Favreina joukowskyi, considered Upper Jurassic indicators in Cuba, were found at 9005 ft (2745 m). Based on scant but reliable paleontological evidence and its position underlying the Aptian (possibly extending into the Neocomian) Guillermo* Formation, the Cayo Coco* is therefore considered to range from the Upper Jurassic into the Aptian. The lower contact has never been drilled. The Cayo Coco* Formation is probably underlain by the Punta Alegre* or San Adrian formations. However, the possibility exists that the lower part of the Cayo Coco*

Formation is synonymous with the upper part of the Punta Alegre* Formation. The upper contact with the Guillermo* Formation is obscured by dolomitization but is believed to be transitional. The Cayo Coco* Formation is time equivalent to the lower and middle part of the Vin ˜ as* Group and represents a similar carbonate bank-evaporitic facies. It is very similar to the Guani*, Bartolome´*, and Palenque* formations of the Yaguajay* belt, the main difference being the presence of anhydrites in the Cayo Coco* Formation. As already mentioned, the absence of anhydrite in the Vin ˜ as* Group

Pre – Upper Eocene Stratigraphy / 105

is believed by some workers to be due in large part to a later solution as indicated by the frequent intraformational dolomite breccias. Except for Hatten, Meyerhoff, and associated authors, the name Cayo Coco* Formation has been used fairly loosely in the literature, scout reports, and other sources of information. The Cayo Coco* Formation was also penetrated in Kewanee Collazo-1 from 8395 ft (2559 m) to total depth at 13,030 ft (3973 m). The interval from 8395 to 12,250 ft (2559 to 3735 m) or 3796 ft (1157 m) of thickness (after correction for an average 108 dip) suggests the upper dolomite section in Shell Cayo Coco-2. Below 12,250 ft (3735 m), 447 ft (136 m) of section (after correction for an average 558 dip) suggests the lower anhydrite-dolomite section in Shell Cayo Coco-2. Favreina joukowskyi was found at 12,730 ft (3881 m). Casablanca Group. — Giedt and Schooler (1959) described an assemblage of lithologies from the coastal plain south of Guaney Beach, Camaguey, northwest of the Sierra de Cubitas. It consists of light-gray to yellowish gray, thin- to medium-bedded, fine-grained limestones, with shaley intervals between the limestone beds. The limestone is slightly chalky and contains an abundant microfauna and poorly preserved ammonites. These lithologies are similar to a section from 950 to 4000 ft (290 to 1220 m) in Shell Cayo Coco-2, where Pardo (1954) named three units, which, in ascending order, are the Guillermo*, Romano*, and Contrabando* formations. In this study, the Casablanca Formation has been elevated to group status, and it includes the three above-named formations. The thickness in Shell Cayo Coco-2 might be exaggerated in view of reported high dips. Guillermo* Formation. — It consists of massivebedded, pelagic foraminiferal white limestone and appears to be unconformably overlain by the Romano* Formation. It contains abundant Nannoconus spp., Favusella washitensis, and Colomiella spp. Based on the fauna, it is considered Aptian to lower Albian and possibly extending into the Neocomian. It is, in part, the deep-water equivalent of the upper Cayo Coco* Formation. In Shell Cayo Coco-2, the type section, it is found between 3500 and 4000 ft (1067 and 1220 m). The Guillermo* Formation has been found in Shell Punta Alegre-2 between 3970 and 4220 ft (1210 and 1287 m) and Shell Manuy-1 between 985 and 1213 ft (300 and 369 m). It is unconformably overlain by the upper Maastrichtian Remedios* Formation. It is absent, possibly faulted out in Shell Punta Alegre-1A, and has not been specifically recognized in Kewanee Collazo-1.

Romano* Formation. — It consists of an interbedding of argillaceous limestones, marls, and some shales. It is comformably overlain by the Contrabando* Formation. Based on abundant planktonic foraminifera with Globigerina cretacea sl., Guembelina sp., and Nannoconus spp., it is considered of Albian age. The influx of argillaceous material in this deep-water environment is a definite departure from the previously predominant pure carbonate environment. Its type locality is the 2380 –3500-ft (726 – 1067-m) interval in Shell Cayo Coco-2. It is also present in Shell Punta Alegre-1A from 1225 to 1520 ft (373 to 463 m). It is missing through unconformity in Shell Punta Alegre-2 and is not present in Shell Manuy-1. It has not been specifically recognized in Kewanee Collazo-1, but it could be present because the interval 8060 – 8395 ft (2457 – 2559 m) has been reported as limestone-chert-shale of Albian – Cenomanian – Turonian age; this could be an interval of tectonically disturbed Casablanca Group. Contrabando* Formation. — It consists of chalky limestone and marl, sometimes dolomitic, containing characteristic nodular black chert stringers. It contains abundant pelagic foraminifera, among them G. cretacea sl., Guembelina sp., and Rotalipora appenninica. It is considered Cenomanian –Turonian age and might extend into the Coniacian. As will be seen later, this unit is lithologically and paleontologically very similar to the Calabazar* Formation of the Las Villas* belt. It is unconformably overlain by the Mayajigua* Formation. The type locality is the 950–2380-ft (290– 726-m) interval in Shell Cayo Coco-2, where the upper part is truncated by the younger Tertiary unconformity. It is present in Shell Punta Alegre-1A from 920 to 1225 ft (280 to 373 m). It is probably present in Kewanee Collazo-1 (see Romano* Formation description above). It is absent in Shell Manuy-1. The Casablanca Group, with its definite openmarine, deep-water, pelagic environment, has been considered, in the past, as one of the characteristics of the Cayo Coco belt (unit). Mayajigua* Formation. —This formation is well represented in the Cayo Coco–Punta Alegre area. It is present in Shell Punta Alegre-1A from 280 to 920 ft (85 to 280 m) and Kewanee Collazo-1 from 7347 to 8065 ft (2240 to 2459 m). It has not been specifically identified in Shell Manuy-1, but based on sample descriptions and the presence of a rich Maastrichtian orbitoid fauna, it is believed to be present under the Cayo Coco* Formation after crossing a major fault at

106 / Pardo

±8000 ft (±2400 m). In Shell Cayo Coco-2, it is missing because of the Tertiary unconformity. Jaula* Formation. — It consists of calcarenite of lower – middle Eocene age. It is present in Kewanee Collazo-1 from 6550 to 7347 ft (1997 to 2240 m), where it overlies the Mayajigua* Formation. It is the correlative of the Sagua* Formation. In Pushcharovsky et al. (1988), the Guaney Formation is overlain by middle Eocene limestone with breccias called the Venero Formation. It is a possible synonym of the Jaula* Formation and even the Turiguano* Formation. Turiguano* Formation. — The type locality of this formation is a small outcrop north of the Isla de Turiguano diapir. It consists of white calcarenite with abundant dolomitization and a few dolomite intervals of lower–middle Eocene age. In Kewanee Collazo-1, it is present from 4325 to 6550 ft (1319 to 1997 m), where it overlies the Jaula* Formation. With correction for an average 208(?) dip, this represents a thickness of 2091 ft (637 m). It is present in Shell Punta Alegre-2 from 3548 to 3970 ft (1082 to 1210 m), where it overlies the Guillermo* Formation with possible unconformity. It is the equivalent to the Caibarien* Formation of the Yaguajay* belt. It is unconformably overlain by various upper Eocene or younger units; however, in the Kewanee Collazo-1 and the Shell Punta Alegre wells, it is overlain by the lower Oligocene Chambas* Formation. Drilling. — In addition to Shell Cayo Coco-2 and Kewanee Collazo-1, several deep wells have been drilled in this area. Sparse information is available on them from the 1985 Cuban geologic map (Cuba, 1985a, b) and Petroconsultants (1989, personal communication) and no dips or lithologic details are given. This makes precise assignment of formational unit and correlation with the other wells in the area very difficult if not impossible. For instance, it is impossible to determine whether the Casablanca Group is present in the ICRM wells, although the equivalent time interval from Aptian to Turonian is shown in several of them. The wells are Shell Manuy-1, and ICRM Cayo Fragoso-1, ICRM Cayo Frances-5, ICRM Cayo Lucas-1, ICRM Cayo Romano-1, and ICRM Moron Norte-1. 1) Shell Manuy-1. Neogene carbonates to ±655 ft (±200 m), Campanian–Maastrichtian limestones to ±1015 ft (±310 m), Aptian–Albian limestones to ±1575 ft (±480 m), Upper Jurassic – Neocomian dolomites (possible Cayo Coco* Formation) to ±7215 ft (±2200 m), Paleocene detrital carbonates to ±7545 ft (±2300 m), and Campanian – Maastrichtian limestones to total depth at 8895 ft

2)

3)

4)

5)

(2712 m). However, reliable reports indicate that the well was cut by several thrust faults; at ±1600, ±6000, and ±8000 ft (±480, ±1800, and ±2400 m), repeating the Casablanca Group and some younger units several times. ICRM Cayo Fragoso-1. Oligocene and younger carbonates to ±2330 ft (±710 m), lower – middle Eocene detrital carbonates to ±2820 ft (±860 m), Coniacian–Maastrichtian limestones and dolomites to ±6079 ft (±1850 m), Albian–Turonian limestones and dolomites to ±11,250 ft (±3430 m), and dolomites and anhydrite of Upper Jurassic and Neocomian age (possibly Cayo Coco* Formation) to total at 16,450 ft (5014 m). ICRM Cayo Frances-5. Neogene and Oligocene limestones drilled from the surface to ±2230 ft (±680 m), middle – upper Eocene limestones to ±2755 ft (±840 m), Albian – Maastrichtian limestones to ±8005 ft (±2,440 m), Neocomian dolomite (no anhydrite) to ±11,415 ft (±3480 m), and Aptian–Turonian limestones and dolomites to total depth at 14,881 ft (4537 m). Petroconsultants reports that the well penetrated Lower Cretaceous limestones and anhydrites at 11,513 ft (3510 m). This could be interpreted as the well having drilled through ±3600 ft (±1070 m) of upper Cayo Coco* Formation before crossing a thrust at 11,513 ft (3510 m). ICRM Cayo Romano-1. This well has the most conflicting information. The 1985 geologic map (Cuba, 1985a, b) shows middle Eocene and younger Tertiary to ±680 ft (±280 m), Campanian – Maastrichtian limestones to ±1445 ft (±440 m), Cenomanian – Senonian dolomite to ±7350 ft (±2240 m), and Aptian – Turonian limestones to total depth at 13,317 ft (4060 m). However, a 1989 Petroconsultants report (personal communication) shows Tertiary to 275 ft (84 m), Maastrichtian to 623 ft (190 m), Cenomanian – Turonian to 1591 ft (485 m) Albian to 4838 ft (1475 m), Neocomian–Aptian to 7915 ft (2413 m), Tithonian to 8397 ft (2560 m), Upper Cretaceous limestones to 11,808 ft (3600 m), Lower Cretaceous dolomite to 12,792 ft (3900 m), and Neocomian dolomite to total depth. In view that the presence of a thick dolomite section in the Upper Cretaceous in this area is rather unusual, the author is inclined to think that the geologic map is in error, and that the well did cross a major thrust fault at 8397 ft (2560 m). ICRM Moron Norte-1. Upper Eocene and younger terrigenous clastics penetrated from the surface

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FIGURE 68. Stratigraphic section: coastal province, Blanquizal area. to ±6165 ft (±1880 m), Cretaceous volcanics to ±9185 ft (±2800 m), Paleocene coarse terrigenous clastics to ±9480 ft (±2890 m), Neocomian dolomite suggesting the Bartolome´* (or Cayo Coco*) Formation to total depth at 16,407 ft (5002 m). The well must have crossed the Domingo thrust at ±9185 ft (±2800 m).

Blanquizal Area Gulf’s Blanquizal III-1 is representative of this area that is characterized by a lack of anhydrite and continuous shallow-water conditions through the Cretaceous. The section shows great affinity to that of the Yaguajay* belt, and this well could have penetrated the offshore extension of this belt (see Figure 68). 0 – 196 ft (0 – 60 m). Gu ¨ ines Formation consisting of light tan reefoidal porous, locally dolomi-

tized limestones, marls, and calcarenites of Miocene age. 196 – 1775 ft (60 –875 m). Upper Cretaceous tan, cream, and gray fine-crystalline limestones with rare dolomites. It is typical of the Remedios* and possibly Palone* formations. 1775 – 2872 ft (541 – 875 m). Upper Cretaceous consisting of dolomitized, richly fossiliferous miliolid limestones, with rudist fragments typical of the Camaco* Formation. A 3-ft (1-m) shaley bed containing rock-forming Pithonella spp. as well as Globigerina cretacea sl. and Guembelina sp. of early Upper Cretaceous age was encountered at 2180 ft (665 m). This was the only evidence of open-water pelagic conditions. 2872 – 5330 ft (875 –1625 m). Lower Cretaceous tan and brown finely crystalline dolomites and dolomite breccias and cream, brown, and tan

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limestones, commonly with miliolids, of the Puntilla* and equivalent Palenque* formations. Littlefield (1959) interpreted the fine-crystalline dolomites as primary. Circulation was lost at 4208 ft (1283 m), indicating the cavernous (boulder) zone. The Aptian – Albian Orbitolina cf. texana is present at 4745 ft (1447 m). The top of the Lower Cretaceous has been a matter of discussion; it is certainly below 2180 ft (665 m), but correlation with Cay Sal-1 could place it as high as 2250 ft (686 m). It should be noted that long stretches of dolomite section are completely devoid of identifiable fossils, and many of the limestones contain only nondiagnostic, facies-dependent faunas. 5330 to total depth at 11,218 ft (1625 to total depth at 3419 m). It consists dominantly of tan, gray, and brown very fine to microcrystalline dolomite of the Lower Cretaceous Bartolome´* Formation. Two intervals of cream, tan, brown, and white fine- to coarse-grained, commonly miliolidrich limestones at 7033–7180 ft (2144–2189 m) and 9875–10,113 ft (3011–3083 m), respectively. Littlefield (1952) interpreted the well as having crossed a major thrust fault at 7650 ft (2332 m), repeating ±3000 ft (±900 m) of section, although this has never been definitely confirmed. G. Winston (1986, personal communication) makes the following correlations with Florida, but considers them ‘‘iffy:’’ Rattlesnake Hammock, 4650 ft (1418 m); Sunniland, 4740 ft (1445 m); West Felda, 6520 ft (1988 m); Pumpkin Bay, 6550 ft (1997 m); Bone Island, 7980 ft (2433 m); and Wood River, 10,350 ft (3155 m). No indication of anhydrite exists, although common dolomite breccias are present, which Littlefield (1952) believed were caused by anhydrite solution. G. Winston’s correlations suggest that the well penetrated the Jurassic at 10,350 ft (3155 m). Gulf’s opinion at the time was that the well’s total depth was still in the Lower Cretaceous. Another well, ICRM Cayo Lucas-1, might also have been drilled in this area, but published information does not permit a positive determination; no evaporites were mentioned. ICRM Cayo Lucas-1. —Upper Eocene and younger limestones drilled from the surface to ±920 ft (±280 m), Campanian – Maastrichtian limestones to ±2100 ft (±640 m), Cenomanian – Santonian limestones to ±2950 ft (±900 m), Aptian – Turonian limestones to ±8460 ft (±2580 m), Neocomian dolomite (possibly Bartolome´* or upper Cayo Coco*) to total depth at 10,152 ft (3095 m).

Florida-Bahamas Area Many wells have been drilled in southwest Florida, and five wells have been drilled in the Bahamas: Superior Andros-1, Chevron Great Isaac-1, Gulf-Mobil Long Island-1, Tenneco Doobloon Saxon-1, and GulfChevron Cay Sal-1. Only the last two have a direct bearing on Cuba’s coastal province. Winston (1991) is a good source of general information on the Bahamas and Florida stratigraphy. 1) Tenneco Doubloon Saxon-1. This well was drilled in the southern Bahamas, 43 km (26 mi) northeast from Cayo Coco-2 and, according to Petroconsultants (1988, personal communication), was in the dolomites and anhydrites of the Cayo Coco* Formation at a total depth of 21,740 ft (6628 m). Oil shows were reported. Unfortunately, no other details are available. 2) Gulf-Chevron Cay Sal-1. This well was jointly drilled 82 km (50 mi) north-northeast of Gulf Blanquizal III-1 by Standard of California and Gulf Oil to a total depth of 18,906 ft (5764 m). According to G. Winston (1991, personal communication), the section is as follows (see Figure 69): 0– 1400 ft (0 – 427 m). Post-Eocene white micritic limestones and white euhedral microcrystalline dolomites. 1400 – 3620 ft (427 – 1104 m). Eocene tan, cream, and white micritic limestones with skeletal remains and orange-brown euhedral fine to microcrystalline dolomite. 3620–4680 ft (1104–1427 m). Paleocene limestone, dolomite bank facies, and dolomite reef facies. The limestone is nonporous, white lithographic, and chalky. The bank facies dolomite is nonporous, cryptocrystalline, light gray, and tan. Numerous beds of porous euhedral fine-crystalline dolomite are interbedded with the above. The reef facies is medium- to coarse-crystalline, euhedral, and porous dolomite. 4680 to ±7300 ft (1427 to ±2226 m). The Upper Cretaceous consists of 1460 ft (445 m) of massive tan, cream, light- to dark-gray, fine- to microcrystalline dolomite. It overlies 470 ft (143 m) of white chalky limestone with dolomite inclusions. The base is made of 690 ft (210 m) of tan and brown, euhedral fine- to medium-, and occasionally, coarsecrystalline dolomite. The coarse dolomite appears to have a reef origin. The dolomite is very porous, and large cavities (caverns at the base of the interval) exist. The exact boundaries are questionable.

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FIGURE 69. Stratigraphic section: Bahamas Gulf-Chevron Cay Sal-1. Lithology and correlations courtesy of G. Winston.

±7300– 10,310 ft (±2226– 3143 m). Much of the Albian and the upper part of the Aptian to the top of the Lake Trafford Formation consist of the lower part of the Rattlesnake Hammock Formation overlain by 2540 ft (774 m) of cream to tan, cryptocrystalline to anhedral dolomite called the Cay Sal dolomite. The lower 480 ft (146 m) of section consists of an interbedding of tan, brown, and cryptocrystalline to euhedral dolomite, cream to tan micritic limestones, and a minor amount of anhydrite. 10,310 –10,460 ft (3143 –3189 m). It consists of tan micritic limestone and tan, euhedral, and microcrystalline dolomite of the Lake Trafford Forma-

tion. Anhydrite is present. This interval represents the beginning of continuous evaporitic conditions in Cay Sal. 10,460–10,620 ft (3189–3238 m). It consists of tan, micritic limestone with rare tan, microcrystalline dolomite and anhydrite of the Sunniland Formation. 10,620–11,500 ft (3238–3506 m). This is the first interval consisting dominantly of anhydrite. The subordinate carbonates are dominantly tan and brown micritic limestones with occasional skeletal remains. Minor microcrystalline tan and brown dolomite also exists. It is considered equivalent to the Punta Gorda Formation.

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FIGURE 70. Stratigraphic sections: coastal province, Gulf Blanquizal III-1 to ICRM Cayo Romano-1. 11,500–13,850 ft (3506–4223 m). This interval consists of dominantly cream, brown, and tan, micritic limestones interbedded with subordinate amounts of brown and tan, medium- to microcrystalline dolomites and subordinate anhydrite of the Able, Twelve Mile, West Felda(?), and Pumpkin Bay formations. 13,850–16,200 ft (4223–4938 m). This interval consists of 35% of anhydrite with tan to brown, micritic to lithographic limestone as the dominant carbonate. The dolomite is tan to brown, very fine to fine crystalline. It represents the Bone Island Formation. G. Winston considers it to represent the lower part of the Coahuilan and the upper part of the Jurassic. The COSUNA Charts (Childs et al., 1988) consider it of Berriasian to Hauterivian (Durangoan) age. 16,200 to total depth at 18,906 ft (4938 to total depth at 5764 m). It consists of anhydrite interbedded with tan to brown cryptocrystalline dolomite with occasional remains of oolites. Some subordinate brown to tan micritic limestones exist. A few thin salt beds are present near the bottom of

the section, which caused considerable drilling difficulties. Winston considers this interval to be the Wood River Formation of Jurassic age. The COSUNA Charts (Childs et al., 1988) consider it of Tithonian (Lacastian) age. At the time of the drilling, Gulf’s geologist on the well, R. A. Worrell, also considered the well to have bottomed in the Jurassic.

Jurassic–Cretaceous Carbonate Platform Discussion The carbonate platform southern boundary is well defined by the Yaguajay* belt. This province can be divided into two areas on the basis of the distribution of facies; however, this facies distribution is not necessarily related to identifiable structural features. Because of the lack of information, it is difficult to draw a boundary between the areas. Figure 70, based on the ICRM wells, Gulf Blanquizal III-1, and Shell Cayo Coco-2 (shown in Cuba, 1985a, b), shows a spectacular increase in the thickness of the interval between the top of the Neocomian

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and the top of the Cretaceous in the 85 km (52 mi) between Shell Cayo Coco-2 and ICRM Cayo Fragoso-1, from ±3410 to ±8365 ft (±1040 to ±2550 m). In Gulf Blanquizal III-1, this interval is at least 5134 ft (1565 m) thick. In the Yaguajay* belt, this same interval is 10,780 ft (3290 m). In addition, this interval is shown containing dolomites in ICRM Cayo Fragoso-1. Dolomites are present in this interval in Gulf Blanquizal III-1 and the Yaguajay* belt, whereas dolomites are absent in the Cayo Coco – Punta Alegre area. In GulfChevron Cay Sal-1, the Upper Cretaceous consists of 3100 ft (945 m) of dominantly dolomites. This indicates that the basic difference between the Cayo Coco– Punta Alegre area and the Yaguajay* belt–Blanquizal area is that in the former, the carbonate platform conditions were replaced by pelagic, deeper water conditions from the lower Aptian to the Maastrichtian, whereas in the latter, they persisted at least until the end of the Cretaceous or Paleocene. This change occurred along a line running approximately from Cayo Frances through Chambas, Moron, Bolivia, and along the northern border of the Sierra de Cubitas, suggesting the presence of a deep-water tongue, possibly an ancestral Old Bahamas Channel, along the north coast of Cuba. The presence of Cenomanian, open-water Oligostegina limestone in Gulf Blanquizal III1 at 2180 ft (665 m) indicates the proximity to such a feature. However, note that in the well ICRM Cayo Romano-1, 3411 ft (1040 m) of Upper Cretaceous limestones were reported under the fault in the Tithonian at 8397 ft (2560 m) compared to the 1315 ft (401 m) in the upthrown block. It is not known whether this difference in thickness is caused by an incomplete section in the upthrown block, steep dips in the downthrown block, or the superposition of two different facies. Anhydrite beds occur, or have been reported, in the Cayo Coco* Formation only in ICRM Cayo Fragoso-1, Shell Cayo Coco-2, and in the lowermost part of the section penetrated by Kewanee Collazo-1. No anhydrite is present, or has been reported, in the Lower Cretaceous or Upper Jurassic of the Yaguajay* belt (Remedios – Sierra de Jatibonico and Cubitas areas), Gulf Blanquizal III-1, Shell Manuy-1, and the ICRM’s wells Cayo Frances-5, Cayo Lucas-1, Cayo Romano-1, and EPEP Moron Norte-1, although collapse breccias in high-saline dolomites are common in the Yaguajay* belt and Gulf Blanquizal III-1. In view of the fact that no dip information for the ICRM wells exists and that Shell Manuy-1 is apparently very disturbed structurally, it is impossible to say whether the above wells might not have drilled through the upper ±3000 ft (±900 m) of the Cayo Coco* Forma-

tion, where no anhydrites are found. The well GulfChevron Cay Sal-1 shows 3010 ft (918 m) of Lower Cretaceous dolomites overlying 8596 ft (2621 m) of interbedded dolomites and anhydrites. This section certainly suggests the Cayo Coco* Formation. However, in this well, the Upper Cretaceous consists of 2620 ft (799 m) of dominantly dolomites with some interbedded limestones with no indication of Casablanca Group lithologies, therefore suggesting a greater affinity to the Yaguajay* belt. The absence of anhydrite in the Yaguajay* belt and Blanquizal area could be depositional and caused by the proximity to the bank edge. However, the presence of abundant monomictic dolomite breccias, interbedded with what has been interpreted as high-saline primary dolomites, suggests that their absence could also be caused by secondary solution (Littlefield, 1952). The age of this solution ranges from the top of the Lower Cretaceous to the upper Eocene. This phenomenon might have been related to the fluid expelled from the deep basin sediments under the advancing thrust sheets; the basic igneous-volcanic province rocks are present over part of the Cayo Coco–Punta Alegre area. As already pointed out, none of the wells drilled along the north coast of Cuba west of Gulf Blanquizal III-1 has ever encountered this bank facies. This suggest that the carbonate bank province does not extend along the coast as a continuous bank farther west than the Blanquizal–Cardenas Bay area, although platform carbonates are present in Pinar del Rio. In conclusion, it appears that the Yaguajay* belt and the Blanquizal area of the coastal province show a strong affinity to the Bahamas section, with continuous sedimentation of bank carbonates (and evaporites in the lower part of the section), throughout the Upper Jurassic and the entire Cretaceous. The importance of the Mayajigua* Formation should be noted. The abundance of indigenous shallow-water fossils, the intertonguing with the Remedios* Formation, and the strong unconformity at the base suggest that it was deposited in shallow waters and, as the result of an uplift of the coastal province, accompanied with the erosion of reefs, during the Campanian – Maastrichtian. In the southeastern part of the Sierra de Meneses, the Campanian–Maastrichtian Mayajigua* Formation breccias rest directly on the Neocomian Bartolome´* Formation, with some 7700 ft (2350 m) of Aptian – Santonian section missing. In Texaco Mayajigua-1, drilled in the same general area, a minimum of 2782 ft (848 m), after dip correction, of Aptian– Albian is present above the Neocomian. In the Cayo Coco–Punta Alegre area, the shallow-water Mayajigua*

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FIGURE 71. Central Cuba: carbonate slope or scarp province.

Formation is in contact with the deep-water Casablanca Group, indicating a strong uplift. Toward the northwest, the Mayajigua is equivalent to the detrital Palone* Formation and, as will be seen later, to part of the Sagua* Formation, a similar conglomerate but apparently deposited in much deeper waters. All this is evidence for strong tectonic relief at the time of the pre-Mayajigua* Formation unconformity, in addition to the natural bathymetric relief of the carbonate banks. At present, it is difficult to estimate the possible tectonic shortening of the carbonate platform across the strike, but it must be appreciable. At least three major reverse fault zones are known in the Cayo Coco– Punta Alegre area, in ICRM Cayo Romano-1, Shell Manuy-1, and Kewanee Collazo-1, and in the Blanquizal area in ICRM Cayo Frances-5 and possibly Gulf Blanquizal III-1. The Yaguajay* fault brings the Upper Jurassic in contact with the Eocene. The total shortening, even assuming high-angle faults, could be of the order of 50,000 ft (15,000 m), or 20% of the original width of 75 km (46 mi) for the entire carbonate platform. This estimate is believed conservative because these faults could be ramps of much larger thrusts over evaporite de´collements. The carbonate platform province in eastern Cuba has certainly strong similarities with central Cuba that suggest the presence of Vin ˜as* Group-type carbonates in the Lower Cretaceous. However, it is not clear if the Camaco*, Palone*, and Remedios* Formation bank type of lithologies are present, or whether they have

been entirely replaced by the pelagic carbonates of the Casablanca Group. Furthermore, few dolomites have been reported, and those have been dated as Upper Cretaceous, so there is no indication that the outcrop section exposes the Jurassic, but this appears unlikely. Therefore, what is known about this section suggests a Cayo Coco – Punta Alegre area type of carbonate for the Aptian through Maastrichtian, but gives no indication about the nature of the pre-Aptian rocks. The low percentage of dolomite clasts in the Embarcadero Formation might be significant in that it probably represents the general composition of the bank. The presence of the Embarcadero overlain by the lower Vigia Formation is a close analog of the Sagua* overlain by the Vega*. It should be noted that, contrary to the Yaguajay* belt in Las Villas and Camaguey provinces, here, no orogenic conglomerate is associated with the Vigia Formation, as in the Rosas* and the Senado formations. On the contrary, the upper Vigia Formation represents a return to volcanic activity in a deep-water environment.

Cretaceous Carbonate Slope or Scarp The carbonate slope or scarp province consists of two belts of outcrops located between and with affinities to the Yaguajay* and the Las Villas* belts. In large part, their rocks seem to represent the foot of the slope where carbonate detritus from the shallow-water banks accumulated. These outcrops belong to the Sagua la Chica* and the Jatibonico* belts (see Figure 71).

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Sagua la Chica* Belt The belt runs south of and parallel to the Yaguajay* belt in the Remedios to Sierra de Jatibonico area. This belt is not well defined geographically. Gulf observed it only in the Sagua la Chica and Camajuani Rivers, where it is very well developed. It could be more than 45 km (27 mi) long and is closely related to, but separated from, the Jatibonico* belt. Originally, the Gulf geologists thought that it was an exceptional development of the lower – middle Eocene Sagua* Formation conglomerates in the Las Villas* belt. Further studies indicated that it contained a more complex stratigraphic sequence, time equivalent to part of the Las Villas* belt section. Unfortunately, it was not mapped in detail. In general, it appears to be a steeply south-dipping block, showing tight folds and imbrications, located between the central part of the Yaguajay* belt and the Las Villas* belt and extending from Sitiecito to south of Remedios. It can reach 3–4 km (1.8–2.5 mi) in width. It is in fault contact with the lower–middle Eocene part of the Sagua*, the San Martin* and Vega* formations that belong to the Yaguajay* belt and outcrop all along its southern flank. It appears that other authors have most certainly included it in the same unit or zone that comprises Gulf’s Las Villas* belt, although Dilla and Garcı´a (1985) created, without fully describing it, a Sagua structurofacial zone. They admit that this zone has not been studied, and they restrict it to the Tertiary. Furthermore, they do not discuss the origin of the name that is very probably Gulf’s. Pushcharovsky et al. (1988) place it in the Camajuani zone. Only Pardo (1975) has mentioned it previously in the English-language literature.

Sagua* Formation At Gulf’s type locality, the Sagua la Chica River in Las Villas province, it is 1000 ft (300 m) thick. In the same river, this section is repeated by faulting, so the total apparent thickness is 2100 ft (640 m). Hatten et al. (1958) who used the same formation name (but from a different type locality at Calabazar de Sagua), estimates 2500 ft (760 m) at other localities, but this thickness could be structurally exaggerated and must include the Sagua*, the Yaguajay* Formation, and perhaps part of the San Martin* Formation. Ortega y Ros (1937) named this unit the Santa Colona Formation, but included in it other lithologies that today are given other formation names. Dilla and Garcı´a (1985) show the Sagua and Jumagua (lower Vega*) formations as equivalent to the Vega Alta Formation that

is a tectonic breccia; this is a serious misconception. Pushcharovsky et al. (1988) show more than 8200 ft (2500 m) of a Vega Formation or ‘‘Brecha Sagua’’ described as ‘‘breccias, conglomerates, limestones, sandstones, siltstones, marls, and claystones’’ in the Camajuani ‘‘structurofacies zone,’’ which is more or less equivalent to the Las Villas* belt. Although this unit must certainly include Gulf’s Sagua*, San Martin*, and Vega* formations, the thickness appears excessive probably because of repeats. This unit is a limestone-dolomite conglomerate with angular components up to several feet in size. Like in the Yaguajay* belt, a fine matrix is very scarce compared to the number of larger blocks. It consists of a mosaic of interlocking fragments, with clean suture contacts, smaller ones perfectly filling the space between larger ones. It is extremely hard, with no porosity and prominent dogtooth weathering. The fragments consist of all older units of the Yaguajay* and Las Villas* belts. Fragments from the Yaguajay* belt are dominant. Chert fragments derived from the Cretaceous Lutgarda* and Calabazar* formations of the Las Villas* belt are abundant toward the base. The Sagua* Formation is very thickly bedded. Many depositional cycles, grading from fine to coarse grained, are visible. Chert nodules are present. In the lower part of the conglomerate section are a few thin beds of dense limestone, suggesting the Florencia* Formation of the Jatibonico* belt. The fauna can be divided into three groups; the dense limestones in the lower part of the section contain common Orbitolina sp., Dictyoconus walnutensis, and Coskinolinoides sp., suggesting an Aptian–Albian age. Higher in the section, a fauna consisting of Globtruncana lapparenti sl., Vaughanina, Orbitoides sp., and Sulcoperculina sp., and Globigerina cretacea sl., identical with that of the Mayajigua* Formation, appears, suggesting a Maastrichtian age. Dense limestone interbeds containing Globigerina cretacea, Gumbelina, and Globotruncana sp. also exist. Finally, toward the upper part of the section, the typical lower–middle Eocene faunas of Discocyclina spp., Asterocyclina spp., Globorotalia spp., and spinose globigerinas are present. Although many of the fossils are found reworked into the conglomerates, the characteristic associations and the dating of the dense limestones interbedded with the conglomerates leaves little doubt of the presence of three ages of beds (Aptian–Albian, Maastrichtian, and lower–middle Eocene) separated by unconformities or hiatuses. However, the breaks are undetectable, and there is no way to subdivide the unit on lithologic grounds.

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Upward, the Sagua* Formation is gradational into the San Martin* Formation. The base was not observed; however, Pushcharovsky et al. (1988) show it overlying directly onto Berriasian to Barremian sediments identified as the Margarita and Paraiso formations. It would be interesting to determine if these are outcrops of Mabuya* or Capitolio* Formation. The lower Aptian – Albian part of the Sagua* Formation has been observed only in the Sagua la Chica belt, although it has great similarities to the ageequivalent Florencia* Formation in the Jatibonico* belt and the Calabazar* Formation of the Las Villas* belt, which also contain numerous detrital limestones with identical fauna as components. The middle part is very similar to and correlates with the Mayajigua* Formation of the Yaguajay* belt and coastal province, although it appears to have been deposited in deeper waters. It is also similar to the deep-water calcarenites of the Lutgarta* Formation of the Las Villas* belt. The lower–middle Eocene part is very widespread and occurs in the Yaguajay* belt from the town of Remedios, in Las Villas, to Gibara in northern Oriente. It has been found in the Las Villas* belt from the subsurface in northern Matanzas to Loma Camajan in Camaguey. The possible origin of this rather unique rock will be discussed later in this study.

San Martin* Formation In this belt, the San Martin Formation is present in its typical development.

Vega* Formation The San Martin* grades into the Vega* Formation, which, in this belt, is characterized by a large development of coarse, poorly sorted polymict conglomerates in its upper member (Rosas* Formation).

Jatibonico* Belt This belt is limited to the northeastern part of the Sierra de Jatibonico. It runs south of and parallel to the Yaguajay* belt. It represents a distinct stratigraphic section with affinities to both the Yaguajay* and Las Villas* belts. It is a south-dipping fault block bounded to the north by the Jatibonico* fault and to the south by the Las Villas* fault (see Figure 72). Other authors have included this belt in the Remedios zone of Ducloz and Vaugnat (1962), Zulueta unit of Hatten et al. (1958), and Remedios structurofacies Zone of Pushcharovsky et al. (1988). Shopov (1982) called it the Jatibonico subzone of the Camajuani zone.

Guani* Formation This unit consists of at least 1300 ft (400 m) of massive dolomites identical with those of the Yaguajay* belt. The base is unknown, and it is conformably overlain by the Mabuya* Formation.

Mabuya* Formation It consists of 2300 ft (700 m) of thin-bedded brown to yellow argillaceous limestone with interbedded yellow weathering claystone and brown crystalline dolomite. The limestone is occasionally pseudo-oolitic and commonly dolomitized. At the top is a sequence of interbedded coarse dolomite conglomerate and medium- to coarse-crystalline banded dolomite 350 ft (107 m) thick. It is overlain with a possible unconformity or hiatus by the Florencia* Formation. Toward the top of the formation, Choffatella sp. and Pseudocyclammina sp. have been found. At the base, associated with the oolitic beds, Calpionella cf. elliptica, Calpionella alpina, Calpionella undelloides, and Nannoconus spp. are present, showing definite openwater pelagic influence. The fauna indicates an age ranging from Upper Jurassic to Aptian. It is equivalent to the Cayo Coco* Formation of the coastal province, the Bartolome´* and, possibly, the lower Palenque* formations of the Yaguajay* belt, and the Capitolio* Formation and upper Trocha* Group (Caguaguas* and Jaguita* formations) of the Las Villas* belt. Lithologically, it definitely shows an intermediate facies between the Yaguajay* and Las Villas* belts.

Florencia* Formation The Florencia* Formation (not related to the Florencia Formation of middle Eocene age described by Hatten et al., 1958) consists of 900 ft (274 m) of white to gray-brown, dense to thin-bedded calcarenites, with interbeds of coarse limestone sharpstone conglomerates. Abundant silicified megafossils are concentrated in layers. Occasional dolomitic limestone beds exist. Near the top, a 120-ft (37-m) very coarse sharpstone conglomerate exists devoid of megafossils. The finer grained units contain rock-forming Nannoconus spp., Globigerina cretacea sl. var., Orbitolina sp. cf. O. texana–O. concava, and miliolids, suggesting an Aptian to middle Albian age. As mentioned before, this formation has great similarities to the lower part of the Sagua* Formation of the Sagua la Chica* belt. It appears to be unconformably overlain by the Mayajigua* Formation, although some structural complications are observed.

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FIGURE 72. Stratigraphic section: Jatibonico* belt.

Mayajigua* Formation

San Martin* Formation

The Mayajigua* Formation is present in its typical development, but with very coarse limestone and dolomite conglomerates. It contains very abundant Campanian – Maastrichtian orbitoids. It is 600 ft (185 m) thick and appears to grade into the lower – middle Eocene part of the Sagua* Formation with no sign of unconformity, although the Paleocene has not been recognized.

It is present in its characteristic development with a marked increase in pelagic forms.

Sagua* Formation Only the lower – middle Eocene part of the Sagua* Formation is present and grading into the overlying San Martin* Formation.

Cretaceous Carbonate Slope or Scarp Discussion The Jatibonico* and Sagua la Chica* belts are very significant for the paleogeographic and paleotectonic reconstruction of Cuba. They have not received the attention they deserve. The Jatibonico* belt shows transitional sedimentation during the Upper Jurassic and pre-Aptian Cretaceous between the Yaguajay* and the Las Villas* belts and continuous, mostly coarse, clastic carbonate sediments from the Aptian to lower–middle Eocene.

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The Sagua la Chica* belt is also characterized by continuous coarse clastic, dominantly carbonate sedimentation, which lasted from the Aptian –Albian to the early – middle Eocene. Although no break in a continuous well-exposed section is observable, no Cenomanian to Santonian or Paleocene faunas have been identified. These coarse deposits might represent the Yaguajay* belt carbonate bank talus, but this interpretation leaves the common presence of pelagic limestones and chert fragments originating from the deeper water sediments of the Las Villas* belt to the south unexplained. Perhaps the Sagua la Chica* belt is evidence for a major fault, lasting from the Aptian to the lower–middle Eocene, responsible for the carbonate bank margin (Hatten et al., 1958). All evidence points toward the Sagua* being a deepwater deposit, although most of the reworked faunas are of shallow-water origin. Perhaps the deeper water fragments are of a tectonic nature, such as contemporaneous active rifts, whereas the shallow-water ones were part of a conventional talus. The argument against this is that, with the exception of the Mayajigua* Formation, components of a typical reef (corals, algae, mollusks) are relatively infrequent; most of the debris appears to have been derived from already solidified back-reef material as if the bank was being tectonically destroyed. The original distance across the strike represented by these two belts and the horizontal displacement of the Sagua la Chica* and Jatibonico* faults is impossible to estimate.

Jurassic Platform to Cretaceous Deep Basin The Jurassic platform to Cretaceous deep basin province comprises three belts, Las Villas*, Placetas*, and Cifuentes*, each representing a characteristic succession of lithologies. These belts may have been brought into proximity by major thrust faults, but their present outcrops are probably caused by later generations of faulting that, in large part, mask or distort the original ones. For this reason, the stratigraphic definition of the belts has been followed. These three belts are believed to be representative of part of a miogeosyncline as originally defined by Marshall Kay, that is, devoid of volcanic activity. As will be seen later, sedimentation was in a shallowwater carbonate platform until the early Tithonian, at which time sedimentation could no longer keep pace with a probably accelerated subsidence. There was no major contribution of silicate clastics until the lower– middle Eocene diastrophism. The influence of volca-

nism was practically nonexistent except in the southernmost part. This is the area where the ‘‘belt,’’ ‘‘unit,’’ ‘‘zone,’’ etc., nomenclature has been the most confused. Gulf subdivided the platform to deep basin province into three belts and five unnamed informal subdivisions. Most subsequent authors saw no need to have more than two subdivisions. Three belts provide the best basis for unraveling the geologic history of Cuba. As will be seen below, the Las Villas* and Cifuentes* belts represent two facies extremes, whereas the Placetas* belt is transitional.

Las Villas* Belt In the province of Las Villas, it strikes essentially parallel to the previous belts and outcrops almost uninterruptedly for 175 km (108 mi) from south of the Bahia de Santa Clara in northern Las Villas to the south end of the Sierra de Jatibonico in northwestern Camaguey. It is limited to the south by a line running through Rancho Veloz, Cifuentes and Mata, Calabazar de Sagua, Vega Alta, Camajuani, slightly south of Zulueta, and parallel to the south edge of the Sierras de Bamburanao and Jatibonico, to Los Barriles. To the west, it has been identified in the subsurface as far as Via Blanca, near Habana. Two windows in the Cifuentes* belt show the Las Villas* belt: the Yabu window 7.5 km (4.6 mi) west of the town of Cifuentes, and the Fidencia anticline 12 km (7.5 mi) south-southeast of the town of Camajuani. In the province of Camaguey, the Las Villas* belt consists of limited outcrops immediately south of the northwestern end of the Sierra de Cubitas and in the northern half of the Sierra Camajan (see Figure 73). This belt was defined by G. Pardo in 1952, who redefined it to exclude the Sagua la Chica* belt (Pardo, 1954). Note that P. Ortegas y Ros described accurately its essential stratigraphy in 1937, but because of the obscurity of the publication, the work remained essentially unknown until the middle 1950s. The following are highlights of what happened to the Las Villas* belt since then: (1) Hatten et al. (1958) named a feature essentially equivalent of the original 1952 Las Villas* belt, the Zulueta tectounit; (2) Ducloz and Vuagnat (1962) named it the Camajuani zone; (3) FurrazolaBermudez et al. (1963) used the name Las Villas structural-facies zone; (4) Meyerhoff and Hatten (1968) named it the Camajuani zone; (5) Kniper and Cabrera (1974) named it the San Felipe zone; (6) Dilla and Garcı´a (1985) named it the Camajuani subzone

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FIGURE 73. Central Cuba, Las Villas* belt.

of the Las Villas structurofacies zone; and (7) Hatten et al. (1988) named it the Zulueta unit. In Pushcharovsky et al. (1988), it is called the Camajuani structurofacies zone. The amazing thing was that all this name changing was done in the absence of any new information and based on mid-1950 data. This could be amusing if each author had not modified the definition, so that a translation is impossible from the literature alone. For this reason, the Pardo, 1954, definition of the belt will be maintained, and in this study, it will be named the Las Villas* belt. In 1954, Gulf used an informal local subdivision named the ‘‘Las Villas* belt southern facies’’ to describe a lithologic sequence intermediate between the Las Villas* and the Placetas* belt.

Las Villas Province Area The Las Villas* belt is characterized by the most complete and fossiliferous Jurassic to lower – middle Eocene sedimentary section in central Cuba. It was used by Gulf as its type section for the pre–upper Eocene of central Cuba. It can reach up to 9.5 km (5.9 mi) in width without counting the windows. It has been recognized in the subsurface along the north coast from the Bahia de Cardenas in Matanzas to La Habana. The Las Villas* belt can be subdivided along its length into a northeastern and a southwestern half by important facies differences. The type localities for most of the formations are located in the Quemado de Gu ¨ ines anticlinorium in

northern Las Villas. The section will be described below (see Figure 74). Trocha* Group.—The Trocha* Group includes several Upper Jurassic–related carbonate and chert lithologies. The lower part of the group was deposited in shallow water, although the presence of some radiolaria indicate open waters. It outcrops mostly in the southwestern half of the belt. The total thickness is at least 2800 ft (850 m). This unit was named the Trocha Formation by Ortega y Ros (1937). In Pushcharovsky et al. (1988), 1310 ft (400 m) of an Upper Jurassic – Tithonian Trocha Formation are present. Although the thicknesses do not match, it is believed to be synonymous with Gulf’s Trocha* Group. In 1952, Gulf geologists divided it as follows: Hoyo Colorado* Formation. —The Hoyo Colorado* Formation consists of a minimum of 2100 ft (640 m) of dense, gray to light gray, in places pseudo-oolitic, limestone and light brown, medium-bedded, finecrystalline secondary dolomite. Occasional red and brown secondary cherts exist. This unit is medium to thick bedded. In the upper part, the fauna is similar to the overlying Jaguita* Formation, and in its lower part, only unidentifiable radiolaria have been found. Based on the fossils and its stratigraphic position, it is considered of possible Kimmeridgian to lower Tithonian age. It definitely seems to have been deposited under shallow-water bank conditions, with the exception of the radiolaria fauna found at the base.

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FIGURE 74. Stratigraphic sections: Las Villas* belt.

It is partly equivalent to the Guanı´* Formation of the Yaguajay* belt and the Cayo Coco* Formation of the Cayo Coco –Punta Alegre area. The base has not been observed, but it could have been originally underlain by the Punta Alegre* or the San Adrian Formation. The present base is very likely to be a fault. It is conformably overlain by and grades into the Jaguita* Formation. Jaguita* Formation. — The Jaguita* Formation consists of 1400 ft (425 m) (some structural repeats are possible) of cream orange, brown gray and gray, pseudo-oolitic to oolitic limestones, interbedded with dense radiolarian limestones occasionally stained

by iron and manganese oxides. This formation is commonly medium to very thick bedded. The fauna consists of Pseudocyclammina sp., Coscinoconus sp., Nautiloculina sp., Lenticulina sp., and radiolaria. Aptychi and ammonites are locally abundant. R. Imlay (1954, personal communication) identified the following ammonites: Pseudolissoceras zittelli, Lithoplites caribbeanus, Protancyloceras hondenses, and Microacanthoceras sp. In addition, several microfossils exist incertae sedis, such as Globochaetes alpina, Eothrix alpina, and Saccocoma spp. Favreina has been found in this formation in Cuban Gulf Hicacos-1. These assemblages indicate a middle Tithonian age and show a

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strong affinity to those described in the Upper Jurassic of the Tethys region. The facies (and microfacies) are also very similar. The fauna is mostly shallow water; however, the presence of radiolaria in dense limestones indicates a definite deepening of the water, and the oolites, as well as the shallow-water assemblage, could well be reworked from nearby banks. This formation is believed to be in part equivalent to the Guanı´* and lower Bartolome´* formations of the Yaguajay* belt and in part to the Cayo Coco* Formation of the Cayo Coco–Punta Alegre area. It is comformably overlain by the Caguaguas* Formation. Caguaguas* Formation.—It consists of 375 ft (115 m) of dense, medium-bedded, gray carbonaceous limestone interbedded with medium-bedded banded limestone. The banded limestone has flesh pink to buff porcelaneous bands alternating with carbonaceous, wavy laminated, gray, dense bands. The wavy laminae are commonly orange colored, and the whole formation on weathering is stained by limonite and manganese oxide. In fresh exposures, the color is black. The Caguaguas* Formation appears to be a transition between the Jaguita* and the overlying Capitolio* Formation. The fauna consists of abundant radiolaria, C. elliptica, and C. alpina. The age is considered upper Tithonian. The Caguaguas* Formation represents a marked water deepening compared with the bank carbonate environment of the Hoyo Colorado* Formation. It is equivalent to the lower Mabuya* Formation of the Jatibonico* belt, the lower Bartolome´* Formation of the Yaguajay* belt, and part of the Cayo Coco* Formation of the Cayo Coco – Punta Alegre area. It grades into the overlying Penton* Group. Penton* Group. —This group was described and named by Ortega y Ros (1937). It consists of 1100 ft (335 m) of medium-bedded buff dense limestone with wavy orange laminations and black and brown interbeds of chert and some secondary silicification. In the southwestern Las Villas* belt, it contains calcarenites and calcirudites. It is subdivided into the following formations. Capitolio* Formation. —The Capitolio* Formation consists of 800 ft (245 m) of buff, dense, biomicrite, with thin, yellow-orange, wavy laminae, interbedded with brown and black thin-bedded banded vitreous chert. Most of the chert is a secondary silicification of limestone (the limestone fabric can be seen in thin sections) containing abundant radiolaria that are now replaced by calcite. The limestone layers are thick and flat-bedded, but commonly split into set plates parallel to the bedding. Aptychi are common along the

surface of these plates. This unit outcrops along the northeast part of the Las Villas* belt. It grades into the overlying Ramblazo* Formation. Hatten et al. (1958) describe 1178 ft (359 m) of a Margarita Formation that appears to be at least partly synonymous with the Capitolio* Formation. Pushcharovsky et al. (1988) show in the Zulueta zone 985 ft (300 m) of biomicrites with little chert of Beriassian – Hauterivian age called the Margarita Formation and 820–985 ft (250–300 m) of stratified limestones (biomicrites) with interbedded cherts of Hauterivian – Barremian age called the Paraiso Formation. These two units appear to be synonymous with the Capitolio* Formation. In addition to aptychi and abundant unidentifiable radiolaria, it contains Nannoconus steinmanni and common Calpionellites darderi, Tintinosporella carpathica, Calpionclla elliptica, and Calpionellopsis oblonga. The Nannoconus is rock forming and, together with the abundant radiolaria, indicates a deep, open-water environment. It is considered of Neocomian age. The conspicuous aptychi are the reason for formerly calling this type of lithology the ‘‘Aptychus Formation.’’ Ramblazo* Formation. — The Ramblazo* Formation consists of 340 ft (104 m) of medium-bedded but very thin-plated, rust-laminated to white dense limestone, similar in microstructure to that of the Capitolio* Formation, but with fewer wavy laminae. Thin stringers of dark-black, waxy chert are present and are one of the distinguishing features of the formation. Some calcirudites with a somewhat argillaceous matrix are present. Thin interbeds of shale that weather white and form a faint white band in air photographs are common throughout the formation. The Ramblazo* Formation has a very characteristic aspect when exposed on roads; each bed separates into a book of very fine plates because of the presence of argillaceous partings. It contains abundant radiolaria and rock-forming Nannoconus steinmanni and Nannoconus spp. Abundant Orbitolina cf. texana exists in the calcarenites. The presence of a shallow form such as Orbitolina in calcarenites interbedded with deep-water sediments indicates the presence of turbidites, probably originating from the carbonate banks to the north. This situation is repeated later in the section. The age is considered Aptian. The Ramblazo* Formation is equivalent to the upper part of the Sabanilla* Formation. It is comformably overlain by the Calabazar* Formation. Hatten et al. (1958) probably include the Ramblazo* Formation in the lower part of the Alunado* Formation. It might be

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included in the Paraiso Formation in Pushcharovsky et al. (1988), but there is no mention of an Aptian unit. Sabanilla* Formation. — The Sabanilla* Formation consists of 500 – 800 ft (150–250 m) of interbedding of Capitolio*-type limestones and cherts with calcarenites, commonly fine grained but sometimes becoming limestone conglomerates. The matrix is conspicuous and consists of a yellow to gray dense, structureless limestone. The fragments are mainly derived from the underlying Jaguita* and Caguaguas* formations, although some are derived from the Capitolio* Formation. It should be pointed out that no components other than carbonates are present. This unit is present in the southwestern half of the Las Villas* belt, and the size of the fragments increases southward, along with the percentage of detrital beds. Along the southwestern edge of the Las Villas* belt, detrital beds completely replace the Capitolio* lithology. The origin of this unit is certainly caused by an unconformity within the Capitolio* Formation; as from north to south, the Sabanilla* Formation is characterized by (1) thin calcarenites interbedded with the Capitolio* lithology, (2) dominantly detrital beds resting on the Capitolio* Formation, and (3) dominantly detrital beds, with components becoming conglomeratic in size, resting on the Caguaguas* Formation. A study of the detrital bed components indicates the southern origin of the sediments. Hatten et al., 1958, mentions the presence of a Tithonian Sabanilla Formation, but no description is given. The fauna is characterized by Coskinolinoides sp., Cuneolina sp., miliolids, Robulus sp., Nannoconus steinmanni, Calpionellites darderi, Tintinnopsella carpathica, Calpionella elliptica, and Calpionellopsis oblonga. This fauna indicates two disparate environments, shallow bank and pelagic, possibly deep water. The upper part of this unit is also the lateral equivalent of the Ramblazo* Formation and is comformably overlain by the Calabazar* Formation. The character of the Sabanilla* Formation suggests Neocomian rifting. Obviously, an area south of the Las Villas* belt either failed to subside or, after an initial subsidence in the early stage of Capitolio* deposition, was uplifted. The nature and mix of the components in the Sabanilla* Formation suggests a steep scarp with fragments of Jaguita*, Caguaguas*, and already deposited Capitolio* formations dropping into a deep basin. The situation was a forerunner of the fault system that later would be responsible for the Sagua la Chica* belt. The shallow-water Aptian fauna could have come from either the north or the south. This fault must have become inactive in the late Aptian,

the time of the earliest Sagua* development, because the Calabazar* Formation conformably overlies both the Ramblazo* and the Sabanilla* formations. Malpaez* Group. —Hatten et al. (1958) named the lower 450 ft (135 m) of this group the Alunado Formation. This group includes several interbedded calcarenites, limestone conglomerates, dense argillaceous white limestones, powdery radiolarites, cherts, and shales. The fact that it contains what appears to be a significant regional break in sedimentation during the Coniacian could be an argument to restrict it to the lower two units. The thickness of the group ranges from 600 to 1000 ft (185 to 300 m). This group is subdivided into the following formations. Calabazar* Formation.—It consists of 230 ft (70 m) of interbedded white to very light-gray weathering dense limestone and waxy black and steel-gray thin cherts. Medium- to coarse-grained calcirudites exist. The bedding is thin, but some medium beds are present. In places, intervals of brown thin-bedded, sometimes thick, vitreous chert and white-weathering, darkgray shale (with no limestones present) are observed. This formation is typical of the Las Villas* belt. In Pushcharovsky et al. (1988), 330 ft (100 m) of limestones (calcarenites and biomicrites), cherts, and breccias (conglomerates) of Albian–Cenomanian age called the Mata Formation exist. This unit must certainly be synonymous with the Calabazar* and overlying Mata* Formation. The lower part contains abundant Nannoconus spp., whereas toward the upper part, it contains abundant Globigerina cretacea sl., Rotalipora appenninica, and Guembelina sp. Radiolaria are abundant, and a calcarenite at the base of the formation contains detrital Orbitolina cf. texana. The age is believed to range from the late Aptian through the Cenomanian. The environment is definitely deep water, but an influx of turbidites brings in shallow-water detritus, most probably from the north. It grades into the overlying Mata* Formation. To the south, the upper part of the Calabazar* becomes equivalent to the entire Mata* Formation. Note that the Calabazar* and Mata* formations have strong lithologic and paleontologic similarities with the Casablanca Group of the Cayo Coco–Punta Alegre area and are generally its equivalent. Mata* Formation. — It consists of 150–220 ft (45– 70 m) of interbedded calcarenites, dense limestones, and cherts. In the lower part of the formation are thinto medium bedded, buff to orange, dense limestones

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interbedded with medium- to coarse-grained heterogeneous calcirudites. In some places, these calcirudites contain chert nodules and, in others, are completely silicified. In its upper part, opaque dense brown and gray cherts consist of silicified radiolarites. The original radiolarite can be seen as a yellow-brown powdery coating on the upper surface of the cherts; it is made entirely of perfectly preserved radiolaria. This unit is distinguished from the underlying Calabazar* Formation by the presence of silicification and absence of black waxy chert. This unit as shown in Pushcharovsky et al. (1988) includes the Maastrichtian Lutgarda Formation. In addition to the abundant radiolarian fauna, it contains Globigerina cretacea sl. and Rotalipora appenninica. It is considered late Cenomanian and Turonian in age. The calcarenites contain an abundant reworked Lower Cretaceous and Upper Jurassic fauna. As suggested by the thickness changes, the weathered appearance of the upper Mata*, the abundant manganese staining at the base of the Lutgarda*, and the regional absence of Coniacian fossils, it is believed to be overlain with disconformity, or slight unconformity, by the Lutgarda* Formation. However, no evidence exists of a shallower-water environment. Lutgarda* Formation. — At the type section, the Lutgarda* Formation consists of 180 ft (55 m) of thinto medium- bedded, heterogeneous calcarenites and calcirudites, bright red and brown chert as beds and nodules, very fine detrital to porcelaneous white limestone, greenish-blue clay, and a characteristic sugarywhite limestone consisting exclusively of small broken rudist fragments, which give it a sparkling crystalline appearance. At the base of the formation, the limestones are strongly stained with manganese, giving them a pink to black color. This unit is shown in Pushcharovsky et al. (1988) as the Maastrichtian Lutgarda Formation. In other outcrop sections, as much as 660 ft (200 m) have been measured, but this extra thickness could be caused by isoclinal folding that, in the Las Villas* belt, becomes common toward the upper part of the section. For the same reason, a question of whether more than one Rudist fragment bed are observed exists. The Lutgarda* Formation is very persistent throughout the Las Villas* belt, but thins southwestward to 20 ft (6 m), across the belt. This thinning results in a spotty outcrop pattern along the southern margin of the belt. The indigenous fauna is very scarce. Only Globotruncana lapparenti sl., Globigerina cretacea sl., and

Pseudorbitoides sp. fragments are found. The very great abundance of rudist fragments suggests that large rudist colonies were living nearby. Other, probably reworked, fossils are abundant such as Cuneolina sp., Coskinolina sp., Dictyoconus sp., Nummoloculina sp., and Dicyclina sp. The age is Santonian through Maastrichtian. This formation appears to grade into the lower – middle Eocene conglomerates of the Sagua* Formation, despite the fact that no Paleocene fauna has been recognized. It correlates with the middle part of the Sagua* Formation in the Sagua la Chica* belt, the Mayajigua* Formation of the Jatibonico* belt and Cayo Coco–Punta Alegre area, and the Remedios* and Palone* formations of the Yaguajay* belt. The Malpaez* Group, therefore, represents a deepwater sequence that ranges from the end of the Aptian to the end of the Cretaceous, and perhaps into the Paleocene, and received progressively increasing amounts of detrital material in the form of turbidites from the carbonate platform to the north. The entire section shows a total lack of silicate clastics. The overlying lower –middle Eocene part of the Sagua* Formation conglomerates represents the culmination of this process. Pszczo´lkowski (1986b) has suggested that the Maastrichtian detrital turbidites were originated by a catastrophic event at the end of the Cretaceous. The Malpaez* Group section indicates that the turbidite deposition was a continuous process of long duration. Sagua* Formation. — This unit is present along the entire length of the northeastern half of the Las Villas* belt, where it is seldom more than 100 ft (30 m) thick and is of lower–middle Eocene age. It thins abruptly across the strike and is either a few feet thick or disappears completely before reaching the southwestern edge of the belt. This formation grades southward into the Camajuani* Formation. Upward, it grades into the overlying San Martin* Formation. Camajuani* Formation. — It is the southern facies of the Sagua* Formation and ranges in thickness from ±20 to 0 ft (±6 to 0 m). It is characterized by a great abundance of black, brown, and red tabular chert clasts derived from the older Malpeaz* Group. Like the Sagua* Formation, it appears to grade into the overlying San Martin* Formation. It is interesting to speculate why the downdip featheredge of the Sagua* Formation would contain such a high concentration of chert. One possibility could be the reactivation of an old source of sediments to the south of the Las Villas* belt, as suggested by the underlying Sabanilla* Formation clastics. Another

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could be the concentration of low-density material, such as silica, at the base of a submarine slope. At any rate, the underlying Calabazar* cherts had to be eroded. Another possibility is that if the cherts were solidified penecontemporaneously with sedimentation in a marly nannoplankton matrix (like chert nodules in chalk), they might have been loosened and reworked by submarine currents. San Martin* Formation. — In the type section, it consists of 220 ft (70 m) of tan, fine to coarse calcarenites with abundant igneous grains. It is interbedded with pebble conglomerates containing abundant chert fragments and with a dull light-gray argillaceous limestone that typically shatters into splinters. The Hatten et al. (1958) name, Gonzal Formation, appears to be synonymous with the San Martin* Formation. As already mentioned, in the Las Villas* belt, as well as in the belts to the north of it, the San Martin* Formation represents the first influx of igneous detritus from the south. It is transitional to the overlying Vega* Formation. The San Martin* Formation contains a rich foraminiferal fauna characterized by Globorotalia sp., Tremastegina sp., Baggina sp., Discocyclina sp., Planorbulina sp., Dyctyoconus sp., and spinose Globigerina sp. Radiolaria are abundant, and coccolithophors and discoasters are rock forming. The age is lower –middle Eocene. This formation is present all along the Las Villas* belt and can reach 1000 ft (300 m) in thickness, although this figure might be tectonically exaggerated. As already mentioned, it is present in the Yaguajay*, Sagua la Chica*, and Jatibonico* belts. Vega* Formation.—At the type section (ChambasTamarindo road, Camaguey) in the southeastern end of the Las Villas* belt (thrusted over the Jatibonico* belt), 3300 ft (1006 m) of this clastic, igneous-derived unit exists. The greatest percentage of fragments is from basic igneous rocks. It is divided into two members, as described below. Lower Member. —The lower member consists of 300 ft (91 m) of calcareous shales, thin-bedded dull-white limestones, and occasional calcareous, igneous-derived sandstones. It is distinguished from the upper member by its calcareous content. Hatten et al. (1958) named the Jumagua Formation, which appears to be synonymous with the lower member of the Vega*. Based on the presence of Truncorotalia cf. aragonensis, Globigerinoides mexicana, and Hantkenina aragonensis, they assign it to the middle Eocene. The unit contains a rich pelagic fossils consisting of foraminifera, radiolaria, and sometimes rock-forming

discoasters and cocolithophors. The age is lower – middle Eocene. This unit is obviously a deep-water turbidite deposit. Upper Member.— The upper member consists of 3000 ft (915 m) of graywacke sandstone, shales, and conglomerates. The sandstones and conglomerates are poorly sorted and commonly thick bedded. The shales are commonly silty and thin bedded. In the coarser conglomerates, the boulders can reach several feet in diameter and commonly consist of various igneous rocks, although limestone and other sedimentary clasts are present. Sometimes, the boulders bleed oil when broken. The general color of the formation is gray when fresh, but the rock weathers to rust brown. The lower part of the upper member is almost exclusively shale and finer grained sandstones, whereas the coarser clastics are toward the top. This member is noncalcareous. The very coarse wildflysch part of the upper member was called by Gulf the Rosas* Formation. This was done because in many instances, it is only the Vega* Formation lithology that can be seen along fault zones. The upper member is essentially barren of organisms except for a few detrital foraminifera and radiolaria. The age is considered lower – middle Eocene because of its stratigraphic position and because it contains fragments of all older units. The Hatten et al. (1958) name, Florencia Formation, appears to be synonymous with the Vega* upper member. The Vega* Formation is certainly included in the Vega Formation in Pushcharovsky et al. (1988), together with the San Martin* and Sagua* formations. It also describes a Senado Formation in the Sierra de Cubitas, which is certainly synonymous with the upper Vega* or Rosas* Formation. The Vega* Formation is widely distributed all along the Las Villas* belt either in synclines or caught in fault planes, where it appears to form the main lubricant. This is especially true in the major Las Villas* fault. For this reason, in addition to poor exposures, it is very difficult to find and measure reliable sections. The Vega* Formation represents a typical flysch deposited in deep waters ahead of the advancing allochthonous basic igneous-volcanic province thrust front. The unit is caught in the deformation and faulting of the more autochthonous units ahead of the thrust plates. As previously mentioned, the Vega* was also deposited over the Yaguajay* (Remedios – Sierra de Jatibonico and Cubitas areas), Sagua la Chica*, and Jatibonico* belts.

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Las Villas* Belt Southern Facies This informal belt forms a narrow band south and adjacent to the Las Villas* belt. It extends for some 45 km (27 mi) from near the town of Camajuani to the town of Iguara´. This belt is lithologically similar to the Las Villas* belt, but is differentiated by the absence of Jurassic and lower–middle Eocene rocks and a slightly different facies in the Maastrichtian. The oldest rocks exposed are a thick (±3000 ft; ±1000 m) development of the Lower Cretaceous Capitolio* and Sabanilla* formations. However, the Sabanilla* Formation is not as characteristically developed, and the conglomerates and detrital limestones do not contain fragments as coarse as in the southern part of the Las Villas* belt to the north. This suggests that the highs responsible for the detritus were linear and relatively narrow as would be expected of fault blocks located between the Las Villas* and the Las Villas* belt southern facies. The succession continues with the Ramblazo* and Calabazar* formations, the last showing an increase in the frequency of red and brown-weathering cherts and shales. The Upper Cretaceous Mata* Formation is occasionally present but not as well developed as in the Las Villas* belt. The Lutgarda* Formation is well represented and apparently thicker than in the Las Villas* belt but has some intervals of the dense, pink porcelaneous limestones found in the Corona* and Amaro* formations of the Placetas* and Cifuentes* belts respectively. In addition, this unit contains a rich pelagic assemblage with Globigerina cretacea sl., Guembelina sp., and Globotruncana lapparenti sl. Little is known about younger rocks. The Sagua* and its equivalent, the Camajuani* formations, are definitely missing because there are scattered occurrences of San Martin* Formation overlying the Lutgarda* Formation. It appears that the lower – middle Eocene was, in large part, not deposited, and whatever was laid down was destroyed by the diastrophism. Central Camaguey Area.—In central Camaguey, the Las Villas* as well as the Cifuentes* belt lithologies outcrop in small faulted windows in the Domingo* sequence, south of the Sierra de Cubitas Yaguajay*. In Pushcharovsky et al. (1988), these lithologies are shown as outcrops of the Esmeralda complex, consisting of detrital and calcarenites, cherts, and argillaceouscalcareous slates of Upper Jurassic through Albian age. The Las Villas* belt lithologies also outcrop in the northern third of the Sierra de Camajan. There, they

are in fault contact with the Cifuentes* belt to the south. In Pushcharovsky et al. (1988), only the Veloz and Carmita formations are shown. The entire feature is surrounded by Domingo* sequence rocks. Northern Cuba Area.—In the Habana and Matanzas provinces, the Las Villas* belt is found only in the subsurface, underlying the basic igneous-volcanic province (see Figure 75). Figure 76 is a correlation chart of the northeastern terrane units recognized in northern Cuba. According to Kuznetsov et al. (1985), who call the Las Villas* (or Mogotes?) belt equivalent the para-autochthonous section, the following units as shown in Figure 77 have been recognized. Upper Jurassic.— Two wells, one in the Boca de Jaruco and the other in the Varadero field, encountered a carbonate and terrigenous section containing Cadosina sp. and Globochaetes alpina that suggests the Francisco Formation. Above this unit are micritic, partially dolomitized, oolitic, and sometimes black limestones with shale partings, which contain Calpionellites darderi, Chitinoidella cubensis, Chitinoidella bermudezi, Favreina sp., Saccocoma sp., Cadosina sp., Calpionella alpina, aptychus, and ammonites and are identified as the Artemisa Formation (A. Pszczo´lkowski [2006, personal communication] considers it an error). Although the measured thickness shown is greater than 4000 ft (1200 m), the real thickness is believed to be not greater than 650 ft (200 m) because of high dips. It should be noted that the Varadero field is the easternmost reported occurrence of terrigenous clastics of Oxfordian age in northern Cuba. This supports the postulated Jurassic age of the exotics in the San Adrian diapir. Cretaceous.—Most of the information on the subsurface is provided by the agencies responsible for drilling for petroleum in Cuba (ICRM, EPEP). They obviously follow the type of geological nomenclature initiated in the former Soviet-era; that is, age determinations based on fossils, not the lithostratigraphic nomenclature used by the U.S. Geological Survey and the Cuban Academy of Sciences. It therefore requires a certain amount of interpretation to correlate the units with the well-established lithostratigraphic sections. Neocomian: — This part of the Lower Cretaceous has been recognized in many wells of the Boca de Jaruco and Varadero fields. Berriasian–Valanginian:—The lower part of the section consists of micritic, cherty limestones with clayey partings correlated with the Sumidero (Capitolio*) Formation. The upper part consists of thin-bedded micritic limestones, marls, and shales that have quartz, feldspars, mica, pyrite, sulfur, and organic matter along

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FIGURE 75. North-central terrane, northern Cuba, generalized geologic map.

the bedding planes. It has been correlated to the Polier (Constancia*) Formation. The fauna consists of Nannoconus sp., Calpionellites darderi, Tintinopsella spp., Calpionellopsis spp., and Remaniella sp. It is estimated to be up to 1300 ft (400 m) thick. Hauterivian–Barremian:—The Hauterivian–Barremian consists of micritic, bituminous limestones with a few shales provisionally considered similar to the Lucas Formation. The fauna consists of Nannoconus spp., radiolaria, aptychus, and ammonites. The Neocomian is believed to be unconformably under the Campanian – Maastrichtian in the Boca de Jaruco, Via Blanca, and Yumuri fields and the middle– upper Paleocene in the Varadero field. Kuznetsov et al. (1985) compares this section to the La Esperanza– Martin Mesa zone, although the considerably reduced thickness, the lesser grade of dolomitization, the smaller quantity of terrigenous material, and the increase in carbonates and cherts indicate a more offshore zone of the miogeosynclinal deposits or to a subzone within the limits of the Las Villas* belt. Aptian–Turonian:—This interval of time is poorly represented, and Kuznetsov et al. (1985) consider it to be only remnants preserved in synclines under the Campanian unconformity.

Aptian–Albian:—The Aptian–Albian interval consists of micritic, cherty limestone containing a fauna of Hedbergella sp., Ticinella sp., Praeglobotruncana sp., and Nannoconus sp. It is equivalent to the Calabazar* Formation. It has been recognized in the Yumuri and Colorados fields, where it reaches 1300 ft (400 m) in thickness. Cenomanian – Turonian: — The Cenomanian – Turonian interval is shown as calcarenite containing Rotalipora sp., Hedbergella sp., and Shackoina sp. It is equivalent to the Calabazar* Formation. It has been recognized only in the Colorados field, where it reaches 2600 ft (800 m). It should be emphasized that the Coniacian and Santonian have not been recognized in northern Cuba. Campanian –Maastrichtian: —The Campanian– Maastrichtian interval consists of up to 1550 ft (470 m) of calcarenites, calcirudites, coarse limestones breccias, calcareous shales, and cherts. The fauna consists of Asatomphalus mayaroensis, Vaughanina cubensis, Globotruncana spp., and orbitoides. It suggests the Lutgarda* Formation and is also similar and coeval to the Amaro* and Cacarajı´cara formations. It is unconformably under the middle–upper Paleocene.

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FIGURE 76. North-central terrane, northern Cuba, correlation chart.

Middle – Upper Paleocene: — The middle – upper Paleocene interval is described as up to 650 ft (200 m) of micritic limestones, calcarenites, marls, shales, and igneous-derived sandstones. The fauna contains Globorotalia velascoensis. This unit is similar and equivalent to the Vega* Formation and the Pica Pica Member of the Manacas Formation. Lower Eocene: — The lower Eocene interval is described as up to 1300 ft (400 m) of an olistostrome complex containing blocks of the underlying limestones, gabbros, serpentine, etc. It contains Globorotalia palmerae, Globorotalia formosa, and Globorotalia rex. It is similar to and correlates with the Rosas* Formation and the Vieja Member of the Manacas Formation.

Las Villas* Belt Discussion The Las Villas* belt shows the most complete sedimentary section in central Cuba. It exposes 3875 ft (1180 m) of Upper Jurassic dominantly shallow-water carbonates, with influx of deeper and/or open-water elements. Conformably over these, the Cretaceous is represented by ±2100 ft (640 m) of lithified nannoplankton and radiolarian oozes interbedded with carbonate bank-derived turbidites. The Neocomian nan-

noplankton limestones are the northern equivalent of southern-derived conglomerates containing Upper Jurassic limestone fragments. The Coniacian and Paleocene have not been recognized. The lower–middle Eocene is represented by at least 3620 ft (1100 m) of detrital sediments, ranging from pure carbonate breccias at the base, shales in the middle, and igneousderived, noncalcareous sandstones and conglomerates at the top. These conglomerates become orogenic megabreccias near the thrusts. It should be noted that no igneous-derived detritus is present in this belt until the lower–middle Eocene, above the Sagua* conglomerate. The rate of sedimentation for the Upper Jurassic is ±260 ft/Ma (80 m/Ma), and its thickness is on the same order of magnitude as in the Yaguajay* belt. However, the rate of sedimentation drops to ±29 ft/Ma (±8.8 m/Ma) for the Cretaceous. This is quite typical of deep-water conditions. For instance, in the Deep Sea Drilling Project Hole-535, drilled in 11,316 ft (3450 m) of water, 1738 ft (530 m) of marly limestones with approximately 35% porosity were deposited in 43 Ma. Correcting for the difference in compaction, one obtains a sedimentation rate of 28 ft/ Ma (8.5 m/Ma).

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FIGURE 77. Stratigraphic section: Las Villas* belt, northern Cuba, subsurface.

The flanks of the Quemado de Gu ¨ ines and Guayabo anticlinoria show a marked stratigraphic asymmetry (Capitolio*-Sabanilla* formations). In view of the fact that (1) their width is on the order of 8 km (5 mi), (2) the dips are in the order of 508, and (3) numerous longitudinal reverse faults exist (dipping both north and south), the original predeformation distance between the two flanks could easily have been between 20 and 30 km (12 and 18 mi). This provides a measure of the rate of the horizon-

tal facies changes that occurred across the Las Villas* belt. In addition, the Yabu window, surrounded by the Cifuentes* belt, is 7.5 km (4.6 mi) southwest of the Guayabo anticlinorium, and the Fidencia anticline is 5 km (3 mi) southwest of the Las Villas* belt and separated from it by the basic igneous-volcanic province. Therefore, the minimum observable width of the belt could have been on the order of 50 km (31 mi). The total displacement of the Las Villas* fault is impossible to estimate.

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FIGURE 78. Central Cuba, Placetas* belt.

Placetas* Belt It has an irregular outline, but in general, has a northwest–southeast trend. It extends from Calabazar de Sagua, through Vega Alta, central Fidencia, north and east of Placetas, disappearing some 16 km (10 mi) to the southeast of Placetas. It reappears again some 10 km (6 mi) farther on to form the core of a 26-km (16-mi)-long canoe-shaped body, the Jarahueca Fenster, with the Jarahueca oil field in its center, south of the town of Jarahueca (see Figure 78). The Placetas* belt was named by Pardo in 1954, and it is part of (1) Hatten et al.’s (1958) Las Villas unit, (2) Ducloz and Vaugnat’s (1962) Placetas zone, (3) Meyerhoff and Hatten’s (1968) Placetas zone, (4) Khudoley and Meyerhoff’s (1971) Las Villas zone, (5) Shopov’s (1982) Cifuentes and Rancho Veloz subzones of the Placetas zone, (6) Dilla and Garcı´a’s (1985) Placetas subzone of the Las Villas zone, (7) Knipper and Cabrera’s (1974) Placetas(?) zone, and (8) Hatten et al.’s (1988) Las Villas unit. In Pushcharovsky et al. (1988), it is part of the Placetas zone. Again, as in the case of the Las Villas* belt, the boundaries of all these belts, zones, and units do not necessarily correspond to each other. The succession can be divided as follows (see Figure 79).

Ronda* Formation This unit has been mapped both in the Placetas* and Cifuentes* belts. It is estimated to be ±1000–

2000 ft (±300 – 600 m) thick, but this figure could be off because of the intense faulting and isoclinal folding commonly present. It consists of thin, platy, bedded limestone and interbedded, thin, yellow and brown calcareous shales. Hatten et al. (1958) describe a Placetas Formation that probably includes the Ronda, but seems to also include several other lithologic units. It is assigned a Neocomian to Cenomanian age. The Ronda Formation is very probably synonymous with the Veloz Formation of many authors, including Hatten et al. (1958) and Pushcharovsky et al. (1988). Some authors (Dilla and Garcı´a, 1985, for example) restrict it to the Berriasian–Valanginian, whereas Pushcharovsky et al. (1988) and others consider it Upper Jurassic through Aptian. Three distinct types of limestones, each with a significant areal distribution, have been recognized. They appear to grade into each other and are as follows: type 1: consists of brown limestone, with slightly wavy laminations of argillaceous, carbonaceous material (somewhat like, but not as pronounced as, in the Capitolio* Formation limestones). type 2: the wavy laminations are absent, and the limestones are uniformly brown. type 3: the limestones are very dark brown to jet black, lack laminations, and have a somewhat coarser crystalline aspect.

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FIGURE 79. Stratigraphic section, Placetas* belt.

Most of the limestones are biomicrites consisting almost entirely of Nannoconus spp. Nannoconus steinmanni is dominant, radiolaria are abundant, and ostracods and ammonite remains are present. Calpionella spp. has been found in the Ronda lithology interbedded with the Jobosi* Formation of the Cifuentes* belt. The age is considered Neocomian and Aptian. The Placetas* belt is characterized by types 1 and 2. In the Placetas* belt, the base of the formation has never been observed, but in the Cifuentes* belt, it grades into and is in part equivalent to the underlying Jobosi* Formation. It is conformable with the overlying

Constancia* Formation. This unit is considered to be correlative with the Capitolio* and Sabanilla* formations of the Las Villas* belt.

Constancia* Formation The Constancia* Formation consists of ±50 ft (±15 m) of brown, sandy, micaceous limestone and limy micaceous quartz sandstone interbedded with yellowtan shales. The sandstones contain abundant mica, some quartz, iron oxide–stained limestone grains, and angular limestone fragments up to 1 cm (0.4 in.) in diameter. These sandstones derive the bulk of their components from metamorphic rocks, as indicated

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by the abundance of muscovite and the presence of tremolite, metamorphic quartz, hornblende, zircon, blue tourmaline, garnet, etc. Although uncommon and badly weathered, some volcanic, mostly basaltic, grains exist. The name Constancia Formation is widely used in the present literature to describe a sandy, arkosic limestone unit underlying the Veloz Formation. It appears to be synonymous with the Jobosi* and has been attributed a Tithonian – Berriassian age. This is the way it is shown in Pushcharovsky et al. (1988). See the comments on the Jobosi-Constancia nomenclature problem under the Jobosi* Formation description for more details. As will be seen below, the source of the abundant metamorphic components, especially muscovite, is puzzling because in the Aptian, the metamorphism of the Escambray massif to the south had not occurred yet, and the known exposed allochthonous preCretaceous basement does not contain muscovite. The fauna consists of Globigerina cretacea sl., Globigerinella sp., Pithonella spp., common radiolaria, and fragments of Orbitolina sp. The Constancia Formation is considered Aptian in age. This unit grades into and is equivalent to the upper part of the older Ronda* Formation. It is partly conformably and partly unconformably overlain by the Carmita* Formation.

Carmita* Formation This unit is probably included in Hatten et al.’s (1958) Placetas Formation, and it is recognized by Dilla and Garcı´a (1985). Unfortunately, because these authors lump the Placetas* and Cifuentes* belts together, they show the Carmita overlying the Santa Teresa Formation instead of being its calcareous equivalent. The thickness of this unit is unknown, but probably is on the order of several hundred feet. It consists of a tan calcilutite to dense slightly argillaceous limestone with abundant secondary nodular black and brown chert. Intervals of thin, flat-bedded primary chert and brown to gray, carbonaceous, and noncalcareous shales with occasional tan dense, nodular limestone stringers exist. The limestones are commonly lightly banded, stained with limonite, and have small, clear, calcite-filled foraminifera and radiolaria arranged in rows parallel to the bedding. At the base of the formation are two recognizable lithologic units, which are described below. Encrucijada* member. — The Encrucijada* member consists of a white, spotted calcarenite with much

clear calcite cement and abundant, angular, creamwhite limestone components, interbedded with brown, nonfissile, thin-bedded shale and reddish brown to brownish gray argillaceous limestone. Bermejal* member.— The Bermejal* member consists of a distinctive limestone conglomerate with conspicuous white and tan angular fragments in a darkbrown carbonaceous limestone matrix. These members were at one time called formations related to the Carmita*. Because of the deformation, the relations between them and the Carmita* Formation are not clear, but they are probably transitional into one another. The fauna of the Carmita* Formation is mostly pelagic and consists of abundant radiolaria, Globigerina cretacea sl., Rotalipora appenninica, Globigerinella sp., Pithonella spp., Schakoina cenomana bicornis, and rare Guembelina sp. Some Nannoconus spp. are present in situ at the base of the formation and are also reworked throughout. The age is therefore considered to extend from the Albian through the Turonian. Some shark remains have been reported and described (Mutter et al., 2005). This formation is equivalent to the Calabazar* and Mata* formations of the Las Villas* belt. The nature of the contact with the overlying Corona* Formation is not clear, but there appears to be a hiatus or a slight unconformity. The Carmita* Formation represents an influx of fine, noncalcareous clastic material and is a transition between beds of equivalent age in the Las Villas* and Cifuentes* belts.

Corona* Formation Other authors do not seem to recognize this unit. In Pushcharovsky et al. (1988), it is probably included in the Amaro Formation of the Placetas zone and assigned a Maastrichtian age. This unit consists of an estimated ±200 ft (±60 m) of an interbedding of 1) gray, medium calcarenite with common green and occasional red and black igneous grains 2) green to yellow-brown calcareous medium to fine sandstones, some with abundant quartz, some with mostly colored volcanic grains 3) pastel green and pink clay shales, sticky in fresh outcrops 4) maroon and brown, thin-bedded primary cherts, some looking like the silicification of the shales 5) argillaceous, very fine, fragmental, soft, maroon limestone

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FIGURE 80. Central Cuba, Cifuentes* belt.

6) pink to light-maroon argillaceous, semiporcelaneous, dense limestone All the above lithologies occur in thin to medium beds, although the calcarenites occur in thick beds or as thick packages of medium beds. The Corona* Formation is unconformably overlain by young Tertiary. Based on its faunal content, it is assigned a Santonian through Maastrichtian age. The Corona* Formation is the southern equivalent of the Lutgarda* and the northern equivalent of the Miguel* Formation. Note that this is the northernmost Upper Cretaceous unit to contain igneous-derived detritus.

Placetas* Belt Discussion The Placetas* belt does not expose rocks older than the lowermost Cretaceous. The reason for this is unknown, but based on the presence of southern-derived conglomerates with Jurassic components in the Las Villas* belt, it is reasonable to assume that the Jurassic was eroded prior to the deposition of the Neocomian. The presence of metamorphic-derived material during the Aptian indicates the erosion of an unknown metamorphic basement. Except for the presence of silicate clastics, the Cretaceous section is very similar to that of the Las Villas* belt, and although thicknesses cannot be accurately measured, they are believed to be on the same order of magnitude as in the Las Villas* belt. In contrast with the Las Villas* belt, there was, in

the Maastrichtian, an influx of igneous detrital material derived from the early orogenic activity to the south. The upper Cenomanian through Coniacian is missing.

Cifuentes* Belt The Cifuentes* belt was named by Pardo in 1954, and it is part of (1) Hatten et al.’s (1958) Las Villas unit, (2) Ducloz and Vaugnat’s (1962) Placetas zone, (3) Meyerhoff and Hatten’s (1968) Placetas zone, (4) Khudoley and Meyerhoff’s (1971) Las Villas zone, (5) Shopov’s (1982) Cifuentes and Rancho Veloz subzones of the Placetas zone, (6) Dilla and Garcı´a’s (1985) Placetas subzone of the Las Villas zone, (7) Knipper and Cabrera’s (1974) Placetas(?) zone, and (8) Hatten et al.’s (1988) Las Villas unit. In Pushcharovsky et al. (1988), it is part of the Placetas zone. Again, as in the case of the Las Villas* belt, the boundaries of all these belts, zones, and units do not necessarily correspond to each other. The Cifuentes* belt outcrops most extensively in Las Villas province; in central Camaguey, the exposures are very limited (see Figure 80).

Las Villas Province Area The bulk of this belt in Las Villas province can be circumscribed by a line running from Coralillo to Rancho Veloz to the southeast, through southwest of Sitiecito, Cifuentes, and swinging back at Loma Bonachea to the northwest, toward Santo Domingo,

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FIGURE 81. Stratigraphic section: Cifuentes* belt, upper (southern) plate. where it disappears under a Neogene cover to reappear southeast of the Motembo oil field. The Cifuentes* belt also can be seen associated with the Placetas* belt, specially rimming the Placetas* belt body in the vicinity of Jarahueca oil field. In the type Cifuentes* belt, near the town of Cifuentes, a stack of three thrust plates has been mapped. The stack is interpreted as a north to south succession of facies, the upper plate being southernmost. Along the strike of the Cifuentes* belt, the number of plates outcropping varies; although all three are present to the northwest, only the upper one is recognizable to the southeast. The units composing

this belt will be described from lower to upper plate. Figure 81 is a composite of the three plates, but is more representative of the upper (southern) plate.

Lower (Northern) Plate Ronda* Formation.— Here, the Ronda* Formation is identical with the brown, with slightly wavy laminations, type 1 described under Placetas* belt. The base is in fault contact with a sliver of basic igneous-volcanic province. It grades upward into the Constancia* Formation. Constancia* Formation.— This unit has the same development as in the Placetas* belt. It grades up into the Encrucijada* Member of the Carmita* Formation.

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Carmita* Formation. — Encrucijada* Member.—It is similar to that described under the Placetas* belt, and it grades laterally into the Santa Teresa* Formation. Santa Teresa* Formation. — Although this unit is considered to be ±500 ft (±150 m) thick, this figure is only an order of magnitude because of the intense folding and faulting. This unit consists of a monotonous succession of thin, 1–2-in. (3–6-cm) flat-bedded red, brown, yellow, gray, and black primary chert interbedded with dark fissile, carbonaceous but sometimes marly or clayey shales of probable volcanic origin. It is mineralized and stained with manganese oxides. This is characteristically a noncarbonate unit. It is a deepwater deposit and received a strong influx of silica and fine detritus from contemporaneous submarine volcanism in the Cabaiguan* sequence to the south. A marked unconformity exists between it and the overlying Amaro* Formation. Hatten et al. (1958) included this unit in the Placetas Formation. The name Santa Teresa appears in much of the present literature. Dilla and Garcı´a (1985) consider it Aptian – Albian. In Pushcharovsky et al. (1988), it is described as above and shown as ranging from the Albian through the Cenomanian. This unit is very poorly fossiliferous, containing only unidentifiable radiolaria and other remains. Because of its stratigraphic relationships, it has been considered to range from upper Aptian through Turonian in age. As already mentioned, it grades laterally into the Carmita* Formation, but it could be equivalent only to the lower part. This is supported by the fact that in some areas, the Carmita* lithology overlies the Santa Teresa*. A marked similarity also exists between the Santa Teresa* and the Huevero* Formation of the volcanic Cabaiguan* sequence to the south. The Huevero* lies immediately under the Cenomanian Gomez* Formation. As will be seen below, the Cenomanian was a time of essentially no volcanic activity in central Cuba and separates an older basic submarine volcanism from younger, more acid, arc volcanics. If the Santa Teresa* Formation is related to volcanism, it should not be of Cenomanian age, but either younger or older. In view of its relationship with the underlying Constancia* and Ronda* formations, and that its lithology suggests an association with submarine instead of arc volcanism, an upper Aptian through Albian age, not younger than lower Cenomanian, is more likely. The Santa Teresa* Formation is very widespread in Cuba, and its lithology has been recognized from

the Pinar del Rio to central Camaguey province (a similar lithology has been reported in Hispaniola). Amaro* Formation.—It consists of ±200 ft (±60 m) of gray, medium heterogeneous limestone with brightgreen igneous grains and small, green clay pellets interbedded with light-gray to white or pink, very dense, porcelaneous, pure limestone with a characteristic network of tiny calcite-filled cracks. It is thickly bedded and, when standing vertically, weathers to a flat but sharply fluted surface that is a distinguishing mark of the formation. The basal part of the formation is a coarse conglomerate made up principally of fragments of chert from the underlying Santa Teresa* Formation and heterogeneous calcarenites containing Jurassic Jaguita* oolites, mollusks (rudists), and other carbonate fragments and igneous grains. In the northern part of the Cifuentes* belt are interbeds of green clay shale. The Amaro* Formation contains a bed, up to 50 ft (15 m) thick, of white, tan, or pink dense limestone, commonly with secondary chert, and characterized by abundant, very small specimens of Guembelina sp. and Globigerina cretacea sl. This bed was formerly referred to as the Macagua* Formation. The name Amaro is widely used in the literature and must be derived from the original Gulf name. Presently, it includes the Rodrigo* Formation and, very likely, the Corona* Formation. In Loma Camajan, central Camaguey, the Camajan Formation is synonymous with Amaro. The Amaro Formation is shown in Pushcharovsky et al. (1988) as 165–1650 ft (50–500 m) of breccias, conglomerates, limestones with components of chert, igneous rocks, and clay of Maastrichtian age in the Zulueta zone. As already mentioned, Pszczo´lkowski (1986b) considers the Amaro* Formation (Amaro* and Rodrigo* formations) a megabed, with a volume of 240 km3 (57 mi3), correlative with the Cascarajı´cara of Pinar Del Rio. He considers them to represent one major turbidite event caused by one large earthquake possibly related to the Chicxulub meteorite impact at the K-T boundary. There is no question about the turbiditic origin, but the correlation with the Lutgarda* Formation, consisting of a large number of turbidite flows interbedded with pelagic sediments ranging from the Santonian through the Maastrichtian, does not support that it was a single depositional event. Perhaps the meteorite triggered a larger flow in an area that was turbidite prone. The Amaro* Formation contains a rich, larger foraminifera fauna, with Sulcoperculina sp., Sulcorbitoides sp., Vaughanina sp., Orbitoides sp., Pseudorbitoides sp., Lepidorbitoides sp., and Dicyclina sp. In addition, abundant Globotruncana lapparenti sl., Globotruncana stuarti,

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FIGURE 82. Central Cuba, Cifuentes* belt basement outcrops.

Globotruncana ganseri, Guembelina spp., Globigerina cretacea sl., and Pithonella spp. are present. This assemblage indicates a Santonian through Maastrichtian age. The mixture of shallow-water and pelagic forms suggest turbidites in open, relatively deep waters. It grades into the overlying Rodrigo* Formation. This unit is correlative with the Corona* and Lutgarta* formations to the north. All three are similar in the sense that they are dominantly detrital biogenic limestones, with closely related faunas, and that most of the components are derived from shallow carbonate banks and deposited in relatively deep waters. However, distinct differences exist, such as textural and bedding characteristics and an increasing influx of igneous-derived material from the south. Rodrigo* Formation. — It consists of ±200 ft (±60 m) of gray to maroon dense, fine, fragmental argillaceous soft limestone with green clay and black carbonaceous inclusions. It is not recognized in the literature. The Rodrigo* Formation contains abundant pelagic foraminifera, among them Globotruncana lapparenti sl., Globotruncana stuarti, Globotruncanella havanensis, Globotruncanella contusa, Globotruncanella ganseri, Globigerina cretacea sl., Rugoglobigerina macrocephala, Globigerinella sp., and Guembelina spp. It also contain Pithonella spp. and Robulus spp. This fauna indicates a late Maastrichtian age. The upper Eocene overlies this unit with marked unconformity.

Middle (Central) Plate. — This plate is identical with the lower (northern) one, except that the Lower Cretaceous Ronda Formation has lost all similarities with the Capitolio* Formation. Here, it consists of typical type 2 brown radiolaria and rock-forming Nannoconus limestones separated by yellow clay intervals. Upper (Southern) Plate. — This plate is characterized by exposing the only known basement of the calcareous sedimentary section (see Figure 82). Basement. —In Las Villas province, one locality exists where the contact between the Cifuentes* belt sediments and basement has been unquestionably observed, near the La Rana village in western Las Villas province. Two other localities show a very probable basement under the sediments, but the contact is tectonically disturbed. These are Sierra Morena and Tre´s Guanos in western and in eastern Las Villas province, respectively. La Rana locality. — About 13 km (8 mi) southsouthwest of the town of Jarahueca is a large outcrop of granodiorite surrounded by Upper Cretaceous volcanics and possibly below a Paleocene conglomerate (Taguasco* Formation) of the volcanic Cabaiguan* sequence. The granodiorite is medium grained and cataclastic and appears similar to several other diorite-granite type of rocks that outcrop in the northern Las Villas province. Patches of serpentine also exist. Over the granodiorite is a granodiorite regolith that grades

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upward into the Jobosi* Formation, the basal conglomerate below the Ronda* Formation. It is a normal sedimentary contact. In view of the presence of Neocomian Calpionella spp. and Nannoconus spp. in the basal Jobosi* Formation, the granodiorite must be pre-Neocomian, possibly Jurassic. The section is nearly horizontal and is allochthonous. It appears to be a large olistolith (or slide block) that perhaps moved during the Paleocene. The presence of this exposure has never been reported in the literature. In Pushcharovsky et al. (1988), an outcrop designated ‘‘Upper Cretaceous granodiorite, etc.’’ is shown at this location but with no indication of overlying Veloz Formation. Tre´s Guanos locality. — At the southeastern end of the Jarahueca area of Placetas* belt exposures are some outcrops of a granodiorite (quartz monzonite) of the same family as the granodiorite at La Rana. Hatten et al. (1958) observed the Quemadito ( Jobosi*) Formation in normal sedimentary contact over the quartz monzonite. Although the relationship is structurally more complex than at La Rana, the Jobosi* Formation is unquestionably present, which is further evidence for a pre-Neocomian age basement. Unfortunately, an age determination of this rock based on the K-Ar method run by Lamont Geological Laboratory on biotite yielded an age of 61 ± 3 Ma. Somin and Milla´n (1981) report a K-Ar determination of 79 ± 5 Ma. This might represent an Upper Cretaceous or early Tertiary overprint and not the true age of the rock. Sierra Morena locality. — About 10 km (8 mi) southsouthwest of the town of Sierra Morena (Socorro, Can ˜as River, Coralillo) is a cataclastic pegmatitic granite associated with marble and patches of serpentine, Jobosi* and type 3 Ronda* formations. The outcrops cover an area of some 12  3 km (7.5  1.8 mi). These units appear to lie in a complex structure surrounded by the Upper Cretaceous of the Cifuentes* belt. Pszczo´lkowski (1983, 1986b) mapped the area in some detail. He interprets the granite as a window through the Cifuentes* belt. The granite and associated outcrops coincide with the strongest Bouguer gravity low of the island (Gulf’s gravity survey), which lends strong support to their being allochthonous and not deep rooted. This basement has been named the Socorro complex (Renne et al., 1989a, b; Iturralde-Vinent, 1996). The analyses of four samples of the granite (Somin and Milla´n, 1981; Renne et al., 1989a, b), dated by whole rock K-Ar method, yielded 142 ± 3, 150 ± 5, 139 ± 6, and 140 ± 2 m.y. The U-Pb method gave the intrusion age of zircons at 172.4 m.y. and the K-Ar age deter-

mination on the marble phlogopite gave the intrusion age at 910 ± 25 and 945 ± 20 m.y. The original limestone is therefore older, suggesting a Precambrian basement affected by a Kimmeridgian–Tithonian magmatic intrusion. Jobosi* Formation.—The Jobosi* Formation consists of ±50 ft (±15 m) of quartz granule to pebble-size conglomerates, sandstones, and siltstones containing abundant fragments of type 3 Ronda* Formation. In addition to Ronda*, the conglomerates have components of quartz and granodiorite, as well as grains of serpentine, sericite schist, and porphyry. The sandstones and conglomerates are interbedded with and grade up into the type 3 black Ronda* Formation limestones. At La Rana, where the lower contact is the best exposed, it grades down into a granodiorite regolith. Hatten et al. (1958) named the Quemadito Formation in Tre´s Guanos, which, by the description, is obviously synonymous to Jobosi*. It should be noted that these authors assign it to the Upper Jurassic, although it has the same type locality and fauna as Jobosi*. My personal opinion is that where it was observed, it is of Neocomian age, but it could very well extend into the Upper Jurassic at other localities. This difference in age assignment and the fact that in some early Gulf reports there was a question whether the Constancia* Formation was the Jobosi* lateral equivalent, have created some confusion in the literature. Some authors have used the name Constancia as a synonym to Jobosi*; Kantchev et al., (1976) and Pushcharovsky et al. (1988) show this unit as the Tithonian– Berriassian Constancia Formation of the Placetas zone, consisting of polymict and arkosic sandstones and sandy limestones underlying the Veloz Formation. Other authors, including Dilla and Garcı´a (1985), used the names Quemadito (Jobosi*) and Constancia as two different units in their original sense. The interbedded type 3 Ronda Formation contains Calpionella spp., radiolaria, and Nannoconus spp., including Nannoconus steinmanni, which are rock forming. The age of the upper part of the formation is considered Berriassian, whereas Tithonian ammonites have been found within the formation (Shopov, 1982). Foraminifera (Globuligerina sp.) of questionable Oxfordian age have been reported (Pszczo´lkowski and Myczynski, 2003). In addition to La Rana, this unit is found in Tre´s Guanos and Rancho Veloz. The Jobosi* Formation must have formed under unique conditions. The granodiorite regolith, with its altered feldspars, indicates weathering of the granodiorite. However, the interbedding with the

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type 3 Ronda* Formation, consisting mostly of nannoplankton, and the nannoplankton in the matrix of the conglomerates indicate deposition in deep, anoxic water. In addition, the presence of black Ronda* fragments, showing no sign of prediagenetic deformation or weathering, suggests that an appreciable thickness of Ronda* was already deposited and at least partially consolidated before its erosion and redeposition, together with granodiorite fragments, in a deepwater environment. This strongly suggests deposition at the base of a very active fault scarp such as in the Upper Jurassic–Lower Cretaceous rifts of west Africa (Lucula-Bucomazi of Cabinda). Similarly, the lack of Jurassic carbonate components in the conglomerates suggests that the Ronda* Formation was deposited on a granodiorite basement after previous erosion of the limestones, or that Jurassic carbonates were never deposited in the area. If the Oxfordian age was confirmed, the latter case would be likely. Ronda* Formation. — In the southern plate, this formation contains only the dark-gray to black type 3 limestones. Good evidence of the pre-Santonian unconformity exists because the Ronda Formation can be overlain by the Maastrichtian Amaro* Formation or separated from it by a much reduced section of Santa Teresa* Formation. Vega Alta Formation.—Pushcharovsky et al. (1988) show a Vega Alta Formation in the Placetas zone that consists of 820–980 ft (250–300 m) of a chaotic complex containing blocks of limestones, serpentinite, and volcanics in a sandy and argillaceous matrix of Paleocene–Eocene age. Although this description suggests the Upper Vega* Formation (Rosas*), Gulf never found any Eocene sediments associated with the belts thought to be equivalent to the Placetas zone (Placetas* and Cifuentes* belts). The absence of Eocene sediments in these belts was considered one of their important features. This was odd because the Vega* Formation was recognized over the Cabaiguan* sequence. From its distribution on the map, the Vega Alta Formation appears to be what Gulf mapped as a complex tectonic mixture (folded and faulted imbrications, olistostromes) of components from the Cifuentes*, Placetas*, Domingo*, and Cabaiguan* sequences, and in places, a Maastrichtian brown shale called the Miguel* Formation (see Domingo* sequence) that appears to underlie the Domingo* sequence. These complexly deformed areas include rubble zones and calcite mesh (ophicalcites). Although the deformation that brought about this tectonic mixture is certainly of lower–middle Eocene age, in the true sense, it was not considered a sedimentary deposit.

Central Camaguey Area In the central Camaguey area, the lithologies of the Cifuentes* belt can be found southwest of the Sierra de Cubitas in small areas surrounded by serpentine. They also outcrop in the southern half of the Sierra de Camajan. They are shown as part of the Esmeralda complex in Pushcharovsky et al. (1988). Sierra de Camajan Locality. —At the Nueva Maria quarry, Iturralde-Vinent and Morales (1988) describes a sedimentary contact between the strongly folded Veloz (±Ronda*) Formation and an underlying sequence of tholeitic basalts (see Figures 82, 83). Nueva Maria Formation. — This unit consists of more than 203 ft (62 m) of interbedded black and gray amygdular pillow basalts, black and gray cataclastic obsidian, and dark-gray laminated tuffs. The chemical composition of the basalts is similar to that of oceanic tholeites. The tuffs contain radiolaria, calpionellids, and molds of small ammonites of a middle Tithonian age. These basalts yielded a K-Ar age of 146 ± 6 Ma. Veloz (Ronda*) Formation. — The Veloz Formation is essentially synonymous with the Ronda* Formation. In this locality, the basal part of the Veloz Formation is conformable over the Nueva Maria Formation and contains thin tuffs and glassy laminae interbedded with the fine-grained limestone biomicrites. The Veloz contains the same middle Tithonian fauna as the Nueva Maria Formation. The entire sequence is allochthonous. This locality is the only one in central Cuba where a carbonate belt is seen in normal stratigraphic contact with the basic igneous-volcanic province, with the type 3 dark-gray to black Ronda overlying the Nueva Maria Formation. As will be seen later, pillow basalts are commonly associated with the deep-water carbonates of the northern Rosario belt in the southwestern terrane of Pinar del Rio. This unit, in turn, is overlain by the Santa Teresa, Carmita, and, separated by a Coniacian – Campanian hiatus, the Amaro formations. Only the Veloz and the Carmita formations are shown in Pushcharovsky et al. (1988).

Northern Cuba Area According to Kuznetsov et al. (1985), the rocks assigned to this belt can be subdivided into two superimposed allochthonous miogeosynclinal thrust plates (not necessarily correlative with those observed in Las Villas area) (see Figures 75, 84). Lower Plate.— The lower plate is recognized in Cantel and Camarioca fields.

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FIGURE 83. Stratigraphic section: Cifuentes* belt, Loma Camajan.

Aptian–Albian.—The Aptian–Albian unit consists of up to an apparent 2755 ft (840 m) of limestones, sometimes dolomitized, and cherts with shales, possibly corresponding to the Ronda* and Santa Teresa* formations. The fauna contains Nannoconus sp., Ticinella sp., Schackoina sp., Hedbergella sp., Pithonella sp., and Globigerinelloides sp. The thickness is certainly structurally exaggerated. Campanian – Maastrichtian. — The Campanian – Maastrichtian unit consists of between 150 and 650 ft (50 and 200 m) of siltstones, sandstones, and calcarenites containing Globotruncana spp., Sulcoperculina sp., Vaughanina sp., and Pseudorbitoides sp. This

unit suggests the Corona* and Rodrigo* formations of the Placetas* and Cifuentes* belts, although it appears to contain a higher percentage of silicate clastics. Upper Plate. — The upper plate is recognized in Varadero, Camarioca, and Guasimas fields. Aptian – Albian. — The Aptian – Albian unit consists of rocks identical with those of the lower plate: up to an apparent 2000 ft (600 m) of limestones, sometimes dolomitized, and cherts with shales, possibly corresponding to the Ronda* and Santa Teresa* formations. The fauna contains Nannoconus sp., Ticinella sp., Hedbergella sp., and Globigerinelloides sp.

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FIGURE 84. Stratigraphic section: Cifuentes* belt (upper and lower plates), northern Cuba, subsurface.

Cenomanian –Turonian. — The rocks representing this interval of time have not been recognized in the lower plate and consist of up to 1650 ft (500 m) of polymict sandstones and siltstones interbedded with limestones containing Globotruncana sp., Rotalipora sp., Schackoina sp., and Hedbergella sp. This section containing abundant coarse clastics has been recognized in a few wells and appears to be in part equivalent to the Santa Teresa* or Carmita* formations, but (barring structural complications) has greater af-

finity with rocks of the same age in the La Esperanza belt of western Cuba and not the Cifuentes* belt. Campanian – Maastrichtian. — The Campanian – Maastrichtian unit consists of up to 2600 ft (800 m) of arkosic sandstones and gravels, occasionally with anhydrite(!), containing Pseudorbitoides sp. It is unfortunate that no better description of this unit is available; the anhydrite could be related to that of the San Adrian diapirs, and if the arkosic sandstones and gravels are in place in the Cifuentes* belt, it could indicate

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a Late Cretaceous erosion of nearby allochthonous granodiorite highs such as the Sierra Morena of central Cuba. Upper Paleocene – Middle Eocene. — The Upper Paleocene–Middle Eocene unit consists of up to 1650 ft (500 m) of shales, siltstones, sandstones, and conglomerates, as well as an olistostrome-containing gabbro and serpentine. This section is reported to contain Globotruncana spp., Sulcoperculina sp., and Vaughanina sp., which is the reason for the assignment to the Campanian–Maastrichtian by Kuznetsov et al. (1985). In my opinion, this section is very suggestive of the younger Vega* and Rosas* formations or the Pica Pica and Vieja Members of the Manacas Formation of upper Paleocene–middle Eocene age (see the following Cifuentes* belt discussion). This same section has been found toward the east in Guasimas, Cardenas, and Camarioca.

Cifuentes* Belt Discussion This belt represents the southernmost part of the miogeosyncline, with minor influences from volcanism (clay and cherts), and the deepest and most anoxic depositional conditions. This is the only belt where basement, although allochthonous, is exposed. This belt was the farthest away from the North American margin and was deposited on granodiorite and tholeites; it is therefore considered the most oceanic of the carbonate belts. As in the Placetas* belt, the thicknesses cannot be measured, and the Tithonian dolomites and oolitic limestones are absent; however, the base of the pelagic carbonates has been considered uppermost Jurassic in places. The Cretaceous sediments that compose this belt are the most extensive in Cuba, having been recognized from the Pinar del Rio to central Camaguey. This belt is also characterized by having most of the Turonian–Santonian missing, although no evidence of a subaerial unconformity exists. Although the area where this belt was deposited was originally the most remote from the carbonate banks, it nevertheless received from them a considerable amount of turbiditic material during the Maastrichtian. In the northern Las Villas province, outcrops of similar diorite-granite igneous rocks have been included in the igneous Domingo* sequence. These show cataclastic alteration. In the field and under the microscope, they are practically indistinguishable from the Manicaragua and southern Camaguey province intrusive bodies that, from field relationships and K-Ar, have been dated as ±85 m.y. of age or Coniacian–Santonian. Presently, no report exists on the ages of most of these bodies. They could be late

intrusions associated with the Cretaceous volcanism or an older Jurassic basement mechanically incorporated in the ultrabasics through tectonism. However, the presence of granodiorite and marbles of possible Precambrian age (±925 m.y.) affected by an Upper Jurassic (±145 m.y.) thermal event and the tholeitic basalts of Upper Jurassic age underlying the Ronda* (Veloz) Formation in normal sedimentary contact suggests that the Precambrian basement of the North American continental margin was fragmented and invaded by oceanic rift basalts during the Middle and Upper Jurassic. Other evidences of Late Jurassic – Early Cretaceous rifting exist, such as the presence of the Sabanilla* and the Jobosi* formations with southern local sources of detritus. An important difference of opinion exists between Hatten et al. (1958, 1988), Meyerhoff and Hatten (1968), and Meyerhoff (in Khudoley and Meyerhoff, 1971), on the one hand, and myself, on the other, on the present position of these basement outcrops. Although I agree that they could represent remnants of a ridge that might have separated the miogeosyncline from the eugeosyncline, I interpret them as the most allochthonous elements of the sedimentary basin, the basement of the highest sedimentary plate below the ophiolite obduction. However, these authors consider them as the relatively autochthonous (nothing is totally autochthonous in Cuba) basement of Meyerhoff’s ‘‘median welt.’’ Drilling. —Several wells have been drilled in the Las Villas*, Placetas*, and Cifuentes* belts. Gulf Hicacos-1. — This was drilled in northeastern Cardenas Bay in 1949 by Cuban Gulf (Gulf Oil). It penetrated the Las Villas* belt at 2290 ft (698 m) to the total depth at 5045 ft (1538 m) below an Eocene to Holocene cover and was cut by a major fault at 4030 ft (1229 m), bringing the lower–middle Eocene (Sagua* or Vega*) under the Upper Jurassic Caguaguas* Formation. Texaco Guayabo-1. — This was drilled by Texaco in the Guayabo anticlinorium, 2.5 km (1.5 mi) southwest of the Las Villas fault. One of the main objectives was to drill through the fault into the underlying Yaguajay* belt; this objective was not reached, indicating that the fault is steeper than 508. The following section was drilled: 0– 103 ft (0 –31 m): alluvium. 103 –183 ft (31 – 56 m): Caguaguas* Formation. 183 –2910 ft (56 – 887 m): Jaguita* Formation. 2910 ft (887 m): Reverse fault.

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2910–3060 ft (887–933 m) Calabazar* Formation. 3060–3292 ft (933–1004 m): Ramblazo* Formation. 3292 – 5760 ft (1004 – 1756 m): Capitolio* Formation. 5760 – 5940 ft (1756 – 1811 m): Caguaguas* Formation. 5940 to total depth at 10,010 ft (1811 to total depth at 3052 m): Jaguita* Formation. The Hoyo Colorado* Formation was not reported, but it is believed to be present under the Jaguita*. The moderate to high dips average 508 to the southwest. The Jurassic has porosities of up to 10%. Tar (18-58 API) shows were present throughout the section, mostly in fractures, and 6 gal of tar were collected in a test between 7488 and 7700 ft (2283–2348 m). Boca de Jaruco – Via Blanca: — These fields are along the north coast between Habana and Matanzas. The following section is interpreted from scout information provided by Petroconsultants (1990, personal communication). 0 ft (0 m): Middle Eocene and younger overlap. ±2550 ft (±780 m): Cabaiguan* sequence consisting of the Maastrichtian Pen ˜alver and possible Via Blanca formations. ±3200 ft (±980 m): Domingo* sequence consisting dominantly of serpentine (only to the south of the field). ±4660 ft (±1420 m): Major thrust under the Domingo* sequence to the south and Cabaiguan* sequence to the north. ±4660 ft (±1420 m): Cifuentes* belt, where the Ronda*, Santa Teresa*, Carmita*, and Amaro* formations are represented in a very complex, chaotic, and structural situation. ±6560 ft (±2000 m): Major thrust, with slivers of Vega* and Rosas* formations caught along the thrust plane overlying the Campanian – Maastrichtian Lutgarda formation. ±6560 – 11,940 ft (±2000 – 3640 m): Strongly deformed and fractured (60 –908 dips) Las Villas* and/or southern Rosario belt, with a unit similar to the Oxfordian Francisco Formation, with quartzose clastics at the base, overlain by the Jagu ¨ita* and Caguaguas* (equivalent to the Artemisa Group), and the Capitolio*, Ramblazo*, and/or Constancia formations (equivalent to the Polier Group). This subsurface section is very important as it proves the structural superposition of the Cabaiguan*, Domingo*, Cifuentes*, and Las Villas* belts.

Varadero – Varadero Sur – Marbella – Marbella Mar – Cantel – Chapellin – Guasimas: — These fields rim the northwest of Cardenas Bay, near Hicacos-1, and a representative section (Varadero) encountered is as follows: 0 to ±2130 ft (0 to ±650 m): Middle Eocene and younger overlap. ±2130 ft (±650 m): Aptian to Maastrichtian Cifuentes* belt section. ±4530 ft (±1380 m): Major thrust fault. ±4530 – 8200 ft (±1380– 2,500 m): The Oxfordian to Valanginian part of the Las Villas* belt section is overlain by the lower middle Eocene Vega* and Rosas* formations. Note that the Oxfordian to Valanginian part of the section correlates with the pre-Eocene of the Gulf Hicacos-1 well.

Jurassic Platform to Cretaceous Deep Basin Province Discussion The part of the depositional basin represented by the Las Villas* and possibly the Placetas* and Cifuentes* belts accumulated shallow-water carbonates during the late Kimmeridgian through the middle Tithonian up to a thickness of at least 2100 ft (640 m) of sediments. Near the close of the Jurassic, there must have been an increase in the rate of subsidence south of the Yaguajay* belt because carbonate bank sedimentation did not keep pace with the deepening of the basin. There might have been other factors preventing the continuation of the buildup of these banks, such as changes in oceanic circulation brought about by the widening of the rift between North and South America. Sedimentation continued under deep-water (oceanic?) conditions during the entire Cretaceous to the middle Eocene. This sedimentation consisted mostly of calcareous nannoplankton during the Neocomian and Aptian. From the Albian through the Turonian, increasing amounts of silica were present in the form of radiolaria and volcanic-derived material. It should be noted that the change from Capitolio* and Calabazar* to type 3 Ronda* and Santa Teresa* indicates an increase in anoxic conditions. The increase in cherts indicates a deepening through the carbonate compensation zone. A total of not more than 2400 ft (730 m) of pelagic carbonates and cherts were deposited in deep waters from the upper Tithonian through the Cretaceous.

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During the same interval of time, some 9000 ft (2750 m) of shallow-water carbonates were deposited on the carbonate platform, suggesting that in the Las Villas* belt, the water depth was more than 6000 ft (2000 m) by the Late Cretaceous. Initially, the rate of basement subsidence under the carbonate platform would have been equal to that under the basinal sediments. As sedimentation continued, basin subsidence must have been much greater than under the banks. During the Neocomian through Aptian, the basin must have been broken by horsts and grabens, as indicated by the localized presence of coarse detrital material apparently deposited in deep water. There are clasts of Upper Jurassic and Neocomian carbonates derived from the south in the southern Las Villas* belt and pre-Neocomian metamorphic and granodiorite detritus of local origin in the southern Cifuentes* belt. From the Aptian onward, an increasing contribution of fine to coarse material was apparently derived in large part from the carbonate banks to the north and deposited as turbidites interbedded with pelagic deposits. The increase in amount of radiolarian cherts indicates a great deepening of the water. Through the Campanian and Maastrichtian, turbidites derived from the north dominated the sedimentation. However, at the same time, toward the south, erosion and redeposition of the Santa Teresa* cherts and the presence of igneous-derived material in the Amaro* Formation indicated early orogenic activity there. In the lower –middle Eocene, the northern half of the basin continued to receive the Sagua* Formation detritus from the carbonate banks, together with those derived from the early deformation and faulting of the Yaguajay* and Las Villas* belts. Finally, the Eocene San Martin* and lower Vega* formations reflect the proximity of the advancing basic igneous-volcanic province thrust sheet. The erosion off that sheet culminated with the deposition of the wildflysch of the upper member of the Vega* (Rosas*) Formation. The entire deep-water nature of this basin is remarkable. Despite the possibility of a Coniacian and Paleocene hiatus, the presence of reworked intraformational detritus, and the direct evidence of unconformities, no indication of deposits of shallow-water origin exist other than turbidites. The possibility of submarine erosion on a regional scale has to be considered because subaerial erosion is unlikely. As has already been mentioned, the entire deep-water Upper Jurassic and Cretaceous section has great lithologic and faunal affinities with the Tethys, suggesting a direct connection with the Tethyan Mediterranean, es-

pecially if one considers the dissimilarity with sections of equivalent age in North and South America. Finally, it should be emphasized that all the contacts between Las Villas*, Placetas*, and Cifuentes* belt deep-water lithologies and those of the basic igneousvolcanic province are tectonic. It is important to attempt an estimate of the original width of the basin in which the sediments of the Las Villas*, Placetas*, and Cifuentes* belts were deposited. As previously mentioned, the Las Villas* belt could have been 50 km (31 mi) in width; the Placetas* belt could have been some 5–10 km (3–6 mi), and the Cifuentes* belt, considering the three plates, could have been some 15–20 km (9–12 mi). Therefore, the basin was a minimum of about 70–80 km (43–49 mi) wide. This distance is only the present estimated original width of the belt’s outcrops without allowing any distance for the facies to change from belt to belt. Arbitrarily, one could allow another 70 km (43 mi) to take care of the overriding of the thrust sheets and the facies changes from belt to belt. As will be described below, large outcrops of Ronda* and Jaguita* formations along the Tuinicu fault exist between the Cabaiguan* sequence and the Manicaragua granodiorite, 25 km (15 mi) south of the southernmost exposure of the carbonate belts. The basin width before deformation could, therefore, have been close to 150 km (93 mi). Intuitively, this distance is on the low side because the type of sediments in these belts suggests the scrapings, or remnants, of a much larger, deep-water, perhaps oceanic, basin. In La Habana and Matanzas, this province has been found only in wells and as far west as the Via Blanca field. Because of serious structural complications, thicknesses are only estimates. Despite problems with the published descriptions of the formations, some important points can be made: 1) The belts are continuous from central Cuba to western Cuba, with the Las Villas* belt (equivalent to the northern Rosario and possibly the Mogotes area) being the lowermost penetrated sheet. 2) The presence of Upper Jurassic Favreina sp. and Globochaetes alpina indicates that, during that time, shallow-water conditions existed uninterruptedly from central to western Cuba, suggesting a continuous basin, with evidence that in the Oxfordian, clastic sedimentation extended east as far as the Cardenas Bay, possibly extending farther east toward the Punta Alegre area (supporting the Jurassic origin of the exotics in the San Adrian and Punta Alegre formations).

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3) As in the rest of Cuba, the Late Jurassic and all of the Cretaceous were times of marked deepening of the basin, shown by the influx of nannoplankton. 4) The Aptian–Santonian appears to be less well represented than in other Cuban regions, and the Coniacian–Santonian has never been identified. 5) The Campanian–Maastrichtian is, like everywhere else in Cuba, characterized by carbonate detritus; however, in the subsurface upper plate of the Cifuentes* belt, there is a reported influx of terrigenous arkosic detritus suggesting the proximity of southern granitic highs, possibly similar to allochthonous Sierra Morena or La Rana, that has never been observed on outcrops—perhaps it belongs to another part of the section. 6) There is no report of middle Eocene carbonate conglomerates such as the Sagua* Formation, indicating that the Bahamas-type carbonate banks were farther away from the Las Villas* belt than in central Cuba. 7) Terrigenous flysch deposits derived from the destruction of the basic igneous-volcanic province characterize the upper Paleocene–middle Eocene, and culminate in the middle Eocene showing the chaotic wildflysch of the Rosas* Formation and Vieja Member of the Manacas Formation.

SOUTHWESTERN TERRANES This province is found in the Guaniguanico Mountains, the Escambray Mountains, the Isla de la Juventud, and as far east as the Asuncion area in Oriente. The southwestern terranes do not show as clear a continental margin succession of facies as do the northcentral terranes. They show, to a greater or lesser extent, a succession of facies that include silicate clastics, bank carbonates, and deep-water pelagic environment. For convenience, they can be generally subdivided into metamorphics and unmetamorphosed sediments. The unmetamorphosed rocks occur in the Guaniguanico Mountains, whereas the metamorphics are found along the southeastern edge of the Guaniguanico Mountains (along the Pinar fault), the Isla de la Juventud, the Escambray massif in central Cuba, and Asuncion in extreme eastern Cuba.

Nonmetamorphics Guaniguanico Mountains Because of the spectacular exposures, Pinar del Rio has historically received more attention from the geo-

logic community than central Cuba. As a result, the discussion here will be based heavily on the published literature, especially on the work of Andrzej Pszczo´lkowski, with references to Gulf’s or other works when pertinent. Several units were first described and named by DeGolyer (1918), Lewis (1932), and Palmer (1945). As in central Cuba, these units turned out to cover a larger time span and may be more complex than originally thought. Although western Cuba was not mapped in detail by Cuban Gulf, P. B. Truitt conducted extensive reconnaissance during 1955–1956, in which he established the basis for the presently used structurofacies zones nomenclature and resolved much of the structural and stratigraphic confusion that existed at the time. It should be noted that one of the important aspects of Truitt’s work is that it was done after the bulk of Gulf’s work in central Cuba had been conducted, and Truitt had been one of the main participants in that study; he was therefore ideally suited to compare the two areas. His regional correlations are still valid (central Cuba names such as Carmita and Santa Teresa formations are presently widely used in Pinar del Rio). In addition, the samples were described, and their fauna were identified by P. Bro ¨ nnimann’s laboratory. During the late 1950s, C. W. Hatten mapped the central part of the Sierra de los Organos, and much of the present structural and stratigraphic concepts and terminology of the area are based on his 1957 California Co. unpublished reports, nationalized by the Cuban revolution. He recognized several peel nappes and identified what is still believed to be the most autochthonous of all the exposed structural elements: the pons autochthon. Since 1970, a team of geologists from the Polish Academy of Science has been involved in mapping and working out the details of the stratigraphic sequences of this area, notably among them A. Pszczo´lkowski, K. Piotrowska, and J. Piotrowski. R. Myczynsky (1987a, b), Myczynsky and Brochwicz-Lewinski (1981), and Myczynsky and Pszczo´lkowski (1987) studied the Ammonite fauna. Consequently, and unlike other areas in Cuba, much has been recently published on Pinar del Rio. In the last several years, Pszczo´lkowski (1999) has made some important and needed revisions to the published nomenclature. The revised nomenclature is used here. As will be seen below, although very important information can be derived from this region, the distribution of exposures and the structural complexities make it very difficult to reconstruct the geologic history from these data alone.

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In contrast with central Cuba, western Cuba has a thick and extensive section of Jurassic and Cretaceous continentally derived clastics, and the Cretaceous carbonate platform is poorly represented. In general, western Cuba has not suffered as much from the nomenclatural nightmare that has afflicted central Cuba, but problems remain. Truitt (1956a, b), the first to use the concept of belts in Pinar del Rio, subdivided the province into the sedimentary Organos*, Rosario*, and Cacarajı´cara* belts and the basic igneousvolcanic Bahia Honda* belt. Pardo (1975) used the same nomenclature. In addition, Truitt named an informal unit: the ‘‘northwestern Rosario* belt,’’ that was also recognized by Hatten (1957), who named it ‘‘La Esperanza.’’ This terminology is, in large part, still in use today, although it has been modified, enlarged, and further subdivided. Pszczo´lkowski (1999) recognizes four facies-tectonic zones: La Esperanza (which is equivalent to Truitt’s northwestern Rosario*), Bahia Honda, Cordillera de Guaniguanico, and Los Palacios Basin. The Cordillera de Guaniguanico is subdivided into Sierra de los Organos, Cangre, northern Rosario, southern Rosario, and Guajaibon-Sierra Azul belts as major subdivisions and a large number of smaller tectonic units. Each one of the smaller units is a separate thrust sheet with a characteristic stratigraphic sequence. The Guajaibon-Sierra Azul belt is equivalent to Truitt’s Cacarajı´cara* belt. Pushcharovsky et al., 1988, show the Bahia Honda, Sierra del Rosario, Sierra de los Organos, La Esperanza and Cangre facies-structural units, and the Los Palacios Basin. The Cangre unit is the metamorphosed southern part of the Sierra de los Organos belt (along and northwest of the Pinar fault), and the lower part of the mostly younger Tertiary Los Palacios Basin is synonymous with Truitt’s southern Bahia Honda* belt. Unfortunately, a serious nomenclatural problem exists: Truitt’s original Rosario–Los Organos belt subdivision was more physiographic than structurostratigraphic and only partially follows the Pardo ‘‘belt’’ or Hatten-Meyerhoff’s ‘‘faciesstructural unit’’ definition (in 1957, Hatten did not use facies-structural units in Pinar del Rio). As will be seen below, from a structural and facies point of view, a large part of the outcrops included by Truitt and others in the Los Organos belt really do belong to the Rosario belt. In this study, an attempt will be made to use a facies-structural nomenclature without creating unnecessary confusion. With the exception of Sierra de los Organos, the names used will be the same as the ones presently used in the Cuban literature or on maps and will be modified to consistently reflect

the structure and stratigraphy. For the sake of uniformity, the major stratigraphic-structural subdivisions will be named ‘‘belt,’’ and because of the structural complexity, the term ‘‘unit’’ will be used for groups of strata that belong to one individual thrust sheet. The names of the major subdivisions used by Pszczo´lkowski (1999) will be used throughout; however, Pszczo´lkowski’s subdivisions (which he calls ‘‘belts’’ but others call ‘‘facies-structural zones’’) will be modified as follows: The Sierra de los Organos belt will be subdivided into the Mogotes area: all the units of the Sierra de los Organos belt minus the Alturas de las Pizarras del Sur unit the Alturas de las Pizarras del Sur area: the Alturas de las Pizarras del Sur unit As will be seen later, the Mogotes area is a window through a thrust sheet of San Cayetano Formation that is partially included in the southern Rosario belt. So far, there is some evidence that the maximum thickness of San Cayetano does not coincide with the thickest Mogote belt carbonates. It appears as if the San Cayetano depocenter was south (restored position) of the Mogotes carbonates depocenter. Figure 85 shows the correspondence of the several nomenclatural systems used in western Cuba. The distribution of the major stratigraphic-structural subdivisions is shown in Figure 86. Figure 87 is a pre– upper Eocene correlation chart of the northwestern terrane units in western Cuba. Pinar del Rio is the area where the Cuban orogen extended between the Bahamas and Yucatan platforms, and consequently, much of the section younger than Late Jurassic consists of rocks originating in a deepwater environment. Here, many authors assume that the general thrusting must have occurred northward toward the deep-water facies of the southern Gulf of Mexico; however, contradictions exist. Truitt (1956a, b) was convinced that the thrusting was directed southward. In Pinar del Rio, it is difficult to establish a natural basinal succession on account of the apparent opposing directions of thrusting or nappe emplacement and the lack of a well-defined continental margin to the north. As will be seen below, some remnants of carbonate banks exist, caught in the thrusting, in the northwestern as well as the central part of the province. These suggest a partial shallow-water link between the Bahamas and Yucatan or perhaps small shallow-water banks surrounded by a deep-water environment (similar to the eastern end of the Bahamas).

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Although the tectonics will be discussed in Chapter 5 of this publication, most authors (Hatten, 1957; Rigassi-Studer, 1963; Piotrowska, 1975, 1978; Pszczo´lkowski, 1971, 1977, 1994a, 1999) agree that (1) part of the section present in the north of the Los Organos region has been displaced northward and thrust over the La Esperanza belt; (2) the southern and lower part of the section of the Los Organos region has also been thrust northward over the carbonates that form the core of the same region; and (3) the Rosario belt is the lateral equivalent of the La Esperanza belt and also of the northern part of the Rosario belt, which has been thrust over the rocks in the Los Organos region. The present general opinion (first published by Iturralde-Vinent, 1994) is that all major thrusting was directed northward and that the basic igneousvolcanic Bahia Honda belt originated south of the sedimentary belts. Regardless, the thrusting directions in Pinar Del Rio have been the subject of much discussion. The major belts that form most of the exposures of the Cordillera de Guaniguanico will be described in the following order: (1) Gujaibon – Sierra Azul, (2) northern Rosario belt, (3) La Esperanza belt, (4) southern Rosario belt, and (5) Sierra de los Organos belt that, in this study, has been subdivided into the Mogotes and the Pizarras del Sur (including Cangre) areas. As will be discussed below, this is not necessarily the original depositional order.

FIGURE 85. Western Cuba belt nomenclature.

Guajaibon–Sierra Azul Belt Sediments belonging to the carbonate platform were recognized in Pinar del Rio by Truitt (1956a, b), who defined the narrow and discontinuous Cacarajı´cara* belt. Herrera (1961) also reported these carbonates. Later workers do not seem to have realized the similarity to the Yaguajay* belt of Las Villas province and included these rocks in the Quin ˜ones unit under the name of Guajaibo´n Formation. Pszczo´lkowski (1978) realized that although the Guajaibo´n Formation was placed in the Quin ˜ones sequence, it should be considered as a distinct tectonic unit. In 1987, as well as in his most recent article, Pszczo´lkowski (1999) considers the Guajaibo´n Formation to belong to a separate unit he called the Guajaibon –Sierra Azul. Although Truitt’s Cacarajı´cara* belt has priority, the Guajaibon – Sierra Azul name will be used in this study. Massive Jurassic shallow-water carbonates have been drilled in EPEP Pinar-1 in the Mogotes area; however, from the descriptions, the types of carbonates

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FIGURE 86. Western Cuba: southwestern terrane generalized geologic map.

FIGURE 87. Correlation chart, southwestern terrane, western Cuba.

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FIGURE 88. Western Cuba, Guajaibon – Sierra Azul belt. are more akin to the lower Las Villas* than to the Yaguajay* belt. For this reason, they will be described under the section on clastics and platform to deep basin province. The Guajaibon–Sierra Azul belt extends as a discontinuous belt for 20 km (12 mi) from San Juan de Sagua to the east-northeast. Its maximum width is 1.5 km (0.9 mi) (see Figure 88). It consists of steeply northward-dipping fault blocks; one of them, the Pan de Guajaibo´n, is the highest elevation in Pinar del Rio. It appears not to have been studied in detail because of difficult access. In Pushcharovsky et al. (1988), it is shown as the Albian–Cenomanian Guajaibo´n Formation that consists of light-gray massive limestones, some being fragmental and richly fossiliferous; some local dolomitization is present. Miliolids, algae, and mollusks are abundant. Bauxite has been reported in the Cenomanian. Truitt (1956a, b) was more precise in characterizing this belt’s lithologies and estimated the total exposed thickness at not more than 1000 ft (300 m). Pszczo´lkowski (1978) gives a thickness of 1250 ft (380 m) at the Pan de Guajaibo´n type section and estimates a maximum of 1650 ft (500 m). The following is Truitt’s description (see Figure 89).

Vin ˜ as* Group.— The Vin ˜as* Group consists of the typical Upper Jurassic to Albian Puntilla* or Bartolome´* Formation lithologies described under the Yaguajay* belt. One sample contained faunas with Jurassic affinities. It is included in the Guajaibo´n formation by Pszczo´lkowski (1978) and Pushcharovsky et al. (1988). Camaco* Formation.— This formation, also included in the Guajaibo´n Formation, is of Cenomanian to Santonian age, is present in its typical development of white, porous algal, and miliolid limestones. Pszczo´lkowski (1987) reports Rotalipora sp., Ticinella sp., Hedbergella sp., and Preaglobotruncana sp. from the upper part of his Guajaibo´n Formation, indicating a lower Cenomanian age. The Manacas Formation overlies this unit with unconformity. Remedios*(?) Formation. — This unit has not been specifically identified in this belt. The presence of Maastrichtian faunas reported by Pszczo´lkowski (1978) in the Guajaibo´n Formation was not confirmed; however, the presence of abundant Remedios* Formation clasts in Eocene conglomerates of the Bahia Honda belt, immediately to the north, as well as in the Cacarajı´cara Formation to the south, suggest its presence, or that it was deposited and subsequently eroded. It must be emphasized that the Gulf’s Remedios*

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FIGURE 89. Stratigraphic section: Guajaibon – Sierra Azul belt.

Formation (as opposed to the general Remedios lithology) has a characteristic Paleocene microfacies easily recognizable in clasts. Manacas Formation. — This name includes several related lithologic units with highly variable thicknesses. They range from 300 to ±1500 ft (100 to ±500 m), of basic igneous-derived sandstone, and shales, argillaceous red to white limestones (Pica Pica Member), and coarse and medium heterogeneous limestone (and chert) conglomerates and orogenic

conglomerates containing blocks of ultrabasic and basic igneous, volcanic, and sedimentary rocks in a clay matrix (Vieja Member). This unit was named Quin ˜ones* Formation by Truitt (1956a, b), who assigned it to the Maastrichtian. Hatten (1957) named the same flysch in Los Organos belt the Pinar Group (including the Pica Pica and Manacas Members, the ‘‘Vieja wildflysch,’’ and the ‘‘Canaletes chert’’) and named part of Truitt’s Quin ˜ones* the Cascarajı´cara (not Cacarajı´cara as presently

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spelled) Formation and considered them lower Eocene and middle to upper Eocene, respectively. Pszczo´lkowski et al. (1975) considered the Pinar Group name invalid and redefined it as the Pica Pica Formation, assigning it to the Paleocene to middle Eocene. Originally, the Cacarajicara Formation was considered to be in part equivalent to the Pica Pica; however, Pushcharovsky et al. (1988) and Pszczo´lkowski (1986a, b) consider it as a distinct unit of Maastrichtian age. In his most recent article, Pszczo´lkowski (1999) follows the current usage, sanctioned by the Cuban Commission of the Paleogene, of naming the unit Manacas Formation. Pushcharovsky et al. (1988) call it the Pica Pica (Manacas) Formation and includes in it the Vieja wildflysch. This does not agree with Hatten’s (1957) original definition of the Manacas Formation. This flysch occurs in all the structural units of the Sierra de Guaniguanico, with a variable character reflecting the underlying stratigraphy. In this belt, it has its thickest development and separates the bank carbonates from the Bahia Honda area Cabaiguan* sequence rocks. It contains a large proportion of basic igneous-volcanic detritus. Compositionally and temporally, this unit is similar to the lower–middle Eocene Vega* Formation of central Cuba, although it is considered to extend into the upper Paleocene. The flysch problem will be further discussed, and the Manacas Formation will be more completely described under the northern Rosario belt section. Guajaibon – Sierra Azul Belt Discussion. — Although essentially nothing has been written about it in the recent literature (except the recognition of the existence of bank carbonates), the presence of the typical Yaguajay* belt lithologies structurally sandwiched between the basic igneous and volcanics of the Bahia Honda belt, and the pelagic sediments of the northern Rosario belt, is of extreme importance. Although in central Cuba, the Domingo* sequence can be found north of the Yaguajay* belt, the presence of Cretaceous and possible Upper Jurassic platform carbonates 280 km (173 mi) west of the westernmost known occurrences of Bahamas Bank lithologies (Gulf Blanquizal-1 and Gulf-Chevron Cay Sal-1) is surprising, although similarity of facies and fauna should not be automatically interpreted as suggesting paleogeographic continuity. The Quin ˜ones unit of the northern Rosario belt dips northward under the Lower to Upper Cretaceous platform carbonates of the Guajaibon–Sierra Azul belt and consists almost entirely of a Neocomian through lower Maastrichtian pelagic section related to the Cifuentes* belt of central Cuba. The section is right-

side up, and the faulting direction could be either northward or southward. As already mentioned, the Guajaibon–Sierra Azul belt is similarly right-side up under the north-dipping basic igneous-volcanic Bahia Honda belt. It should be noted that its thickness is only a fraction of that of the Yaguajay* belt, with only parts of the Lower and Upper Cretaceous represented. Regardless of the thrusting direction, these outcrops suggest a Cretaceous, prethrusting, basic igneousvolcanic–carbonate platform–deep basin succession. If the thrusting responsible for the present configuration of the belts was from north to south, then a source of volcanics must have been present to the north, within the carbonate bank province, which would be surprising. If the thrusting was from south to north, then carbonate banks were far removed from the Bahamas, south of the deep basin and north of the volcanics. The presence of bauxite in the Cenomanian suggests a proximity to volcanic activity. Perhaps the Guajaibon–Sierra Azul belt represents the remnants of Jurassic – Cretaceous isolated banks, not connected to the Bahamas and surrounded by a deep-water environment; this is the situation with the Jurassic limestones of the Catoche Knoll or the present Bermuda Island. The age of the base of these banks is somewhat questionable, but is believed to be at least Early Cretaceous. At any rate, the banks must have been fairly extensive and continuous to have supplied the material for the Cacarajı´cara and Manacas formations and other related detritals of the northern Rosario and Bahia Honda belts. Perhaps these banks were deposited over the continuation of the Lower Cretaceous Rancho Veloz and La Rana basement highs. As an explanation for the position of the carbonate banks, which is the reverse from that of central Cuba, one can invoke opposing thrusting directions (northward thrusting of the Bahia Honda belt over the carbonate bank, followed by southward thrusting of both over the previously thrusted complex of deep-water basin sediments), but this would considerably complicate the structural picture.

Northern Rosario Belt The name Rosario was derived from a range characterized by low rounded topography caused by the presence of thin-bedded cherty and chalky limestones, and distinguished from the Los Organos (The Organs) Mountains characterized by sheer cliffs of massive, thick-bedded, limestone in a mature karst topography (mogotes). The original Rosario belt has been subdivided for structural and stratigraphic reasons into

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FIGURE 90. Western Cuba, northern Rosario belt. a northern and southern Rosario belt. The northern Rosario belt corresponds quite well to the original definition of belt or facies-structural zone. The sequence of this subdivision of Truitt’s Rosario* belt was defined by Pszczo´lkowski (1977, 1978, 1994a, b, c, d; 1999). The northern Rosario belt, as shown in Figure 90, has been subdivided into several low-angle, mostly north-dipping thrust sheets or units; from lower to higher, these are as follows: 1) Belen Vigoa unit. This is the lowest of the sequence and overlies the southern Rosario belt. It is overlain in the east by the Naranjo and in the west by the Cangre units. 2) Naranjo unit. It generally overlies the Belen Vigoa unit and, to the east, the southern Rosario belt. From east to west, the Dolores, La Serafina, and Cangre units overlie the Naranjo. 3) Dolores unit. It is limited to the eastern part of the northern Rosario belt, where it overlies the Naranjo unit and is overlain by the La Serafina unit. 4) La Serafina unit. It is also limited to the eastern part of the Rosario belt and is mostly underlain by the Dolores unit and overlain by the Cangre unit.

5) Cangre unit. It is rather extensive and covers twothirds of the northern Rosario belt. From east to west, La Serafina, Naranjo, Belen Vigoa units, and the southern Rosario belt underlie the Cangre. Between the Cangre and the Naranjo units, a large elongated serpentine body exists. Everywhere, the Sierra Chiquita unit overlies the Cangre unit. The name Cangre has been used for the metamorphosed equivalent of the Alturas de las Pizarras del Sur area, or unit, of the Los Organos belt. 6) Sierra Chiquita unit. Extending for the entire length of the northern Rosario belt, it is underlain by the Cangre unit and the southern Rosario belt to the west. It is mostly overlain by the Quin ˜ ones unit and in the east by the Bahia Honda area of the Cabaiguan* sequence. 7) Quin ˜ ones unit. It is the highest unit of the sequence. It extends for 45 km (27 mi) east-northeast of San Juan de Sagua immediately south of the Cacarajı´cara* belt. In addition, there is the Martin Mesa window, consisting of northern Rosario belt sediments surrounded by basic igneous and volcanics of the northern Bahia Honda area and outcropping between Mariel and

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FIGURE 91. Stratigraphic section: northern Rosario belt.

Guanajay in western Habana province. The rocks exposed in the Martin Mesa window are tectonically highly crushed and show no direct structural relationships with any of the units of the northern Rosario belt. The stratigraphic sections of the northern Rosario belt and the Martin Mesa window in western Habana province are described below.

Northern Rosario Belt (Sensu Stricto). — This belt extends for 65 km (40 mi) from south of the Sierra de Cajalbana to Cayajabos, along the south flank of the Cacarajı´cara* belt. It has a wedge shape and is bound by what are considered to be major north-dipping faults. It fits the definition of belt in that it has a set of characteristic sequences and is bounded by faults. The section is as follows (see Figure 91).

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Basement. — El Sabalo Formation: —El Sabalo Formation consists of 500 to more than 650 ft (150 to more than 200 m) of an interbedding of 1) Basic igneous rocks ranging in thickness from ±1 to 23 ft (±0.3 to 7 m) in thickness, consisting of dark-green, massive diabases and basaltic flows exhibiting pillow structures, mostly toward the upper part of the layer. Sometimes, the basalts are spilitized. In some cases, the pillows contain vesicles. These volcanics form 60–80% of the section. The chemical composition of these rocks suggests oceanic tholeiites. 2) Dark-gray to black, weathering light-gray to gray, well-bedded to finely laminated limestones up to 16 ft (5 m) in thickness. Some samples contain abundant G. alpina and phosphatic (fish) remains. Didemnoides moreti, Didemnum carpaticum, Didemnum minutum, ‘‘Colomisphaera’’ cf. pieniniensis, and ‘‘Colomisphaera’’ cf. nagyi have also been found. Although this assemblage is not very diagnostic, its local occurrence suggests a pre-Tithonian, Oxfordian(?)–lower Kimmeridgian age. These carbonates were deposited under reducing conditions. 3) Well-bedded calcareous shales. There are occasional marly limestones containing fine pyroclastic material. Occasional tuffs and rare thin siliceous lenses are associated with the volcanics. This unit is well developed and present only in the Naranjo and Belen Vigoa units. It is believed to be equivalent to the Francisco (in which a basalt has been identified) in the southern Rosario belt, and it also correlates and show similarities with the Jagua Formation in the Cangre belt. It is also believed to have similarities with the basalts associated with the base of the La Esperanza Group in the western La Esperanza unit, although these have been attributed to the Tithonian–Berriassian. This section is probably related to the Nueva Maria (Ronda*) Formation section in the Sierra de Camajan that also shows Tithonian limestones in contact with tholeiitic basalts. Like the southern Cifuentes* belt in central Cuba, it could well represent a sliver of basement belonging to the transition between the northern and southern Rosario belts caught in the thrusting. Vin ˜ ales group. — This term is not being presently used (Pszczo´lkowski, 1999) because it is too general, but appears widely in the literature. It is mentioned in this publication for historic reasons.

DeGolyer (1918) proposed the name ‘‘Vin ˜ ales limestone’’ for all the ‘‘mogote-forming’’ limestones of the Sierras de Los Organos and Rosario. No type section was given. Truitt (1956a, b) and Hatten (1957) limited the Vin ˜ales Formation to the Los Organos belt. Herrera (1961) elevated the Vin ˜ales to Group, including in it many limestone types in both the Los Organos and the Rosario belts. This move was not justified because the original intent was to separate the mogote-forming, shallow-water massive Jurassic limestones (San Vicente Formation) from the deep-water, thin-bedded cherty limestone of Jurassic and Cretaceous age. These two types of limestones give the distinctive physiographic character to the Los Organos and Rosario belts. In outcrops, it consists of a maximum of 2625 ft (800 m) of limestone with minor quantities of sandstones, cherts, and shales. It is present in the entire Guaniguanico Mountains. It has been subdivided into the Guasasa, Pons, Artemisa, Polier, and Lucas formations. The Artemisa Formation is restricted to the Rosario belts, and the Polier and Lucas formations are restricted to the northern Rosario belt. Artemisa Formation. — The Artemisa Formation consists of 150 – 1300 ft (50 – 400 m) of well-bedded fine-grained limestones, calcilutites, calcarenites, and a few calcirudites. In a few places, thin beds of radiolarian chert and some marly shales exist. At the base of the formation are occasional fine-grained sandstones and siltstones. The limestones emit a strong petroleum odor when fresh (dry or wet), and asphalt is commonly found in fractures. The Artemisa Formation contains three members: San Vicente, La Zarza, and Sumidero. Of these, only La Zarza and Sumidero are found in the northern Rosario belt, and only Sumidero can be recognized in all the sections. This formation was named the ‘‘Artemisa Limestone’’ by Lewis (1932), the ‘‘San Andre´s formation – eastern part’’ by Vermut (1937), ‘‘Aptychus limestone’’ by Palmer (1945), Artemisa Formation by Truitt (1956a, b), and the Rosario limestone by Hatten (1957). In contrast to the mogotes-forming Guasasa Formation, the Artemisa forms low to moderate rolling hills. La Zarza Member: — La Zarza Member consists of 250 –650 ft (80 –200 m) of thin-bedded micritic limestones interbedded with thin shales overlain by more massive beds of gray fine-grained limestones interbedded with bioclastic limestones and coquinas containing ammonites and aptychi. Some parts of the section are tectonically disturbed. Aptychi are present throughout but rare.

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The fauna consists of Cubaspidoceras sp., Microsphinctes sp., Pseudolissoceras sp., Butticeras sp., Paradontoceras sp., Corongoceras sp., Protoncyloceras sp., Dickersonia sp., and Vin ˜ alesites sp. They, together with Chitinoidella sp., indicate an age ranging from the late middle Oxfordian–early upper Oxfordian to Tithonian. The presence of Calpionella sp. in the upper part of the section indicates that La Zarza Member reaches the upper Tithonian or Berriasian. This unit grades into the overlying Sumidero Member. It is equivalent to the upper Pimienta Member of the Jagua Formation and to the San Vicente, El Americano, and lower Tumbadero members of the Guasasa Formation in the Mogotes area. It is equivalent to the Jagu ¨ ita*, Caguaguas*, and lower Capitolio* formations of central Cuba. However, it appears to have been deposited in much deeper water than the Jagu ¨ ita*. Sumidero Member:— The Sumidero Member consists of 150 – 650 ft (50 – 200 m) of a succession of micritic pink and brown limestones, interbedded lightgray limestones and thin cherts, and finally, toward the top, gray to bluish gray micritic limestones interbedded with thick, radiolarian cherts and laminated limestones. Abundant calcified radiolaria exist. An abundant fauna exists characterized by Calpionella alpina, Calpionella elliptica, Crassicolaria brevis, Tintinnopsella cf. carpathica, Tintinosporella longa, Remaniella cadischiana, Calpionellopsis simplex, Calpionellopsis oblonga, and Calpionellites darderi. In addition, the ammonites Thurmaniceras cf. novhispanicus and Karsteniceras cf. subtilis have been identified. The age is considered Berriasian to Hauterivian. The contact with the overlying Polier Formation is conformable. This unit is equivalent to the upper part of the Tumbadero and the Tumbitas Members of the Guasasa Formation in Los Organos belt and to the Capitolio*, Sabanilla*, and Ronda* formations of central Cuba. Polier Formation. —The Polier Formation consists of thin-bedded micritic limestones interbedded with sandstones and shales. The sandstones are best developed in the Sierra Chiquita and Cangre units, where the formation is 650 – 1000 ft (200 – 300 m) in thickness, decreasing to less than 100 ft (30 m) southward in the Belen Vigoa unit. This unit is absent in the southern Rosario belt. The lower part of the formation consists of thin-bedded gray micritic limestones interbedded with claystones and sandstones. The sandstones are thin bedded, gray to dark gray, hard, finegrained with calcareous cement. They show organic and inorganic markings at the base, graded bedding,

and horizontal and cross-laminations. Some of the sandstones reach 3 ft (1 m) in thickness. The dominant component is poorly rounded quartz with subordinate plagioclases and muscovite. They are considered to be turbidites. This formation was named by Pszczo´lkowski (1977) and was formerly included in the upper part of the Artemisa Formation. Truitt (1956a, b) recognized it as a separate unit and named it Soroa Formation. The base of the Polier Formation has yielded Calpionellopsis simplex, Calpionellopsis oblonga, and Calpionellites sp. The Polier Formation contains a rich ammonite fauna, including Partschiceras infundibulum, Lytoceras cf. stephanensis, Biasaloceras cf. subsequens, Macroscaphites cf. yvani, Leptoceras cf. studeri, Hamulinites parvulus, and Karsteniceras polieri, which indicates a Valanginian–Aptian age, although most of the deposits are believed to be Hauterivian–Barremian. In the upper part of the Polier Formation is a distinct lithologic unit named the Roble Member. Roble Member: —The Roble Member consists of ±80 ft (±25 m) of thick- to medium-bedded, mediumgrained quartz sandstone. Most of the sandstone beds show graded bedding, cross-bedding, current marks, groove marks, and prod casts indicating an origin as turbidites coming from the northwest and north. Some fine interbeds of shales exist, as well as a few micritic limestones in the middle part of the member. At the top of the member is a 3-ft (1-m) bed of detrital limestone. This unit contains only poorly preserved, unidentifiable fossils, and the age is considered Aptian–Albian based on the stratigraphic position. Although the contact is sharp, the Roble Member is conformable with the overlying Santa Teresa Formation. The Polier Formation, especially the Roble Member, shows an influx of quartz sand with muscovite. There could be a relationship with the deep-water Constancia* Formation of central Cuba of Aptian age, which is quite unique in showing quartz and abundant muscovite. It is also very similar to and coeval with the La Esperanza Formation of the La Esperanza belt. Lucas Formation. —The Lucas Formation (named by Pszczo´lkowski, 1977) consists of 650–1000 ft (200– 300 m) of thin-bedded, gray micritic limestones intercalated with hard, calcareous shales and marly shales. The limestones contain abundant aptychi, a few ammonite imprints, and calcified radiolaria, and the unit is considered of upper Hauterivian to Barremian age. It is comformably overlain by the Santa Teresa Formation. It is in part equivalent to the Polier Formation and is restricted to the Sierra Chiquita and Quin ˜ones units. It is also equivalent and lithologically similar

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to the Capitolio*, Ramblazo*, and Ronda* formations of central Cuba. Buenavista group.— This name is not in use at present (Pszczo´lkowski, 1999). It consisted of 650–1300 ft (200 – 400 m) of an association of three lithologies; cherts, limestones, and shales. This group was formerly named the Buenavista Formation by Pszczo´lkowski, 1977, 1978. It is subdivided into four formations; the Santa Teresa, Carmita, Pinalilla, and Moreno. The Buenavista Group was time equivalent to the upper Guasasa and most of the Pons Formation in the Mogotes area. In the Rosario belt, it was mapped by Truitt (1956a, b) as the Carmita* Formation of central Cuba because of its lithologic similarity and time equivalence, and he recognized the change to the dominantly chert Santa Teresa* Formation facies toward the Mogotes area. Santa Teresa Formation. — The Santa Teresa Formation consists of up to 130 ft (40 m) of green, thinbedded, and laminated radiolarian cherts and silicified argillite at the base, turning into red to reddish brown cherts toward the top. This unit, the name of which was originally established in central Cuba, was formerly named the Sabanilla Member of the Buenavista Formation and was included in the lower member of the now invalid Sierra Azul Formation by Pszczo´lkowski (1977, 1978). It is synonymous with the Panchita Formation of the La Esperanza unit. It was mapped as part of the Carmita* Formation by Truitt (1956a, b), although he recognized that locally, it was more similar to the Santa Teresa. This unit contains a fauna of Ticinella sp., indicating an Albian to lower Cenomanian age. A sample of the Polier Formation immediately below the Santa Teresa yielded Nannoconus wassalli and Nannoconus cf. carniolensis latus, indicating an Aptian age. A sample at the top of the formation yielded Rotalipora appenninica, Rotalipora cf. reicheli, Rotalipora cf. cushmani, Praeglobotruncana stephani, Praeglobotruncana cf. delrioensis, Hedbergella cf. delrioensis, and Schackoina sp., indicating an upper Cenomanian age. The age therefore ranges from the Aptian through the Cenomanian. It grades upward into an interbedding of limestones and cherts characteristic of the Carmita Formation, but in some units (mostly in the southern Rosario belt), it has been subject to erosion and is unconformably overlain by the Cacarajı´cara Formation. This formation appears in all the units of the northern and southern Rosario belts. The formation is equivalent to the Pons Formation of the Mogotes area. This unit is lithologically similar

to and partially correlates with the Santa Teresa* Formation (Cifuentes* belt) of central Cuba. Carmita Formation. — The Carmita Formation consists of 0 –230 ft (0 – 70 m) of an interbedding of micritic limestones, cherts, and detrital limestones, which are calcareous turbidites, with graded bedding, containing common fragments of organisms, and rare foraminifera. They also contain occasional detritus of angular quartz, sandstone, graywacke, and plagioclase. This unit, whose name was originally established in central Cuba, was called the ‘‘Limestone and Chert Member’’ of the Buenavista Formation by Pszczo´lkowski (1977, 1978). It was recognized and mapped as Carmita Formation by Truitt (1956a, b). This member is typical of the northern Rosario belt and is particularly well developed in the Sierra Chiquita, Cangre, and La Serafina units. It is only partially present because of erosion in the Belen Vigoa, Naranjo, and Dolores units. It is absent in the Quin ˜ones unit. The planktonic fauna indicates a Cenomanian – Turonian age; however, in the upper part of the formation, which is commonly barren of fossils (or only contains unidentifiable ones), a fauna of Archeoglobigerina cf. cretacea, Globotruncana cf. linneiana, and Rugoglobigerina sp. has been found, suggesting a Coniacian– lower Santonian(?) age. This unit is lithologically similar to and correlates with the Carmita* Formation (Placetas* and Cifuentes* belts) of central Cuba. Pinalilla Formation. — The Pinalilla Formation (originally named the Pinalilla Member of the now invalid Sierra Azul Formation by Pszczo´lkowski, 1977, 1978) consists of a 560-ft (170-m)-thick, massive, thickbedded, gray-green micritic limestone. The fauna consists of planktonic foraminifera and radiolaria that indicate a Turonian age. It is confined to the Quin ˜ones unit. The contact with the Santa Teresa and Moreno formations is sharp, but appears transitional. Moreno Formation. — The Moreno Formation consists of 0– 800 ft (0– 240 m) of argillite, polymictic sandstones, and marly detrital limestones. The lower part of the section is dominated by argillites interbedded with limestones. Toward the top, the limestones become rare, and sandstones and conglomerates containing clasts of volcanics, all interbedded with the shales, appear. Intercalations of green dacitic tuffs are also present. This formation was formerly named the Moreno Member of the Buenavista Formation and included in the upper member of the now invalid Sierra Azul Formation by Pszczo´lkowski (1977, 1978) and was included in the Carmita* Formation by Truitt (1956a, b).

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This member is well developed in the Cangre and Quin ˜ones units. It is present in all other units, with the exception of Belen Vigoa. The following microfauna has been identified: Dicarinella cf. concavata, Dicarinella cf. imbricata(?), Marginotruncana pseudolinneiana, Marginotruncana cf. marginata, Globotruncana mariei, Globotruncana arca, Globotruncana saratogensis, Globotruncana ventricosa, Globotruncana linneiana, Globotruncana cf. linneianamariei, Globotruncana cf. bulloides-linneiana, Globotruncana cf. tricarinata, Globotruncana cf. insignis-orientalis, Globotruncanita elevata, Globotruncana cf. elevata, Globotruncana stuartiformis, Globotruncana cf. stuartiformis, Globotruncana calcarata, Globotruncana cf. subspinosa, Globotruncana cf. stuarti, Rosita fornicata, Rosita cf. patelliformis, Archaeoglobigerina cretacea(?), Hedbergella monmouthensis, Hedbergella cf. crassa, Plummerita hantkeninoides(?), Rugoglobigerina cf. rugosa, Rugoglobigerina cf. pilula, Rugoglobigerina cf. pilula-rugosa, Rugotruncana sp., Hastigerinoides sp., Globotruncanella sp., Globigerinelloides sp., Schackoina cf. cenomana, Sulcoperculina cf. diazi, Sulcoperculina cf. globosa, Vaughanina cf. cubensis, Pseudorbitoides sp., Orbitoides(?) sp., Sulcorbitoides(?) sp., Nummoloculina heimi, Stomiosphaera sphaerica, Pithonella ovalis, Pithonella cf. trejoi, and Globochaete sp. This fauna indicates a Santonian(?) to Campanian age, but mostly Campanian. This formation exhibits an unconformable contact with the overlying Cacarajı´cara Formation. The Moreno Formation shows great similarity with the Corona* Formation of the Placetas* belt. In central Cuba, the Corona* Formation is considered Santonian to Maastrichtian and is equivalent to the Amaro* Formation. It could be, however, older than the Amaro* because the Amaro* is not present (eroded?) in the Placetas* belt, and the Corona* is overlain by younger Tertiary. Cacarajı´cara Formation. — The Cacarajı´cara Formation consists of 330–1475 ft (100–450 m) of limestone and chert breccia grading up into a coarse calcarenite. Most of the fragments consist of shallow-water limestones containing algae, rudists, echinoids, miliolids, and large foraminifera. The lower part of the formation, named the Los Cayos Member, can be chaotic and contain very large clasts; the limestone components can reach 4 ft (1.3 m) and are richly fossiliferous with benthonic foraminifera and rudists. A block of chert 16 ft (5 m) wide has been observed. Olistoliths of Santa Teresa Formation (formerly called the ‘‘upper chert’’ member of the Buenavista Formation) exist. The blocks are tightly packed with no visible matrix.

This unit was named Quin ˜ones* Formation by Truitt (1956a, b) and assigned to the Maastrichtian. Hatten (1957) named the same flysch in Los Organos belt the Pinar Group and named part of Truitt’s Quin ˜ones* the Cascarajı´cara (not Cacarajı´cara as presently spelled) Formation and considered them lower Eocene and middle to upper Eocene, respectively. The Pinar Group name was considered invalid by Pszczo´lkowski et al. (1975), who redefined it as the Pica Pica Formation and assigned it to the Paleocene to middle Eocene. Originally, the Cacarajicara Formation was considered to be in part equivalent to the Pica Pica; however, Pushcharovsky et al. (1988) and Pszczo´lkowski (1986a, b) consider it as a distinct unit of Maastrichtian age. It was formerly included in the now invalid ‘‘calcareous breccia,’’ ‘‘upper chert,’’ and Los Cayos members of the Buenavista Formation by Pszczo´lkowski (1977, 1978). Fragments of deep-water biomicrites, radiolarian cherts, dolomites, shales, sandstones, quartzites, and volcanics are also present. The terrigenous material forms up to 5%, and the volcanic fragments form up to 2% of the clasts. The matrix is sparse and consists of fine detritals. The upper part of the formation is fine grained and can be well bedded. The fauna consists of Omphalocyclus cf. macroporus, Globotruncana arca, Globotruncana bulloides, Globotruncana lapparenti, Globotruncana linneiana, Globotruncana ventricosa(?), Globotruncanita calcarata, Globotruncanita stuarti, Globotruncanita cf. conica, Rosita patelliformis, Rosita fornicata, Rosita cf. contusa, Gansserina ganseri(?), Globigerina stuarti, Rugoglobigerina scotti, Rugoglobigerina rugosa, Pseudotextularia elegans, Sulcoperculina cf. globosa, Sulcoperculina cf. diazi, Sulcoperculina dickersoni(?), Abathomphalus cf. mayaroensis, Racemiguembelina fructicosa(?), Globotruncanella havanensis, Globotruncanella minuta, Plummerita hantkeninoides, Lepidorbitoides sp., Pseudorbitoides sp., and Vaughanina sp., indicating an upper Maastrichtian age. The upper sedimentary contact of this formation with the Anco´n has been observed in a few sections; however, the contact is commonly tectonic. This unit is best developed and is thickest in the northern Rosario belt, where it outcrops continuously for 53 km (32 mi) in the Sierra Chiquita unit. It is absent in the Quin ˜ones unit. It correlates with and is lithologically very similar to the Amaro* Formation (Cifuentes* belt) of central Cuba. It is also similar and coeval with the Pen ˜alver Formation of northern Cuba. Anco´n Formation.—The Anco´n Formation reaches a maximum of 325 ft (100 m), but is commonly 65–100 ft (20 – 30 m) thick. It consists of micritic limestones

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containing planktonic foraminifera and radiolaria characterized by a reddish or greenish gray color. Truitt (1956a, b) named this unit first from the Finca Anco´n locality. Hatten (1957) also named an Anco´n Formation from the same type locality. Truitt considered the age Upper Cretaceous, whereas Hatten considered it lower Eocene. From the descriptions, they are certainly the same unit, and Truitt’s age must have been based on the abundant reworked fauna. The following fauna has been reported: Morozovella pseudobulloides, Morozovella cf. trinidadensis-precursoria, Morozovella uncinata, Morozovella cf. angulata, Morozovella cf. acuta(?), Morozovella cf. aequa, Morozovella cf. velascoensis-acuta, Planorotalites compressa, Planorotalites cf. pseudomenardii, Acarinina cf. soldadensis, Acarinina cf. brodermani, Globigerina cf. triloculinoides, and Globigerina chascanonna. The age is considered upper Paleocene–lower Eocene. In places, the upper part of the formation is characterized by reddish, marly limestones that grade into the overlying red or yellow shales of the Manacas Formation. In one locality, the lower part of the Anco´n Formation contains thinly interbedded polymictic sandstones and red shales. The red calcisiltite of the Anco´n Formation has been observed filling fractures in the underlying Cacarajı´cara Formation. The Anco´n Formation has been identified in the Naranjo, Dolores, La Serafina, and Quin ˜ones units. Manacas Formation. — The Manacas Formation consists of 1500 ft (500 m) to a few tens of feet of dominantly shales, sandstones, and limestones in the lower part and chaotic megaconglomerates and breccias (olistostromes) in the upper part. There have been differences of opinion as to the classification of these deposits. They have been described under the names of Pinar Group, Manacas, Pica Pica, and Quin ˜ ones* formations, Vieja wildflysch (also referred to as the ‘‘Big Boulder bed’’), and Canaletes chert. Hatten (1957) named the Pinar Group and divided it into the Manacas Formation, the Vieja wildflysch (Big Boulder bed), and the Canaletes chert. They were described as follows: 1) Manacas Formation — Graywackes and lithic wackes predominate in the Manacas Formation. The sequence is marine. The color of the weathered outcrop is generally light olive brown; however, some horizons are light olive to pale green. Bedding is poorly developed. The sediments are poorly sorted, ranging from 2 mm (0.08 in.) to material the size of silt. Graded bedding is com-

monly present in the formation. Much of the material seems to be made up of angular quartz and feldspar grains and fine volcanic rock fragments; all this is enclosed in a matrix of silt and clay. Common greenish gray shale horizons are found interbedded with the graywackes; some of these have been reported to be tuffaceous. Besides the above graywackes and lithic wackes, some pebbly conglomerates also exist with angular limestone clasts of a bank and near-reef type, dolomite, and rounded volcanics of olivine basalt and some intermediate porphyritic rocks. Also present are coarse grains of angular felspar and quartz. Organic material is sparse in the Manacas; the ratio of sediment to fossil remains is high. This seems to be a typical characteristic of flysch deposits of the Alpine type. On the strength of the presence of Globigerina cf. bulloides, this unit is considered lower Eocene in age. 2) Vieja Wildflysch — The Vieja Wildflysch is made up of dark greenish grey to grayish blue green highly sheared serpentinized rock. This serpentinized rock has been observed to have many varied textures. Sometimes relic crystals of enstatite(?) up to 3 mm in size can be seen. More often the serpentine is very fine grained to aphanitic. Many ‘exotic’ blocks of amphibolite, actinolite garnet schists, and hornblende-quartz rocks are enclosed by the serpentinized rock. These metamorphics are of unknown origin. Some large blocks of sharpstone conglomerate with abundant limestone clasts are frequently found. Blocks of the metamorphics as well as the conglomerate have been seen as large as 6 to 8 feet in diameter. Hatten’s Vieja wildflysch, which is intimately related to the base of the basic igneous-volcanic thrust sheet, could be a mixture of a true orogenic conglomerate and serpentine with exotics, which is common in the lower Domingo* sequence of central Cuba. 3) Canalete Cherts—The cherts are generally dark grey but weather to light grey. Bedding is generally well developed with beds uniformly near 1 cm in thickness. Between individual beds, a thin, approximately 2 to 3 mm, siliceous shale bed occurs. Radiolaria are abundant to common in the cherts and shales. No diagnostic fauna has been found in the cherts or shales. The exact stratigraphic position is therefore uncertain. From field observations, there is considerable evidence that the cherts are associated with the Pinar Group.

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Truitt (1956a, b) described a unit that he named the Quin ˜ones* Formation showing great similarity to Hatten’s Pinar Group description. It consists of basic igneous-derived conglomerate, sandstone, shale and siltstone. Dirty argillaceous red white limestone. Coarse and medium fragmental heterogeneous orbitoid limestone and limestone conglomerate. Dark brown and black thin-bedded cherts near the base. Rare basalt porphyry. Near the top are enormous tectonically jumbled blocks of actinolite schist, serpentine, diabase, spilite, tuff, and assorted flow rocks mixed with the sediments. These blocks are probably a very coarse orogenic conglomerate. Truitt considered his Quin ˜ones* Formation to be of Maastrichtian age (possibly on account of the abundant reworked fauna) and, unlike Hatten’s Manacas, included in it the chaotic megaconglomerates. Pszczo´lkowski et al. (1975) proposed the name Pica Pica Formation to replace Hatten’s Manacas and Canaletes cherts. Piotrowska (1975) describe the Pica Pica at the type locality as calcareous shales and sandstones (10.0 m), interbedding of polymict sandstones and grey micritic limestones (2.5 m), light grey and red micritic limestones (2.5 m), calcarenites with tuffaceous material (3.0 m), green tuffaceous shales (8.0 m), interbedding of polymict sandstones with shale and cherts (15.0 m), thin bedded red chert (5.0 m), polymict sandstones interbedded with breccias and shales (20.0 m). Higher up in the section chaotic rocks appear. The thickness of the Pica Pica Formation in the stratotype is 85 m. At the co-type locality it is described as yellow shales with sandstones with graywacke composition (6.0 m), a breccia with limestone and chert fragments (2.5 m), shales and graywacke sandstones (up to 30.0 m) and in the upper part, volcanic rocks (diabase and andesite) and tuffaceous rocks (30.0 m). The total thickness of the Pica Pica Formation in this section is almost 80 m. These rocks are overlain by chaotic rocks. (Note: The position of the volcanics in the Pica Pica Formation is not clear. The contact could be tectonic or they could belong to the chaotic rocks.) This unit contains abundant reworked Upper Cretaceous foraminifera and a scarce Paleogene fauna. Globorotalia cf. velascoensis has been found in the lower limestones of the formation. Therefore, the age was believed to range from the upper Paleocene through the lower Eocene. Pszczo´lkowski (1982) considered Hatten’s Manacas Formation to be the lower Manacas Member of the Pica Pica Formation and the Canalete chert to be an informal upper member of the same formation.

He did not, however, include the chaotic rocks (capas de grandes bloques) in the Pica Pica Formation. However, Pushcharovsky et al. (1988) use the name of Pica Pica (Manacas) Formation, which is defined as including olistostromes. More recently, Pszczo´lkowski (1994d) has renamed most of the Pinar Group the Manacas Formation. He subdivides it into the lower Pica Pica and upper Vieja members and considers the Canaletes chert invalid. He describes the section as follows. Pica Pica Member: — Consists of several feet to 325 ft (a few to 100 m [330 ft]) of interbedded yellow weathering clay-shales, graywacke sandstones, marly limestones, and detrital limestones. This member contains an abundant foraminifera fauna in which the following forms have been identified: Morozovella aequa, Morozovella brodermani, Morozovella cf. crassata (spinulosa), Morozovella cf. pseudobulloides, Morozovella cf. velascoensis-acuta, Morozovella cf. subbotina, ‘‘Globorotalia’’ cf. perclara, Planorotalites cf. pseudoscitula (convexa), Planorotalites compressa, Planorotalites cf. pseudomenardii, Pseudohastigerina cf. wilcoxensis, Acarinina cf. soldadensis, Globigerina cf. triloculinoides, and Chiloguembelina sp. This assemblage suggests an upper Paleocene–lower Eocene age. In addition, abundant reworked Cretaceous foraminifera exist. This member grades into the overlying Vieja Member and is in part equivalent to the Anco´n Formation. Vieja Member: —The Vieja Member consists of up to ±1300 ft (400 m) of a silty and argillaceous matrix in which are embedded pebbles to large blocks of sedimentary, metamorphic, and igneous rocks. Commonly, the lower part of the section contains limestones and chert breccias containing abundant Campanian– Maastrichtian foraminifera, with little terrigenous material. In the upper part of the member are large olistoliths (reaching several hundred meters) where serpentine dominates. Large olistoliths of interbedded basalts and cherts also exist, containing well-preserved radiolaria, very similar to the Encrucijada Formation of the Bahia Honda belt. Metamorphic blocks are also present, including eclogitic ophiolites and garnet amphibolites. Most blocks are strongly deformed (especially serpentine and pelagic limestones), indicating violent tectonic activity prior to inclusion in the deposit. The components of the breccias and conglomerates at the base of the member commonly reflect the composition of the rocks of the belt they are associated with, whereas the igneous, metamorphic, and volcanic components are commonly concentrated toward the top. No indigenous fossils have been found,

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FIGURE 92. Western Cuba, Martin Mesa area. but this unit is considered lower–middle Eocene. The upper contact is always tectonic. The presence of ‘‘Manacas chert,’’ which was somewhat puzzling in such an environment, is explained as large olistoliths of an older chert section that slid into the basin in front of the advancing thrust and has chaotically mixed within the Vieja wildflysch. It should be noted that on maps, the Pica Pica, Manacas, and Quin ˜ones* formations and the Pinar Group all have a similar distribution and, therefore, are synonymous in their practical usage. It is very important to note that Truitt’s (1956a, b), Hatten’s (1957), and the most recent of Pszczo´lkowski’s (1994d) descriptions convey the impression of the Vega* and Rosas* Formation flysch of central Cuba; they obviously depict the destruction of an advancing basic igneous-volcanic front with its detritus caught in successive, stacked, thrust sheets. On the basis of regional considerations, the Manacas Formation probably correlates with the San Martin*, Vega*, and Rosas* formations of central Cuba and the Paleocene–lower (middle?) Eocene versus lower– middle Eocene age assignments probably have more to do with the vagaries of paleontological determinations than true age differences.

As already mentioned, the Manacas Formation is present in all the belts of the Guaniguanico Range with the exception of the La Esperanza belt and the Quin ˜ ones unit of the northern Rosario belt. This is in contrast with central Cuba, where the Vega* is restricted to the Las Villas* and northern belts. Perhaps the Miguel* Formation, underlying the Domingo* sequence, is a somewhat equivalent facies of the Pica Pica Member. Northern Rosario Belt (Martin Mesa Window).— This window, containing the northern Rosario belt sediments surrounded by basic igneous and volcanics of the Bahia Honda belt, extends for 15.7 km (9.7 mi) between Mariel and Guanajay in the western Habana province (see Figure 92). The sediments within the window are tectonically very disturbed, and for this reason, the entire section has been named the Martin Mesa Group with no formal subdivisions. Martin Mesa group. — This unit is considered a tectonic complex. It consists of thin-bedded, sometimes massive, gray micritic limestones. The limestones are associated with medium-grained, brownish gray sandstones and calcareous slates. In places, the sandstones are dominant.

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The fauna consists of Nannoconus sp., Ticinella sp., Stomiosphaera sp., Pithonella sp., Rotalipora appenninica, Rotalipora cushmani, Globigerinelloides sp., and radiolaria. The age is considered Albian to Turonian, although it could extend down into the Neocomian. This unit appears to be made of Artemisa and Polier Formation components. The Martin Mesa Group (including some Upper Jurassic) has been found in several wells in northern Cuba where it has been correlated with the PlacetasCamajuani zone (Las Villas* – Cifuentes* belt) of central Cuba. According to Pszczo´lkowski (1999), the EPEP Martin Mesa-1 well was spudded in the Via Blanca Formation and encountered the Lower Cretaceous Polier Formation at 2460–5250 ft (750–1600 m), drilled across a thrust into the Campanian–Maastrichtian Cacarajicara Formation to 4105 ft (1800 m), and back into the Polier to the total depth of 9350 ft (2850 m). Northern Rosario Belt Discussion. — This belt is characterized by tholeiitic basalts interbedded with a relatively shallow-water Oxfordian sedimentary section, overlain by a complete Late Jurassic, Cretaceous, and early Paleogene section. 1) Middle and early Upper Jurassic. Nothing is known about these sediments because they do not occur in this belt. Their absence might be entirely caused by structural reasons, although the possibility exists that they were never well developed in this area or were displaced by a younger oceanic basement. 2) Middle Oxfordian– upper Oxfordian. This period of time is represented by outpourings of tholeiitic basalts, believed to be representative of a passive margin’s rifting episode. The limestones interbedded with the basalts indicate shallower than deep pelagic, reducing, and quiet water conditions. They were possibly less than 1000 ft (300 m) deep, but somewhat deeper than those in the Mogotes area. 3) Upper Oxfordian –Tithonian. A marked deepening of the basin exists in this belt accompanied by carbonate deposition, contrasting with shallower conditions of the Mogotes area. The outpouring of submarine basalts continued through the Tithonian as indicated by their presence in the La Esperanza belt. 4) Berriasian to Albian. Deep-water pelagic sedimentation continued near the carbonate compensation depth (CCD) or 3500 – 4500 m (11,482 – 14,763 ft) as indicated by the appearance of cherts and abundant radiolarians. There was an influx

of quartz turbidites of the Roble Member of the Polier Formation, probably flowing along the axis of the basin, possibly from northwest to southeast. This quartzose material, with subordinated feldspars and muscovite, probably extended as far as the Constancia* Formation of central Cuba. As will be seen later, these clastics probably correlate with those of the La Esperanza Formation in the La Esperanza belt. 5) Cenomanian to lower Maastrichtian. The Buenavista Group is a complex unit that is probably not well understood. It is still of probable deep-water origin with cherts, micritic limestones, and detrital limestones to polymictic carbonate and chert breccias. Some volcanic-derived sandstones exist. 6) Upper Maastrichtian. This time interval is represented by up to 2100 ft (700 m) of graded fragmental carbonate of the Cacarajı´cara Formation. This is an unusual detrital carbonate bed similar to and contemporaneous with the Amaro* Formation of central Cuba. 7) Upper Paleocene to lower–middle Eocene. The Manacas Formation is found capping most sections near fault zones in the same way as the Vega* Formation does in central Cuba. Its absence between the southern Rosario and the Guajaibon–Sierra Azul belts requires an explanation. It appears that the northern Rosario belt represents a post–San Cayetano–rifted basin that received an influx of quartzose clastics during the upper part of the Lower Cretaceous; this appears to be a regional Cuban phenomenon because the same sequence of events can be observed in central Cuba. During the upper Maastrichtian, it also received a large influx of turbiditic clastics from an unknown but obviously large source of shallow-water carbonates, which also appears to be of a regional nature.

La Esperanza Belt This belt extends along the north coast of Pinar del Rio for 105 km (65 mi) between Rio Blanco and Mantua, averaging less than 3 km (1.8 mi) in width over most of its length. In southwesternmost Pinar del Rio, it is repeated by folded faults. It is believed to be the western equivalent of the northern Rosario belt, possibly the lower units (see Figure 93). This belt was recognized (but not defined) by Truitt (1956a, b); he gave it the informal name of ‘‘northwestern Rosario* belt.’’ Hatten (1957) also recognized it and gave it the name ‘‘La Esperanza.’’ Both Truitt (1956a, b) and Hatten (1957) considered it as being

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FIGURE 93. Western Cuba, La Esperanza belt. related, but with a much higher percentage of Cretaceous clastics, to the sequences of the Rosario belt. Pszczo´lkowski (1976a, b, 1977, 1978) considered it a major, distinct structurofacies zone. Pszczo´lkowski (1999) does not consider it part of the Guaniguanico terrane, although he considers it equivalent to the northern Rosario belt. Most of the published descriptions are poor and incomplete, in part because of poor exposures, but mostly due to the fact that the best data are from drilling because the information supplied by EPEP is scarce and of poor quality when available; they commonly ignore the existing lithostratigraphic nomenclature. Toward the southwestern end of the belt, Pushcharovsky et al. (1988) show several serpentine and gabbro bodies associated with this unit; some are shown in fault contact with the sediments, but others are not. The largest one, the ‘‘Cabeza de Horacio window,’’ is a generally oval-shaped body, 2  5.5 km (1.2  3.4 mi) of folded gabbro and serpentine present south of Dimas. Originally, it was thought that it was surrounded by the San Cayetano Formation. However, Pushcharovsky et al. (1988) show that it is associated, and partially surrounded, by the La Esperanza Formation. It is not an intrusive as postu-

lated by Truitt (1956a, b) and Ducloz and Vaugnat (1962), but is a different tectonic unit. Pardo (1975) considered it part of the Bahia Honda belt, but it could also represents ultrabasics (El Sabalo?) associated with the La Esperanza belt. The serpentine could be related to the Vieja Member, although the Manacas Formation is not shown. In general, no good published description of the section exists. Some of the reports are conflicting, and much of the information is sketchy. Truitt (1956a, b) remarked that in the area north of the Organos* belt west of La Palma almost all the limestones of the Rosario* belt are missing and the sandstones and shales of the Cayetano Formation are overlain by the sandstones, shales, and cherts of the Lower and Upper Cretaceous. The sandstones and shales are all derived from an acid igneous source, probably from the same source, and except for the interbedded cherts in the Upper Cretaceous, are almost impossible to separate into age groups. Furthermore, the exposures of this part of the Rosario* belt are very poor, and most of the area is covered. Towards the west, towards Santa Lucia, the interbedded cherts are missing, and it is unknown whether the belt continues to the west as a solid sandstone and shale belt, representing both

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FIGURE 94. Stratigraphic section: La Esperanza belt. the Jurassic and Cretaceous time, or whether the only rocks exposed are the Cayetano Formation. Pszczo´lkowski (1978) states that there are some deposits in the La Esperanza Zone in which facies are similar to the Polier and Buenavista formations of the northern Sierra del Rosario. They probably represent the Lower and Upper Cretaceous. These deposits contain greater quantities of turbiditic sandstones than are present in many sections of the Sierra del Rosario, from which it can be inferred that there was a terrigenous influx from the northwest in Early Cretaceous.

Several wells, 10,827–18,144 ft (3300–5532 m) deep, have been drilled in this belt: EPEP Esperanza-1 and 2, EPEP San Ramon-1, EPEP Dimas-1, and EPEP Los Arroyos-1 and 2. Kuznetsov et al. (1985) and Cuba (1985a) published some incomplete information on some of these wells. Pushcharovsky et al. (1988) also provide some general information. What has been published about this belt can be summarized as follows (see Figure 94). Basic igneous rock.—In the area north of Mantua and near the Cabeza de Horacio window are several

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basic igneous bodies interbedded with the sediments of the La Esperanza Formation. They are not similar in character to El Sabalo Formation, although they are reported to be Tithonian to lowermost Cretaceous. Unfortunately, little information is available. La Esperanza Formation (Santa Lucı´a Formation). — According to Pushcharovsky et al. (1988), it consists of 3940 ft (1200 m) of interbedded sandstones, shales, and limestones of Tithonian through Neocomian age. This unit is named a formation in Pushcharovsky et al. (1988). It is informally referred to as a group by Kuznetsov et al. (1985). This section is described by Kuznetsov et al. (1985), and their description unfortunately leaves much to be desired (Spanish translation of a Russian paper). However, they divide the section into three groups of lithologies that from the bottom to the top can be named: (a) carbonate-terrigenous complex (sandyshaly-carbonaceous), (b) terrigenous complex (sandyshaly-carbonaceous), and (c) carbonate complex. In general, the section of the Esperanza Group contains several types of limestones: micrites; biomicrites; sandy, nodular, dolomitized limestones; dolomites with terrigenous material represented by calcareous sandstones; quartziferous sandstones; and thin clay beds. The Esperanza Group shows lithologic variations with the presence of carbonate rocks that contain dolomite and anhydrite in the Puerto Esperanza wells. As can be seen, this description leaves much to be desired, but suggests a possibility of a shallower-water environment of deposition with clastic influx. Unfortunately, the descriptions do not mention thicknesses, dips, type of fauna, microfacies, texture, etc., and do not mention whether the anhydrite is in beds or just fills voids and fractures (it is probably fracture filling). Furthermore, no information is present as to the nature of the dolomites. However, Kuznetsov et al. (1985) emphasize that they are similar to the Perros Formation (understood to be the Cayo Coco* Formation) of the Remedios zone. However, the presence of polymict terrigenous material in the middle of the section shows its similarity to the isochronous sections in the Sierra del Rosario (Sumidero, Polier, and Lucas formations), but these do not contain dolomites and anhydrites. They emphasize the fact that the Neocomian deposits of the La Esperanza are dissimilar from those of the Sierra de los Organos, outcropping near the Puerto Esperanza wells. According to some Cuban sources, there is a certain amount of politics involved; the La Esperanza drilling program was based on the theory that the

wells would encounter autochthonous, shallow-water sediments at depth. The reports are written emphasizing this aspect and minimizing the disturbed, deepwater turbiditic aspect. The logs of EPEP Dimas-1, EPEP San Ramon-1, and EPEP Esperanza-2 are shown in Kuznetsov et al. (1985) and in Cuba (1985a). The two sets of logs, which differ somewhat from each other, are very sketchy, but indicate that in the three wells, the section is repeated, and the Tithonian overrides the Neocomian. These logs show that the Tithonian (equivalent to the middle of the Guasasa and Artemisa formations) contains approximately 50% sandstones and shales, and that the dolomites are present in the Neocomian. In EPEP Dimas-1, a ±3300-ft (±1000-m)-thick (unknown dip) Paleogene chaotic breccia, containing gabbros and diabase (very likely the Vieja Member of the Manacas Formation), was encountered at ±13,280 ft (4050 m), below what was supposed to be the lower La Esperanza section. In the 1985 geologic map of Shien et al., 1984, logs of only a few dips are shown, and most range from 40 to 758. In Pushcharovsky et al. (1988) the surface dips shown range from 30 to 908 with the majority in the high range. Although Kuznetsov et al. (1985) considers it very important that the lower La Esperanza section is little disturbed, there is no question that it has been involved in much deformation. The La Esperanza Formation, which is considered by Pszczo´lkowski (1999) to be in part equivalent and similar to the Polier Formation, is conformable to, and possibly in part equivalent with, the overlying Santa Teresa Formation. Santa Teresa Formation. — The Santa Teresa Formation (formerly locally named the Panchita Formation) consists of 325 – 650 ft (100 – 200 m) of typical radiolarian cherts, shales, and tuffs with occasional sandstones. According to Truitt (1956a, b), the cherts seem to disappear westward, and the entire section becomes clastic. If this is the case, the Santa Teresa Formation is time equivalent to the upper part of the La Esperanza Formation, and the clastics would reach into the Upper Cretaceous. According to Pushcharovsky et al. (1988), it outcrops in the eastern part of the La Esperanza belt and has not been reported from the subsurface, although Kuznetsov et al. (1985) shows the chert symbol in the Neocomian of the EPEP Esperanza-2 well. La Esperanza Belt Discussion. — Obviously, not enough attention has been paid to this belt, and much more work needs to be done. From the sparse descriptions in a few publications, it seems to be a northwestern equivalent of the northern Rosario belt,

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with a considerable increase in acid igneous-derived clastics. It was considered as such by Truitt (1956a, b) and Hatten (1957) and, more recently, by Pszczo´lkowski (1999). The source for these clastics is debatable (Pszczo´lkowski, 1999, suggests Yucatan), but their composition suggest that they might have had the same origin as those of the San Cayetano Formation, and in the Aptian–Albian, they spread out as far east as central Cuba (Constancia* Formation). The relationship with the San Cayetano Formation of the southern Rosario belt (Pizarras del Norte subbelt) is more difficult to establish; no section has been described showing a sedimentary contact between the San Cayetano and the La Esperanza formations (the oldest reported La Esperanza is Tithonian, and the youngest San Cayetano is middle Oxfordian). The only character in common is that the clastics of both formations seem to have a similar composition. It is possible that the La Esperanza Formation stratigraphically overlies the San Cayetano and belongs to the same major thrust sheet. If this were to be the case, the fault separating the Pizarras del Norte subbelt from the La Esperanza belt would be a relatively minor imbrication. This could be supported by the absence of Manacas Formation between the La Esperanza belt and the Pizarras del Norte subbelt, although it has been found under the La Esperanza belt. However, the presence of El Sabalo-like volcanics suggests that the San Cayetano might not be present under the La Esperanza Formation, and that the La Esperanza belt, like the northern Rosario belt, forms a major thrust sheet over the southern Rosario belt and the Alturas de las Pizarras del Sur area. However, despite the presence of the Vieja Member below the La Esperanza Formation in EPEP Dimas-1, the possibility still exists that it is less displaced than the other nappes, in which case it would be related to the Gulf of Mexico, and its presence could contradict the southern origin of the San Cayetano clastics. This problem will be discussed later in this chapter.

Southern Rosario Belt In this study, the southern Rosario belt is defined as including all the exposed sediments south of the northern Rosario and La Esperanza belts and north of the window exposing the thrust units of the Mogotes area. It therefore includes the former Pizarras del Norte. Pszczo´lkowski (1977) defined the sequence of this subdivision of Truitt’s Rosario belt. The geographic distribution of the conventional southern Rosario belt was more difficult to describe, and as already mentioned and like the former Los

Organos belt, it did not fit the belt and facies-structural unit concept. To the east, the belt was bounded by major faults from the northern Rosario belt; however, the separation from the Pizarras del Norte unit of the former Los Organos belt was very questionable (see Figure 95). Like the northern Rosario belt, it has been subdivided into several structural units consisting of superimposed, thrust fault slivers (scales) repeating the section. These are, from bottom to top, 1) San Francisco–Soroa windows. These small features are believed to expose the uppermost part of the lowest sheets in the Sierra del Rosario. Only the Manacas Formation is exposed. La Zarza unit mostly surrounded the windows. 2) La Zarza unit. It is the lowest, fully exposed unit and, from east to west, is overlain by the northern Rosario belt, and the Los Tumbos, Cinco Pesos, and Taco Taco units. 3) Taco Taco unit. It overlies the La Zarza and underlies the Cinco Pesos and Caimito units. In the west, La Zarza is exposed in a window. 4) Caimito unit. It overlies the Taco Taco and underlies the Cinco Pesos, Los Bermejales, and El Mameyal units. The Caimito unit forms the axis of a broadly folded, northwest–southeast-trending stack of thrust sheets. 5) Cinco Pesos unit. It is found on the northeastern flank of the Rosario belt and overlies the three previously mentioned units. It is below the El Mameyal, Niceto Perez, and Los Tumbos units. It is also overlain by the northern Rosario belts. 6) Los Tumbos unit. It is of small extent and overlies the Cinco Pesos and La Zarza units and underlies the volcanic-sedimentary and the northern Rosario belts. 7) El Mameyal unit. East of La Palma, it overlies the Caimito and Cinco Pesos units and underlies the northern Rosario belt; it overlies the Bahia Honda area and La Esperanza belt. South and west of La Palma, it overlies the Los Bermejales (Loma Colorada), Loma del Puerto, La Paloma, and the northeastern Pizarras del Norte (La Llave, Loma del Muerto) units. It is the uppermost thrust sheet in the western part of the southern Rosario belt. 8) Niceto Perez unit. It is a small sheet that overlies the Cinco Pesos and El Mameyal units and underlies the northern Rosario belt. It is the uppermost sheet in the eastern part of the southern Rosario belt.

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FIGURE 95. Western Cuba, southern Rosario belt. 9) Los Bermejales (Loma Colorada) unit. It overlies the Mogotes area and the Caimito unit and underlies the El Mameyal unit. It appears to have a structural position equivalent to that of the Cinco Pesos unit. 10) Loma del Puerto unit. It overlies the Mogotes subbelt and underlies the El Mameyal and La Paloma units. 11) La Paloma unit. It overlies the Mogotes subbelt and the Loma del Puerto unit and underlies the Loma del Muerto and El Mameyal units. 12) Loma del Muerto unit. In most of the recent published information, including Pushcharovsky et al. (1988), this unit is named Pizarras del Norte, which is somewhat arbitrarily divided into the eastern Pizarras del Norte unit, belonging to the Los Organos belt, and the western Pizarras del Norte unit, belonging to the southern Rosario belt. The contact between these two units is poorly defined, with no clear reason given for the distinction. The division appears unfounded, and Pszczo´lkowski (1994a, b, c, d; 1999) replaces the term ‘‘Pizarras del Norte’’ by Loma del Muerto and La Paloma units belonging entirely to the southern Rosario belt. In this study, it extends

from La Palma to Mantua and Guane to the west. It approximately replaces the term Pizarras de Norte. It overlies the La Paloma unit and underlies the El Mameyal unit. It is in contact with, sometimes over or sometimes under, the La Esperanza belt. It structurally overlies the Sierra de los Organos belt. The composite exposed section, as shown in Figure 96, is as follows. San Cayetano Formation. — The San Cayetano Formation consists of a thick monotonous section where shales, sandstones, and siltstones dominate. Occasional interbeds of conglomerates and limestones (commonly at the top) exist. The color is dark gray to black when fresh, weathering to white, grayish orange, red, or grayish black. Bedding is exceptionally well developed, ranging from 1 mm (0.04 in.) laminae to 6 ft (2 m) thick. In outcrop, the formation is soft and porous; however, it is very hard and dense in the subsurface. Some authors report a slightly metamorphosed aspect. The original name was the Cayetano Formation given by DeGolyer (1918). The name was changed to San Cayetano Formation by Schuchert (1935), Imlay

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FIGURE 96. Stratigraphic section: southern Rosario belt.

(1942), and others. The present usage is San Cayetano Formation. This formation is well developed in the Pizarras del Norte subbelt, Loma del Puerto, La Paloma, Mameyal, Cinco Pesos, and Taco Taco units. It is missing or poorly represented in the La Zarza unit to the east. Pushcharovsky et al. (1988) divide the San Cayetano into a lower unit A and an upper unit B or Castellanos

Formation. According to the map legend, unit A contains sandstones, shales, and siltstones, whereas unit B is characterized by phyllitic carbonaceous schists, shale, siltstones, and limestones. The meaning of this subdivision is not entirely clear; it appears to be a lithostratigraphic subdivision, but it does not correspond to other descriptions. For instance, Pszczo´lkowski (1977) and Haczewzki (1987) report

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the sandier, and coarser, section to be near Soroa, in the eastern part of the southern Rosario belt, whereas Pushcharovsky et al. (1988) show it to be the upper unit B, which is characterized by finer materials. If it is a true time division, the criterion for the assignment is unknown. The Pizarras del Norte subbelt contains mostly outcrops of unit B; however, outcrops of unit A also exist in the northwest of the subbelt. Note that the Castellanos Formation and the units A and B scheme were never formally described. In the Mameyal, Cinco Pesos, and Taco Taco units, the San Cayetano Formation is mostly described as sandy-silty-shaly deep-water turbidite facies; a deepwater, coarse sand, fan facies is found toward the east. Although up to 1500 ft (500 m) of San Cayetano is exposed below the contact with the overlying carbonates, only some ±650 ft (±200 m) have been measured and described, which is a small percentage of the possible thickness of the entire San Cayetano Formation. The finer grained sediments are micaceous and contain occasional limestone beds. The coarse-grained facies occurs in thick beds, with pebbles up to 2 in. (5 cm), and in addition to quartz, they contain, as minor components, shale fragments, sparry carbonates (including dolomite), quartzite, chert, quartzsericite schists, granitoids, and volcanics. Plant remains are abundant. Because of the intense deformation and the monotonous nature of the section, no reliable thickness measurements exist. In the Matahambre mine, a minimum thickness of 5000 ft (1500 m) has been measured. Khudoley and Meyerhoff (1971) give estimates ranging from 10,000–16,000 ft (3000–5000 m). Pushcharovsky et al. (1988) show a thickness of more than 12,500 ft (3800 m), including 2600 ft (800 m) for the upper unit B. These estimates are compatible with the fact that the San Cayetano Formation outcrops over a large area. It should be emphasized that in the southern Rosario and Mogotes areas, the exposures of San Cayetano that underlie the carbonates are relatively thin. This could be a reflection of the original thickness of this formation. No San Cayetano has been reported in the EPEP Pinar-1 well. The Francisco or Artemisa Formation conformably overlie this unit. In this part of the belt, the following ammonites were collected from the upper part of the formation: Perisphinctes spathi, Glochiceras cf. subclausum, and Ochetoceras sp., giving an Oxfordian age; however, there is good evidence that the upper part of the San

Cayetano is equivalent to the Jagua Formation of the Mogotes area. Consequently, the San Cayetano facies becomes younger from the Mogotes toward the Rosario belt. It is not entirely clear whether the San Cayetano shown in Pushcharovsky et al. (1988) includes the western time equivalents of younger carbonate units. Francisco Formation. —The Francisco Formation consists of a maximum of 80 ft (25 m) of shales, siltstones, fine-grained limestones, and thin-bedded sandstones. Sometimes, the shales contain limestone concretions. This formation was named by Pszczo´lkowski (1976a, b). It was previously considered as the transition between San Cayetano and Artemisa formations. A few ammonites have been found as well as fish and plant remains. Globochaetes sp. has been identified. The fauna indicates a late middle Oxfordian age. This unit occupies the same position as the Jagua Formation, but is of a discontinuous nature. This unit represents a transition between the underlying San Cayetano Formation and the overlying Artemisa Formation. It is well developed over most of the belt where the Artemisa Formation is present except for parts of El Mameyal unit, where the Artemisa overlies directly the coarse-grained development of the San Cayetano. In the type area, at San Francisco, a 20-in. (50-cm) volcanic bed exists within the laminated limestones interbedded with the sandstones. It consists of basalt with albitized alkaline feldspars. This volcanism correlates with the volcanics present in the metamorphosed Jagua Formation of the Pino Solo unit and is believed related to the previously described El Sabalo Formation. Artemisa Formation.—This unit is well developed in the eastern and southern part of this belt where the La Zarza and Sumidero members are generally present. However, in addition to the two above members, the San Vicente Member of the Guasasa Formation (characteristic of the Mogotes area) intertongues with La Zarza Member. It is absent in the Pizarras del Sur and the western part of the Pizarras del Norte subbelts. San Vicente Member. —The San Vicente Member consists of up to 30 ft (10 m) of light-gray to black, massive and thick-bedded, partially dolomitized limestones with gray or black chert nodules. Micrites commonly form the base, whereas calcarenites are present in the upper part. This unit contains gastropods (Nerinea sp.), pelecypods, algal fragments, echinoid spines, and benthonic foraminifera. This assemblage indicates shallow-water

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conditions of deposition. Because of the San Vicente Member’s relation to other units, it is considered late Oxfordian to early Tithonian. La Zarza Member. — It has the same character as in the northern Rosario belt and has its best development in the La Zarza and Cinco Pesos units. Sumidero Member. — It has the same development as in the northern Rosario belt and is always present in the upper part of the Artemisa Formation. The age has been determined to be Valanginian. The Santa Teresa Formation overlies the Artemisa Formation (1) transitionally and (2) with a discontinuity (hiatus?). Buenavista group. —The term is not in use at present (Pszczo´lkowski, 1999). It occurred in the southern and central parts of the belt (lower thrust sheets), where it used to consist of the Santa Teresa, Carmita, and Moreno formations. Santa Teresa Formation. — In this belt, the Santa Teresa Formation (formerly called Sabanilla Member of the Buenavista Formation by Pszczo´lkowski, 1977, 1978) can reach 130 ft (40 m) and contains abundant Rotalipora sp., Praeglobotruncana sp., Clavihedbergella sp., Schackoina sp., and Hedbergella sp., indicating a Cenomanian to lower Turonian(?) age. However, this unit is in contact with the Artemisa Formation; therefore, here, it could range from Hauterivian to lower Turonian(?). However, it is questionable if the advent of such a characteristic chert section (observed throughout the island), which is the result of largescale geologic events (submarine volcanism), can be heterochronous. The base of the chert deposition could be an important time marker in the Aptian – Albian. It has been recognized in all the units of this belt. Carmita Formation. — This limestone-chert formation (formerly called the Limestone and Chert Member of the Buenavista Formation by Pszczo´lkowski, 1977, 1978) occurs sporadically and does not contain detrital sediments. It has been recognized in the Loma Del Puerto, Los Bermejales, La Paloma, Caimito, La Zarza, and Cinco Pesos units. Moreno Formation. —This formation is mostly absent and has been recognized only in the Loma Del Puerto and Los Bermejales units. Cacarajı´cara Formation. — This detrital unit, formerly called Breccia Member of the Buenavista Formation by Pszczo´lkowski (1977, 1978), is well represented in here, where it is 6–100 ft (2–30 m) thick and overlies unconformably the Carmita or the Santa Teresa Formation. It contains mostly limestone clasts and subordinate chert fragments.

This member is well developed in all the tectonic units with the exception of the Taco Taco unit. Anco´n Formation. — It is present in the Loma del Puerto, Los Bermejales, La Paloma, Caimito, La Zarza, and Cinco Pesos units. Manacas Formation. —This formation is present in all the tectonic units of this belt, overlying all older rocks, along the trace of the faults separating the units from each other. Drilling. — EPEP Guanahacabibes-1. The 1985 geologic map of Shien et al. (1984) shows a highly diagrammatic log of the EPEP Guanahacabibes-1 well drilled on the shores of the Golfo de las Corrientes in southwesternmost Cuba. It shows that the well penetrated Lower–Middle Jurassic shales and siltstones, under late Paleogene, at ±3345 ft (±1020 m) and slightly metamorphosed terrigenous sediments of the same age at ±4840 ft (±1475 m) until total depth at 7223 ft (2202 m). This is obviously the San Cayetano. It could represent the Cangre belt. Southern Rosario Belt Discussion. —The southern Rosario belt represents a transition between the northern Rosario belt and the Sierra de los Organos belt. 1) Middle and early Upper Jurassic. In this belt, the San Cayetano is very well developed. In the eastern part of the belt, it mostly consists of slope turbidites and coarse sandstone fan facies. In the northwestern part of the belt, shales and siltstones tend to dominate, whereas in the southern part, nearshore conditions seem to have prevailed. Fossiliferous limestones are common in the upper part of the unit, indicating shallower conditions of deposition. 2) Middle Oxfordian. It is represented by a transition between the clastics and the overlying Artemisa Formation. A good development of shale exists with ammonite-bearing limestone concretions, indicating a moderate depth of deposition with quiet conditions. In some cases, the transition is sharp. Occasional volcanics are present, possibly related to the El Sabalo Formation. 3) Upper Oxfordian–Tithonian. This is as in the northern Rosario belt. A marked deepening of the basin exists in this belt, with deeper-water carbonate deposition contrasting with shallower conditions of the Mogotes area. However, near the base of the section are tongues of the shallow-water San Vicente Member of the Guasasa Formation interbedded with the deeper water limestones of the Zarza Member of the Artemisa Formation, indicating a transition between the two belts.

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4) Berriasian to Hauterivian. Deep-water pelagic sedimentation continued near the CCD as indicated by the appearance of cherts and the abundant radiolaria. 5) Hauterivian to Albian. The deep-water sedimentation continued with the deposition of limestones, cherts, and clays of the lower Buenavista Group, and unlike the northern Rosario belt, silicate detritus is totally absent. 6) Cenomanian to lower Maastrichtian. The Buenavista Group is not as well developed in this belt as in the northern Rosario belt. It is of probable deep-water origin with cherts, micritic and detrital limestones, to polymictic carbonate and chert breccias. Some volcanic-derived sandstones exist. 7) Upper Maastrichtian. This time interval is represented by up to 100 ft (30 m) of graded fragmental carbonate of the Cacarajı´cara Formation. 8) Upper Paleocene to lower–middle Eocene. The Anco´n and the Manacas formations are found capping many sections near fault zones. The southern Rosario belt exhibits marked differences from the northern Rosario belt; it shows a very thick, possibly southern-derived, clastic section in the Lower(?) and Middle Jurassic. No evidence of extensive Upper Jurassic volcanism exists, and during the upper Oxfordian, the carbonates were deposited in shallower waters. Furthermore, no silicate clastics exist in the Early Cretaceous. The upper Maastrichtian Cacarajı´cara breccias are not as well developed as in the northern Rosario belt. Like in other parts of Pinar del Rio, the Paleocene –middle Eocene Vieja tectonic conglomerates and breccias are invariably present near fault zones.

Sierra de los Organos Belt The Sierra de los Organos belt is not a belt in the Pardo (1953) sense. It consists of a grouping of several similar carbonate-containing units and a large area where the silicoclastics of the San Cayetano alone are exposed. To better reflect the geological conditions and to avoid changing existing nomenclature, the Sierra de los Organos belt has been subdivided into the Mogotes area and the Alturas de las Pizarras del Sur area. Furthermore, the Mestanza unit of the Cangre belt, although treated as a separate belt, belongs to the Sierra de los Organos belt. Mogotes area. — The Mogotes area (the name Mogotes area has been created for this publication, but Pszczo´lkowski, 1978, 1987, described the section) is defined as a complex window, showing several stacked

thrust sheets containing the massive carbonates of the Sierra de los Organos, through the clastics of the southern Rosario belt and Alturas de las Pizarras del Sur area. It extends for 105 km (65 mi) from San Diego de los Ban ˜os to Mantua and Mendoza. Its width is commonly less than 8 km (4.9 mi) (see Figure 97). Its name is derived from the spectacular vertically faced limestone hills, named Mogotes, that form a median mountain range in the Sierra de Guaniguanico, the Sierra de los Organos. The name Mogotes Area has been created for this study, but Pszczo´lkowski (1978, 1987) described the section. Like the Rosario belt, this area has been subdivided into several units, each representing the outcrops of a nearly horizontal thrust sheet with a characteristic stratigraphic sequence. The results of the deep EPEP Pinar-1 well in the Pons Valley, in the central Mogotes area, have been recently published. A previously unknown, thick Upper Jurassic, shallow-water carbonate bank section has been reported. The previously unknown lower part of the Valle de Pons unit has also been described. This new information will be described separately in more detail. These units, the outcrops of which are shown in Figure 97, are as follows. 1) ‘‘Pinar-1’’ unit. It is the lowest unit and is only known from the deep EPEP Pinar-1 well. The unit has not been formally named, and the name ‘‘Pinar-1’’ is used only in this study. It underlies the Valle de Pons unit, and its base is unknown. 2) Valle de Pons unit. Its upper part is known from outcrops in the Pons Valley, but the lower part is only known from Pinar-1. Because of a repeat of section in the well, Pszczo´lkowski (1999) considers that two units are involved; this is possible. This unit is probably equivalent to the outcrops exposed in the Los Portales window in the southwest of the Mogotes area. The Quemado, Infierno, Vin ˜ ales, and Pizarras del Norte units overlie it. 3) Quemado unit. It outcrops only south of the town of Pons, where it overlies the Valle de Pons unit. The Infierno unit overlies it. In the southwestern Mogotes area, it is probably equivalent to the Paso Real unit that overlies Los Portales outcrops and is overlain by the Guane unit. 4) Infierno unit. It occurs mostly in the south-central part of the Mogotes area and overlies the Valle de Pons and Quemado units. To the southwest, the Guane unit is considered equivalent to the

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FIGURE 97. Western Cuba, Sierra de los Organos belt, Mogotes area.

5)

6)

7)

8)

9)

Infierno. A minor structural segment included in this unit is named the Celadas unit. Vin ˜ ales unit. This is the most extensive of the carbonate units and overlies the Infierno and the Valle de Pons units. The Anco´n, Pico Grande, and Pizarras del Norte units overlie it. Sierra la Gu¨ira unit. It occurs in the northeast of the Mogotes area. It lies over the Vin ˜ales unit. The Loma del Puerto, Los Bermejales, and Pizarras del Sur units of the southern Rosario belt overlie it. Toward the southwest, it overlies the Pizarras del Sur that is believed to be a local structural phenomenon. Pico Grande. This unit occurs between the Vin ˜ ales and Anco´n units (it is the lower part of the original Rigassi-Studer, 1963, Anco´ n unit). Toward the east, The Loma del Puerto and La Paloma units of the southern Rosario belt overlies it. Anco´n unit. It the highest carbonate unit from the Mogotes area. It is developed mostly toward the northeast, where the La Paloma unit overlies it. Limonar – Cayo las Damas window. This long and narrow window through the Pizarras del Norte sub-

belt extends from La Palma to south of Mantua. It shows mostly the underlying Manacas Formation and other outcrops of unidentified lower units. Note that the descriptions of all the stratigraphic units are based on sections exposed in the various thrust sheets forming the complex core of the Mogotes area; here, the maximum exposed San Cayetano is less than 300 ft (100 m). No proof exists that the thick, shallow-water Jurassic carbonates were originally underlain by a thick clastic section; in EPEP Pinar-1, no clastics were reported under the Valle de Pons unit. In the following, the section will be described in ascending order (see Figure 98). San Cayetano Formation. — Here, this unit consists of up to 1200 ft (400 m) of exposures of interbedded sandstones, shales, and claystones. Occasional limestones, found near the top of the section, are not more than 6 ft (2 m) thick, dark gray to black, bituminous, well bedded, recrystallized, highly fossiliferous (oyster hash), and emit a strong fetid odor when hit with a hammer. Some conglomerates are present. The base of the section is always tectonic. The San Cayetano Formation grades conformably upward into the Jagua

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FIGURE 98. Stratigraphic section: Sierra de los Organos belt, Mogotes area.

Formation, and the age of the contact varies slightly from place to place, becoming younger toward the north and east. It should be emphasized that these gradational relationships have been observed only in the units of the Mogotes area. Jagua Formation. —The Jagua Formation (named by Palmer, 1945, and described later by Pszczo´lkowski et al., 1975) consists of 100–520 ft (30–160 m) of dense, black, bituminous, medium-bedded limestones, thick beds of ‘‘oyster hash,’’ and purple-black shale with

limestone concretions in which a rich fauna of ammonites, fish, and reptile bones have been found. The Jagua Formation is characteristic of the Mogotes area and has been subdivided into the following members. Pan de Azucar Member:—The Pan de Azucar Member (originally named the Azucar Formation by Hatten, 1957, but reduced to member rank by Pszczo´lkowski, 1978) consists of 130 ft (40 m) of well-bedded, dense, bioclastic limestones (3–4 ft [1–1.5 m] thick). The

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color is dark gray to black, weathering to light gray. Some sandy limestones exist in the lower part of the member. Beds or lenses of silicified limestones contain a large number of pelecypod shells. Ostreidae and pelecypods are common, and Gryphaea mexicana is abundant. Conicospirillina basillensis is the only identified microorganism. Conicospirillina sp. has an age ranging from the Bathonian to the Kimmeridgian. Based on stratigraphic relationships, this member is assigned to the middle Oxfordian. This member is restricted to the Anco´n and Vin ˜ ales units, the Mestanza unit, and to some sections in the Pizarras del Norte and Pizarras del Sur units, lies on the San Cayetano, and is overlain by the Jagua Vieja Member of the Jagua Formation. It is the lateral equivalent of the Zacarı´as Member. Zacarı´as Member: — It consists of up to 130 ft (40 m) of argillites with fine coquina and siltstone beds. It contains abundant poorly preserved ammonite prints. In addition, less frequently, it contains Liostrea sp., Ostrea sp., Exogyra sp., and Plicatula sp. The age, based on the ammonites, is considered middle Oxfordian. This unit is restricted to the Anco´n unit, rests directly over the San Cayetano, and is overlain by the Jagua Vieja Member. It is the lateral equivalent of the Pan de Azucar Member. Jagua Vieja Member: —It consists of up to 200 ft (60 m) of laminated black shales and marly limestones with typical calcareous concretions. The calcareous concretions contain a well-preserved ammonite fauna. In this unit are the best known Cuban Jurassic fossil localities. A partial list is Paracenoceras mullerreidi, Euaspidoceras o’connelli, Ochetoceras canaliculum var. burckhardti, Ochetoceras mexicanum, Perisphinctes (Discosphinctes) subgraneri, Perisphinctes (Discosphinctes) carribeanum, Perisphinctes (Discosphinctes) antillarum, Perisphinctes (Orthosphinctes) rutteni, Perisphinctes (Arisphinctes) aguayoi, Vin ˜alesphinctes roigi, Vin ˜alesphinctes niger, and Vin ˜alesphinctes brodermani. Wierzbowski (1976) and Myczynski (1976) consider it lower Bimammatum-Bifurcatus zone or upper Oxfordian. The Jagua Vieja Member is characteristic of the Mogotes area and grades upward into the overlying Pimienta Member. It is the lateral equivalent of the Francisco Formation of the southern Rosario belt. Pimienta Member: —It consists of up to 200 ft (60 m) of interbedded dark-gray to black, well-bedded limestones and shales. The limestones are micrites, sometimes marly and medium bedded. No calcareous concretions exist in the shales.

This member contains some ammonites and has been assigned to the upper Oxfordian. The limestones contain poorly preserved planktonic foraminifera and Globochaete alpina has been identified. This member is restricted to the tectonically lessdisturbed sections of the Mogotes area and is equivalent to the contact between the Francisco and Artemisa formations of the Rosario belt. This member grades into the overlying Guasasa Formation of the Vin ˜ales Group. Guasasa Formation.—The Guasasa Formation (named by Herrera, 1961, and is, in part, synonymous with the Vin ˜ales Formation of Truitt, 1956a, b; Hatten, 1957) consists of 1000 ft (300 m) in the Anco´n unit to 2600 ft (800 m) in the Vin ˜ales unit of bedded to massive, medium-gray to black, bituminous, sometimes dolomitized limestones. In some sections, a sedimentary breccia exists at the base consisting mostly of Guasasa fragments but also containing fragments of Jagua Formation. Chert nodules are present in the lower part, and chert beds are present in the upper part. The limestones are responsible for the characteristic rugged mogotes landscape that is a mature stage of karst topography. Streams flow uninterruptedly underground through limestone hills and ridges. The age ranges from the upper Oxfordian to the early Valanginian. It has been subdivided into five members: San Vicente, El Americano, Tumbadero, Tumbitas, and Infierno. San Vicente Member: — The San Vicente Member consists of up to 1000 –2150 ft (300 –650 m) of lightgray to black, massive, and thick-bedded, partially to totally dolomitized limestones with gray or black chert nodules and lenses. In places, the limestones are bedded, oolitic, and contain abundant pellets. Micrites commonly form the base, whereas calcarenites are present in the upper part. In places, the dense micrites at the base of the formation have a peculiar pseudoporphyritic texture with euhedral anhydrite clusters of phenocrysts. In several sections, at the base, a conglomeratic limestone is made up almost entirely of Vin ˜ales and upper Jagua fragments. This conglomerate can be very thick in the south of the Mogotes area. This unit contains belemnites, gastropods (Nerinea sp.), pelecypods, algal fragments, echinoid spines, and benthonic foraminifera. Oolitic limestones containing Favreina sp. are also present in the upper part of the member. This assemblage indicates shallowwater conditions of deposition. This member has been found in all the complete sections of the Mogotes area.

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Because of the San Vicente’s relation to other members, it is considered late Oxfordian to Kimmeridgian. It is equivalent to the lower part of the La Zarza Member of the Artemisa Formation in the Rosario belts and extends as a tongue within that member in the southern Rosario belt. It also resembles and is very probably synonymous with the shallow-water carbonates of the EPEP Pinar-1 well. The upper part of this member is coeval and lithologically suggests the Hollo Colorado* and Jagu ¨ ita* formations of central Cuba. El Americano Member: —El Americano Member consists of 65 – 180 ft (20 –45 m) of dark-gray to black, granular, well-bedded limestones. Some dolomites and dolomitic limestones are present. Occasional intraformational unconformities are also present. Ammonites are present, among them Mazapilites sp. and Pseudolissoceras sp., that indicate a Tithonian age. Microfossils include Chitinoidella bermudezi, Chitinoidella cf. cubensis, Chitinoidella cf. boneti, Calpionella alpina, Calpionella elliptica, and Crassicollaria brevis. In addition, brachiopods, gastropods, pelecypods, reptile bones, and fish teeth and vertebrae are present. This fauna indicates a middle and upper Tithonian age. This member shows an increase in pelagic conditions compared to the San Vicente Member. This member also appears in the Infierno and Vin ˜ ales units. The El Americano Member is conformable with the overlying Tumbadero Member and is equivalent to the upper part of the La Zarza Member of the Artemisa Formation and the Caguaguas* Formation of central Cuba. Tumbadero Member:—It consists of 65–160 ft (20– 50 m) of well-bedded, thinly laminated, micritic limestones and calcilutites with intercalations of black chert. Rare ammonites are present, as well as a rich microfauna; Calpionella alpina, Calpionella elliptica, Crassicollaria brevis, Tintinnopsella carpathica, Tintinnosporella longa, Remaniella cadischiana, Calpionellopsis simplex, and Calpionellopsis oblonga are part of it. These indicate a Berriasian age. This member is present in all complete sections of the Guasasa Formation. It is equivalent to the lower Sumidero Member of the Artemisa Formation and is also similar and equivalent to the Capitolio* Formation in central Cuba. Tumbitas Member: —It consists of 130 – 260 ft (40 –80 m) of light-gray, dense, micritic limestones with some thin beds of darker color. The beds are commonly mottled because of bioturbation. A rich microfauna is present, with Calpionella alpina, Calpionella elliptica, Tintinosporella carpathica,

Tintinosporella longa, Romaniella cadischiana, Romaniella dadayi, Calpionellopsis simplex, Calpionellopsis oblonga, Calpionellopsis darderi, Globochaetes alpina, and Nannoconus sp., among others. The age is considered to be late Berriasian to early Valanginian. This member has been also recognized in the Infierno and Vin ˜ ales units. This unit is considered equivalent to the upper Sumidero Member of the Artemisa Formation and to the upper Capitolio* and Ronda* formations of central Cuba, although aptychi are not common. It is conformable with the overlying Infierno Member. The upper Guasasa Formation used to be called Infierno Member (very likely synonymous with Truitt’s Guajanı´ Formation; it is included in Hatten’s [1957] upper Vin ˜ales), consisting of 0–160 ft (0–50 m) of wellbedded, light-gray, micritic limestones and black cherts. This member was present in the Infierno and Vin ˜ales units. However, Pszczo´lkowski (1999) eliminated the term and considers it part of the lower Pons Formation, equivalent to the Santa Teresa Formation. It also resembles and is part equivalent to the Ramblazo* and Calabazar* formations of central Cuba. The upper boundary of the Guasasa Formation is erosional and overlain by the Paleocene breccias of the Anco´n Formation. Pons Formation. —The Pons Formation consists of 650 ft (200 m) of light-gray to almost black, wellbedded, micritic limestones interbedded with thin, black chert beds, nodules, and lenses. Some thin yellowish brown shales are present. In the lower part, thick-bedded, light-gray mottled limestones are more common. The microfauna of the lower part consists of Globigerina cretacea, Planomalina buxtorfi, Praeglobotruncana sp., Ticinella sp., Globotruncana lapparenti, Rotalipora cf. appenninica, Thalmalinella cf. greenhornensis, Nannoconus truitti, N. wassalli, Nannoconus bucheri, and Nannoconus elongata. Hatten (1957) considered this unit to extend from the Albian through the Campanian. More recently, the range has been extended from the Hauterivian(?) to the Turonian. Hatten (1957) described and named two superimposed stratigraphic units that he called the Pons and Pen ˜as formations. Piotrowska (1975) considered both of them lithologically similar and included the Pen ˜as into the Pons Formation. The present thinking is that both formations should be recognized (Pszczo´lkowski, 1999). The Pons Formation outcrops are restricted to the Pons Valley, in the central part of the Sierra de los

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Organos, in windows exposing the Pons and Pica Pica units. These are the lowermost thrust sheets observable on the surface. Consequently, the base of the Pons Formation has not been observed in the type section. This unit is lithologically similar and equivalent, and could well be synonymous, with the Infierno Member of the Guasasa Formation and the Carmita Formation of the Buenavista Group. It also appears to be equivalent to the Aptian – Albian part of the deep-water carbonate section drilled in EPEP Pinar-1 (spudded in the Pons Valley) between 1640 and 2870 ft (500 and 875 m), although in this section, cherts are not mentioned. The Pons Formation is equivalent to the Ramblazo* and certainly part of the Malpaez* Group (Calabazar* and Mata* formations) in central Cuba. Pen ˜ as Formation. — It is similar to the Pons Formation, but the beds are thinner; the color of the limestone tends to be darker, with white calcite veins; and the chert beds are more abundant. The limestones give off strong petroleum odor when freshly broken. In the type section, it is 250 ft (80 m) thick. It contains Globigerina cf. cretacea, Rugoglobigerina sp., Rugotruncana calcarata, and Globotruncana lapparenti sl. The age is considered Campanian – Maastrichtian. Recent paleontological studies indicate the presence of a hiatus in the Sierra de los Organos comprising the late Turonian and the Santonian. Moncada Formation. — The Moncada Formation (described and named by Tada et al., 2003) consists of 6 ft (2 m) of a calcareous sandstone complex. It contains a mixed faunal assemblage from Aptian to Maastrichtian. It is considered to represent the sediments produced by the Chicxulub meteorite impact at the K/T boundary. Grains of impacted quartz are abundant, and the upper calcareous claystone bed is rich in iridium. This unit correlates with the Cacarajicara. Anco´n Formation. — The Anco´n Formation consists of 0 – 160 ft (0 – 50 m) of well-bedded, pink, green, yellowish brown, and red, laminated, marly, micritic limestones. The limestones are highly fossiliferous. Interbeds of breccias and conglomerates exist with subangular clasts up to several centimeters consisting of oolitic limestones, calpionellid-bearing limestones, cherts and dolomites. Occasionally, thin beds of lightgreen volcanic sand grains occur in the calcareous sandstones. The Anco´n Formation rests disconformably on the Pen ˜as and Pons formations. No angular unconformity exists, but an irregular erosion surface can be observed. In the Mogotes area, it has been divided into three members: La Gu ¨ ira, ‘‘Marly Micritic

Limestone,’’ and La Legua. This formation has been found in all the units of the Mogotes area. La Guira Member: —It consists of up to 160 ft (50 m) of a breccia with fragments up to 16 in. (40 cm), derived mainly from the limestones of the various members of the Guasasa Formation. Chert is also present. The matrix is commonly invisible. Marly limestones can be observed at the top of the breccia and are also its lateral equivalent. The breccia contains reworked fossils of all the underlying units. This member is found in the Sierra de la Gu ¨ira, Anco´n, Vin ˜ ales, Infierno, Valle de Pons and La Legua units. Marly Micritic Limestone Member:— As indicated by its name, it consists almost entirely of the abovedescribed limestones. This unit is richly fossiliferous, and the following foraminifera have been identified: Globorotalia (Morozovella) velascoensis (very abundant), Globorotalia (Morozovella) wilcoxensis, Globorotalia (Morozovella) brodermani, Globorotalia (Morozovella) elongata, Globorotalia (Morozovella) occlusa, Globorotalia (Morozovella) cf. aequa, Globorotalia (Morozovella) cf. acuta, Planorotalia (Planorotalites) pseudomenardii, Acarinina cf. soldadoensis, and Globigerina velascoensis. This assemblage indicates the upper Paleocene. La Legua Member. — La Legua Member consists of a breccia similar to the La Gu ¨ ira Member, but commonly occurs at the top of the formation. It can reach 80 ft (25 m) in thickness, and the blocks are 16 ft (5 m) in length. Fewer chert fragments are present. The Anco´n Formation has obviously been deposited in deep water as indicated by the rich pelagic fauna in the micritic limestones and the interbedded coarse breccias without visible matrix, suggesting the Sagua* Formation of central Cuba. In this case, the talus origin of the breccia has certainly to be ruled out because no shallow banks were present to supply the coarse detritus. The breccias must have been originated from an uplift of the previously deposited carbonates and cherts. The Anco´n Formation is younger than the Cacarajı´cara and older than the Sagua* Formation. The Manacas Formation overlies the Anco´n with strong unconformity. Manacas Formation. — It is well developed in the Mogotes area where it was originally described; it is found at the top of every structural unit. Pinar-1. — Two of the units of the Mogotes area deserve special description because the complete sections have been seen only through drilling of EPEP Pinar-1, a deep, parametric well drilled to 17,056 ft (5200 m) in the Pons Valley, 4 km (2.5 mi) south of

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FIGURE 99. Stratigraphic section: Sierra de los Organos belt, Pinar-1 unit.

the town of Pons (see Figure 97). This well, located in the middle of the complex Pica Pica and other outcrops belonging to the Valle de Pons unit of the Mogotes area, encountered a possibly autochthonous, shallow-water carbonate section of Jurassic age. The base has not been observed. Lopez Rivera et al. (1987) and Pszczo´lkowski (1994a, b, c, d; 1999) described the section, which is partially repeated three times, and the lithostratigraphic units have not been formally named. A recurring problem in Cuba is that, accord-

ing to the Soviet-era stratigraphic philosophy (strongly biostratigraphic), the geologists working for EPEP emphasize the fossil content and the age of the section penetrated by the drill and only summarily describe the lithology and, contrary to the geologists working for the Academy of Science, seldom attempted to classify them within the established lithostratigraphic framework (see Figure 99). Pinar-1 Unit: —The Pinar-1 unit is present from 7872 to 17,056 ft (2400 to 5200 m). Part of the section

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is repeated by a fault at ±10,500 ft (±3200 m). This unit is entirely subsurface and is not in the literature; it has been named solely for this study. Guasasa Formation(?): Pinar-1 Shallow-Water Carbonate:— It consists of 4920 ft (1500 m) of massive limestones. Lower section:—The lower section consists of 2296 ft (700 m) of fine-grained limestones with variable amounts of coproliths and organic remains. The color is dark gray to black, and gypsum and anhydrite commonly fill fractures and vugs. The anhydrite increases toward the lower part of the hole. The fauna consists of Favreina salavenses, Didemnoides moreti, Globochaete alpina, and Cadosina sp., indicating an Upper Jurassic age. Upper section: —The upper section consists of 2624 ft (800 m) of fine-grained limestones, with variable amount of clay and varying degrees of dolomitization. Abundant coral and pelecypod fragments, echinoderm spines, coproliths, molds of ostracods, brachiopods, and benthonic foraminifera are present. Questionable recrystallized radiolaria are also present. The following forms have been identified: Saccocoma sp., Cadosina sp., Favreina salavensis, and miliolids, indicating an Upper Jurassic age. This shallow-water carbonate unit has similarities (although much thicker) and is partly coeval with the San Vicente Member of the lower Guasasa Formation of the Mogotes area and also suggests the Hollo Colorado* Formation of the Las Villas* belt in central Cuba. Although gypsum and anhydrite are reported, there is no mention of evaporite beds. Note that the crustal measurements described in Chapter 6 of this publication indicate that the top of the basement in Pinar del Rio is at ±5 km (±3.1 mi). This is close to the total depth of EPEP Pinar-1, and yet, there is no indication of the presence of terrigenous clastics. Guasasa Formation(?): Pinar-1 Deep-Water Carbonate:—It consists of 3575 ft (1090 m) of a tectonically repeated 1800-ft (550-m) section of fine bioclastic, massive, light-gray to black limestone. The section can be subdivided from bottom to top into three biozones as follows. 1) Upper Jurassic (Tithonian) containing Saccocoma sp., Aptychus sp., Cadosina sp., and molds of radiolaria. 2) Neocomian containing Cadosina sp., Nannoconus steinmanni, Nummulites cf. bermudezi, Tintinosporella longa, Calpionellopsis simplex, Remaniella sp.(?), Globochaete alpina, and Calpionella sp. Radiolaria and embryonic ammonites are also present.

3) Aptian – Albian containing Nannoconus truitti, Nannoconus elongatus, Nannoconus spp., Hedbergella cf. infracretacea, Hedbergella spp., Clavihedbergella sp., Cadosina sp., Globigerinelloides sp., Ticinella sp., Preaglobotruncana sp.(?), Tintinopsella sp.(?), and Heteroelicidae. The middle zone is argillaceous with clay beds, whereas the lower zone has pronounced light-gray and black banding. In general, the dips are low (58 or less; only one core shows 408 dips). This section is correlative with the upper Guasasa Formation of the Mogotes area and the upper Artemisa – lower Buenavista Group of the southern Rosario belt. It also suggests the Caguaguas*, Capitolio*, and Ramblazo* formations of central Cuba, although no chert is reported. Manacas Formation: — In the Pinar-1 unit, this formation consists of 689 ft (210 m) of breccia, with an argillaceous matrix containing fragments of several types of limestones, chert, silty shales, quartz sandstones, diabase, and tuffs. The fragments contain a fauna consisting of Orbitocyclina sp., Pseudorbitoides sp., Sulcoperculina globosa, Ctenorbitoides cardwelli, Globotruncana sp., Globigerinelloides sp., Stomiosphaera sp., Sulcorbitoides pardoi, and rudist fragments, echinoid spines, and mollusks. The age of the components is as young as Maastrichtian, although the Manacas Formation is considered of Paleocene to middle Eocene age. Valle de Pons Unit: Lower Section. — The lower section of the Valle de Pons unit is present from the surface to 7872 ft (2400 m). In Pinar-1, the interval from the surface to 7872 ft (2400 m) is found a sequence of Lower Cretaceous deep-water and Upper Jurassic shallow-water carbonates below the Manacas Formation. This section represents the lower part of the Valle de Pons unit, which has never been observed on the surface. Parts of the section are missing, and intense fracture zones are present. The drilled interval seems to be part of a complex thrust sheet. Guasasa Formation(?): Pinar-1 Shallow-Water Carbonate: — This section is present from 2870 to 7872 ft (875 to 2400 m). The thickness of 5000 ft (1525 m) is believed to be in part caused by a repeat by a reverse fault. The dips are not mentioned, but the contact with the overlying deep-water carbonates is believed to be faulted. Guasasa Formation(?): Pinar-1 Deep-Water Carbonate:—The Pinar-1 deep-water carbonate is present from less than 1640 to 2870 ft (500 to 875 m). This section is believed to be part of a recumbent fold

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because the top and bottom of the section contains Aptian–Albian faunas, whereas the center of the interval is of Neocomian age. This inversion could be caused by faulting. Manacas Formation: —This unit occurs from the surface to less than 1640 ft (500 m). It is described as a volcanic sequence pertaining to an olistolith in the Vieja Formation or, not very likely, as the eugeosynclinal overthrust. The lower contact is questionable because the well was spudded in the Manacas Formation, and no data were taken until 1640 ft (500 m). Mogotes area discussion. — The Mogotes area represents a series of thrusts, or nappes, supposedly directed toward the north. The possibility exists that the Pinar-1 unit is very nearly in place and is resting directly over basement. The predeformation succession of facies is not as easy to visualize as in central Cuba. The most important aspects of the present facies distribution are as follows. 1) Middle Jurassic to middle Oxfordian. The continental margin clastics of this age are not well developed in this belt. Although the base of the Pinar-1 unit was not reached, clastics were not reported between the base of the Valle de Pons unit and the top of the Pinar-1 unit. The only rocks of this age observed in the higher structural units are middle Oxfordian and characterized by shallowwater, anoxic sediments as indicated by abundant oyster-hash sulfurous limestones, suggesting \swamp conditions. These shallow-water conditions appear to be somewhat younger in the Rosario belt than in the Mogotes area. 2) Middle Oxfordian. The Jagua Formation and the Zacarı´as and Jagua Vieja members indicate nearshore conditions of deposition in an anoxic environment probably less than 350 ft (100 m) deep. The large, laminated, early diagenetic concretions and the abundant undamaged ammonite shells indicate quiet conditions not affected by waves and currents. The rate of sedimentation must have been low, and the presence of wood remains indicates some connection to a delta and/or swamps. 3) Upper Oxfordian. The equivalent of the base of the Artemisa Formation indicate a decrease in terrigenous material, an increase in planktonic microorganisms, and a deeper water carbonate platform environment. 4) Kimmeridgian and early Tithonian. The sedimentation was of shallow-water bank carbonates; oolites, oncolites, biomicrites, coprolitic micrites, etc. Favreina spp. is a common fossil. These de-

5)

6)

7)

8)

posits appear to be the thickest in the Pinar-1 unit, reaching more than 4920 ft (1500 m) in the lower thrust sheet. This gives a rate of sedimentation (after compaction) of ±410 ft/Ma (±125 m/Ma), which is quite comparable with that of sediments of the same age in the Las Villas* belt. On the outcrop, the thickness reaches 2132 ft (650 m). It should be mentioned that the San Cayetano facies was not reached in EPEP Pinar-1, although according to seismic studies, the total depth is supposed to be near the top of the basement. The next higher thrust sheet, the Valle de Pons unit, still does not show clastics at the base. Only the uppermost outcropping sheets, Quemado and higher, shows the transition from San Cayetano, through Jagua, into the San Vicente Member of the Guasasa Formation. Middle Tithonian. There was regional subsidence and a marked deepening of the sea. The deeper water, pelagic facies of El Americano Member, with abundant tintinids and radiolaria, replaced the shallow waters of the San Vicente Member. The sedimentation rate (after compaction) dropped to ±33 ft/Ma (±10 m/Ma). The depth was probably close to the aragonite compensation depth. These deposits, and the depth change they represent, are very similar and might be coeval with the change from the shallow-water, oolitic Jaguita* to those of the Caguaguas* Formation of central Cuba. Upper Tithonian through Valanginian. Deep-water conditions continue throughout the Mogotes area, with the deposition of pelagic limestones containing tintinids, nannoconids, and radiolaria of the Tumbadero and Tumbitas members of the Guasasa Formation. These units are coeval and lithologically very similar to the Sumidero Member of the Artemisa Formation and to the Capitolio* and Ronda* formations of central Cuba. Hauterivian and Barremian. Deep-water conditions continue with added siliceous sediments of the Tumbitas Member and the lower part of the Pons Formation. These suggest that the water depth was near the carbonate compensation depth. These sediments correlate with the lower part of the Santa Teresa Formation and the Polier Formation. However, no traces of clastics exist, which would indicate that the Polier Formation clastics could not have come through the Mogotes area. Aptian through Albian. This is represented by the Pons Formation and its possible equivalent in a

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different structural unit, the Santa Teresa Formation. The deposition of chert continues, indicating a continuing deep-water environment, possibly near the carbonate compensation depth (CCD). 9) Upper Cretaceous. The Pons Formation continues into the Turonian; however, the Pen ˜ as Formation of Campanian–Maastrichtian age has similar facies. It is separated from the Pons by a hiatus. The total thickness of the Pons and Pen ˜as is not more than 650 ft (200 m), which could represent the entire Cretaceous, or a sedimentation rate (after compaction) of ±8.8 ft/Ma (±2.7 m/Ma). This is very low compared to other deep-water sedimentation rates and indicates that part of the section is missing. It should be noted that the Maastrichtian carbonate detritus of the Cacarajı´cara Formation have not been reported in this belt, but is replaced by the calcarenites of the Moncada Formation. 10) Paleocene. The Anco´n Formation marks an important break in the section; an influx of breccias and polymict detritus exists in a deep-water environment characterized by marls and cherts. The rate of sedimentation is still low, and the type of sediments indicates some early deformation and subaerial erosion of carbonates as well as a basic igneous-volcanic terrane. 11) Lower –middle Eocene. This time span witnesses the continuation of the influx of polymict detritus (Pica Pica Member) of the Manacas Formation and subsequent chaotic rocks of the Vieja Member. This is an orogenic conglomerate containing not only large-size components of the nearby carbonates, but also of volcanics, gabbros, serpentine, schists, etc., in a graywacke matrix. It is very significant that this breccia is found mostly in fault zones above the carbonate section in the Mogotes area as well as in the Rosario belts. It has never been found in stratigraphic contact with the underlying San Cayetano Formation of the Pizarras del Norte unit and Alturas de las Pizarras del Sur area; the nearly continuous band of Manacas outcrops in contact with the San Cayetano shown in the Pushcharovsky et al. (1988) is a window through the Pizarras del Norte unit. This indicates that the unit was deposited as the youngest layer in the basin, possibly as a large-scale olistostrome, prior to the faulting, but after some erosion or collapse of the basic igneous-volcanic terrane to the south had occurred. Whether it was synchronous over the

entire basin or was deposited as a wave in front of an advancing thrust sheet is not known. At any rate, it must have been deposited over a short period of time. Alturas de Las Pizarras del Sur area. —This area is to the south of, and tectonically overlies, the carbonate units of the Mogotes area. To the south, the Pinar fault and the Cangre belt form its southern limit (see Figure 100). It is the southern equivalent of the Pizarras del Norte unit. The section consists entirely of the San Cayetano clastics because the contact with the overlying carbonates has only been observed in the metamorphosed Cangre belt. This group of rocks should not be part of the Mogotes area and, in view of its following fairly well the definition of belt or facies-structural zone ( because it is limited by faults and has a characteristic stratigraphy), should be a belt. The section is shown in Figure 101. San Cayetano Formation. —It consists of the same thick monotonous section of shales, sandstones, and siltstones as present in the southern Rosario belt, except that coarser clastics predominate. The shales are phyllitic with common sericite. Rare carbonaceous zones with carbonized wood particles are present. The sandstones are poorly sorted with two generations of quartz. One is rounded, whereas the other is angular. More than half of the matrix consists of silt or finer particles. The cement is ferruginousargillaceous. Feldspars are rare, and muscovite is common. The sandstones weather to a soft friable sand. The coarse sandstones and conglomerates have fragments up to 2 in. (5 cm) in diameter. In addition to quartz, they contain, as minor components, shale fragments, sparry carbonates (including dolomite), quartzite, chert, mica schists, granitoids, and volcanics. The sedimentary features include cross-bedding, graded-bedding, slump folds, load-casts, and cut-andfill structures. As already mentioned, Pushcharovsky et al. (1988) subdivide the formation into units A and B informal members and shows that most of the outcrops in the Alturas de las Pizarras del Sur area belong to the sandier unit A. A normal stratigraphic contact between the San Cayetano and the overlying Jagua (or Francisco) has not been reported in the Alturas de las Pizarras del Sur area. Pushcharovsky et al. (1988) show such a contact only in the easternmost part of the Pizarras del Sur unit, near San Diego de los Ban ˜ os. Pszczo´lkowski (1999) shows it to be a window exposing the

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FIGURE 100. Western Cuba, Sierra de los Organos, Pizzaras del Sur area.

Mogotes area Vin ˜ales unit. The base has never been observed. The San Cayetano Formation is very poorly fossiliferous in this area. Very few fossil localities are known, and these contain only pelecypods and plant remains. One fossil locality yielded Cuspidaria sp., Modiolus sp., and Trigonia sp., nondiagnostic of either Jurassic or Cretaceous. However, the trigonias have affinities to species from the Middle to Late Jurassic. Another locality had an assemblage of Eocallista spp., Vaugonia spp., Gervillia sp., and Neocrassina spp. of undetermined age. As already mentioned, ammonites were collected from the upper part of the formation in the southern Rosario belt, Perisphinctes spathi, Glochiceras cf. subclausum, and Ochetoceras sp., giving an Oxfordian age. The transitional contact with the Jagua Formation, observed in the Mogotes area and the Cangre belt, has been well dated at upper middle Oxfordian to lower upper Oxfordian, therefore fixing the age of the top of the San Cayetano at middle Oxfordian. However, no reliable evidence exists for the age of the base of the formation; guesses range from the Middle to the Lower Jurassic (Triassic has even been proposed).

Of great importance is the origin of the San Cayetano clastics. Haczewski (1976, 1987) published the result of a sedimentological reconnaissance of the San Cayetano. He recognized nine facies characteristic of deltaic sedimentation on a continental margin. Most of the fluviatile, delta-plain, and nearshore facies were found to the southwest in the Alturas de las Pizarras del Sur area and western Pizarras del Norte unit; the turbidite deposits are characteristic of the eastern southern Rosario belt (eastern Pizarras del Norte unit, El Mameyal unit), and the slope deposits were located to the northeast of the Mogotes area (Anco´n unit). This pattern suggests that the deep water is to the east-northeast of the Sierra de Guaniguanico. What it was before deformation is another story. In addition, measurements on ripple marks indicate that the direction of transport was in a general northeasterly direction, indicating a southwestern source. The exact meaning of these observations is not clear until the relative motions of the Mogotes, Pizarras del Sur areas, and Rosario belt are resolved. At any rate, the San Cayetano exposures in the Pizarras del Norte show a higher percentage of fine-grained clastics and clay than the Pizarras del Sur. Assuming that both

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FIGURE 101. Stratigraphic section: Sierra de los Organos belt, Pizzaras del Sur area.

sections were continuous, approximately of the same age, and that the Pizarras del Norte were deposited south of the Pizarras del Sur, this supports the argument of the northern origin of the clastic detritus. If the thickness of the detritus exposed under the different thrust sheets has any bearing on the original thickness of sediments (the de´collement might have been at the base of the clastics), then the San Cayetano would have been well developed only in the Pizarras del Sur and southern Rosario belts. The Mo-

gotes area and the northern Rosario belt would have been originally underlain by thin or no San Cayetano. Therefore, regardless of the direction of thrusting, no autochthonous Jurassic clastics should be expected in the present northern half of Pinar del Rio. Alturas de Las Pizarras del Sur area discussion. — The San Cayetano Formation in this area represents deposition in a relatively deep basin receiving sediment from a major continental source such as an important river delta. The depth of deposition

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FIGURE 102. Western Cuba, Cangre belt. is difficult to estimate because of the lack of wellpreserved faunas (which is common in turbid sediments). The sedimentological studies indicate nearshore, shallow-water deposits as well as deeper water turbidites and fans. These suggest a southern source of sediments; however, because of the absence of recognizable markers in the section and the structural dislocations, it is impossible to reconstruct the three-dimensional geometry of the deposits. In general, field mapping indicates that the lower part of the section contains a dominance of coarser sediments, whereas the upper part, with few exceptions, is characterized by a much higher percentage of shales. As already mentioned, the possibility exists that the Alturas de las Pizarras del Sur area is the northern and western equivalent of the southern Rosario belt.

Pszczo´lkowski (1976a, b) to identify a structural unit in the northern Rosario belt. It is present along the northern upthrown side of the Pinar fault and extends for some 72 km (44 mi). It has been subdivided into two units:

Cangre Belt

Although Piotrowski (1977) reports the section as overturned, Pszczo´lkowski (1985) shows the Mestanza unit to be right-side up, with the Pino Solo unit riding over rocks ranging from the Guasasa to the Manacas Formation. The total exposed thickness of the Pino Solo thrust sheet is 1990 ft (610 m) and is considered the highest thrust fault of the Cangre belt. The lower

This narrow belt is called Cangre unit in Pushcharovsky et al. (1988) (and other publications) (see Figure 102). This unit is referred to as the Cangre structurofacies unit in the Pushcharovsky et al. (1988) and other publications. This name will not be used in this study because it has been previously used by

1) Mestanza unit. It is a thin, south-dipping, thrust sliver wedged between the Alturas de las Pizarras del Sur area and the Pino Solo unit. It is characterized by a thin Jurassic carbonate section and by some degree of metamorphism. 2) Pino Solo unit. It extends for 70 km (43 mi) along the Pinar fault and represents the uppermost and most metamorphosed thrust sheet of the Alturas de las Pizarras del Sur area. North of it is a klippe of the same subunit named the Cerro de las Cabras unit.

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FIGURE 103. Stratigraphic section: Cangre belt.

Mestanza unit exposes some ±650 ft (±200 m) of section (see Figure 103). The section is as follows. Mestanza unit. — San Cayetano Formation. —In this unit, only the uppermost outcrops of this formation are present. A gabbro is present at the top of the formation. Jagua Formation.— The Jagua Formation consists of 100 (30 m) of a section very similar to the nonmetamorphosed section in the Mogotes area. It contains limestone concretions with middle Oxfordian

ammonites. The volcanics consist of a gray chloritic tuff and, higher in the section, several horizons of a very altered, greenish gray, volcanic rock, which is believed to have been originally a basalt of intermediate composition (Piotrowski, 1987). This unit grades conformably into the Guasasa Formation. Guasasa Formation. —The base of this massively bedded unit, with the exception of some recrystallization, is identical with the unmetamorphosed section

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of the Mogotes area. In the Piotrowski (1977) description of the section, it is not clear if this lithology belongs to the Pino Solo or Mestanza units. According to Pszczo´lkowski (1985), more than 230 ft (100 m) of Guasasa normally overlies the Jagua Formation in the Mestanza unit. It is represented by the San Vicente Member, which is unconformably overlain by the Guı¨ra Member of the Anco´n Formation. Anco´n Formation. — In this unit, this formation consists of some 15 ft (5 m) of metamorphosed breccias of the Guı¨ra Member and the red and gray recrystallized, schistose limestone with a breccia at the top. The Manacas Formation conformably overlies it. Manacas Formation. —The unit consists of some 25 ft (8 m) of red, green, and gray schists of the Pica Pica Member of this formation. This is the youngest unit present under the Pino Solo unit basal thrust sheet and represents the youngest metamorphism in western Cuba, lower – middle Eocene. Pino Solo Unit. — Arroyo Cangre Formation.—This formation is 1836 ft (560 m) of a metamorphosed, dominantly clastic sequence described by Piotrowski (1977) from south to north as follows: 59 ft (18 m): Polymictic meta-sandstones, quartzchlorite schists, and marbles. 62 ft (19 m): Recrystallized limestones, banded, with oriented texture caused by the presence of muscovite and sericite; quartz lenses. 43 ft (13 m): Quartz-chlorite-muscovite schists interbedded with meta-sandstones. 30 ft (9 m): Fine-grained amphibolite with lepidoblastic structure and oriented texture. 33 ft (10 m): Metasiltstones, metamorphosed limestone, and chloritic schists. 20 ft (6 m): Cataclastic gabbro. 590 ft (180 m): Interbedding of fine to medium grained quartz meta-sandstones, containing subordinate amounts of volcanic rocks, plagioclase, mica, and epidote, and quartz-muscovite schists. 836 ft (255 m): Interbedding of muscovite-chloritequartz crystalline schists with sericite and beds of metasandstones. Although this section is reported to be continuous and overlain by the Jagua Formation, the contact between the two units is always reported as strongly tectonized. The thickness of 1436 ft (435 m) for the San Cayetano equivalent appears low compared to its thickness in the Alturas de las Pizarras del Sur area.

This unit, which is very similar to and the equivalent of the San Cayetano Formation, was given a different name on account of the marbles near the top, the metamorphism, and the presence of volcanics. The volcanics in the southern 246 ft (75 m) of the section are tuffs consisting of a cryptocrystalline mass in which quartz, feldspars, chlorite, and sericite can be recognized. This mass is saturated with epidote. Above the tuffs are cataclastic, medium-grained, crystalline basalts and a porphyroclastic gabbrolike rock. In the northern 164 ft (50 m) of the Arroyo Cangre Formation, near the contact with the Jagua Formation (probably belonging to the Mestanza unit), are thin lamprophyres (monchiquite) interbedded with the carbonate rock. It is worth mentioning that the lower Mestanza thrust sheet is less metamorphosed than the upper Pino Solo sheet, which is reminiscent of the situation in the Escambray and other metamorphic massifs. Cangre Belt Discussion. — In the metamorphic Cangre belt, volcanics are present in the Jagua Formation; they are equivalent in age to the El Sabalo Formation and to the basalts found in the Francisco Formation. These are the oldest volcanics associated with the Mesozoic sediments of Pinar del Rio and are therefore not related to the thermal activity responsible for the lower–middle Eocene regional metamorphism of the metamorphosed units. Also of great interest is the fact that the regional metamorphism is dated as middle Eocene or younger and appears to be equivalent or even predate the thrusting; remnants of the metamorphosed Arroyo Cangre are found along the southern border of the Pizarras del Norte unit. The reason for this metamorphism is not clear; it could be related to the ophiolite obduction.

Guaniguanico Mountains Sediments Discussion As mentioned, unlike central Cuba, the paleoconfiguration of the platform to deep basin province will depend heavily on the structural interpretation (and vice versa); it is difficult to set an a-priori facies distribution. An attempt will be made to reconstruct some likely models of what this sedimentary province might have been like prior to the deformation. It is not the purpose of this book to revise the present stratigraphic nomenclature of Cuba; however, it is pertinent to remark that, until now, the terminology tended to obscure the important aspects of Pinar del Rio stratigraphy. Although E. DeGolyer’s original name of Vin ˜ ales limestone was poorly defined and much misused, the way it was used by Truitt (1956a, b) and Hatten (1957) described well the

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shallow-water, massive, commonly very thick, mogoteforming limestones of Upper Jurassic age. It is a major stratigraphic unit of the area, which, in today’s nomenclature, is lost as the San Vicente Member of the Guasasa Formation of the Vin ˜ales Group. The same is true for Lewis’ Artemisa Formation, also poorly described, but given a precise meaning by Truitt (1956a, b) and Hatten (1957), who called it the Rosario Formation. It was originally the thin-bedded, argillaceous, deep-water equivalent of the Vin ˜ales Formation. Until recently, it was the La Zarza Member of the Artemisa Formation of the Vin ˜ ales Group. However, some very distinctive and approximately coeval lithologic assemblages, all characterized by the presence of thin-bedded chert with variable amounts of thin-bedded limestones and clays, are given names with the rank of formation or members within or outside higher hierarchical units. For instance, until recently, the Pons Formation of the Vin ˜ ales Group was similar to (1) the Infierno Member of the Guasasa Formation of the Vin ˜ ales Group, (2) the Sumidero Member of the Artemisa Formation of the Vin ˜ ales Group, (3) the Sabanilla Member of the Buenavista Formation, and (4) the Sierra Azul Formation. Recently, Pszczo´lkowski (1994a, b, c, d; 1999) improved the situation by not using the Vin ˜ ales Group, the Buenavista Formation, and the Infierno Member and substituting Santa Teresa Formation (of much wider usage) for both a part of the Sierra Azul Formation and the Sabanilla Member. Nothing is wrong in establishing a large number of lithostratigraphic units if these are necessary to depict the configuration of a basin, but these should be grouped in a lithologically significant manner and not according to their geographic position or historical precedents. Truitt (1956a, b) named all the above units Carmita* (and Santa Teresa*), and Hatten (1957) named all the above units the Pons and Pen ˜as formations. An attempt will be made to relate the facies of the previously described stratigraphic units to see if some coherent picture of a basin, or parts of basins, can be made. It will be first assumed that the Cretaceous Bahia Honda belt, as in central Cuba, originally belonged to a separate basin. Except for some ash and siliceous material, it did not interfinger with the sedimentary belts of the clastic and platform to deep-water basin province. Although some volcanics are interbedded with the Late Jurassic, these are of the tholeiitic oceanic type and probably representative of an early rifting phase. The most important units are as follows.

San Cayetano. — This formation, characteristic of Pinar del Rio, is unfortunately too disturbed internally for drawing conclusions based on its thickness or zonation. It is well represented in the Southern Rosario and Alturas de las Pizarras del Sur areas but is not represented in the northern Rosario belt, and has not been reported at the base of the Valle de Pons unit in Pinar-1. This could be an indication that the San Cayetano is absent or thin under the northern Rosario belt and under the Pinar-1 and Valle de Pons units of the Mogotes area. It is worth mentioning that there is some evidence that the San Cayetano of the northeastern southern Rosario belt was deposited in deeper waters than in the Pizarras del Sur or the Mogotes areas. The relation between the Alturas de las Pizarras del Sur area and Pizarras del Norte unit is not clear, except that both overlie all the Mogotes area carbonate units. In the Mestanza unit, the Guasasa Formation is generally thin, commonly less than 300 ft (100 m), and only part of it has been recognized as the San Vicente Member. The upper part of this member (thin bedded with chert nodules) is overlain by the Anco´n Formation. The Jagua and Anco´n formations are also thinner. This indicates that the thinning of the Guasasa could be tectonic in origin and a consequence of the thrusting. San Cayetano Formation–Vin ˜ ales Group Boundary.—The Jagua Formation, which is present transitionally below the shallow-water carbonates of the San Vicente Member, is well developed, 100–520 ft (30–160 m) thick in the thrust sheets, showing through the window of the Mogotes area. It is quite probable that the underlying San Cayetano was thin and was deposited in shallow to moderate depth (shelf) conditions. However, in the southern Rosario belt where a probably thick San Cayetano is overlain by the deeper water sediments of the La Zarza Member, its equivalent, the Francisco Formation, is much thinner, 80 ft (25 m), and sometimes absent altogether. Evidence exists that the San Cayetano clastics under the Artemisa Formation in the southern Rosario belt are progressively younger northeastward and, therefore, equivalent to the Jagua Formation of the Mogotes area. Late Jurassic Tholeiites. — The Jagua Formation in the Cangre belt and equivalent Francisco Formation in the southern Rosario belt contain volcanics related to the dominantly volcanic El Sabalo Formation of the northern Rosario belt. The equivalent La Esperanza belt contains similar volcanics, although they are considered Tithonian instead of Oxfordian (the age

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difference might not be real; the information on the La Esperanza belt is very sketchy). The presence of these oceanic volcanics interbedded with Upper Jurassic limestones at the base of the northern Rosario and La Esperanza belts along the fault that separates the thick from the absent San Cayetano suggests, as in central Cuba, that rifting was active during that time and might have been responsible for the basin configuration. San Vicente Member–Guasasa Formation.—This unit is the only Jurassic, massive, shallow-water carbonate unit in Pinar del Rio. The age is late Oxfordian – early Tithonian, and the thickness ranges from 4920 ft (1500 m) in the Pinar-1 unit, to 985 – 2130 ft (300 – 650 m) in most outcropping units of the Mogotes area, and 230 ft (100 m) in the Alturas de las Pizarras del Sur area. It is absent or very thin (10 m; 33 ft) in most of the southern Rosario belt and absent in the northern Rosario belt, although the coeval, much deeper water, lower La Zarza is well developed in both belts. The San Vicente Member is lithologically similar to and coeval with the Hollo Colorado* and Jagu ¨ ita* formations of central Cuba; no known counterpart to the lower La Zarza exists. As already mentioned, the Pinar-1 unit is nearly autochthonous. This member therefore indicates that, during the late Oxfordian – early Tithonian, the carbonate bank conditions were much more widespread than during the late Tithonian and Cretaceous and might have extended south of the present Bahamas Platform, from Yucatan to at least as far as central Cuba. Here, however, contrary to central Cuba, evidence exists that the carbonate banks had a possibly southern equivalent deep-water facies. The lower part of the La Esperanza Formation, which is considered Tithonian, consists of interbedded limestones, sandstones, and shales. The base of this unit has never been observed nor has its stratigraphic relation to the San Cayetano. It could therefore be a partial equivalent of the San Vicente Member. Middle and Late Tithonian.— The entire basin is under deep-water conditions as indicated by the El Americano Member in the Mogotes area and the upper La Zarza Member of the Rosario belts. No outcrops of time-equivalent sediments in the Quin ˜ones belt exist. This deepening of the basin is synchronous with the basin deepening in central Cuba as indicated by the character of the Caguaguas* Formation. Cretaceous Pelagic Sediments and Cherts. — A relatively thin section of pelagic sediments and the presence of chert beds and nodules characterize the Cretaceous. This indicates deposition in the vicinity of 4000 m (13,100 ft) CCD. The approximate max-

imum thicknesses of Cretaceous pelagic sediments (excluding massive turbidites) for the different belts are as follows: Quin ˜ones belt (no pre – upper Hauterivian recognized), greater than 2950 ft (900 m); northern Rosario belt, 1540 ft (470 m); southern Rosario belt, 890 ft (270 m); and Mogotes area, 600 ft (180 m). Although these figures are very approximate, they show systematic thickening from south to north. This increase in thickness could be caused by an increase in small- to medium-size turbidite bodies. Turbiditic Sediments. —Turbidites are characteristic of the La Esperanza, Rosario, and Quin ˜ones belts. In the Tithonian and throughout the Lower Cretaceous are abundant turbiditic quartz-feldsparmuscovite sandstones and shales in the La Esperanza Formation. In the Lower Cretaceous, they are interbedded with dolomites, which, together with the presence of anhydrite, suggests a conflicting shallowwater environment of deposition. The relationship between these turbidites and the San Cayetano is always reported as a fault; however, the possibility remains that the La Esperanza Formation was transitional with and deposited over the San Cayetano. In the Albian–Cenomanian, these turbidites are interbedded with the cherts of the deep-water Santa Teresa Formation, which they can totally replace. In the northern Rosario belt, the Polier Formation, of Valanginian through Albian age, also contains similar quartzose turbiditic sandstones that are considered correlative to the upper La Esperanza Formation. The Polier Formation has been recognized only in the northern Rosario belt, where it reaches 1000 ft (300 m) in the north, thinning abruptly to the south; it is absent in the Quin ˜ones unit and the southern Rosario belt. These sandstones are time equivalent and similar in composition to the Constancia* Formation of central Cuba (although much better developed here) in the Placetas* and Cifuentes* belts. In the Upper Cretaceous are several well-developed carbonate turbidites, apparently derived from carbonate banks. The thickest and most extensive is the Cacarajı´cara Formation of late Maastrichtian age, which has its maximum development of 1475 ft (450 m) in the northern Rosario belt. It is present (originally identified as the calcareous breccia member of the Buenavista Formation) in a much reduced thickness in the southern Rosario belt. This unit correlates with and is similar to the Amaro* and Rodrigo* formations of the Cifuentes* belt in central Cuba, and in both areas, these turbidites contain a small but significant amount of quartz and volcanic detritus. These detrital components suggest a southern source.

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Manacas Formation. — In its broadest sense, this unit includes the end of the basinal sedimentation and an early stage of flysch sedimentation, abruptly followed by the wildflysch from the destruction of a basic igneous-volcanic orogenic front to the south. The presence of the thin Pica Pica Member suddenly overlain by orogenic breccia (Vieja Member) in almost every major fault slice over the entire Guaniguanico area suggests a major collapse of the orogenic front and an olistostrome of large proportions. This collapse occurred in a relatively short period of time and simultaneously with the early stages of deformation. The generally low dips, absence of overturning, and attitude of the faults indicate that here, in contrast with central Cuba, gravity was the main cause of the observed deformation. From the standpoint of reconstruction, this means that, by the Paleocene, the clastic and platform to deep basin province formed one continuous geomorphic unit. It is also intriguing that the Manacas has not been mapped at the contact between the Pizarras del Norte subbelt and the La Esperanza belt, although it underlies both. Perhaps the compositional differences between these two tectonic units, as observed by Truitt (1956a, b), is more apparent than real. However, the presence of thick Vieja Member under the La Esperanza belt in Dimas-1 indicates that the Manacas flysch deposition extended farther north than the present position of the La Esperanza belt. It appears that the clastic and platform to deep basin province is represented in a continuous stack of sheets. These sheets have been described as scales of variable limited extent. The basin represented by these sheets was asymmetric and can be summarized as follows: 1) Basement (continental or oceanic) and/or thin Jurassic clastics overlain by thick, massive, shallowwater carbonates covered, in turn, by Upper Jurassic deep-water carbonates and cherts (Mogotes area) 2) (a) East Guaniguanico Mountains: thin to thick Jurassic deep- to shallow-water clastics overlain by Upper Jurassic shallow- to deep-water carbonates and covered, in turn, by Cretaceous deepwater carbonates and cherts (eastern southern Rosario belt); and (b) west Guaniguanico Mountains: thick Jurassic deep- to shallow-water clastics overlain by thin Upper Jurassic shallow- to deep-water carbonates (western southern Rosario and Alturas de las Pizarras del Sur areas, including the metamorphosed Cangre belt)

3) (a) East Guaniguanico Mountains: middle to late Oxfordian oceanic rift volcanics overlain by thin Upper Jurassic deep-water carbonates, covered in turn by Cretaceous deep-water carbonates, clastics, and cherts with influxes of miscellaneous turbidites (northern Rosario belt including the Pizarras del Norte unit); and (b) west Guaniguanico Mountains: Tithonian oceanic rift volcanics overlain by shallow- to deep-water Lower Cretaceous carbonates and continental derived clastics overlain by deep-water cherts and clastics (La Esperanza belt) 4) Lower and Upper Cretaceous bank carbonates (Guajaibon – Sierra Azul belt) Whatever the direction of movement of the different structural units or scales, it is important to arrive at some sort of estimate of the width of basin involved. The northern and southern Rosario belts have been subdivided into 17 rather extensive structural units, the Mogotes area has been subdivided into at least 9, and the Alturas de las Pizarras del Sur area has been subdivided into 3 in addition to the La Esperanza and the Cacarajı´cara belt; this is a minimum of 31 tectonic units. Assuming that, prior to the thrusting, folding, and stacking, each unit was as wide as half the width of the Sierra de Guaniguanico (an average of 12 km [7.5 mi]), a total width of approximately 375 km (233 mi) is indicated. This extrapolative guess gives an order of magnitude of the area involved. As a comparison, the total carbonate basin in central Cuba was estimated at a minimum of 225 km (139 mi). Again, it is worth mentioning that one could be dealing with much larger areas because most of the sediments involved consist of pelagic, oceanic-type deposits, and there is much less evidence of compression than in central Cuba. The present thinking is that despite structural complications, all major movements were from south to north. If one attempts to restore these scales back to their predeformation position, that is, the higher sheets south of the lower ones, one can obtain a sequence not unlike the one of central Cuba, where the shallowwater Jurassic carbonates are to the north (Las Villas* belt) and the deep-water limestones and cherts are to the south (Cifuentes* belt). The major difference is the presence in western Cuba of a thick Jurassic clastic basin between these two extremes. The presence of oceanic tholeiites of uppermost Jurassic age suggests that, as in central Cuba, rifting was responsible for the basin configuration. The relationship of the Guajaibon –Sierra Azul belt to this basin still has

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FIGURE 104. Isla de la Juventud: metamorphics.

to be resolved, as well as the possibility of southwarddirected faults in the Rosario belt. However, the strongest argument for northward-directed movement is the fact that, except in the uppermost Cretaceous, Paleocene, and Eocene, the Guaniguanico section does not contain any appreciable amount of volcanicderived clastics. Furthermore, whatever volcanics occur, they are found in the southernmost belts (after restoration), Cangre and La Esperanza. This is evidence that the Bahia Honda igneous and volcanics were carried to their present position from south of the Guaniguanico terrane.

Metamorphics Under this heading will be grouped rocks that show great similarity to those outcropping in the Guaniguanico Mountains, but exhibit various degrees of metamorphism.

Pinar Fault Area The sediments outcropping along the southern edge of the Guaniguanico Mountains, on the northern side of the Pinar fault, although showing some metamorphism, have been described under the Guaniguanico Mountains. They form the Cangre belt.

Isla de la Juventud The metamorphic province forms the core of the outcrops in the Isla de la Juventud (see Figure 104). In a quick reconnaissance of the island, Truitt (1956a, b) pointed out the similarity between its metamorphic section and the unmetamorphosed rocks of Pinar del Rio. This part of the study will be mostly based on the work of Milla´n (1981, 1992), who, with Somin (Milla´n and Somin [1975; 1976; 1981; 1985a, b]), has studied the Cuban metamorphics for more than 30 yr. The 1988 geologic map (Pushcharovsky et al., 1988) is also based on his work. The internal structure of the Isla de la Juventud is somewhat less complex than that of the Escambray Mountains. The main feature is a large dome in the southwest area of the exposures, which has been subdivided into six structural units. These units are interpreted as folded and faulted major fault blocks. They are 1) 2) 3) 4) 5) 6)

Rio de los Indios antiform Guayabo antiform San Juan synform Nueva Gerona area Caballos tectonic wedge Sierra de las Casas nappe

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The massif has also been subdivided into five metamorphic zones where, generally speaking, zone I, the lowest grade, is in the center of the Rio de los Indios antiform, and zone V, the highest grade, occupies a small area, in the north of the massif near the Cretaceous volcanic Sabana Grande zone (Teneme Formation). Generally speaking, the metamorphic grade increases from zone I in the lowest stratigraphic unit to zone V in the uppermost part of the section, giving (as in the Escambray massif) the impression of inverse metamorphism. Here, however, the correlation between metamorphic grade and structural unit, or thrust sheet, is not as well defined as in Escambray. The metamorphism is described as moderate pressure–high temperature. The zones are characterized as follows: Zone I. It is the lowest metamorphic grade and is found at the base of the section in the Rio de los Indios antiform. The shales show the following assemblages: quartz-muscovite-biotite, quartzmuscovite-biotite-chlorite, quartz-muscovitechlorite, and quartz-muscovite. It appears to grade into zone II, but is in fault contact with zones III and IV. Zone II. It shows complete recrystallization. The sedimentary schists contain the following assemblages: garnet-biotite-muscovite, kyanitebiotite-muscovite, staurolite-biotite-muscovite, staurolite-muscovite, garnet-muscovite, staurolitebiotite-chlorite-muscovite, and zoisite-biotitemuscovite. The calcareous-silicate rocks contain some diopside and potassium feldspars. These occurrences show the beginning of the amphibolitic phase. It grades into zone I, but is in fault contact with zones III and VI. Zone III. The sedimentary schists contain the following assemblages: kyanite-staurolite-muscovite, kyanite-staurolite-biotite-muscovite, kyanitestaurolite-andalusite-muscovite, kyanite-muscovite, and garnet-muscovite. The kyanite and staurolite are abundant, and the crystals can become very large. The contacts with zones II and IV are tectonic. Zone IV. The sedimentary schists contain assemblages that represent all the combinations of garnet, kyanite, staurolite, muscovite, biotite, sillimanite, and andalusite. Oligoclase and andesine are commonly present and can be as much as 10% of the rock. The calc-silicate rocks and some marbles contain diopside (commonly partially replaced by tremolite or actinolite). The calc-silicate rocks also contain basic plagioclase, calcite, scapolite, zoisite, epidote, hornblende, phlogopite, and

potassic feldspar. The contacts with zones I, II, and III are tectonic and gradational into zone V. Zone V. This zone is transitional with and appears included within zone IV. It consists mostly of gneisses. It shows intense migmatization and granitization shown by bands of gneiss interbedded with bands of granite; commonly, these are intensely contorted. The mineral association quartz-andesine-hornblende-biotite is present. The stratigraphic section of Figure 105 shows the stratigraphic units as well as the metamorphic zone to which they belong. It should be mentioned that in most cases, the given thicknesses are estimates. Can ˜ ada Formation. — It consists of at least 1650 ft (500 m) of quartz-muscovite and quartzplagioclase-muscovite, graphitic, fine-grained schists interbedded with similar coarser grained schists. The fine-grained schists are dark gray to black when fresh because of the disseminated graphite; they are pink, reddish, or reddish brown when weathered. The coarser quartz schists are light gray to light greenish gray; they have a whitish color when weathered. Rare occasional outcrops of a dark-gray, fine- to mediumgrained marble are present. This formation, which makes up 40% of the metamorphic massif outcrops, comprises most of metamorphic zone I and zone II in structural unit 1. However, it is found in metamorphic zone III in the core of unit 2. This formation is believed to be equivalent to the Lower to Middle Jurassic San Cayetano Formation of Pinar del Rio. Agua Santa Formation. —The Agua Santa Formation consists of at least 3000 ft (1000 m) of interbedded fine-grained, graphitic schists and occasional to common marbles that can reach several meters in thickness. Locally, quartz-muscovite schists are interbedded with quartzites. The schists are greenish gray, dark gray, or black when fresh and weather reddish to reddish brown. The marbles are gray or black, fine to medium grained, commonly graphitic and schistose, and at times banded. Small amounts of gray or white, sugary dolomitic marble and calcareous quartzmuscovite-graphite schist are present. The Agua Santa Formation, which makes up 50% of the metamorphic massif outcrops, comprises most of metamorphic zone II in structural unit 1. It forms zone III and zone IV in the other structural units. This Agua Santa Formation is believed to be equivalent to the Middle to Upper Jurassic part of the San Cayetano Formation of Pinar del Rio.

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FIGURE 105. Stratigraphic section: metamorphic province Isla de la Juventud (Isle de la Juventud).

Isla de la Juventud marbles.—This informal group of lithologies consists of several types of marbles that form only 5% of the metamorphic massif outcrops. They are generally found in the troughs of the synforms. They are believed to be interbedded with, or lie above, the upper part of the Agua Santa Formation. Their relative stratigraphic position is not entirely clear. The aggregate thickness is believed to be on the order of 1500 ft (450 m), although they might not constitute a continuous stratigraphic succession.

Playa Bibijagua marble. — It consists of a black, graphitic, fossiliferous marble with interbeds of sugary dark-gray dolomite. This unit is only a few meters thick and is in stratigraphic contact with the Agua Santa Formation. The black marbles contain a possible Jurassic microfauna and cephalopods, possibly nautiloidea. Asiento Viejo marbles.—They consist of less than 100 ft (30 m) of a flaggy, banded, sometimes graphitic, marble with thin beds of metamorphosed cherts (quartzite), garnet amphibolite, and calc-silicate

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schists. It is in stratigraphic contact with the Agua Santa Formation. Colombo marbles. —They consist of more than 300 ft (100 m) of fetid gray marbles with interbedded sugary, dark-gray, tremolitic marbles. In places, thin beds of metamorphosed cherts (quartzite) and marbles derived from an intraformational breccia are present. This rock unit is in stratigraphic contact with the Playa Bibijagua marble and the Sierra Chiquita marbles. Sierra Chiquita marble. —It consists of more than 150 ft (50 m) of light-colored, commonly banded and sugary, dolomitic marbles that contain thin beds of metamorphosed chert. These are interbedded with gray, fetid, medium- to coarse-grained, gray marbles. These marbles are found only in the tectonic unit 5, where they are in stratigraphic contact with the Colombo marbles and the Sierra de Caballos marbles. Sierra de Caballos marbles. — They consist of at least 300 ft (100 m) of bluish gray, fetid marbles with thin beds of metamorphosed chert. In places, layers of garnet amphibolite, a calc-silicate rock and sugary gray dolomites. It is in stratigraphic contact with the Sierra Chiquita marble. Las Casas marble. —It consists of nearly 300 ft (100 m) of light-gray, very coarse-grained, fetid, massive, homogeneous, sometimes banded marbles. Commonly, they contain millimeter-thin laminae of a black, sugary, graphitic dolomite. In places, interbeddings of dark-gray, medium-grained marble and a white to light-gray, fine- to medium-grained marble are present. These rocks constitute the tectonic unit 6 (Sierra de las Casas nappe). La Reforma Calc-Siliceous rock. — This consists of ±100 ft (±30 m) of a commonly banded quartz and calcite rock containing abundant diopside and basic plagioclase. Generally, it contains layers of centimeter-thick, light-gray marble forming boudins. Daguilla amphibolite. —This consists of groups of strata, several centimeters to several meters thick, of hornblende (occasionally with remains of clinopyroxene), intermediate plagioclase, and garnet amphibolite. It is interbedded with a calc-silicate schist rich in diopside and basic plagioclase of sedimentary origin. This amphibolite appears to be interbedded with the Agua Santa Formation; the original rock could have been a basic tuff, basalt, or diabase, although a sedimentary origin is not completely discarded.

Isla de la Juventud Section Discussion The section exposed in the Isla de la Juventud shows a terrigenous section with interbedded carbonates that become more numerous and thicker to-

ward the upper part of the section. It is considered to be entirely of Jurassic age and equivalent to the San Cayetano and possibly Jagua and lower Vin ˜ ales. Interbedded with the carbonates and terrigenous sediments, presumably toward the upper part of the section, are some amphibolites that could be equivalent to the Oxfordian El Sabalo or the volcanics in the Cangre belt. It must be noted that most of the marbles are dark, graphitic, and with a sulfurous odor, suggesting deeper water original carbonates. The age of the metamorphism is considered synchronous with the deformation. This is supported by K-Ar age dating, giving ages ranging from 49.3 ± 3.8 to 78 ± 4.0 m.y. with a median value of 66.0 Ma or early Paleocene (Iturralde-Vinent et al., 1996). Milla´n (1981) recognizes four or five superimposed stages of deformation. As already mentioned, the metamorphism is distinctively zoned with four mesozones and one catazone. It appears inverse in relation to the section and the structures (less metamorphism in the older sediments in the cores of anticlines and more metamorphism in the younger sediments in the troughs of synclines). The zonation appears to be transitional and not related to individual thrust sheets as in the Escambray massif (perhaps it is, but the Isla de la Juventud has not been as intensively mapped and studied as the Escambray massif). The metamorphism is of high temperature and relatively low pressure compared to the high pressure and low temperature for Escambray. Inverse regional metamorphism is a phenomenon difficult to understand. The original explanation by Milla´n and Somin (1976) for the Cuban apparent reversal of metamorphism was that the hot slab of basic igneous and volcanics was thrusted over the Escambray and Isla de la Juventud massifs with a greater accompanying metamorphism of the upper layers of the section than that of the lower layers. If all the regional metamorphism was related to the activity of the arc and, therefore, to the Manicaragua granitoid (Cenomanian–Maastrichtian?), it must precede the overthrusting of the Domingo*-Cabaiguan* sequences (Maastrichtian?–middle Eocene); this is not the case. In light of available data, the thrusting hypothesis is the most likely. The predeformation width of the Isla de la Juventud is highly uncertain, but because 40 km (25 mi) are exposed, it must represent a minimum of 80 km (50 mi).

Escambray Massif This province in the Escambray massif consists of two outcropping domal uplifts near the southern

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FIGURE 106. Escambray massif.

coast of Cuba: the Sierra de Trinidad to the west and the Alturas de Sancti Spiritus to the east (see Figure 106). No similar rocks have been reported from the Camaguey Province. Gulf conducted only short reconnaissance trips to this area, so the following discussion is mostly based on the excellent work of Milla´n and Somin (1975, 1976, 1981, 1985a), Somin and Milla´n (1977, 1981), Milla´n and Myczynsky (1979), and Milla´n-Trujillo (1990). The 1988 geologic map (Pushcharovsky et al., 1988) is also based on their work. The Escambray massif is, in large part, made up of generally low-grade metamorphics that have been fairly well dated and correlated with the unmetamorphosed Upper Jurassic – Lower Cretaceous section of Pinar del Rio. The internal structure of these two domes is very complex with steep, radially directed dips. The Trinidad and the Sancti Spiritus domes have been subdivided into six structural units each or eight different

units between the two domes (see Figure 106). These units are interpreted as folded and faulted superimposed thrust sheets. Each dome has also been subdivided into distinct packets of thrust sheets called units. In general, unit 1 is found at the highest level of each dome, in contact with the Mabujina amphibolite. Units 4 –6 are found in the core of the domes. Each unit has a characteristic degree of metamorphism, generally decreasing from unit 1 to units 4– 6. It is described as high pressure and low temperature. The metamorphism of units 4– 6 shows little recrystallization and much preservation of the original texture. The shales show preservation of the original sedimentary structures with little or no schistosity. The volcanics show an assemblage of chlorite, clinozoisite-epidote, actinolite, and white mica. Quartzites can have white mica, clinozoisite, garnet, and magnetite. The marbles contain tremolite and white mica. Units 2 and 3 show complete recrystallization.

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FIGURE 107. Correlation chart, central and eastern Cuba metamorphics. The sedimentary schists have white mica and occasionally chlorite, and some show remnants of the original structures, exhibiting the same minerals found in zone I, plus lawsonite. The quartzites contain the same minerals as zone I, but with a greater variety of garnet. In unit 1, the sedimentary schists, chlorite has disappeared, and albite can be abundant. Quartzalbite-white mica schists are common. Some crystalline schists contain garnet, glaucophane, diopside, hornblende clinozoisite, epidote, zoisite, and lawsonite. In the metabasic rocks, hornblende is present instead of actinolite and so are glaucophane, garnet, clinozoisiteepidote, white mica, diopside, zoisite, and lawsonite. Quartzites can contain garnet, magnetite, glaucophane, riebeckite, hornblende, zoisite, clinopyroxenes, and diopside. White mica is always present. In marbles, zoisite is occasionally present. Figure 107 is a correlation chart of the named formations, and Figure 108 shows, from the center of the domes (units 4 – 6) toward the rim, the order of the structural units and the names of the units. In general, units 3, 4, and 6 are the internal units, whereas units 1 and 2 are the external ones. It should be

mentioned that in most cases, thicknesses are impossible to determine; however, they are occasionally estimated.

Unit 1 Herradura Formation. —It consists exclusively of quartz and quartz muscovite schists commonly with abundant graphite. It is in stratigraphic contact with the Boqueron Formation. It is characteristic of unit 1 on the northern margin of both domes. However, the degree of metamorphism is less than in unit 2, which is nearer the core of the domes. Boquerones Formation. — It is characterized by a sequence of calcareous schists (with white mica and graphite) and black to dark-gray, very foliated marbles. In places, cherts and greenschists are present. It is very similar to the Cobrito Formation.

Unit 2 Yayabo Formation. — The Yayabo Formation consists of a sequence of amphibolites made of hornblende, acid plagioclase, white mica, clinozoisite, and garnet. It contains beds of metaquartzite with

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FIGURE 108. Stratigraphy: Escambray massif.

muscovite and garnet. The Yayabo is considered Jurassic in age. This unit is shown in Pushcharovsky et al. (1988). These amphibolites appear to be independent of all other units within the massif. In their association with other rocks, they are different, both petrographically and chemically, from the Mabujina amphibolite. Unlike the Mabujina,

the Yayabo does not appear to be a remnant of basement. Loma La Gloria Formation. — It consists of a sequence of quartz schists, quartz-muscovite schists, and muscovite schists, commonly with abundant graphite. Calcareous schists are common, and sometimes, intercalations of garnet-eclogite with glaucophane

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and garnet amphibolite are present. This formation occurs in unit 2, which is peripheral to both domes. It is shown in Pushcharovsky et al. (1988). Included in this formation are bodies of multimineralic crystalline schists, commonly calcareous, that are named ‘‘Algarrobo crystalline schists.’’ K-Ar dating from four samples of white mica yielded ages from 71 to 82 m.y. (Campanian–lower Maastrichtian). Cobrito Formation. — It consists of a succession of calcareous schists and schistose marbles with a fine, rhythmic stratification. Compositionally, calcite dominates, with subordinated white mica, graphite, quartz, and variable quantities of albite. Occasionally, chlorite, clinozoisite, and lawsonite are present. Commonly included in the schists are small boudins, less affected by the metamorphism, of black dolomitic and crystalline limestone, with radiolaria (Spumellaria spp. and Nassellaria? spp.) and other organic remains. Some of the fossils have been tentatively identified as the Upper Jurassic–Neocomian Globochaetes alpina and Cadosina sp. Poorly preserved remains also exist, suggesting Calpionella or Chitinoidella. Breccias with black graphitic marble components are common. This formation is in possible stratigraphic contact with the underlying Loma la Gloria Formation and could be, at least in part, equivalent to part of the San Juan Group. This sequence is characteristic of unit 2 in both domes. This unit is shown in Pushcharovsky et al. (1988).

Unit 3 Collantes Formation. — The Collantes Formation consists of a sequence of well-bedded black marble, with abundant graphite. Schistosity is well developed, and generally, the marbles are nonfetid and nonbituminous. Chert is absent. The thickness is estimated at tens of meters. It belongs to zone II and unit 2 in the Trinidad dome. In Pushcharovsky et al. (1988), this unit is included in the Yaguanabo formation. Its stratigraphic relationships are not well known, but it conformably underlies the Loma Quivican and Charco Azul formations. The age is estimated as Upper Jurassic – Lower Cretaceous. Loma Quivican Formation.—The Loma Quivican Formation consists of estimated tens of meters of light-colored (whitish, grayish, greenish, pink, and violet), fine-grained, crystalline limestones. They show good foliation, with thin laminae of white mica and thin chert beds. In addition, they contain intercalations of greenschists (tuffaceous?), sometimes calcareous, and intraformational breccias up to 13 ft

(4 m) thick. Most of the contacts are tectonic; however, it conformably overlies the Collantes and underlies the Charco Azul and La Sabina formations. In Pushcharovsky et al. (1988), this unit is included in the Yaguanabo formation. In contrast with the limestones of the San Juan Group, this formation appears to have been deposited in an open, pelagic, marine environment. The age is considered Lower Cretaceous, possibly extending into the early Upper Cretaceous. It belongs to unit 3 in the Trinidad dome. Charco Azul Formation.—The Charco Azul Formation consists of metaquartzites, muscovite-chlorite and muscovite-quartz schists, light-colored calcareous rocks, and to a minor degree, metamorphosed sandstones with albite and chlorite and green metavolcanic schists. This unit belongs to unit 3 in the Trinidad dome. In Pushcharovsky et al. (1988), this unit is included in the Yaguanabo formation. This unit comformably overlies the Collantes Formation and is the lateral equivalent of the Loma Quivican Formation. The Yunaguabo Formation overlies this unit with apparent conformity. Near the contact of this formation, a Tithonian–Lower Cretaceous microfauna has been recognized in marbles. Yaguanabo Formation. — It consists of metavolcanic greenschists, interbedded with gray marbles and minor amounts of quartzites and siliceous mica schists. It conformably overlies the Charco Azul Formation. It is believed to be of Cretaceous age, but whole rock chemical analyses argue against being a metamorphosed equivalent of the Cabaiguan belt; the TiO2 content is much higher than in similar rocks of the Cabaiguan* sequence. This formation occurs in unit 3 of the Trinidad dome. This unit is shown in Pushcharovsky et al. (1988), but it also includes Loma Quivican, La Sabina, Charco Azul, and the Tambor formations. La Sabina Formation. —The La Sabina Formation consists of well-bedded quartzites, occasionally stained with manganese, interbedded with quartz mica schists. Occasional marbles occur. This unit belongs to unit 3 in the Trinidad dome. In Pushcharovsky et al. (1988), this unit is included in the Yaguanabo formation. It overlies the Loma Quivican Formation and appears to be the metamorphosed equivalent of the Santa Teresa Formation. Therefore, it is considered Cretaceous. El Tambor Formation. — The El Tambor Formation is described as a metamorphosed alpine-type flysch. It consists of well-bedded, rhythmic, sometimes calcareous, fine-grained chlorite schists to

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greenschists that include coarse-grained metamorphosed sandstones. Numerous interbeds of lightcolored marbles and a few beds of metaquartzite occur. This formation seems to contain olistoliths of older formations. It is assigned to the Upper Cretaceous and is believed to overlie the Yaguanabo Formation, but apparently, the contact has not been observed. This unit occurs in unit 3 of the Trinidad dome. In Pushcharovsky et al. (1988), this unit is included in the Yaguanabo formation. Note that the metamorphism of the flysch and olistostromes indicates strong tectonic activity simultaneously with, or prior to, the thermal activity of the arc. It means that some tectonic activity was early Maastrichtian or older.

Units 4–6 Naranjo Group. —The name Naranjo has been used to describe all the metamorphics of a terrigenous origin that form the lower part of the section in the Escambray massif. The Naranjo Group was named the ‘‘series of crystalline schists’’ by Thiadens (1937), the ‘‘crystalline schists of the Trinidad series’’ by Hatten et al. (1958), the ‘‘Trinidad Formation’’ by Khudoley and Meyerhoff (1971), and the ‘‘Naranjo Group’’ by Milla´n and Myczynski (1979). In 1981, Milla´n and Somin described it as a formation. In 1985a, b, Milla´n and Somin assigned new formation names to the different parts of this unit. In view of the fact that the Naranjo Formation name appears in Pushcharovsky et al. (1988), whereas some of the new units do not, it will be treated as a ‘‘group.’’ It includes the following formations. La Llamagua Formation. —It consists of an interbedding of quartz-arenites and lustrous phyllites. This unit stratigraphically underlies the basal, middle Oxfordian marbles of the San Juan Group and is considered equivalent to the Jurassic San Cayetano Formation of Pinar del Rio. It outcrops in the Trinidad dome. La Chispa Formation. — It consists of a sequence of mica schists (quartz muscovite or muscovite schists at times rich in graphite) of terrigenous origin, interbedded with quartzites, micaceous siliceous schists, metavolcanic greenschists with lawsonite, marbles, and calcareous schists. The greenschists with lawsonite and black marbles are named the Felicidad greenschists and are considered Lower–Upper Jurassic or Oxfordian. It is shown in Pushcharovsky et al. (1988) in the Trinidad dome, but in the Sancti Spiritus dome, it is included in a Jibacoa Group. San Juan Group.— It consists of ±1000(?) ft (±300? m) of well-bedded, black to dark bluish gray marbles

and calcareous schists. They are commonly graphitic and have a fetid odor. They form 40 – 45% of the outcrops of the metamorphic province. This group was named the ‘‘series of crystalline schists’’ by Thiadens (1937a, b) and ‘‘San Juan marbles’’ by Hatten et al. (1958). The group is shown in Pushcharovsky et al. (1988), but not the individual formations. The formations of the San Juan Group appear to have all been deposited under restricted, anoxic conditions, as indicated by the dark color, abundant graphite, and common hydrogen sulfide odor. Under the proper conditions, they could have served as petroleum source rocks prior to the Late Cretaceous metamorphism. Narciso Formation. —It consists of 130 ft (40 m) of beige and light- to dark-gray, finely crystalline limestones containing much detrital quartz. Many unidentifiable fossil remains occur. It outcrops in the Trinidad dome. The ammonites Perisphinctes and Microsphinctes have been identified, giving a late middle Oxfordian age. The Sauco Formation conformably overlies the Narciso. This unit is thought to correlate with the Jagua and Francisco formations in Pinar del Rio. Sauco Formation. — It consists of medium-bedded, fine- to medium grained, dark bluish gray to almost black crystalline limestones. They are very fetid and at times show a high concentration of graphite. The Sauco outcrops in the Trinidad dome. It is barren of organisms, but is assigned an upper Oxfordian –lower Tithonian age. Mayari Formation. —It consists of 300(?) ft (100? m) of gray, bluish gray to black, graphitic, crystalline limestones, always bituminous and fetid. They are commonly well stratified and thin-bedded and are intercalated with thin beds or nodules of chert. It outcrops mostly in both domes. Based on ammonites of the Perisphinctidae family, the age is considered Tithonian, but it could be extended into the Neocomian. It is considered equivalent to the Guasasa and Artemisa formations of Pinar del Rio and the Caguaguas* Formation of Las Villas* belt. In the Sancti Spiritus dome, Pushcharovsky et al. (1988) include it in the Jibacoa Group.

Escambray Massif Section Discussion The Escambray massif consists of the superposition of a minimum of six sedimentary thrust sheets (nappes) of Jurassic and Cretaceous age. This superposition shows that rocks of different facies and increasing metamorphic grade, but of equivalent age, have been stacked on each other. In addition, a

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sheet of amphibolite, the Yayabo Formation, is believed to be significantly different from the Mabujina amphibolite. As has been already mentioned, the Escambray sections show greater similarities to the unmetamorphosed Guaniguanico sections than to the central Cuba carbonate belts. This has been reported by many authors such as Somin and Milla´n (1981), Pszczo´lkowski (1987, 1999), and Iturralde-Vinent (1996). Such similarity has led these authors to postulate an early rift between the Yucatan and South America, predating the central Cuba basin succession. The development history of the massif is complex and will benefit from additional work on dating the original rocks, the stages of deformation, and the metamorphism. Several radiometric dates by the K-Ar technique (Iturralde-Vinent et al.,1996) give ages for the high-pressure metamorphism ranging from 43 to 85 m.y. or Maastrichtian. The median value is 66 m.y. or Paleocene. Stanek et al. (2006) consider the end of the subduction at approximately 70 Ma, followed by northward thrusting. It must be pointed out that the southeasternmost outcrops of thrust sheets in the Guaniguanico Mountains, the Cangre belt, contain volcanics and show inverse metamorphism of Paleocene to middle Eocene sediments (Guasasa, Anco´n, and Pica-Pica formations), predating the thrusting. Despite a general correspondence between the structural units and the metamorphic zonation, definite evidence exists that some thrusting occurred prior to the metamorphism, whereas more thrusting occurred afterward. For instance, in the Sancti Spiritus dome, it appears that the La Chispa Formation of units 4 – 6 rode over the Cobrito Formation of unit 2, with a very low angle, and both were later folded and metamorphosed. This is supported by the fact that the metamorphosed El Tambor Formation, of probable Upper Cretaceous age, is described as an alpine flysch with olistostromes. Because the age of the thermal metamorphism is not later than Maastrichtian and can be as early as the Albian, the thrusting must have occurred in the pre-Maastrichtian and even Early Cretaceous, simultaneously with the deposition of the Cabaiguan* sequence and, therefore, much earlier than the deformation of the volcanic and carbonate belts to the north. The Cretaceous Yaguanabo Formation also significantly contains volcanics. The Escambray massif is 29 km (18 mi) at its widest point. Considering the complex folding and the general high dips, 20–708, this could conservatively represent a 50-km (31-mi) distance before folding. If

the metamorphosed sediments are stacked in seven thrust sheets, the distance between the most autochthonous at the base and the most allochthonous at the top could be on the order of 300 km (186 mi) or more. The lowermost plate, units 4– 6, with the lowest metamorphic grade, consists of dominantly quartz sandstones of Middle to Upper Jurassic age, overlain by dark organic limestones of Oxfordian to Lower Cretaceous age that suggest restricted, anoxic, conditions. The uppermost plate, unit 1, with the highest metamorphic grade, shows an age-equivalent section consisting entirely of quartz-muscovite schists with graphite, suggesting a much more argillaceous original sediment. This section is overlain by lightcolored calcareous schists and marbles, with a fine rhythmic stratification, which contain radiolaria and other organic remains. This upper plate, with the highest metamorphic grade, was therefore originally farther away from a source of sediment, possibly by some 200 km (124 mi), and seems to have had more open-marine conditions in the Late Jurassic– Early Cretaceous; it was also closest to the source of metamorphism. It is impossible from the published data to draw much of a trend for the Cretaceous. There appear to be two distinct groups of facies: (1) a carbonate-chert overlain by clastics and (2) a clastic overlain by volcanics and occasional carbonates. Both groups of facies overlie the Upper Jurassic Collantes open-water carbonates and grade transitionally into each other. It is not clear if these volcanics are related to the Cabaiguan* sequence; based on the TiO2 content, Milla´n and Somin (1985b) consider them of a different origin. At any rate, these volcanics are believed to be related to the metamorphism, which would place them in a direction opposite to the less metamorphosed quartz sandy section and, consequently, away from the source of sediments. Although it has been generally assumed that the direction of thrusting was from south to north, this direction of movement is uncertain; Milla´n and Somin (1985b) and Iturralde-Vinent (1996) recognize this possibility. Therefore, the direction of the source of the clastics that accumulated during the Jurassic is unknown. It might be significant that unit 1 is present only along the northern rim of the domes and is less metamorphosed than unit 2 that underlies it. The possibility exists that there were two sets of movements along the thrusts; for instance, an early south-to-north movement before metamorphism, followed by a late north-to-south one. The above data

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FIGURE 109. Eastern Cuba, metamorphic southwestern terrane.

could also be further evidence that the metamorphism of the Escambray massif was caused by a different phenomenon than the one that was responsible for the emplacement of the Manicaragua granodiorite.

Asuncion Area: Eastern Cuba It is a relatively small area 10  12 km (6  7 mi) near the town of Asuncion (see Figure 109) and in fault contact to the west with the metamorphics of the Purial massif. The stratigraphic thicknesses have not been measured, and those shown in Figure 110 are for illustration purposes only. This area was also studied by Milla´n and Somin (1981, 1985b) Chafarina Formation. —The Chafarina Formation consists of schistose calcitic and sometimes dolomitic marbles. In the east, the marbles are dark, micaceous, banded, commonly graphitic, and sometimes bituminous and grade transitionally into calcareous schists. Toward the west, the marbles are gray, cream, and pinkish, interbedded with dark-gray marbles. Dark-gray to black cherts are present and sometimes abundant. These beds are intensely deformed in isoclinal folds, making the measurement of thickness impossible; however, this might reach several hundreds of meters. In some dark-gray marbles, near the contact with the Sierra Verde Formation, are remnants of a dark-gray limestone with Ophtal-

midium sp., Spirillina sp., Chitinoidella(?) sp., and miliolids, suggesting an Upper Jurassic age possibly extending into the Lower Cretaceous. Sierra Verde Formation. —The Sierra Verde Formation consists mostly of phyllites and metamorphosed shales, with beds of crystalline limestone, metavolcanics, and metamorphosed cherts. The phyllites constitute 80% of the section and are black when fresh, graphitic, schistose, and finely banded. They weather to pinkish, violet, creamy, and greenish and occur in groups 600–1000 ft (200– 300 m) in apparent thickness. They contain sericite, graphite, quartz, chlorite, albite, and commonly, lawsonite. The quartz grains maintain their original sedimentary shape, and abundant detrital zircon exists. Isolated beds, or groups of beds, up to 65 ft (20 m) in thickness of a green to grayish green, fine- to medium-grained, sometimes banded rock with an imperfect schistosity exist. It contains albite, chlorite, actinolite, epidote, and sphene. Glaucophane and white micas are also present but in lesser quantities. This rock appears to be metamorphosed basic volcanics. One body of amygdular basalt, with altered plagioclase phenocrysts, was also observed. Regular interbeds of gray, schistose, laminated crystalline limestones up to 10 ft (3 m) thick exist, which

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FIGURE 110. Stratigraphic section: Asuncion metamorphics, eastern Cuba – southeastern Oriente.

occasionally contains small remnants of a uncrystallized cream limestone in which microfossils have been found. The fauna consists of Calpionella sp., Nannoconus sp., and undetermined globigerinidae (Ticinella? sp. and Hedbergella? sp.), suggesting a Neocomian age, possibly extending into the Tithonian.

Common interbeds of metamorphosed cherts and an argillaceous, lustrous (sericitic), meta-silicate schist showing abundant remains of radiolaria also exist. This unit is in fault contact with the metamorphic Gu ¨ ira de Jauco Formation to the west. The nature of the contact with the Chafarina Formation has

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not been described, but it is assumed that the Sierra Verde overlies it. According to Milla´n and Somin (1985a), the Sierra Verde Formation is similar to (with less sandstone) and possibly of the same age as the La Esperanza (and possibly the Santa Teresa) Formation of northern Pinar del Rio, but not the San Cayetano Formation as previously supposed (Somin and Milla´n, 1981). It also strongly suggests the Cifuentes* belt of central Cuba.

Asuncion Area Discussion The metamorphics of Asuncion show a possible slightly metamorphosed equivalent of the La Esperanza belt in Pinar del Rio and not the Jurassic clastic sequence that is present in other metamorphic massifs. This is very significant because it indicates the extent of the La Esperanza sandy facies, and it is also suggestive of the outcrops of the unmetamorphosed Neocomian Ronda* Formation along the Tuinicu fault separating the Manicaragua belt from the Cabaiguan* sequence north of the Escambray massif in central Cuba. The relation between the metavolcanics of the Purial and the Asuncion metamorphics is tectonic and further confused by the presence of ultrabasics. However, the band of ultrabasics separating the metamorphosed Cabaiguan* sequence from the Gu ¨ ira de Jauco amphibolites is believed to be part of the major ultrabasic Mayari-Baracoa thrust sheet that formerly covered the Purial massif and was wedged along the faults that separate the Purial from the Asuncion area. It is no coincidence that in central and western Cuba, amphibolites (Mabujina, Daguilla) are also found in contact with metamorphosed sediments, suggesting that the Asuncion area was originally part of a window of metamorphosed sediments showing through the thrust sheet of amphibolite basement under the Purial metavolcanics.

BASIC IGNEOUS-VOLCANIC TERRANE This province is a belt in the Pardo (1954) sense. It includes a wide variety of igneous rocks, metamorphic rocks, volcanic rocks, igneous- and volcanic-derived sediments, and some carbonates. Originally, Pardo (1954, 1975) subdivided it into the Domingo* basic igneous and the Cabaiguan* volcanic belts. In this study, it will be subdivided into the Domingo* and Cabaiguan* sequences. The Domingo* sequence (formerly Pardo’s Domingo* belt and part of Hatten’s Manicaragua unit) is generally to the north and

south of the volcanic terrane and consists mainly of basic to ultrabasic igneous rocks; the Cabaiguan* sequence (formerly Pardo’s Cabaiguan* belt and part of Hatten’s Manicaragua unit), generally in the center of the province, consists of mostly unmetamorphosed basic to arc volcanics and associated sediments and includes an Upper Cretaceous intrusive granodiorite body. The name Zaza is widely used in the present literature to describe the area where these types of rocks occur, but unfortunately, it has suffered the same nomenclatural confusion as the other belts. The Zaza tectounit was used by Hatten et al. (1958) for much of the rocks included in the basic igneous-volcanic terrane. However, the igneous rocks outcropping north of the Placetas* and Cifuentes* belts were, in large part, considered by them to be the basement of the Las Villas tectounit, whereas they were included in the Domingo* belt by Pardo (1954). Furthermore, the Zaza unit did not include the Manicaragua unit. This terrane was named (1) the Santa Clara zone by Ducloz and Vaugnat (1962), (2) the Zaza zone by Khudoley (1967), (3) the Santa Clara zone by Meyerhoff and Hatten (1968), (4) the Seibabo and Santa Clara zones by Knipper and Cabrera (1974), (5) the Zaza and Santa Clara zones by Dilla and Garcı´a (1985), and (6) the Zaza and Manicaragua units by Hatten et al. (1988). The Zaza zone in Pushcharovsky et al. (1988) appears to coincide fairly well with Domingo* sequence of this publication. In this chapter, the names have been extended to the entire island. These two sections are intimately related, and it is believed that at one time, the Domingo* sequence, including the metamorphosed Mabuyina amphibolite, was part of an oceanic basement upon which the Cabaiguan* sequence was deposited.

Central Cuba Central Cuba is considered the type area for the basic igneous-volcanic province and will be described first, followed by western Cuba, northern Cuba, and Oriente. For each region, the Domingo* and Cabaiguan* sequences will be described together (see Figure 111). Figure 112 is a correlation chart of all the basic igneous-volcanic terrane units of central Cuba. In the literature, the Mabuyina amphibolite and the granodiorite have been referred to as the Manicaragua belt (unit) and have been associated with the Escambray metamorphics. (A possible source of geographic confusion exists. In prerevolution days, the mountains along the south coast of Cuba, near the town of Trinidad,

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FIGURE 111. Central Cuba: basic igneous-volcanic generalized geologic map.

known then as the Trinidad Mountains, now appear in the literature as the Escambray massif. It includes the Sierra de Trinidad and the Alturas de Sancti Spiritus, whereas a range of low serpentine hills near the city of Santa Clara was used to be known as the Escambray Mountains and appear under that name in many old reports.) In this publication, the Mabuyina amphibolite is considered to be part of the Domingo* sequence, and the granodiorite intrudes and is part of the Cabaiguan* sequence. In Las Villas province, the basic igneous-volcanic province is bound on the north by the Domingo* fault and its imbrications and to the south by the Escambray fault zone that is considered to correlate with the Domingo* fault.

Domingo* Sequence The Domingo* sequence consists of an association of intermediate to ultrabasic igneous and metamorphic rocks having definite layering. Its distribution is almost impossible to describe accurately. It occurs north of the Jatibonico* belt, in long linear bands

between the Las Villas* and Cifuentes* belts and between the Las Villas* and Placetas* belts. To the south, it forms a nearly complete ring at the base of the volcanic section around the Escambray metamorphics. However, it mostly occurs south of the Cifuentes* and Placetas* belts. The width of the Domingo* sequence ranges greatly from a few kilometers to as much as 22 km (13 mi) in its maximum development southeast of Santa Clara. In central Camaguey, it mostly forms a large body south and east of the Sierra de Cubitas (see Figure 113). In Las Villas province, in general, this section can be divided into a Vega-Tamarindo area, a Santa Clara– Arroyo Blanco area occurring generally south of the first, and a northern Escambray area. The VegaTamarindo and Santa Clara–Arroyo Blanco areas are separated by a possible major imbrication of the Domingo* sequence at the base or within the serpentine. The Vega-Tamarindo area of the Domingo* sequence continues in a much reduced and structurally highly disturbed condition to the northwest between the Cifuentes* and Las Villas* belts. In the northern Escambray area, they rim a window of metamorphics

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FIGURE 112. Correlation chart, basic igneous-volcanic terrane, central Cuba.

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FIGURE 113. Central Cuba, Domingo sequence.

that can be seen through the Domingo* thrust. These rocks will be described according to their location as well as to their position in the sequence. The Domingo* sequence rocks outcropping in the central part of the Camaguey province will be described under the central Camaguey area section below.

Vega-Tamarindo Area It extends from Vega to Tamarindo, between the Placetas* and Las Villas* belts (see Figure 114). It is the northern part of what recent literature refers to as the Iguara´-Perea area (Iturralde-Vinent, 1996). Its northern boundary is along the Domingo* fault over the Las Villas* and Jatibonico belts. Its southern boundary is formed by an intra–Domingo* sequence imbrication, the Jarahueca* fault, that brings the serpentinites of the Santa Clara–Arroyo Blanco area in contact with the various lithologies described as follows (see Figure 115). Intermediate Igneous Rocks. — Within this group are diorites, quartz diorites, and granodiorites that have many common characteristics. The main rock type is a gray, medium-grained quartz diorite, commonly with black hornblende and biotite crystals standing out from a salt-and-pepper matrix. Some samples have a distinct gabbroic appearance. Quartz is not visible in most hand specimens. The principal mafic is a dark-green hornblende. The feldspar is labradorite or andesine. Most of the samples from this rock show crushing of the grains and appear to

be a mechanical mixture between diorite and basic igneous rocks. K. Dickson (1955, personal communication) stated that All the quartz diorites except for some few aplitic differentiates are cataclastic in varying degrees; no occurrence is lacking some stress phenomena. Quartz is crushed and rounded into granules, which appear as relicts in patches of newly formed, limpid, untwined albite. Biotite and chlorite are bent and smeared, and feldspar laths are cracked, show undulatory extinction and incipient replacement. . .Whether this cataclasis is due to emplacement in a crystalline state, or postintrusion deformation due to thrusting, or both, is unknown. . .. A great similarity in texture and composition exists between this igneous rock and the granodiorites that form the basement below the upper (southern) plate of the Cifuentes* belt. Gulf geologists recognized another widespread type of intermediate igneous rock and named it the Andre´s* Formation. The Andre´s* Formation is believed to be synonymous with the Perea metamorphics of Hatten et al. (1958), which they consider to be the result of the intrusion of a diabase by the Tre´s Guanos granodiorite (quartz monzonite) (Hatten et al., 1988). Hatten et al. (1958) also reported the intrusion of the San Marcos troctolite by the Tre´s

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FIGURE 114. Domingo* belt, Vega-Tamarindo, Santa Clara – Arroyo Blanco areas. Guanos granodiorite. Gulf considered the San Marcos troctolite as part of the ultrabasic sequence, the Venegas* Formation, which will be described below. The similarity among all the rocks of intermediate type, and the apparent intrusion of the Perea metamorphics and the San Marcos troctolite by the Tre´s Guanos granodiorite, is the main reason for including all these units as part of the pre–Lower Cretaceous basement, the median welt, of the Las Villas unit (Placetas* and Cifuentes* belts) by Hatten et al. (1958), Meyerhoff and Hatten (1968), Meyerhoff, in Khudoley and Meyerhoff (1971), and Hatten et al. (1988). This unit consists of a mixture of hornblende dolerite, hornblende-augite gabbro, hornblende dacite or quartz porphyry, and quartz diorite. This unit appears to be the result of the intrusion of basic igneous rock by quartz diorite. As already mentioned, the Tre´s Guanos granodiorite, outcropping in the southeastern rim of the Jarahueca window, and associated with the Jobosi* Formation, is probably the metamorphosed basement of the Cifuentes* belt upper plate. Therefore, it appears that in the Vega-Tamarindo area of the Domingo* sequence, a pre – Lower Cretaceous oceanic crust was intruded by and mechanically mixed with granodiorite as indicated by the

metamorphism and the abundant cataclasis. Milla´n and Somin (1981) consider the metamorphism to be of high temperature and low pressure. The timing of this intrusion has been a long-standing problem because of the similarity of all the granitoids in central Cuba. Several K-Ar age determinations have yielded ages from 70 to 88 m.y. (Milla´n and Somin, 1981, 1985b), correlating with the Upper Cretaceous volcanic arc, although there are arguments for the Andre´s Formation to be older and metamorphosed during the Upper Cretaceous. Ultrabasics.—In this area, the serpentine is characteristically absent, and the ultrabasics are represented by the gabbros of the Venegas* Formation. Venegas* Formation. —This formation consists of an unknown thickness, but probably several thousands of feet, of fine- to very coarsely crystalline uralite gabbro, olivine gabbro, hornblende gabbro, hornblende diallage gabbro, augite-hornblende gabbro, and epidiorite. It is of dark-gray color and weathers to dark greenish gray or powdery white and black. The feldspars, commonly up to 5 mm (0.2 in.) or larger, are borderline labradorite-bytownite, commonly replaced by zeolites. The coarse-grained development is restricted to the top of the unit. It is in contact

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FIGURE 115. Stratigraphic section: Domingo* sequence, Vega-Tamarindo area.

and intermixed with the underlying intermediate igneous described above. In places, it appears to be in conformable contact with the overlying serpentine, but is very probably in fault contact. The metabasites of the Venegas* Formation are considered to have been subjected to low-pressure (