Changes

* the southwestern sedimentary terranes, with primarily thin stratigraphic sections of platform to [[pelagic]] [[carbonate]]s and [[chert]]s but locally with great thicknesses of older, continental-derived [[sandstone]]s and [[shale]]s showing various degrees of [[metamorphism]].

* the southwestern sedimentary terranes, with primarily thin stratigraphic sections of platform to [[pelagic]] [[carbonate]]s and [[chert]]s but locally with great thicknesses of older, continental-derived [[sandstone]]s and [[shale]]s showing various degrees of [[metamorphism]].

The most striking feature about the geology of the island is the great disparity between the [http://geology.about.com/od/platetectonics/a/ophiolite.htm ophiolite]-volcanic [http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3598.html] sequence of the basic igneous-volcanic terranes and the sedimentary sequences of the north-central 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 ophiolite-volcanic sequence is totally [[Allochthon|allochthonous]]. [[:file:St58OverviewFG5.JPG|Figure 3]] shows a map of Cuba's major structural features and terrane distribution, and [[:file:St58OverviewFG6.JPG|Figure 4]] shows, in cross section, the structural relations between the various terranes.

The most striking feature about the geology of the island is the great disparity between the [http://geology.about.com/od/platetectonics/a/ophiolite.htm ophiolite]-volcanic [http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3598.html] sequence of the basic igneous-volcanic terranes and the sedimentary sequences of the north-central 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 [http://geology.about.com/od/platetectonics/a/ophiolite.htm ophiolite]-volcanic sequence is totally [[Allochthon|allochthonous]]. [[:file:St58OverviewFG5.JPG|Figure 3]] shows a map of Cuba's major structural features and terrane distribution, and [[:file:St58OverviewFG6.JPG|Figure 4]] shows, in cross section, the structural relations between the various terranes.

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 [[plate]]s. 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]].

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 [[plate]]s. 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]].

Close similarities exist between the [[Mesozoic]] igneous [http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3598.html intrusive] and associated volcanic rocks of Cuba and those of the Caribbean.

Close similarities exist between the [[Mesozoic]] igneous [http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3598.html 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 [http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry45.html serpentinized] as in the northern Caribbean. Cuba's outcrops of [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000012 ultrabasic] rocks are the most extensive in the region.

[http://geology.about.com/od/platetectonics/a/ophiolite.htm 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 [http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry45.html serpentinized] as in the northern Caribbean. Cuba's outcrops of [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000012 ultrabasic] rocks are the most extensive in the region.

Similarities exist between the Caribbean and the Cuban Upper Cretaceous volcanic and associated [http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3598.html intrusive] rocks. The Cuban Upper Cretaceous [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000073 granodioritic] intrusion has counterparts outcropping in Hispaniola, Jamaica, and Puerto Rico in the north (where the intrusive's ages range into the [[Paleogene]]) 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.

Similarities exist between the Caribbean and the Cuban Upper Cretaceous volcanic and associated [http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3598.html intrusive] rocks. The Cuban Upper Cretaceous [https://wwwf.imperial.ac.uk/earthscienceandengineering/rocklibrary/viewglossrecord.php?gID=00000000073 granodioritic] intrusion has counterparts outcropping in Hispaniola, Jamaica, and Puerto Rico in the north (where the intrusive's ages range into the [[Paleogene]]) 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.

In these maps, [[autochthon]]ous nappes, allochthonous [[nappe]]s, and [[subduction]] will be used to describe, respectively, the thrusting toward the continent of the sediments, the [[Wikipedia:Basic_rock|basic]] igneous-volcanic rocks, and the subduction. Supported by observations in Cuba and elsewhere, these maps show subduction as the main cause of the uplift of a [http://geology.com/nsta/convergent-plate-boundaries.shtml 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.

In these maps, [[autochthon]]ous nappes, allochthonous [[nappe]]s, and [[subduction]] will be used to describe, respectively, the thrusting toward the continent of the sediments, the [[Wikipedia:Basic_rock|basic]] igneous-volcanic rocks, and the subduction. Supported by observations in Cuba and elsewhere, these maps show subduction as the main cause of the uplift of a [http://geology.com/nsta/convergent-plate-boundaries.shtml 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,<ref name=Burke_1988>Burke, K., 1988, Tectonic evolution of the Caribbean: Annual Review of Earth and Planetary Sciences, v. 16, p. 201-230.</ref> Pindell and Barrett,<ref name=Pindellandbarrett_1990>Pindell, J. L., and S. F. Barrett, 1990, Geologicla evolution of the Caribbean region, a plate-tectonic perspective, ''in'' The geology of North America, v. H: The Caribbean region: Geological Society of America, p. 405-432.</ref> Iturralde-Vinent,<ref name=Iturraldevinent_1996>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 Circum-Caribbean realm), 254 p.</ref> Cobiella-Reguera,<ref name=Cobiellareguera_2005>Cobiella-Reguera, J. L., 2005, Emplacement of Cuban ophiolites: Geologica Acta, v. 3, no. 3, p. 273-294.</ref> Garcia-Casco et al.,<ref name=Garciacascoetal_2006>Garcia-Casco, A., R. L. Torres-Roldan, M. A. Iturralde-Vinent, G. Millan, K. Nunez Cambra, C. Lazaro, and A. Rodriguez Vega, 2006, High pressure metamorphism of ophiolites in Cuba: Geologica Acta, v. 4, no. 1-2, p. 63-88.</ref> Giunta et al.,<ref name=Giuntaetal_2006>Giunta, G., L. Beccaluav, and F. Siena, 2006, Caribbean plate margin evolution: constraints and current problems: Geologica Acta, v. 4, no. 102, p. 265-277.</ref> and Pindell et al.<ref name=Pindelletal_2006>Pindell, J. L., L. Kennan, K. P. Stanek, W. V. Maresh, and G. Draper, 2006, Foundations of Gulf of Mexico and Caribbean evolution: Eight controversies resolved: Geologica Acta, v. 4, no. 1-2, p. 303-341.</ref> have interpreted the Cretaceous Cuban subduction as northeast [[dip]]ping and [http://en.wikipedia.org/wiki/Geomagnetic_reversals reversing polarity] to the southwest during the Late Cretaceous. Cuba's geology suggests that the subduction was continuously north dipping, and this concept is discussed in more detail below.

Burke,<ref name=Burke_1988>Burke, K., 1988, Tectonic evolution of the Caribbean: Annual Review of Earth and Planetary Sciences, v. 16, p. 201-230.</ref> Pindell and Barrett,<ref name=Pindellandbarrett_1990>Pindell, J. L., and S. F. Barrett, 1990, Geologicla evolution of the Caribbean region, a plate-tectonic perspective, ''in'' The geology of North America, v. H: The Caribbean region: Geological Society of America, p. 405-432.</ref> Iturralde-Vinent,<ref name=Iturraldevinent_1996>Iturralde-Vinent, M. A., ed., 1996, Ofiolitas y arcos volcanicos de Cuba (Cuban [http://geology.about.com/od/platetectonics/a/ophiolite.htm 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 Circum-Caribbean realm), 254 p.</ref> Cobiella-Reguera,<ref name=Cobiellareguera_2005>Cobiella-Reguera, J. L., 2005, Emplacement of Cuban ophiolites: Geologica Acta, v. 3, no. 3, p. 273-294.</ref> Garcia-Casco et al.,<ref name=Garciacascoetal_2006>Garcia-Casco, A., R. L. Torres-Roldan, M. A. Iturralde-Vinent, G. Millan, K. Nunez Cambra, C. Lazaro, and A. Rodriguez Vega, 2006, High pressure metamorphism of ophiolites in Cuba: Geologica Acta, v. 4, no. 1-2, p. 63-88.</ref> Giunta et al.,<ref name=Giuntaetal_2006>Giunta, G., L. Beccaluav, and F. Siena, 2006, Caribbean plate margin evolution: constraints and current problems: Geologica Acta, v. 4, no. 102, p. 265-277.</ref> and Pindell et al.<ref name=Pindelletal_2006>Pindell, J. L., L. Kennan, K. P. Stanek, W. V. Maresh, and G. Draper, 2006, Foundations of Gulf of Mexico and Caribbean evolution: Eight controversies resolved: Geologica Acta, v. 4, no. 1-2, p. 303-341.</ref> have interpreted the Cretaceous Cuban subduction as northeast [[dip]]ping and [http://en.wikipedia.org/wiki/Geomagnetic_reversals reversing polarity] to the southwest during the Late 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 Pszczolkowski.<ref name=Pszczoklowski_1999>Pszczolkowski, A., 1999, The exposed passive margin of North America in western Cuba, Caribbean basins, ''in'' P. Mann, ed., Sedimentary basins of the world: Amsterdam, Elsevier Sciene B.V., v. 4, p. 93-121.</ref> 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. '''Stratigraphic unit names followed by an asterisk (i.e., Capitolio*) were originally named by Gulf Oil Company geologists and might, or might not, be used today in the same context.'''

The paleogeographic history presented here is in general agreement with that of Pszczolkowski.<ref name=Pszczoklowski_1999>Pszczolkowski, A., 1999, The exposed passive margin of North America in western Cuba, Caribbean basins, ''in'' P. Mann, ed., Sedimentary basins of the world: Amsterdam, Elsevier Sciene B.V., v. 4, p. 93-121.</ref> 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. '''Stratigraphic unit names followed by an asterisk (i.e., Capitolio*) were originally named by Gulf Oil Company geologists and might, or might not, be used today in the same context.'''