Paleogeography and Geological History of Greater Antilles

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Abstract
The Greater Antilles Mesozoic-early Tertiary orthogeosyncline originally was either a basin between the Bahamas platform on the north and a land-mass on the south (on the site of the present Caribbean), or an island-arc system between the Bahamas-Turks and Caicos-Atlantic Ocean basin on the north, and an oceanic basin (modern Caribbean Sea) on the south. The Greater Antilles was not continuous with, or a part of, the Lesser Antilles arc, which is a younger, independent tectonic unit. The oldest Greater Antillean rocks may be Paleozoic, and are present mainly in central and western Cuba. They consist of metamorphosed graywacke, argillite, tuff, mafic igneous extrusive flows, mafic sills, and carbonates. The oldest rocks dated paleontologically are Early and Middle Jurassic terrigenous clastic strata and evaporites in Cuba. The Greater Antilles orthogeosyncline formed in latest Jurassic-Early Cretaceous time from Cuba to the Virgin Islands, and persisted until Eocene time. Locally 10 to 12 km of mafic to silicic igneous rocks and clastics accumulated. In Cuba and the Bahamas, 6 to 7 km of carbonates and evaporites were deposited. A Cretaceous foredeep trough occupied northeastern Jamaica. This trough faced the western Jamaica Paleozoic(?) “backland,” which the writers interpret to be an eastward extension of the Paleozoic-Tertiary Northern Central American orogen. Since Eocene time, isolated basins developed in which carbonate sedimentation was dominant, and the Greater Antilles no longer was a tectonically active arc. Orogeny and related crustal movements have been almost continuous since the Jurassic. Wrench-type and vertical block faulting, beginning locally in middle Cretaceous or earlier time, gradually fragmented the once-continuous orthogeosyncline. Granodioritic intrusions, having radiometric dates ranging from 180 to 46 m.y., are scattered through the orthogeosynclinal sequence. Tectonism—not of the island-arc type—continues today.

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