GEOLOGIC RATIONALE FOR HYDROCARBON EXPLORATION IN THE CARIBBEAN AND ADJACENT REGIONS

Sedimentary basins in the Caribbean and adjacent areas are assessed in terms of the plate‐tectonic and paleogeographic history of the regions. Primary phases of development were rifting and passive margin development during Jurassic‐Cretaceous drift of North from South America; and the Late Cretaceous to Recent relative eastwards migration of the Caribbean Plate from the eastern Pacific area to its present position between North and South America. Two primary stratigraphic suites of rock occur in the Caribbean region: (I) autochthonous Jurassic, Cretaceous and Cenozoic passive margin sediments deposited along the rifted margins of North and South American basement: and (2) allochthonous oceanic crustal and magmatic arc rocks and overlying sedimentary units of the migrating Caribbean Plate. The tectonic boundary between these suites coincides roughly with the limit of circum‐Caribbean thrusted metamorphic/mafic rocks above the formerly passive Proto‐Caribbean shelf rocks (episutural foredeep basins), and juxtaposition youngs from west (latest Cretaceous in southern Yucatan) to east (late Neogene in Trinidad). Although Jurassic rift/early drift‐related source rocks occur in some areas. such as in Cuba—Bahamas. the primary source rocks in both suites were deposited well after rifting in the “medial” Cretaceous. Basin development during the Late Cretaceous to Recent tectonic juxtaposition of the two suites (i.e. Caribbean migration) directly controlled both clastic reservoir facies deposition and hydrocarbon maturation in many areas around the Caribbean. Basin development, source and reservoir rock deposition, and maturation of source rocks in all basins in the region can be directly related to plate‐tectonic evolution. A satisfactory understanding of the hydrocarbon potential of the Caribbean/northem South American province therefore requires a full appreciation of the region's plate‐tectonic evolution.