Circum-Caribbean Sedimentary Basin Development and Timing of Hydrocarbon Maturation as a Function of Caribbean Plate Tectonic Evolution

Abstract

Sedimentary basin development in the Caribbean region is closely tied to the region’s plate tectonic evolution, which involved (1) Jurassic rifting and passive margin development between North and South America, and (2) Late Cretaceous to Recent relative eastward 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: (1) an autochthonous suite of Jurassic, Cretaceous, and Cenozoic passive margin sediments that was deposited along the rifted margins of North and South American basement after Jurassic continental breakup, and (2) an allochthonous suite consisting of oceanic crustal and magmatic arc rocks and overlying sedimentary units of the Caribbean Plate. The boundary of these suites coincides roughly with the limit of circumCaribbean thrust belts of metamorphic/mafic rock above the formerly passive Proto-Caribbean shelf rocks. Most of the sediments of the allochthonous Caribbean Plate were deposited during the relative eastward translation between the Americas, and the older sections (Cretaceous) were deposited while thePlate was still in the eastern Pacific realm. Primary source rocks in both suites were deposited in the early Late Cretaceous, well after rifting and plate separation in the Proto-Caribbean Seaway between the Americas.The timing of maturation of source material for hydrocarbons in the circum-Caribbean region is predicted herein to match the times of (1) highest heat flow or (2) most rapid subsidence and sediment accumulation in various basins around the Caribbean. Early maturation (Jurassic or Early Cretaceous) of Jurassic, Proto-Caribbean rift sediments, if local source material was present in them, may have occurred in areas of high heat flow related to rifting such as along some extensional basins of the northern Andes (e.g., Sierra Perija, Cordillera Merida, and Oriental). In contrast, well-known lower Upper Cretaceous source rocks of the Proto-Caribbean suite, deposited long after rifting, probably did not mature until a sufficient sedimentary overburden had accumulated above them. Throughout the primary circum-Caribbean basins (Guatemalan Sepur, southern Bahamas/Cuban, Venezuelan Maracaibo and Maturin), thick clastic units were deposited in foredeep basin settings above the previously passive (shelf) margins of the Proto-Caribbean Seaway. Development of the foredeep basins and rapid sedimentation (and predicted onset of hydrocarbon maturation) occurred in relation to the relative eastward advance of the Caribbean Plate from the Pacific, as the leading edge of the Caribbean Plate overthrust the former passive margins of the Proto-Caribbean Seaway. Peak maturation is predicted to have occurred in the latest Cretaceous to early Paleogene in southern Yucatan (Guatemalan Sepur), the Paleogene in northern Cuba/ Bahamas and the Maracaibo area of Venezuela and Colombia, and in the Neogene and Quaternary in eastern Venezuela and Trinidad. In addition, however, Neogene intermontane basin sedimentation related to Andean uplift in northwest South America (e.g., Maracaibo), provided a second, Neogene to Present period of predicted maturation in the basins there. Hydrocarbon potential from the Cretaceous section of the allochthonous, Caribbean suite of rocks has yet to be realized.KeywordsSource RockLate CretaceousPassive MarginCaribbean RegionHigh Heat FlowThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.