CUBAN GEOLOGY - A NEW PLATE-TECTONIC SYNTHESIS

Cuba is considered here to consist of two separate geological units: a foldbelt and a neoatttochthon. The foldbelt can be subdivided into: (i) continental units, comprising Mesozoic Bahamian Platform and slope deposits, which are overlain by a Paleocene- Late Eocene foreland basin; and the Cuban SW terranes (Guaniguanico, Pinos and Escambray), which were probably originally attached to the Yucatan Platform; (ii) oceanic units, namely: the northern ophiolite belt; the Cretaceous (?Aptian-Campanian) volcanic arc, which is overlain by a series of Latest Cretaceous - Late Eocene ''piggy-back'' basins; and the Paleocene-Middle Eocene volcanic arc which is overlain by a late-Middle - latest Eocene ''piggy-back'' basin. The neo-autochthon is composed of slightly-deformed, latest Eocene to Recent sedimentary rocks, which unconformably overlie the folded belt. A large number of tectonic models for the Caribbean area have been published in recent years, but rarely include modern data on the geology of Cuba. The Author here presents a plate-tectonic model for the western Caribbean which is based on the following premises: (i) opening of the Caribbean took place along several parallel rifts-zones, and a main transform fault located between the entrance of the Gulf of Mexico and the Demarara Plateau; (ii) the Cretaceous Greater Antilles volcanic arc faced the ProtoCaribbean Sea, and essentially northward-dipping subduction took place; and (iii) the western Caribbean Paleocene-Middle Eocene volcanic arc also faced the Caribbean Sea, with subduction dipping towards the NNW. Hydrocarbon production in Cuba comes from oilfields located in both continental and oceanic units. The Northern Oil Province coincides with the Bahamian platform and slope deposits and the Guaniguanico Terrain. The Southern Oil Province is represented by the latest Cretaceous - late Eocene sedimentary basins and the Cretaceous volcanic arc.