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 basi n; and the Cuban SW terranes (Guaniguanico, Pinos and Escambray), whic h were probably originally attached to the Yucatan Platform; (ii) ocea nic units, namely: the northern ophiolite belt; the Cretaceous (?Aptia n-Campanian) volcanic arc, which is overlain by a series of Latest Cre taceous - 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-defo rmed, latest Eocene to Recent sedimentary rocks, which unconformably o verlie the folded belt. A large number of tectonic models for the Cari bbean area have been published in recent years, but rarely include mod ern data on the geology of Cuba. The Author here presents a plate-tect onic model for the western Caribbean which is based on the following p remises: (i) opening of the Caribbean took place along several paralle l rifts-zones, and a main transform fault located between the entrance of the Gulf of Mexico and the Demarara Plateau; (ii) the Cretaceous G reater Antilles volcanic arc faced the ProtoCaribbean Sea, and essenti ally northward-dipping subduction took place; and (iii) the western Ca ribbean Paleocene-Middle Eocene volcanic arc also faced the Caribbean Sea, with subduction dipping towards the NNW. Hydrocarbon production i n Cuba comes from oilfields located in both continental and oceanic un its. The Northern Oil Province coincides with the Bahamian platform an d slope deposits and the Guaniguanico Terrain. The Southern Oil Provin ce is represented by the latest Cretaceous - late Eocene sedimentary b asins and the Cretaceous volcanic arc.