Una introducción a la metalogenia de Cuba bajo la perspectiva de la tectónica de placas

Abstract

Six main metallogenic epochs can be distinguished in the geological constitution of the island of Cuba. A first stage from Jurassic to Early Cretaceous times, included a rift episode involving materials from the Bahama and Yucatán continental paleomargin. Base metals sedex deposits (Pb-Zn-Cu) and Mn, associated with gold and silve r, are to be found in the detrital and carbonated series associated to this process. An arc (or arcs) of volcanic islands developed during the Aptian (Neocomian?)-Campanian stage. Three metallotects are to be found associated to the formation and development of this arc: a) the uppermost part of the suprasubduction zone mantle section, where bodies of ophiolitic chromitites occur, b) the back-arc volcanosedimentary submarine series, with volcanogenic deposits of massive sulfides (Kuroko and Cyprus type), Mn oxide exhalative mineralizations and zeolite deposits, and, c) the intrusive series and rocks in the axial zone of the arc, with iron and polymetallic skarn deposits, porphyry copper deposits and Au-Ag epithermal deposits. The first collisional process, between the Yucatán paleomargin and the Cretaceous volcanic arc, as well as the beginning of the collision between the Caribbean plate and the North-American plate, took place during the late Campanian-Danian stage. Orogenic gold mineralizations and, probably, tumgsten deposits date from this period. A volcanic arc, trending E-W, developed in eastern Cuba from Late Danian to Middle Eocene times. Major volcanogenic Mn deposits in Cuba are located within the Paleogene volcanic island arc in eastern Cuba. This volcanic activity also originated some major volcanogenic sulfide deposits, skarn and porphyry copper deposits, as well as zeolite deposits. Known metallotects in this geodynamic environment include: a) the volcanic and volcanosedimentary series located along the axial arc-back arc boundary, with volcanogenic sulfide deposits (Kuroko type) and Mn oxide volcanogenic deposits, and b) granitic intrusives related to the axial arc volcanic, with skarn and porphyry copper deposits. In western and central Cuba, in turn, piggy-back sedimentary basins associated to the collisional process between the Caribbean plate and the North-American plate developed during Danian-Middle Eocene times. Major orogenic gold mineralizations are associated with this process. A series of post-volcanic basins developed during the Middle Eocene-Late Eocene stages in eastern Cuba, some of which are associated to Mn resedimented mineralizations. Meanwhile, the development of sedimentary basins with olistostromes, associated to the collisional process, continued in central and western Cuba. Cuba finally joined the North-American plate at the end of this episode. Orogenic gold mineralizations may also occur in association with these processes. A shelf environment was established in Cuba from Late Eocene to Quatern a ry times. At that point, extensive Fe-Ni-Co laterite crusts (one of the largest examples of this type of deposit worldwide), bauxite crusts, gossan deposits (Fe, Au, Ag), resedimented Mn deposits, and marine and fluvial placer deposits, rich in noble metals, originated.