OUTLINE OF THE GEOLOGY OF CUBA

The Cuban segment of the Greater Antilles orogen is a collage of tectonic terranes which represent both continental and oceanic lithosphere. Continental basement is represented by Neoproterozoic and Paleozoic marble and schist and Early Jurassic granites, overlain by Jurassic-Cretaceous units of the former Bahamas borderland and Guaniguanico terrane. Mesozoic sediments are represented by NW-SE elongated deformed belts, where passive continental margin rocks are unconformably overlain by synorogenic Paleocene-Eocene foredeep deposits recording the collision of the western Caribbean Plate (CARIB) with the Bahamas. Former Maya block (Yucatan) borderlands outcrop in tectonic units represented by Caribeana metamorphic terranes which yield HP/LT subduction-related metamorphism, associated with the latest Cretaceous collision between N. America and CARIB. The leading edge of the CARIB plate along the northern half of the island is represented by a subduction-related serpentinite mélange with HP/LT inclusions and by forearc Mesozoic ophiolites deformed from latest Cretaceous through Late Eocene time. CARIB volcanic arc rocks occur in distinct settings. Cretaceous arc rocks are represented by Early Cretaceous arc tholeiites, unconformably overlain and intruded by Albian-Coniacian calc-alkaline and Coniacian-Campanian high-K calc-alkaline plutonic and volcanic rocks. The Late Cretaceous Mabujina amphibolite arc complex, cropping out in south central Cuba, underlies the weakly metamorphosed Cretaceous magmatic arc rocks. Latest Cretaceous-Late Eocene synorogenic deposits unconformably rest above the Cretaceous arc and ophiolitic rocks. The Paleocene-Eocene section laterally grades into arc tholeiites, restricted to eastern Cuba. The youngest components of the Cuban foldbelt are Latest Eocene to Recent postorogenic autochthonous deposits characterized by slight deformation, with the exception of a highly deformed strip along the active Caribbean plate boundary (Oriente transform).