The oldest part of the Caribbean region proper is in northern Central America, where Permian (?) and Lower Permian marine deposits rest on metamorphic rocks of unknown, possibly middle Paleozoic, age. According to present dating, geosynclinal deposition spread eastward in Late Jurassic time to include Cuba, farther eastward and southward in Early Cretaceous time to include Hispaniola and probably Jamaica, and still farther eastward in Late Cretaceous time to include Puerto Rico, the Virgin Islands, and St. Croix.
Throughout the Caribbean region, the Cretaceous is characterized by volcanics of great thickness, pyroclastics being more widespread and thicker than flows. These volcanics evidently were derived from lands of unknown size that are now under the waters of the Caribbean Sea. Land still persisted south of eastern Cuba during Eocene time. Thereafter no geological evidence is now available pointing to land in the Caribbean Sea.