Geologic Significance of Radiometric Dates from Cuba

Abstract

Nine radiometric dates from Cuba indicate that at least two thermal events have affected the island. One is 103-121 m.y. old (Neocomian-Cenomanian), and may correspond to an Early to middle Cretaceous orogeny, the evidence for which is well established by field mapping. Probably most of the granodioritic plutons of central and western Cuba are Early to middle Cretaceous, though more dates are needed to prove their age. A 180-m.y. date (Early Jurassic) from southern Las Villas Province does not fit the known history of Cuba, and its significance is not understood. Dates ranging from 61 to 78 m.y. (Campanian-early Paleocene) in the central and western parts of Cuba may reflect the onset of Campanian-Eocene orogeny, which culminated with the intrusion, 46-58 m.y. ago (late Paleocene-middle Eocene), of quartz diorite batholiths and stocks in southern Oriente Province, eastern Cuba. Except for the 180-m.y. date, the history of thermal events shown by the radiometric dates is similar to that of the Greater Antilles geosyncline (island arc) east of Cuba--from Jamaica and Hispanola to the Virgin Islands.