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Regional Studies |
Lunar and Planetary Institute, 3303 NASA Road One, Houston, Texas 77058, USA
Seismic Research Unit, University of the West Indies, St Augustine, Trinidad
Department of Physical Sciences, Florida International University, Tamiami Trail, Miami, Florida 33134, USA
Department of Geology, George Washington University, Washington DC, 20006, USA
The ophiolites of the northern Caribbean represent latest Jurassic and Cretaceous oceanic crust which was obducted from the mid-Cretaceous to the Paleogene. The majority of these ophiolites are early Cretaceous in age and were emplaced during the late Cretaceous. The late Cretaceous geological history can be successfully interpreted in terms of a northward-migrating island arc which subducted Atlantic crust to the south beneath Pacific crust. This arc collided with southern Yucatan in Campanian times to form the Guatemalan ophiolites, and in Paleogene times with the Bahamas platform to form the central and western Cuban ophiolites. Both these collisions involved underthrusting by carbonate-mantled continental forelands. However, the eastern extension of this subduction zone, the North Coast belt of Hispaniola, has not been thrust over the Bahamas platform. The provenance of these arc-related ophiolites should be Atlantic ocean crust. Back-arc spreading to the south of this arc during the late Cretaceous — Paleocene may have produced the source material for the Jamaican and Oriente ophiolites and also for the Dumisseau Fm. of the Southern Peninsula of Haiti. The oldest ophiolites in central Hispaniola and Puerto Rico are possible candidates for crust of Pacific provenance, perhaps isolated during an early Cretaceous change of subduction polarity. However, our preferred model for the Cordillera Central of Hispaniola is as the base of an accretionary prism with southward-dipping subduction. All but the Cuban ophiolites have suffered varying degrees of strike-slip dismemberment during the Cenozoic.
