HR: 1340h
AN: T33B-1386    [Abstracts]
TI: Arc-continent collision on the southern Margin of North America: Cuba and Hispaniola
AU: * Draper, G
EM: draper@fiu.edu
AF: Dept. of Earth Sciences, Florida International University, SW 8th Street, Miami, FL 33199 United States
AU: Pindell, J
EM: jim@tectonicanalysis.com
AF: Tectonic Analysis Ltd., Chestnut House, Burton Park, Duncton, GU28 0LH United Kingdom
AB: Comparison of the geology of Cuba and Hispaniola demonstrates how different tectonic styles can be produced in closely adjacent parts of the accretion arc. Cuba is a laterally extensive fold-and-thrust belt that includes a narrow belt of Early Cretaceous to Campanian arc rocks, ocean crust, sub-oceanic mantle and metamorphosed continental crust. Hispaniola represents a broader and more complete (although deformed) Early Cretaceous to Eocene arc structure with a single accreted, metamorphosed continental terrane. We suggest that Cuba's preset arc terrane is essentially a fore-arc that was underplated by continental crust in the Campanian collision of the Greater Antilles arc with southern Yucatan. Following this collision, the proto Caribbean lithosphere detached from the eastern margin of Yucatan resulting in rapid, north directed rollback. This, in turn, developed extension of the over-riding Cuban lithosphere and exhumed the underplated continental crust as extensional metamorphic core complexes. The present Cuban fold belt was formed as a result of collision with the southern margin of North America in the mid-Eocene. In contrast, Hispaniola was to the east of Cuba and was not detectably involved in the Campanian collisional event. At present, it is not clear if the extensional rollback event that affected Cuba had any significant effect on Hispaniola. Hispaniola's collision with North America began in the late Eocene(?) and culminated in the Oligocene and was highly oblique. This event resulted in highly oblique, south-verging thrusting that telescoped the back arc basin. It also produced a pop-up structure that reveals evidence of an earlier, mid-Cretaceous collisional event within the arc. This oblique collision persists until the present.
DE: 8102 Continental contractional orogenic belts
DE: 8105 Continental margins and sedimentary basins
DE: 8110 Continental tectonics--general (0905)
DE: 8158 Plate motions--present and recent (3040)
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting