Plate tectonic evolution of the Caribbean region in the mantle reference frame
- 1 January 1984
- book chapter
- Published by Geological Society of America
Abstract
The mantle reference frame defined by stationary hotspots has been used to determine the positions and motions of continental and oceanic plates surrounding the Caribbean region from late Jurassic time (140 m.y.) to the present. First, the position of the Pacific plate and the Pacific-Farallon spreading ridge has been reconstructed using the ages and geometry of island and seamount chains emanating from Pacific hotspots. Then, by assuming symmetric spreading across the Pacific-Farallon ridge, the motion of the Farallon plate relative to the mantle has been calculated. This shows that the postulated oceanic plateau which may form the core of the present Caribbean plate could have been erupted onto late Jurassic to early Cretaceous oceanic lithosphere as the Farallon plate passed over the Galapagos hotspot, hypothesized to have been initiated in mid- to late Cretaceous time (100 to 75 m.y. B.P.). The thickened volcanic plateau collided with the Greater Antilles Arc, then filling the gap between South America and nuclear Central America, in late Cretaceous time (80 to 70 m.y. B.P.) and was not subducted; instead, subduction of the Farallon plate commenced behind the plateau. This buoyant, indigestible piece of oceanic lithosphere drove the Greater Antilles Arc northeastwards, accompanied by subduction of proto-Caribbean crust, until it collided with the Bahama platform in late Eocene time. Concomitantly, the trench and island arc which developed behind (southwest of) the plateau generated what is now a part of Central America. Subsequent westward subduction of Atlantic lithosphere beneath the Lesser Antilles Arc and continuing eastward subduction of oceanic lithosphere beneath Central America, together with transform faulting (left-lateral Cayman transform fault in the north, right-lateral strike-slip motion in and off Venezuela in the south) defined the present boundaries of the Caribbean plate.Keywords
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