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Detailed Reference Information |
Montgomery, H., Pessagno, E.A., Lewis, J.F. and Schellekens, J. (1994). Paleogeography of Jurassic fragments in the Caribbean. Tectonics 13: doi: 10.1029/94TC00455. issn: 0278-7407. |
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Jurassic rocks of the Caribbean are a sampling of 100 million years of Farallon Plate history with fragments originating at diverse paleolatitudes and from varied tectonic settings. Fragments with clear paleogeographic signatures are components of the basement complexes of Duarte in Hispaniola, Bermeja in Puerto Rico, and La D¿sirade off Guadeloupe. Paleolatitudinally sensitive radiolarian faunas document origination of Duarte as equatorial, La D¿sirade as higher latitude, and various Bermeja cherts as both equatorial and higher latitude. Red ribbon chert of Duarte and Bermeja of the same age, physical appearance, and lithological association are probably dismembered components of the same slab of Pacific crust. La D¿sirade red ribbon chert is slightly younger than the Duarte and Bermeja red ribbon chert and was deposited at higher latitude. Bermeja tuffaceous chert is also of higher latitude and probably had an arc-proximal origin. On the basis of modeled plate trajectories in the Pacific, the origin of various cherts from different paleolatitudes that end up in the same location requires different arrival times at the trench between North and South America. Based on radiolarian paleobiogeography plus indications of origin at a spreading ridge and ignoring the poorly constrained, modeled trajectories for the Late Jurassic, at least one of the higher latitude fragments may have originated in the southern hemisphere. The accumulation of multifarious chert, greenstone, and other ocean floor components was accomplished by offscraping strata transported to the subduction zone along the eastern Pacific margin and warehousing this material in an accretionary complex prior to entry of the Caribbean Plate into the gap between North and South America. |
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Abstract |
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Keywords
Marine Geology and Geophysics, Plate tectonics, Marine Geology and Geophysics, Micropaleontology, Information Related to Geologic Time, Mesozoic |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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