Goreau
Peter David Efran
Goreau
Peter David Efran
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ThesisThe tectonic evolution of the North Central Caribbean plate margin(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1981-01) Goreau, Peter David EfranThe results of a detailed geophysical survey are used in conjunction with all available information in a study of the tectonic development of the Cayman Trough and the Greater Antilles Ridge. This development is connected with the relative motions of the North and South Americas and the eastern Pacific plates. Thus, the pre-Tertiary history of the region is one of simple convergence. This contrasts with the complex tectonism of primary translation, with secondary convergence and divergence during the Tertiary. The ancestral Greater Antillean Arc suffered fracturing during collision with the Bahamas stable platform in the Late Cretaceous. Oblique convergence re-established itself across the remnant fragments of the ancestral arc in the Tertiary, producing a sheared welt partially decoupled from both the North American and Caribbean plates. Pronounced temporal and structural heterogeneity occurs within this Plate Boundary Zone. Along its northern margin secondary convergence with the North American plate formed the massive subduction complex of the Cuchillas Uplift and the Sierra Septentrional. Convergence between the Plate Boundary Zone and the Caribbean plate resulted in the triple virgation of the fold belts extending westward from the Los Muertos Trough to Oriente Province (Cuba), the Cayman Trough and the Nicaraguan Rise. Tectonism along these fold belts youngs southwestward preserving the stratigraphy of the Caribbean Basin at the time of their formation during the early, middle, and late Tertiary. The Caribbean/North American Plate boundary occurred along the zones of major strain accomodation within the Plate Boundary Zone. The Cayman Trough was produced during a period of divergence between the Nicaraguan Rise and the North American plates during the Miocene. Since the Pliocene, the shear boundary within the Cayman Trough occurs along the Oriente Deep proceeding via the Windward Passage Deep and the Valle del Cibao to the Puerto Rico Trench. Convergence and shear predominate the present tectonic framework of the Plate Boundary Zone.