DROXLER, ANDRE, and ANDREW CUNNINGHAM, Rice University, Houston, TX, A. C. HINE, PAMELA HALLOCK, and DAVID DUNCAN, University of South Florida, St Petersburg, FL, ERIC ROSENCRANTZ and RICHARD BUFFLER, University of Texas, Austin, TX, and EDWARD ROBINSON, UWI, Kingston, Jamaica.

ABSTRACT: Late middle (?) Miocene Segmentation of an Eocene to Early Miocene Carbonate Megabank on the Northern Nicaragua Rise Tied to the Tectonic Activity at the North America/Caribbean Plate Boundary Zone

The Northern Nicaragua Rise (NNR) is comprised today of the eastern Honduras/Nicaragua and southern Jamaica carbonate shelves, and a series of relatively small detached carbonate banks (i.e., Pedro, Rosalind, Serranilla, Diriangen, and Bawika Banks) separated from each other by intervening basins and seaways. The NNR basins and seaways, because of their common north trending orientation, have been previously interpreted as Paleocene, Eocene, and possibly Oligocene rifts, becoming progressively younger from the eastern to the western part of NNR.

Results from three recent (1988 and 1992) high resolution seismic surveys within these major seaways and basins, (1) Walton Basin, (2) Pedro Channel, and (3) seaways and Serranilla Basin on the western side of the NNR, show that the present bank and basin configuration evolved from a once continuous megabank that covered the entire length of the NNR, including the Island of Jamaica from Eocene through early Miocene times. In the late middle (?) Miocene, this megabank progressively broke up into a series of smaller banks, basins and seaways, mainly as the result of tectonic movements related to the overall strike-slip displacement within the North American and Caribbean Plate Boundary Zone of the Cayman Trough. At the same time (late middle Miocene), the most eastern portion of the meg bank was uplifted and today forms most of central and south Jamaica. The timing of the megabank segmentation has tentatively been constrained by dating several blocks of shallow water limestone dredged from parts of the megabank outcropping on the sea floor of different seaways.

AAPG Search and Discovery Article #90988©1993 AAPG/SVG International Congress and Exhibition, Caracas, Venezuela, March 14-17, 1993.