ABSTRACT: Carbonate Platforms Along the Bahama-Hispaniola Collision Zone

H. T. Mullins, J. F. Dolan, N. A. Breen, B. C. Andersen

During July 1989 a SEAMARC II seismic reflection profile survey was conducted around the deep-water margins of carbonate platforms along the North American-Caribbean plate boundary where the southeast Bahamas are actively colliding with Hispaniola. Results indicate that the small, isolated carbonate banks of the southeast Bahamas are clearly remnants of once-larger platforms. A variety of processes appear to be responsible for the retreat of these platforms. Backstepping has resulted in the majority of retreat producing a single, large deep-water plateau along the northern margin of the southeast Bahamas and a series of deep-water, steplike terraces to the south that may be fault related. SEAMARC side-scan images have also defined spectacular, large-scale scalloped margin as well as well-developed upper gullied slopes which appear to be responsible for continued gradual retreat. Well-defined avalanche chutes, which may be the result of periodic collapse, extend down the deep margin of northern Silver Bank, funneling large volumes of debris over the Bahama Escarpment. The retreating nature of the isolated southeast Bahama Banks, located in a tectonically active setting, contrast sharply with the large, coalesced banks of the more passive northwest Bahamas.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990