Accreted shallow-water carbonate terranes are a common feature of many ancient mountain belts, yet the tectonic history of the majority these terranes remains poorly understood. In many cases, this is because early deformational structures associated with initial accretion have been overprinted and obliterated by post-accretion structural and metamorphic events. In order to fully understand the mechanism(s) of these shallow- water carbonate terranes, an active collision zone involving a shallow-water carbonate bank must be studied. A detailed swath mapping and seismic reflection study of the active collision between the southeastern Bahamas and the island of Hispaniola will be used. Here, the small, isolated banks of the Bahamas are colliding obliquely with the northern margin of Hispaniola, as part of the broad, transpressional North American-Caribbean Plate boundary. The collisional setting of the southeast Bahamas contrasts markedly with the tectonically quiescent, passive-margin setting of the northwest Bahamas, providing an unparalleled opportunity to compare and contrast the development of shallow-water carbonate banks in widely differing tectonic regimes. proposed use of the SeaMARC II seafloor mapping system, in conjunction with digitally recorded single-channel seismic reflection profiles, provides a system that is ideally suited for our proposed studies, which will focus on documenting shallow structures and surficial sedimentary features within the collision zone. %%% Carbonate deposits in mountain belts are commonly associated with shallow marine sediments that have been thrust onto the continent during tectonic episodes. This project will study carbonate sediments on the Hispaniola margin as a modern analog of the type of carbonate terrains that are found in tectonically active regions. The sedimentology and structural setting will be examined using a combination of coring, seismic stratigraphy, and side-scan sonar imaging (SeaMarc II). Results may be used to interpret carbonate sediments in the many accreted terrains where such deposits are found.
