Seismic Stratigraphy and Geologic Development of an Open-Ocean Carbonate Slope: The Northern Margin of Little Bahama Bank

Carbonate slope development north of Little Bahama Bank (LBB) has been investigated via a seismic stratigraphic analysis of approximately 1350 km of air-gun seismic reflection profiles.Slope development is shown to be complex because of the interaction of slope accretion, sediment bypassing, and submarine erosion to produce a single open-ocean carbonate slope.The present slope north of LBB did not develop until after the complete drowning of the southern Blake Plateau near the end of the Cretaceous.Beginning in the early Tertiary and continuing through the present, this slope has accreted laterally by the accumulation of periplatform oozes along its upper slope, whereas submarine slides and sediment gravity flows have bypassed the upper slope, resulting in a lower slope apron of slide blocks, turbidites, and debris flows.Slope sedimentation north of LBB was more or less continuous, with the exception of a late Oligocene erosional event that may be correlative with the "A u " unconformity in the western North Atlantic.Overall, slope accretion, sediment bypassing, and submarine erosion have acted together during plate tectonic drift to higher latitudes, numerous sea-level fluctuations, and local tectonics to produce a single, open-ocean carbonate slope.This area is well-suited for future Deep Sea Drilling Project drill sites to evaluate the demise of a shallow-water carbonate platform and subsequent carbonate slope development.