A re-evaluation of facies on Great Bahama Bank I: new facies maps of western Great Bahama Bank

A re-evaluation of the sediment distribution patterns on western Great Bahama Bank shows a facies distribution with two end-members. Coarse-grained sediments in the north, west and south of the bank surround a mud-dominated realm located on the western leeward side of Andros Island. This facies distribution is comparable to earlier maps, but shows considerably more detail and a complex distribution from grainstones to mud-rich wackestones. As in other carbonate platforms, sediment distribution appears to be infl uenced by (1) tidal currents, (2) prevailing wind direction, and (3) the interaction of the rate of Holocene sea-level rise with the pre-existing Pleistocene topography. The grain-size distribution very precisely refl ects current-infl uenced and protected areas on the platform. The correlation between the distribution of pellets and the 63–125 µm grain-size fraction most probably refl ects the predominantly biological origin of this grain size. Aragonite dominates the mineralogy on the platform, low-magnesium calcite and high-magnesium calcite occurs in higher quantities only in