ABSTRACT

The carbonate mineralogy of the sediments in ten cores from Exuma Sound is interpreted to reflect Pleistocene sea level changes. Sediments in the lower parts of the cores contain abundant low-magnesium calcite and relatively little aragonite. This carbonate mineral assemblage is interpreted as representing a mineralogically stable, recycled sediment derived from the extensive Bahama Banks which were exposed during the latest Pleistocene sea level lowering. During this period of exposure the mineralogically unstable, aragonite-rich bank sediments were subaerially altered to low-magnesium calcite.

The restoration of sea level and the return to the normal biological aragonite producing processes are reflected in the increased aragonite content in the upper parts of the cores studied. The mineralogic inflection with increasing core depth from the aragonitic to the calcitic sediments is abrupt and does not appear to be related to textural changes in the cores.