Erik A. Shamberger, 1998, Depositional History of a Coastal Evaporite Salina - Salt Pond, San Salvador Island, Bahamas.

ABSTRACT

Salt Pond is a coastal salina on the eastern shore of San Salvador Island, Bahamas. The salina is unusual among San Salvadoršs many lakes in that it undergoes a period of dessication on a regular basis, according to local and anecdotal sources. Historical salinity, rainfall, and lake level data demonstrate a high degree of correlation between lowered precipitation, lake level, and higher salinities. Because of its location on the windward side of San Salvador Island, the salina has unique potential to act as a sediment trap to record events that affect the local climate, such as storms. Investigation of the salinašs thin veneer of sediment (< 2 m thick) demonstrates a succession from a marine subtidal environment, to a fresh water condition, followed by periods of saline intrusion and increasing salinity. The pond sediments also demonstrate several marked zones of presumed storm washover events left by a series of storms. These markers may be useful in determining the local climatic history of San Salvador and give insight into the frequency of hurricane or tropical cyclone events in the past 2,000 years. Currently, carbonate sediments in the pond are undergoing dolomitization. X-ray diffraction analysis of the sediment from one core in the salina has detected dolomite at approximately 37 cm. Porewater chemical analyses demonstrate that the sediment in the salina, under normal island conditions, are within the dolomite stability field at the surface. As such, it offers a unique opportunity to study this process as it occurs.