Hydrogeology of Southern Cumberland Island, Georgia. Kings Bay EnvironmentalMonitoring Program Cumberland Island National Seashore, 1990

摘要

The aqueous geochemistry of three aquifers at a 9-square mile study site on thesouthern end of Cumberland Island, Georgia was investigated at 10 wells on the southern end of the island. The geochemistry of the surficial aquifer varied spatially across the island. The ground water types in the surficial aquifer ranged from sodium-chloride to calcium-bicarbonate, depending on the location. A zone of dispersion associated with the freshwater-saltwater interface was encountered in the Pliocene-Miocene age aquifer and the Miocena-age sand aquifer, but was not encountered in the surficial aquifer. The zone of dispersion resulted from mixing of fresh carbonate ground water seawater. The freshwater region of the zone of dispersion (3%-5% seawater) was characterized by a calcium-chloride water type which likely resulted from freshwater-seawater mixing, calcium carbonate dissolution, and reverse ion exchange.