Investigating the Origin and Possible Structural Control of Artesian Springs in the Southeastern Coastal Plain of Georgia

Data from a preliminary investigation suggests that two well-known carbonate springs in the southeastern coastal plain of Georgia are artesian in nature and are structurally controlled. The general chemistry of the springs shows the water to be a calcium-bicarbonate type, and plots on a mixing line whose end members consist of deep-well water and surface waters in the area. The chemical data also show that the spring water is mixing with shallow groundwater prior to discharging at the spring head. Other geologic data suggest that the two springs, located 30 kilometers apart, are related to possible deep-seated basement structures. Here the two springs lay along the trace of a strong gravity and magnetic anomaly that trends east-northeast, which is consistent with known basement features in the area. At one site the spring head is located in limestone that has been determined to be Oligocene in age, and is in stratigraphic juxtaposition with the surrounding clastic rocks of Miocene age. It is hypothesized that the missing geologic section is either fault related or due to non-deposition.

The preliminary data from this investigation are significant in that few other data are available on the mechanism for spring flow in the southeastern Georgia coastal plain. This study also adds to the very limited data that exists on the structural influence of groundwater flow in the region. Additional geochemical and field mapping are planned which should help characterize the hydrologic and structural controls of the two springs.