An Actualistic Model of Cementation Patterns in a Modern Regional Carbonate Aquifer

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This is a systematic and integrated petrographic, hydrologic, and hydrochemical study of carbonate cementation in the Ocala and Suwannee Limestones of the upper Floridan aquifer in southwestern Florida. The objectives are to determine (1) if cements are forming and if so, why, (2) what is the source of the cements, and (3) how the cementation history of these rocks relates to hydrogeochemical history of the aquifer. Work includes evaluation of the distribution, nature, and geochemical signatures of the aquifer cements and the relationship of these attributes to the hydrology and hydrochemistry of the aquifer. The diagenetic products will be characterized by standard petrographic techniques, and microprobe and isotopic analyses. The hydrology and hydrochemistry will be investigated using existing data. Groundwater flow paths, flow volumes, and chemical mass fluxes will be calculated. Chemical evolution along flow paths will be compared to the traversed geology and cement geochemistry. The result of this study will be an actualistic, predictive model of carbonate cementation in a modern, regional carbonate aquifer. The results will tell what happens diagenetically, where, and why. This will be the first comprehensive investigation of a modern, regional, confined aquifer with respect to cementation. As such, it will serve as a test of the ideas and models derived from the many examples of carbonate cementation in ancient regional aquifers.