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

这是一项系统和综合的岩石学、水文学和水化学研究，研究了佛罗里达州西南部上佛罗里达含水层的Ocala和Suwannee灰岩中的碳酸盐胶结作用。目的是确定(1)胶结是否正在形成，如果形成，原因是什么；(2)胶结的来源是什么；(3)这些岩石的胶结历史如何与含水层的水文地球化学历史联系起来。工作包括评估含水层胶结物的分布、性质和地球化学特征，以及这些属性与含水层水文和水化学的关系。成岩产物将通过标准岩石学技术、显微探针和同位素分析进行表征。水文和水化学将利用现有数据进行调查。将计算地下水流动路径、流量和化学物质质量通量。沿着流动路径的化学演化将与穿越的地质和水泥地球化学进行比较。本研究的结果将是现代区域碳酸盐含水层中碳酸盐胶结的实际预测模型。结果将告诉我们成岩作用发生了什么，在哪里发生，以及为什么发生。这将是第一次就胶结作用对现代区域承压含水层进行全面调查。因此，它将作为对从古代区域含水层中碳酸盐胶结的许多例子中得出的想法和模型的检验。

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.