Geochemical investigation of salt-water intrusion into a coastal carbonate aquifer: Mallorca, Spain
Geochemical investigation of salt-water intrusion into a coastal carbonate aquifer: Mallorca, Spain
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盐水侵入沿海碳酸盐含水层的地球化学调查：西班牙马略卡岛
DOI：
10.1130/0016-7606(1991)103
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发表时间：
1991
影响因子：
4.9
通讯作者：
J. Herman
中科院分区：
文献类型：
--
作者：
R. Price;J. Herman
研究了西班牙马略卡岛混合带内碳酸盐矿物成岩作用和更新世石灰岩含水层内孔隙度和渗透率变化的地球化学过程。在靠近海岸的两个地点，从淡水区、混合区和海水区顶部采集了岩芯和地下水样品。在一个研究地点附近抽取地下水，使地下水位降至海平面以下，造成海水侵蚀和稀薄的混合区。对岩芯进行的实验室测试表明，孔隙度和水力传导性没有增强内的过渡位置的现代混合区。岩芯中的洞穴区与地下水位的大致位置相对应。由于地下水相对于碳酸盐矿物是过饱和的，因此无法预测现今混合带的石灰岩含水层的溶解。质量平衡和源岩计算结果表明，相对于保守混合的预期，混合区沃茨中的钙和锶过量。这些升高的浓度被假设为导致石灰石溶解在渗流带。
Geochemical processes occurring within the mixing zone on Mallorca, Spain, were investigated in relation to the diagenesis of carbonate minerals and to the development of porosity and permeability within the Pleistocene limestone aquifer. Rock core and ground-water samples were obtained from the fresh-water zone, the mixing zone and the top of the sea-water zone at two sites near the coast. Ground-water withdrawals in the vicinity of one study site depressed the water table to below sea level, resulting in sea-water encroachment and a thin mixing zone. Laboratory tests conducted on the rock core indicated that porosity and hydraulic conductivity were not enhanced within the transitory location of the present-day mixing zone. Vuggy zones in the core correspond to the approximate location of the water table. Because the ground water was supersaturated with respect to the carbonate minerals, dissolution of the limestone aquifer is no predicted for the present-day mixing zone. Results of mass-balance and source-rock calculations indicated an excess of calcium and strontium in the mixing-zone waters in relation to what was expected from conservative mixing. These elevated concentrations are hypothesized to result from limestone dissolution in the vadose zone.