Mixing of Sea Water with Calcium Carbonate Ground Water

作者：L. Niel Plummer · 发表于：Geological Society of America eBooks · 年份：1975 · DOI：10.1130/mem142-p219 · 被引用次数：175 · 研究领域：Groundwater and Isotope Geochemistry、Calcium Carbonate Crystallization and Inhibition

The mixing of sea water and (or) saline subsurface water with fresh calcium carbonate ground water can be of major importance in the chemical diagenesis of carbonate rocks and sediments. A computational scheme for calculation of the theoretical distribution of dissolved species in mixtures of two solutions was developed and used to evaluate the effect of mixing saline water with fresh calcium carbonate ground water. The calculations include data on (1) mixtures of surface sea water (pH 8.15) with solutions in equilibrium with calcite at CO2 partial pressures from 10−4 to 1.0 atm at 5°, 15°, 25°, and 35° C; (2) mixtures of surface sea water with solutions twofold saturated with calcite; and (3) mixing of actual saline water and fresh carbonate ground water from central Florida and the Yucatan Peninsula. The results show that the amount of undersaturation in mixtures is a function of PCO2, temperature, ionic strength, degree of calcite saturation, and pH of end-member solutions prior to mixing. All mixtures of surface sea water and saturated calcium carbonate ground water investigated containing 0 to 10 percent sea water by volume were undersaturated with calcite. The range of undersaturation increased greatly with increasing PCO2 (above 10−3 atm) in calcite-saturated water and with decreasing temperatures. No undersaturation occured in mixtures of surface sea water and supersaturated calcium carbonate ground water (twofold saturated) having CO2 partial pressures less than 10−2...