Gneiss-Water Interaction and Water Evolution During the Early Stages of Dissolution Experiments at Room Temperature  

作　　者：朱义年 Ingrid Stober Kurt Bucher 

机构地区：[1]Dept. of Resource and Environmental Engineering, Guilin Institute of Technology [2]Geological Survey, Baden-Württemberg [3]Institute for Mineralogy, Petrology and Geochemistry, University of Freiburg

出　　处：《Chinese Journal Of Geochemistry》2003年第4期302-312,共11页中国地球化学学报

基　　金：FinancialsupportbyDAAD (GermanAcademicExchangeService)andtheSachtlebenBergbauGmbHisgratefullyacknowledged.

摘　　要：Gneiss\|distilled water interaction at room temperature was investigated with batch\|reactors to study water\|rock reaction and geochemical evolution of the aqueous phase with time. The ion concentrations in water were controlled not only by the dissolution of primary minerals, but also by the precipitation of secondary minerals. The decreasing fraction sizes of gneiss could favor dissolution and precipitation simultaneously. Ca\+\{2+\} and K\++ were the major cations, and HCO\+-\-3 was the major anion in water. All the ions except Ca\+\{2+\} increased in concentration with time. The Ca\+\{2+\} release from the rock to the aqueous phase was initially much faster than the release of K\++, Na\++ and Mg\+\{2+\}. But after about 5-24 hours, the Ca\+\{2+\} concentrations in water decreased very slowly with time and became relatively stable. During the experiment, the water varied from the Ca\|(K)\|HCO\-3\|type water to the K\|Ca\|HCO\-3\|type water, and then to the K\|(Ca,Na)\|HCO\-3\|type water. The water\|gneiss interaction was dominated by the dissolution of K\|feldspar in the solution. The remaining secondary minerals were mainly kaolinite, illite and K(Mg)\|mica.Gneiss\|distilled water interaction at room temperature was investigated with batch\|reactors to study water\|rock reaction and geochemical evolution of the aqueous phase with time. The ion concentrations in water were controlled not only by the dissolution of primary minerals, but also by the precipitation of secondary minerals. The decreasing fraction sizes of gneiss could favor dissolution and precipitation simultaneously. Ca\+\{2+\} and K\++ were the major cations, and HCO\+-\-3 was the major anion in water. All the ions except Ca\+\{2+\} increased in concentration with time. The Ca\+\{2+\} release from the rock to the aqueous phase was initially much faster than the release of K\++, Na\++ and Mg\+\{2+\}. But after about 5-24 hours, the Ca\+\{2+\} concentrations in water decreased very slowly with time and became relatively stable. During the experiment, the water varied from the Ca\|(K)\|HCO\-3\|type water to the K\|Ca\|HCO\-3\|type water, and then to the K\|(Ca,Na)\|HCO\-3\|type water. The water\|gneiss interaction was dominated by the dissolution of K\|feldspar in the solution. The remaining secondary minerals were mainly kaolinite, illite and K(Mg)\|mica.

关 键 词：gneLss WATER INTERACTION WATER evolufion 

分 类 号：P588.345[天文地球—岩石学]