二氧化硅和锶的地球化学迁移影响因素研究

Study on the Factors Influencing Geochemical Migration of Silicon Dioxide and Strontium

[目的]研究在表生地球化学环境下,有益组份二氧化硅和锶在地下水中形成及迁移的影响因素。[方法]通过研究盘山地区含水介质的矿物成分、表生地球化学作用、造岩矿物的风化程度和水交替强度,研究了二氧化硅和锶的地球化学迁移的影响因素。[结果]微量元素锶在风化石英二长岩中的平均含量为0.075%,在原岩中为0.076%。该区流量大于20m3/h的井均位于岩脉两侧或接触带上,年均降雨量677.1mm。半风化岩石的有益组份溶出量最高,新鲜岩石次之,全风化岩石溶出量最少。二氧化硅和锶的溶出受水动力条件影响较大。[结论]盘山地区二氧化硅和锶的地球化学迁移与含水层介质的岩性、表生地球化学作用的发生、造岩矿物的风化程度及地下水交替强度关系密切。

[Objective] The purpose was to study the factors influencing the formation and migration of beneficial components such as silicon dioxide and strontium in underground water under hypergenic geochemistry- environment. [Method] The factors influencing geochemical migration of dioxide silicon and strontium were studied through studying the mineral composition of aquifer medium, hypergenic geochemistry process, weathering degree of rock-forming mineral and water-exchange intensity in Panshan area. [Result] The average content of microelement strontium was 0.075% in weathered adamellite and 0.076% in original rock. In this area, the wells whose fluxes were bigger than 20 m^3/h all located in both the sides or contact zone of dyke and the annual average rainfall was 677.1 mm. The dissolved amount of beneficial components from semi-weathering rock was highest, that from fresh rock was secondary and that from thoroughly weathered rock was least. The dissolution of dioxide silicon and strontium was more influenced by hydrodynamic condition. [Conclusion] The geochemical migration of dioxide silicon and strontium in Panshan area closely related to the lithology of aquifer medium, occurrence of hypergenic geochemistry process, weathering degree of rock-forming mineral and exchange intensity of underground water.