西宁盆地地下热水的TDS分布特征及富集机理  

Distribution characteristics and enrichment mechanism of TDS geothermal water in Xining Basin

作　　者：孙红丽[1,2,3] 王贵玲 蔺文静[1,2] Sun Hongli;Wang Guiling;Lin Wenjing(Insitute of Hydrogeology and Environmental Geology,CAGS,Shijiazhuang 050061,China;Technology Innovation Center of Geothermal&Hot Dry Rock Exploration and Development,Ministry of Natural Resources,Shijiazhuang 050061,China;National Observation and Research Station on Groundwater and Land Subsidence in Beijing-Tianjin-Hebei Plain,Shijiazhuang 050061,China)

机构地区：[1]中国地质科学院水文地质环境地质研究所,石家庄050061 [2]自然资源部地热与干热岩勘查开发技术创新中心,石家庄050061 [3]京津冀平原地下水与地面沉降国家野外科学观测研究站,石家庄050061

出　　处：《地质科技通报》2022年第1期278-287,299,共11页Bulletin of Geological Science and Technology

基　　金：国家重点研发项目(2019YFB1504101);国家自然科学基金项目(41602271);中国地质调查项目(1212011220842)。

摘　　要：西宁盆地大部分地下热水中TDS含量较高,极大限制了地热水的可利用性,研究盆地地下水TDS的成因机理,可为后期指导地热资源开发利用提供参考价值。通过对西宁盆地药水滩至盆地中心沿线地下水的常、微量组分的分析,探讨了区内TDS的分布特征及富集机理。结果表明:从盆地边缘到盆地中心,地下水由HCO_(3)-Ca·Mg型淡水逐渐向SO_(4)·Cl-Na、SO_(4)-Na型盐、卤水变化,地下水具有陆相沉积水特征,且变质程度逐渐增强;盆地内不同区域TDS的富集机理也有显著差异,盆地边缘以降水入渗、溶解混合作用为主,湟水中心区域以蒸发浓缩作用和混合、水-岩相互作用为主,而盆地中心区域则以深部沉积物质随热液上涌的混合作用和封闭环境下的水-岩相互作用为主。The high concentration of TDS in most of the geothermal water in Xining Basin greatly restricted the availability of geothermal water.In order to provide reference value for the later development and utilization of geothermal resources,the enrichment mechanisms of TDS were identified.Based on the analysis of major and trace components of hot and cold underground water along the line from Yaoshuitan to central basin,the distribution characteristics and enrichment mechanism of TDS in the basin were discussed.It was shown that the groundwater changed from fresh water to brine with hydrochemical types changed from HCO_(3)-Ca·Mg to SO_(4)·Cl-Na and SO_(4)-Na,characterized by continental sedimentary water.The metamorphic degree gradually increased from the edge to the central part of the basin.The enrichment mechanisms of TDS were also significantly different in different regions of the basin.On the margin,the precipitation infiltration,minerals'dissolution and mixing among different aquifer were the dominated mechanisms;In Huangshui transitional zone,evaporation,mixing and water-rock interaction were the main mechanisms;while in the central basin,the dominated factors were the mixing of deep sediments or saline material upwelling with hydrothermal from the deep and the water-rock interaction in closed environment.

关 键 词：西宁盆地 高TDS 分布特征 富集机理 

分 类 号：P641[天文地球—地质矿产勘探]