摘要
太原盆地是新生代断陷盆地,盆地内受南北和东西多组断层控制形成了多个断垒、断块,岩溶热矿水主要分布在三给地垒以南和田庄断裂以北的区域。岩溶热矿水的主力产水层为奥陶系的峰峰组和上、下马家沟组的碳酸盐岩储层。项目组采集了18个地热水样品,同时收集了已有文献中的9个地热水和3个地下冷水的水化学数据。根据分析化验结果,岩溶热矿水的水化学类型为SO4-Ca·Mg型。根据热矿水中的离子浓度关系和主要矿物的饱和度指数可以推断水化学类型主要受石膏层的影响。地下水溶滤过程中除了方解石与白云石溶解作用外,石膏的溶解作用占主导地位。根据矿物饱和度指数,石膏溶解产生过多Ca2+以及热矿水温度的升高还导致了方解石或者白云石更加饱和,可能发生沉淀。西温庄隆起内的岩溶热矿水混合了古水,年龄均大于20 000 a,岩溶热储温度为72.6~91.1℃,循环深度为2123~2663 m。长时间的水岩相互作用,为热矿水的形成提供传导加热的时间和丰富的矿物质组分。西温庄隆起作为岩溶热矿水温度、TDS以及锶浓度的高值区,是盆地内热矿水的汇水区,同时也是区域热矿水条件最好的区域。TDS和Sr浓度升高趋势反映了地下水从补给区到盆地内排泄区明显的溶滤作用,并且发生了由低TDS的HCO3-Ca·Mg型地下冷水往高TDS的SO4-Ca·Mg型岩溶热矿水的发展。
Taiyuan Basin is a Cenozoic fault basin.The formation of faults block and horst in the basin is controlled by the north-south and east-west faults.The karst thermal mineral water is mainly distributed in the area between the Sanji horst and the Tianzhuang fault.The main aquifers of karst thermal water are the carbonate of the Ordovician Fengfeng group,the upper and lower Majiagou groups.We took 18 geothermal water samples in the field,and collected the hydrochemical data of 9 geothermal water and 3 geothermal water in the existing literature.According to the analysis and test results,the hydrochemical type of karst thermal water is SO4-Ca·Mg type.According to the ion concentration relationship and the saturation index of the main mineral in the thermal mineral water,it can be inferred that the hydrochemical type is mainly affected by the gypsum layer.In addition to the dissolution of calcite and dolomite,the dissolution of gypsum plays a leading role in the process of groundwater dissolution and filtration.According to the mineral saturation index,Ca2+produced by gypsum dissolution and the increase of geothermal mineral water temperature also lead to the saturation of calcite or dolomite,which may lead to precipitation.The effect of the dissolution of gypsum on the dissolution of calcite and dolomite has an inhibitory effect.The age of karst thermal mineral water in the Xiwenzhuang uplift is more than 20000 a,which is mixed with ancient water.The temperature of karst thermal reservoir is 72.6~91.1℃,and the depth of circulation is 2123~2663 m.Long-term water-rock interactions provide the time of conduction heating and enriched mineral components for the thermal mineral water.As the high value area of the temperature,TDS and Sr concentration in karst thermal mineral water,Xiwenzhuang uplift is the catchment area of thermal mineral water in the basin,and also the best area of regional thermal mineral water.The increasing trend of TDS and Sr concentration reflects the obvious dissolution and filtration of groundwater from recharge area to drainage area in the basin.There are occurred such a trend:cold underground water with low TDS and hydrochemical type of HCO3-Ca·Mg to karst thermal mineral water with high TDS and hydrochemical type of SO4-Ca·Mg.
作者
罗璐
毛翔
汪新伟
朱霞
何春艳
刘芮
LUO Lu;MAO Xiang;WANG Xinwei;ZHU Xia;HE Chunyan;LIU Rui(Sinopec Star Petroleum Ltd.,Beijing 100083,China;Key Laboratory of Geothermal Resources Exploitation and Utilization,Sinopec,Beijing 100083,China)
出处
《工程地质学报》
CSCD
北大核心
2020年第4期925-934,共10页
Journal of Engineering Geology
基金
中国石化集团科技项目(资助号:JKL18033)。
关键词
岩溶热矿水
太原盆地
石膏层
Karst thermal mineral water
Taiyuan basin
Gypsum layer
