鲁中隆起北缘地热区岩溶热储水化学特征及形成机理  

Hydrogeochemical characteristics and formation mechanism of the karst thermal reservoir at the northern edge of the Luzhong Uplift

作　　者：江露露 隋海波 康凤新 李常锁 魏善明 于令芹 李越 JIANG Lulu;SUI Haibo;KANG Fengxin;LI Changsuo;WEI Shanming;YU Lingqin;LI Yue(801 Institute of Hydrogeology and Engineering Geology,Shandong Provincial Bureau of Geology&Mineral Resources,Jinan,Shandong 250014,China;Shandong Engineering Research Center for Environmental Protection and Remediation on Groundwater,Jinan,Shandong 250014,China;College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;Shandong Engineering Technology Research Center for Geothermal Clean Energy Exploitation and Reinjection,Dezhou,Shandong 253072,China)

机构地区：[1]山东省地质矿产勘查开发局八〇一水文地质工程地质大队,山东济南250014 [2]山东省地下水环境保护与修复工程技术研究中心,山东济南250014 [3]山东科技大学地球科学与工程学院,山东青岛266590 [4]山东省地热清洁能源探测开发与回灌工程技术研究中心,山东德州253072

出　　处：《中国岩溶》2023年第5期1005-1026,1036,共23页Carsologica Sinica

基　　金：国家自然科学基金项目(42072331,U1906209)。

摘　　要：通过研究鲁中隆起北缘岩溶热储地热水水化学特征,分析岩溶热储地热水的形成机理。以鲁中隆起北缘地热区内32个地热井为研究对象,采用Piper图解、Schoeller图解、离子组分比率特征、同位素特征、Na-K-Mg平衡图解、矿物饱和指数计算与评价等方法,研究地热水的补给来源、水岩作用过程、运移途径、循环演化特征和形成机理。结果表明:在岩溶地下水向地热田径流方向上,岩溶地下水的水化学类型与地热水的明显不同,岩溶水的TDS含量呈增加趋势,而HCO3-含量百分比呈现降低趋势;同一地热田区段的地热水水化学成分相似、水化学类型相同。研究区地下热水中微量组分F、Li、Sr、偏硅酸等含量表现出增加的趋势。通过使用玉髓地热温标计算的地热区岩溶热储温度为39~70℃,地热水的循环深度为856~1877 m,结合测温曲线特征分析,确定研究区地热系统为对流-传导型。水文地球化学演化、离子组分比率、同位素等多种分析方法,揭示出岩溶热储地热水的补给来源为地热区南部泰山北麓山区晚更新世寒冷气候条件下古大气降水的入渗;大气降水入渗补给岩溶含水层后,经地下水深循环径流运移,在大地热流、地下水运移传导-对流加热作用下形成地热水。The geothermal area in the northern edge of the Luzhong Uplift is located between Mount Tai and the northwest plain of Shandong.In terms of the geotectonic division,the study area is located in the Luzhong Uplift of the Luxi Uplift in the North China Plate,which is fan-shaped with the arc facing north in the plane,and it is a monoclinal structure with the stratum tilting gently to the north.There is a very thick layer of Cambrian-Ordovician carbonate strata in the northern edge of the Luzhong Uplift,which has the geothermal geological conditions for the formation of a large karst geothermal field.Under the influence of the collision of the Pacific Plate and Eurasian Plate,especially the tectonic activity on the rim of the Pacific Plate since the Mesozoic,NW and NE oriented fracture structures have been widely developed in the study area.This combination of tectonic structures with different ages and properties provides the preconditions for the formation of karst geothermal resources characterized by the convection-conduction between low and medium temperatures in this area.The main aquifer in the study area is the Cambrian and Ordovician carbonate aquifer,which is directly or indirectly replenished by atmospheric precipitation in the exposed karst area in the upper and middle reaches.Some of the precipitation is concentrated and flows out in a small area,and the remaining water continues to flow to form a karst water enrichment zone in the downstream piedmont,intermountain basins and hidden limestone distribution areas in the valleys.The karst thermal reservoirs in the northern edge of the Luzhong Uplift in Shandong Province are rich in low-and medium-temperature geothermal resources,which are characterized by a large water yield and easy recharge.Thus,we can study the hydrogeochemical characteristics of the geothermal water to analyze the formation mechanism of the geothermal resources,which is of great significance in promoting the effective development and utilization of geothermal resources.In this study,32

关 键 词：岩溶热储 地热水 同位素特征 地热温标 成因机理 

分 类 号：P641.134[天文地球—地质矿产勘探] P314.1[天文地球—地质学]