青海省贵德县热水泉干热岩体地质-地热地质特征  

Characteristics of regional and geothermal geology of the Reshuiquan HDR in Guide County,Qinghai Province

作　　者：张森琦[1] 吴海东 张杨[1] 宋健 张林友 许伟林 黎敦朋[3] 李胜涛[1] 贾小丰[1] 付雷[1] 李旭峰[1] 冯庆达 ZHANG Senqi;WU Haidong;ZHANG Yang;SONG Jian;ZHANG Linyou;XU Weilin;LI Dunpeng;LI Shengtao;JIA Xiaofeng;FU Lei;LI Xufeng;FENG Qingda(Center for Hydrogeology and Environmental Geology Survey,China Geological Survey,Baoding,Hebei,071051;Environmental Geological Prospecting Bureau of Qinghai Province,Xining,810007;College of Zijin Mining,Fuzhou University,Fuzhou,350116)

机构地区：[1]中国地质调查局水文地质环境地质调查中心,河北保定071051 [2]青海省环境地质勘查局,西宁810007 [3]福州大学紫金矿业学院,福州350116

出　　处：《地质学报》2020年第5期1591-1605,共15页Acta Geologica Sinica

基　　金：国家重点研发计划(2018YFB1501801);中国地质调查局地质调查项目(编号DD20190131、DD20160192、DD20190127、DD20189113、DD20190132)资助的成果。

摘　　要：贵德县热水泉干热岩体平面上呈半椭圆形展布于NNW向区域性新街断裂带组分的热光断裂之西,面积约122km2。ZR1孔钻探结果表明:干热岩体上部为具自封闭盖层性质的中温水热型地热田,2800~3050m属相对完整或隔水的次高温花岗岩体,3050.68m深处温度为151.34℃,进入干热岩段。干热岩体热储为侵位于233.2~222.3Ma的中晚三叠世花岗岩,岩石类型主要有闪长岩、花岗闪长岩、二长花岗岩和钾长花岗岩等。具正花状构造结构的新街-瓦里关走滑挤隆构造带为区域性控热导热构造,并对干热岩体的就位有明显的控制作用。基于大地电磁测深、高分辨率重力异常、电阻率与Rayleigh波群相速度线性反演,以及地质综合分析认为,以壳内部分熔融层供热为主,地幔热流供热、沿走滑断裂带上升的晚期小熔体与双倍地壳U、Th、K等放射性元素衰变生热为叠加热源,一并构成的复合型热源,是热水泉干热岩体最有可能的热源机制。The Reshuiquan hot dry rock(HDR)in the Guide County,with an area of approximately 122 km2,is characterized chiefly by semi-elliptical shape and lies in the west of the Reguang fault which is part of Xinjie fault zone with NNW trend.The ZR1 well reflects that the upper part of the Reshuiquan HDR is a medium-temperature hydrothermal system with self-enclosed capping properties.A relatively complete or impermeable sub-high temperature granite body is observed from 2800 mto 3050 m.The temperature of the stratum at 3050.68 mis 151.34°C,indicates that a HDR layer is developed.This HDR reservoir is mainly composed of middle-late Triassic granite whose time intruded into the stratum is 233.2~222.3 Ma.The rock types of the granite can be subdivided into diorite,granodiorite,monzonitic granite and K-feldspar granite.The Xinjie-Waliguan strike slip and extrusion structural zone,marked by a regular flower structure,is a regional heat conduction channel and controls the regional distribution for the HDR.Comprehensive analysis on the magnetotelluric sounding,high-resolution gravity anomaly,linear inversion of resistivity and phase velocity of Rayleigh wave group,and geology show that the heat source mechanism of the Reshuiquan HDR is most probable a compound heat source.These partial melting layers within the continental crust are the most important heat sources for this HDR.Furthermore,a superposition heat source for this HDR comes from the mantle heat flux,small melting body rising along the strike-slip fault zone during the late period,and decay of radioactive elements such as U,Th,and K within the double crust.

关 键 词：地热地质 干热岩 花状构造 热源机制 贵德县热水泉 

分 类 号：P314[天文地球—固体地球物理学]