藏南拉康温泉地质特征及雄曲河谷两岸地热分布不均成因分析  

GEOLOGICAL CHARACTERISTICS OF LAKANG HOT SPRING IN SOUTHERN TIBET AND GENETIC ANALYSIS OF UNEVEN DISTRIBUTION OF GEOTHERMAL ENERGY IN XIONGQU RIVER VALLEY

作　　者：石圣 赵德军[1] 蒋祥 翁新海 陈伟 Shi Sheng;Zhao Dejun;Jiang Xiang;Weng Xinhai;Chen Wei(College of Earth Science,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Zhejiang Design Institute of Water Conservancy and Hydroelectric Power,Hangzhou,Zhejiang 310002,China;Zhejiang Jingchang Construction Co.LTD.,Hangzhou,Zhejiang 310002,China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]浙江省水利水电勘测设计院,浙江杭州310002 [3]浙江景昌建设有限公司,浙江杭州310002

出　　处：《矿物岩石》2021年第1期106-115,共10页Mineralogy and Petrology

摘　　要：西藏山南地区洛扎县雄曲河拉康段在600 m距离内出露温泉4处,仅1处位于河谷右岸;平硐勘查显示两岸岩性、产状、构造一致,地热异常却仅在左岸平硐内部显著,右岸平硐地热异常不明显。本次研究以此异常为出发点,通过片麻状花岗岩不同切面导热实验、片麻状花岗岩与板岩相同切面导热实验,温泉水δ~2H,δ~(18)O同位素测试分析等方法,探究该处河谷两侧地热异常的成因,得出以下结论:1、该处地热资源为干热岩型地热资源,热源是深部岩浆,氢氧同位素显示温泉热水来源于大气降水;2、片麻状花岗岩平行和垂直片麻理方向存在导热各向异性,当温度恒定时平行于片麻理方向比垂直于片麻理方向温度高5.5%~6.0%;3、河流的下切作用使得两岸岩体覆盖程度存在差异,导致两岸地热异常不均。本次研究成果可以为深切峡谷地区寻找浅层干热岩、干热岩发电与水力发电共同开发提供一定启示。In the Lakang section of the Xiongqu River in Luoza County,Shannan Prefecture,Tibet,there are 4 hot springs within 600 meters,only 1 of which is located on the right bank of the valley.Adit exploration shows that the lithology,occurrence and structure of both banks are consistent,but the geothermal anomaly is only obvious in the left bank adit,and not obvious in the right bank adit.Taking the anomaly as a starting point,this paper explored the causes of geothermal anomalies on both sides of the valley through thermal conductivity experiments on different sections of gneissic granite,thermal conductivity experiments on the same section of gneissic granite and slate,and throughδ2H andδ18O isotope tests and analysis of hot spring water.The results show that the geothermal resources in this area are dry hot rock geothermal resources originated from deep magma.The analysis of hydrogen and oxygen isotopes shows that the hot spring water comes from meteoric precipitation.There is anisotropy of thermal conductivity in the parallel and vertical directions of gneissic schistosity.When the temperature is constant,the temperature in the direction parallel to gneissic schistosity is 5.5%-6.0%higher than that in the direction perpendicular to gneissic schistosity.The downcutting of the river causes the difference in the coverage degree of rock mass between the two sides,resulting in uneven geothermal anomalies.The research results of this paper can provide some enlightenment for the exploration of shallow dry hot rock in deep canyon area and the joint development of dry hot rock power generation and hydroelectric power generation.

关 键 词：地热资源 片麻状花岗岩 导热各向异性 干热岩发电 雄曲河 

分 类 号：P584[天文地球—岩石学] P641.3[天文地球—地质学]