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

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δ2H,δ18O同位素测试分析等方法,探究...

GEOLOGICAL CHARACTERISTICS OF LAKANG HOT SPRING IN SOUTH-ERN TIBET AND GENETIC ANALYSIS OF UNEVEN DISTRIBUTION OF GE-OTHERMAL ENERGY IN XIONGQU RIVER VALLEY

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.