成都理工大学学报（自然科学版）2025，Vol.52Issue(4)：223-235,13.DOI:10.12474/cdlgzrkx.2024020201
西藏南北地堑典型地热田水化学特征与热储温度空间分布规律
Hydrogeochemical characteristics and spatial distribution of reservoir temperature in the north-south trending grabens of southern Xizang
摘要
Abstract
Many high-temperature geothermal systems have developed in the north-south trending graben system of southern Xizang,which is located at the middle of the Mediterranean-Himalayan geothermal belt.However,the evolutionary characteristics of the fluid geochemistry and the distribution of reservoir temperature in graben-controlled geothermal systems are poorly understood.In this paper,the geochemical characteristics of thermal water from 15 geothermal systems in selected grabens(Shenzha-Dingjie,Yadong-Gulu,and Cuona-Woka)are analyzed through a combined geological survey,hydrogeochemical sample measurements,and data compiled from 258 hot springs.The reservoir temperatures of different geothermal fields are estimated using geochemical geothermometer measurements.The results indicate that the water in the thermal spring from the northern grabens is HCO3-Na and Cl-Na type,while that in the southern part is Cl-Na type.The depth of fluid circulation,the mixing ratio with cold groundwater,water-rock interactions,and the dissolution and precipitation of mineral are all factors controlling the water type.Meteoric water,snow meltwater,and magmatic water are the water sources of the hot spring in the north graben,while the sources of the hot spring in the south part are meteoric water and snow meltwater.The reservoir temperature of the geothermal field is characterized by being higher in the north and lower in the south,and the thermal reservoir in the Yadong-Gulu graben is the hottest.There are two high-temperature reservoirs with temperatures of 180～220℃and 240～300℃and one medium-temperature reservoir with a temperature of 100～140℃in the north part,while there are two high-temperature reservoirs with temperatures of 150～180℃and 240～260℃in the south.The results in this paper allow us to determine the genesis mechanism of high-temperature geothermal systems in graben systems,which provides guidance for the exploitation and utilization of geothermal resources.关键词
藏南地堑系/水化学演化/氢氧同位素/热储温度/空间特征Key words
graben system,southern Xizang/hydrogeochemical evolution/hydrogen and oxygen isotopes/reservoir temperature/spatial characteristics分类
地球科学引用本文复制引用
周金林,王迎春,范宇和,全三余,罗璐,宋荣彩..西藏南北地堑典型地热田水化学特征与热储温度空间分布规律[J].成都理工大学学报（自然科学版）,2025,52(4):223-235,13.基金项目
国家自然科学基金项目(42130809,42372301). （42130809,42372301）
