四川稻城地热资源的分布特点及温泉水的同位素地球化学特征

Distribution Characteristics of Geothermal Resources and Isotopic Geochemistry of Hot-Water in the Daocheng County, Sichuan Province

在分析四川稻城地区地热资源形成的地质背景的基础上,初步研究了该区地热资源分布特点和温泉水的同位素地球化学特征。结果表明,稻城县地热水的径流和排泄受构造作用的控制,断裂、断层地带地下径流多,是形成温泉的主要地区。在深大断裂发育处或断裂交汇地带,温泉往往成群出露。温泉水的同位素组成具明显的季节性效应;与大气降水季节性效应相反:夏季温泉水相对富轻同位素,冬季则明显富重同位素;反映其夏季主要受δD、δ18O值低的高山常年积雪溶融水补给,冬季主要为δD、δ18O值高的地下水补给。

Based on the analysis of geological background in the Daocheng County, Sichuan Province, this paper examined distribution characteristics of geothermal resources and isotopic geochemistry of thermal springs in this area. The run-off and drainage of geothermal water are controlled by structures. At places where big and deep rifts developed or converged, hot wells emerge usually in groups. Isotope composition of thermal springs shows an obvious seasonal effect, which is contrary to the seasonal effect of precipitation.The thermal spring water has a light isotope composition in summer and a heavy isotope composition in winter.This suggests that in summer the thermal spring is mainly recharged by melted ice and snow from high mountains with lower δD and δ^(18)O values, while in winter it is chiefly recharged by underground water with higher δD and δ^(18)O values.