摘要
康定地热田位于四川盆地西缘山地和青藏高原的过渡地带,属于高热流背景上的深循环高温地热系统。本文以康定地热田地下热水为研究对象,通过采集地热田内的主要两个热显示区(榆林河和雅拉河地区)的温泉和地热井的地下热水样,进行水化学和稳定同位素测试分析,研究其地下热水的补给来源和热储温度。雅拉河地下热水的水化学类型主要为HCO3-Na型水,榆林河地下热水的水化学类型主要为HCO3?Cl-Na型水,均显示了深部地下热水沿断裂上涌与浅部冷水混合的特点。根据地下热水同位素的结果分析计算,康定地热田地下热水的起源均来自大气降水,雅拉河地下热水的补给高程为5 600~5 900 m,榆林河地下热水的补给高程为5 300~6 300 m,来源于南部的贡嘎山的可能性较大。榆林河地下热水具有明显的氧-18漂移现象,其原因为较高的热储温度,二氧化硅温标和阳离子温标的结果证明了这个判断,雅拉河地下热水的热储温度为172~188℃,榆林河地下热水的热储温度为192~288℃。
The Kangding geothermal field is located in the transitional zone between the western margin of the Sichuan Basin and the Tibetan Plateau.It belongs to the deep circulation high temperature geothermal system on the background of high heat flux.In this paper,geothermal water in the Kangding geothermal field was taken as the study object.Through sampling the geothermal waters from hot springs and geothermal wells in two main thermal display areas,i.e.,Yulinhe and Yalahe,and analyzing water chemistry and stable isotopes,the authors studied the recharge source and reservoir temperature of geothermal water.The hydrochemical type of geothermal waters in Yala and Yulin river areas are HCO3-Na and HCO3?Cl-Na,indicating the characteristics of deep geothermal water mixed with shallow water along the upwellings.According to the analysis and calculation of geothermal waters’isotope analyses,the recharge source of geothermal waters are precipitation in Gongga Mountain,and the recharge elevation of geothermal waters in Yalahe and Yulinhe areas are 5 600~5 900 m and 5 300~6 300 m respectively.Because of the higher reservoir temperature,the geothermal waters in Yulinhe area has obvious phenomenon of oxygen drift,and the results of silicon and cation geothermometers are consistent with the above judgment,which demonstrates that the reservoir temperature of geothermal waters in Yalahe and Yulinhe areas are 172~188℃and 192~288℃respectively.
作者
卞跃跃
赵丹
BIAN Yue-yue;ZHAO Dan(Geological Museum of China,Beijing 100034;China University of Geosciences(Beijing),Beijing 100083)
出处
《地球学报》
EI
CAS
CSCD
北大核心
2018年第4期491-497,共7页
Acta Geoscientica Sinica
基金
国家自然科学基金项目(编号:U1602233)资助~~
关键词
地下热水成因
康定
水化学
同位素
genesis of geothermal waters
Kangding
hydrogeochemistry
stable isotopes
