西藏水热活动区处于印度大陆与亚洲大陆碰撞造山带的关键地带,隶属于地中海—喜马拉雅地热带,水热资源丰富,作为了解地质构造演化、地热系统、气候变化的重要窗口之一,一直是地学界的研究热点。本文利用西藏地区336个温泉水化学数据,采用多种地球化学温标对区域内热储温度进行了评估,揭示了地热异常空间分布规律,并探究其地质环境效应。结果表明:泉口热水温度介于10.12~97.64℃,其中60℃以上占总样本的38.9%;热储温度介于87.12~277.64℃,其中87.12~120℃的占18.7%,在120~200℃的占40.5%,高于200℃的占40.8%,显示区内中高温地热系统分布广泛。高温热储区集中于藏南,有南强北弱特点,并沿着断裂带以“簇丛”状分布,可初略划分为狮泉河—玛旁雍区、措勤—搭格架区、当雄—羊八井—定日带、雅鲁藏布江大拐弯区4个区。温泉密度和高温热储区与SN向的断裂带及地震活动性在空间上有较好的匹配关系。
The hydrothermal activity area of Tibet is located in the key area of Indian-Eurasia collision orogenic belt, belonging tothe Mediterranean-Himalayan tropical and rich in hot water resources. As one of the important window to study geological tectonicevolution, geothermal system properties, and climate change, the hydrothermal activity area of Tibet has been one of the keyscientific problems in the field of geology. Based on 336 water chemical data of hot springs and using a variety of geochemicalgeothermometers, the authors evaluated thermal reservoir temperature, inferred the spatial distribution of geothermal anomaly, andexplored its geological environmental effect. The results show that the hot water temperature ranging from 10.12 °C to 97.64 °C andhigher than 60 ℃ accounted for 38.9% of the total samples. Reservoir temperature ranging from 87.12 °C to 277.64 °C and thetemperature between 120 ° C, 200 ° C and 277.64 ° C made up 18.7%, 40.5% and 40.8%, respectively. It is shown that hightemperature geothermal systems are widely distributed in the area. High temperature thermal storage areas are concentrated insouthern Tibet, which are stronger in the south and weaker in the north and distribution in clusters along fault zones. Hot springsdensity and high temperature heat storage areas have good matching relationship with NS-trending fault zone and seismic activity inspace, but they are not in accord with the volcanic rock distribution.