地质科技通报2025，Vol.44Issue(4)：142-153,12.DOI:10.19509/j.cnki.dzkq.tb20240477
西藏卡吾地热水地球化学特征及其成因机制
Geochemical characteristics and genesis mechanisms of Kawu geothermal water in Tibet
摘要
Abstract
[Objective]The Kawu area is a typical high-temperature hydrothermal system in southern Tibet,with high potential for exploitation.However,the current understanding of its genesis mechanisms is still insufficient,which limits the further development and utilization of geothermal resources.This study aims to investigate the genesis and thermal sources of the Kawu geothermal region.[Methods]Hydrogeochemical characteristics and hydrogen-oxygen isotope data of geothermal and shallow cold waters were analyzed to assess the thermal reservoir temperatures of the geothermal system.The hydrogeochemical processes involved in the formation of geothermal waters,including water-rock interactions,cold water mixing,and water-steam separation,were explored.Additionally,the deep thermal sources of the geothermal system were identified,shedding light on the genesis mechanisms of the system.[Results]The results indicated that the geothermal waters primarily exhibited a neutral to weakly alkaline HCO3-Cl-Na chemical type.The Na-K geothermometer estimated the uniform deep thermal reservoir temperature at 280℃,while the K-Mg and quartz geothermometers estimated the shallow thermal reservoir temperature at approximately 175℃.The cold-water mixing ratio ranged from 50%to 76%.The deuterium and oxygen isotopic values of the reduced deep thermal reservoir ranged from-207.20‰ to-185.25‰ and-22.26‰ to-17.74‰,respectively.Based on these findings,a conceptual model for the Kawu geothermal system is proposed.It is suggested that Kawu area is a geothermal system with a magmatic heat source,where a uniform deep geothermal fluid rises along various regional fractures and undergoes different hydrogeochemical processes,resulting in the formation of four distinct shallow thermal reservoirs with varying distributions.This ultimately leads to the emergence of Kawu geothermal water.[Conclusion]The study provides important guidance for the rational development and efficient utilization of geothermal resources in the Kawu geothermal region and offers valuable insights for studying the genesis mechanisms of similar geothermal systems in southern Tibet.关键词
地热系统/水文地球化学/成因机制/岩浆热源/西藏卡吾地热区Key words
geothermal system/hydrogeochemistry/genesis mechanism/magmatic heat source/Kawu geothermal region,Tibet分类
天文与地球科学引用本文复制引用
王轲,刘明亮,师红杰,卫兴,黄丽浈..西藏卡吾地热水地球化学特征及其成因机制[J].地质科技通报,2025,44(4):142-153,12.基金项目
国家自然科学基金项目(41902257) （41902257）
第二次青藏高原科考项目(2022QZKK0202) （2022QZKK0202）
地热资源勘查与开发利用山西省重点实验室开放基金项目(SX202205) （SX202205）
自然资源部深部地热资源重点实验室开放基金项目(KLDGR2022G01) （KLDGR2022G01）
