藏川滇高温地热泉水化学空间变化规律与成因机制对比  

Comparison on hydrochemical variation patterns and formation mechanism of high-temperature geothermal spring along belt Tibet-Sichuan-Yunnan

作　　者：朱鸿恺 谭红兵[1] 石智伟 薛飞[1] ZHU Hongkai;TAN Hongbing;SHI Zhiwei;XUE Fei(School of Earth Science and Engineering,Hohai University,Nanjing 211100,China)

机构地区：[1]河海大学地球科学与工程学院,南京211100

出　　处：《中国有色金属学报》2025年第2期681-696,共16页The Chinese Journal of Nonferrous Metals

基　　金：第二次青藏高原综合科学考察项目(2022QZKK0202)。

摘　　要：西藏、四川、云南是我国高温地热资源的主要分布区,许多热泉水异常富集稀碱金属元素(Li、Rb、Cs),部分达到工业开采品位,西藏许多高温地热系统甚至形成独特的泉华沉积型铯矿床。然而,地热泉中典型富集元素的物源机制与空间分布规律尚未查明,制约了对热泉型矿产资源的正确评价。通过对西藏沿雅江缝合带、川西与滇西的中、高温地热泉野外调查,对比分析各类常、微量元素,发现三地水化学特征、典型元素富集规律与组合关系差异显著:西藏高温地热泉普遍超常富集稀有元素Li、Rb、Cs及类金属元素B、As、Sb,川西与滇西部分高温泉富集贵金属元素Au,滇西部分高温泉U元素存在显著异常。综合地质与地球化学特征,西藏雅江缝合带地热系统中特征元素的异常富集与地壳重熔型残余岩浆流体密切相关;滇西地热泉水化学演化由幔源岩浆脱气、火山活动与强烈的水−岩作用共同主导,川西则普遍受控于强烈的断裂构造活动与水−岩作用,特别是与区域大规模富锂岩石淋滤作用有关。Tibet,Sichuan and Yunnan are the main distribution areas of high-temperature geothermal resources in China,and many geothermal springs are abnormally enriched in rare alkali metal elements(Li,Rb,Cs),some of which have reached the industrial mining grade,and many high-temperature geothermal systems in Tibet have even formed unique quanhua sedimentary cesium deposits.However,the source mechanism and spatial distribution pattern of typical elements enriched in geothermal springs have not yet been identified,which restricts the correct evaluation of geothermal spring-type mineral resources.Through the field investigation of the middleand high-temperature geothermal springs along the Yajiang Suture Zone in Tibet,western Sichuan and western Yunnan,and the comparative analysis of various types of normal and trace elements,it is found that there are significant differences in the hydrochemical characteristics,typical element enrichment patterns and combinatorial relationships among the three places.The high-temperature geothermal springs in Tibet are generally enriched in the rare elements Li,Rb,Cs,and the metalloids B,As,and Sb in excess of the norm,and the high-temperature geothermal springs in western Sichuan and western Yunnan are enriched in the precious metal element Au,and there are significant anomalies of U elements in some geothermal springs in western Yunnan.Combining geological and geochemical features,the anomalous enrichment of characteristic elements in the geothermal system of the Yajiang Suture Zone,Tibet,is closely related to the crustal remelting of highly dissimilar residual magmatic fluids.The hydrochemical evolution of the geothermal system in western Yunnan is dominated by mantle-source magma degassing,volcanism,and strong water-rock interactions,whereas in western Sichuan,the geothermal system is generally controlled by strong tectonic rupture and water-rock interactions,especially related to the large-scale regional lithium-rich rocks.

关 键 词：地中海−喜马拉雅地热带 地热 水化学 富集规律 稀碱金属 

分 类 号：P641.3[天文地球—地质矿产勘探]