西昆仑地区苦水湖富锂盐湖水化学特征及成盐元素来源

苦水湖是近年来在青藏高原西昆仑山腹地新发现的富锂盐湖，查明其水化学组成特征对丰富青藏高原盐湖型锂矿床基础资料具有重要的现实意义.然而受区域自然地理条件限制，对包含该盐湖卤水及补给水系的基础性研究还很少.综合运用Piper三线图、Gibbs图解和离子比例关系分析方法探讨了湖表卤水及湖周补给水系水化学组成、演化及主要离子来源.结果表明，由"补给源"到"汇"，各离子组成发生了显著变化，水化学类型由碳酸钙镁型向硫酸钠亚型过渡转变，水化学的演化由岩石风化控制向蒸发结晶控制演变.根据离子比例关系，识别出3个主要离子来源:东北径流补给以碳酸盐岩、硅酸岩风化溶质来源为主；南部甜水海水系以盐岩溶解补给为主；湖周冷泉中的溶质则可能主要来自于同生沉积卤水与浅层地下水混合，或长英质火山岩、碳酸盐岩等的深部水-岩作用淋滤. 

Hydrochemical Characteristics and Salt-Formation Elements Sources of Li-Rich Brines in Kushui Lake,West Kunlun

Kushui lake is a newfound lithium-rich salt lake in the West Kunlun Mountain hinterland of Tibetan plateau. It is of great significance to find out the characteristics of hydrochemical composition for enriching the basic data of the Li-rich brines deposits on the Tibetan plateau. However, limited by the regional physical and geographical conditions, the basic research on the brine and recharge water system of the salt lake has not been reported yet. Piper diagram, Gibbs diagram and ion ratio analysis method were comprehensively used to discuss the chemical composition, evolution and main ion sources of the surface brine and the peripheral recharge system. The results show that from "source" to "sink", not only the composition of each ion is changed significantly but also the hydrochemical type shows transition from carbonate-type to sodium sulfate subtype, and the evolution of hydrochemistry in water changes from rock weathering control to evaporation crystallization control. According to the ion content ratio relationship, three main ion sources were identified. (1)The weathering products of carbonate and silicate are the main solute in the recharge water system of northeastern Kushui lake. (2)The Tianshui lake recharge water system in the southern part of the lake mainly supplies evaporate dissolved substances. (3)There may be solute sources in the cold spring around the lake from mixed fluid of syn-sedimentary brine and shallow groundwater, or the leaching products of felsic volcanic rocks and carbonatite.