西藏北羌塘盆地浩波湖一带盐泉水化学特征及物质来源探讨  

Hydrochemical Characteristic and Ore-forming Materials for Salt Springs Water in Haobo Lake Area of North Qiangtang Basin,Tibet

作　　者：屈李华 赵芳 伊永国[1] 夏辉 赵同寿 Qu Lihua;Zhao Fang;Yi Yongguo;Xia Hui;Zhao Tongshou(The Geophysical Team of Xinjiang Geology Mineral Exploration and Development,Changji,Xinjiang,831100,China)

机构地区：[1]新疆维吾尔自治区地质矿产勘查开发局物化探大队,新疆昌吉831100

出　　处：《新疆地质》2023年第2期178-188,共11页Xinjiang Geology

基　　金：自然资源部西藏盐湖锂钾资源调查评价(1212011120982)地质调查项目资助。

摘　　要：西藏北羌塘盆地是我国侏罗系寻找钾盐的主要目标区域。浩波湖一带发育一系列含钾异常的盐泉水,研究这些盐泉水的水化学特征,探讨盐泉成矿物质来源,对区内进一步寻找钾及科学研究具重要意义。在区域地质背景基础上,研究盐泉水成分及氢氧锶同位素特征。结果表明:盐泉水具富Na^(+),Mg^(2+),Cl^(-),贫K^(+),SO_(4)^(2-),HCO^(3-),CO_(3)^(2-)特征;Cl^(-)含量与矿化度及Na^(+)呈正相关,Na^(+),Mg^(2+),K^(+),SO_(4)^(2-)与矿化度呈正相关。盐泉水钠氯系数和溴氯系数反映其属地层溶滤水。盐泉水氢氧同位素投点落于全球大气降水线附近,反映出盐泉水受大气降水的补给。锶同位素与区域背景值对比反映盐泉水在地下循环过程中可能溶滤了夏里组二段和索瓦组一段中的蒸发岩,区内夏里组和索瓦组有可能蕴含成盐成钾层系。同位素数据指示,不同采样点的盐泉水在地下运移路径和形成过程明显不同。The North Qiangtang Basin in Tibet is one main Jurassic target area of potash exploration in China,There is a series of springs with a potassium anomaly in Haobo area.Research on Hydrochemical characteristics and summarize Sources of Ore-Forming Materials of salt springs water in the Haobo area has an important significance for potash explo-ration and scientific value.Based on the geological background of this area,Chemical composition,δD andδ^(18)O,^(87)Sr/^(86)Sr of salt springs were studied in detail.The results show that the salt springs have a high concentration of Na^(+),Mg^(+),C1^(-)and a poor concentration of K^(+),SO_(4)^(2-),HCO^(3-),CO_(4)^(2-).Content of C1^(-)have a positive correlation with TDS and Na+,moreover,Na^(+)、Mg^(2+)、K^(+)、SO_(4)^(2-)have a positive correlation with TDS.According to the coefficients of nNa^(+)/nC1^(-)and Br-10^(3)/nC1^(-)of salt springs,springs water are from stratum lixiviation water.Hydrogen and oxygen isotopic date of springs water fall near lines of the global atmospheric precipitation and regional precipitation,which indicates that the salt spring is replenished by atmospheric precipitation.The comparison for ^(87)Sr/^(86)Sr value of salt springs and its background value shows that groundwater might 1ixiviate evaporite from 2nd Member of Xiali Formation and 1nd Member of Suowa For-mation.Xiali Formation and Suowa Formation are the most possible stratum of forming potash.In addition,The isotopic data suggest that the migration path and formation process of salt spring water in different sampling sites are obviously different.

关 键 词：西藏 盐泉水 水化学特征 稳定同位素 成矿物质来源 

分 类 号：P619.211[天文地球—矿床学]