投稿时间：2025-06-04
修订日期：2025-07-23
网络发布日期：2025-10-31
中文摘要:柴达木盆地西部狮子沟背斜是典型的储卤构造，其古近系下干柴沟组上段赋存了富含钾、锂、硼元素的卤水资源，明确其物质来源与成因机制对矿产勘探与开发具有重要价值。文章综合水化学统计与氢-氧、硫、锶、锂硼同位素分析，系统地研究了卤水的水化学特征与成因。结果表明，狮子沟卤水为Cl-Na型，富含K+、Li+、B3+而贫Ca2+、Mg2+，其成因以溶滤作用为主，并兼具深部流体贡献。氢-氧同位素显示其受大气降水补给，锶、硫、锂硼同位素指示物源包括石膏、石盐等溶滤及深部流体输入。成矿过程始于晚始新世石盐与碳酸盐岩沉积，构成初始卤水储集体与孔隙-断裂输导网络。大气降水沿断裂下渗，溶滤蒸发岩矿物，富集K+、Na+、Cl-等离子。中新世以来，阿尔金断裂活动引发深部富钾锂硼热液上涌，与浅部卤水混合并叠加强烈水岩反应与蒸发浓缩，最终形成现今深层卤水矿床。
Abstract:TThe Shizigou Anticline in the western Qaidam basin represents a typical brine-bearing structure, where the upper member of Paleogene Xiaganchaigou Formation hosts brine resources rich in potassium, lithium and boron, clarifying its material sources and genetic mechanisms holds significant value for mineral exploration and development in the region. This study systematically investigated the hydrochemical characteristics and genesis of brines by integrating hydrochemical statistics with hydrogen-oxygen, sulphur, strontium, lithium and boron isotope analyses. Results indicate that the Shizigou brines exhibit a Cl-Na type, enriched in K+, Li+ and B3+ while depleted in Ca2+ and Mg2+. Their genesis is primarily dissolution-leaching, supplemented by deep fluid contributions. Hydrogen and oxygen isotopes indicate atmospheric precipitation recharge, while strontium, sulphur, lithium and boron isotopes suggest source materials including gypsum, halite dissolution and deep fluid input. Mineralization commenced during Late Eocene with halite and carbonate sedimentation, forming the initial brine reservoir and pore-fault conduit network. Atmospheric precipitation infiltrated along fractures, dissolving evaporite minerals and enriching ions such as K+, Na+, and Cl-. Since the Miocene, tectonic activity along the Altyn fault triggered the ascent of deep potassium, lithium and boron-rich hydrothermal fluids, which mixed with shallow brines, superimposing intense water-rock reactions and evaporative concentration, ultimately forming the present-day deep brine deposits.
keywords:deep brine hydrochemical characteristics genesis analysis,potassium lithium and boron-rich isotope tracing Shizigou structure
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基金项目:本文得到国家重点研发计划课题（编号：2023YFC2906501）、基本科研业务费（编号：KK2210）、地质调查项目（编号：DD20230203604）和自然资源部高原荒漠区战略性矿产勘查开发技术创新中心开放课题（编号：KFKT20230103）联合资助
引用文本：
薛燕,牛新生,侯献华,乜贞,苏奎.2025.柴达木盆地狮子沟构造深层卤水水化学特征及成因研究[J].矿床地质,44(5):1114~1126XUE Yan,NIU XinSheng,HOU XianHua,NIE Zhen,SU Kui.2025.Study on hydrochemical characteristics and genesis of deep brines in Shizigou structure, Qaidam basin[J].Mineral Deposits44(5):1114~1126
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