柴达木盆地别勒滩区段固体钾盐液化后矿物沉积特征  

Research on the sedimentary characteristics of solid sylvite after liquefaction in the Bieletan area of Qaidam basin

作　　者：宋高 赵元艺[1] 马宏涛 胡涵 SONG Gao;ZHAO Yuanyi;MA Hongtao;HU Han(MNR Key Laboratory of Saline Lake Resources and Environments,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;Key Laboratory of Exploration Research of Salt Lake Resources in Qaidam Basin of Qinghai Province,Qaidam Comprehensive Geological and Mineral Exploration Institute of Qinghai Province,Golmud,Qinghai 816099,China)

机构地区：[1]中国地质科学院矿产资源研究所,自然资源部盐湖资源与环境重点实验室,北京100037 [2]青海省柴达木综合地质矿产勘查院,青海省柴达木盆地盐湖资源勘探研究重点实验室,青海格尔木816099

出　　处：《地质学报》2024年第10期2873-2882,共10页Acta Geologica Sinica

基　　金：青海盐湖工业股份有限公司科技计划项目“察尔汗盐湖别勒滩区段固液转化效果评价”(编号HE 2205);中国地质调查局地质大调查项目“钾锂硼等紧缺盐类矿产综合调查”(编号DD20230037)联合资助的成果。

摘　　要：别勒滩区段是柴达木盆地察尔汗盐湖固体钾矿的主要分布地区,也是企业固液转化进行生产的主要矿区。本文通过对别勒滩区段涩聂湖东北部生产区S2T3钻孔样品进行X射线粉晶衍射分析、扫描电镜能谱分析、化学元素分析、盐矿鉴定及物性参数分析,研究该地区固体钾盐液化后地层中矿物的沉积特征。经调查,液化后地层中主要的含钾矿物为杂卤石、光卤石和钾石盐,且以杂卤石为主,在2320 cm岩芯中分布最广、含量最高;根据沉积特征分析,2200~1700 cm地层中的杂卤石多为准同生沉积阶段形成的原生杂卤石,呈竹片状、花瓣状和绒球状等与石盐共生,而1000~1700 cm层位杂卤石则为后生交代成因。涩聂湖东北部1000~1700 cm以及300 cm以上层位是S2T3钻孔中光卤石含量最高的地层,可为下一步固液转化生产靶区选取提供参考;300~500 cm地层为杂卤石含量最高层位,既有后生交代形成的杂卤石也有现阶段正在生成的杂卤石,可为后续杂卤石开发研究提供材料与参考。Bieletan,the main area for solid potassium deposits in the Qarhan Salt Lake,is the principal mining region for brine exploitation and potash production.This study investigates the sedimentary characteristics of minerals after dissolution in the Bieletan area,focusing on borehole S2T3 in the northeast production area of Senie Lake.Using XRD,SEM,chemical element analysis,salt mineral identification,and physical parameter analysis,we identified polyhalite,carnallite,and sylvine as the main potassium minerals in the post-liquefaction strata.Sylvine,the dominant component,exhibits the widest distribution and highest content in the 2320 cm core of S2T3.Sedimentary characteristic analysis reveals that polyhalite in the 1700~2200 cm layer is mostly of primary origin,formed during the penecontemporaneous sedimentary stage and coexisting with halite in the shape of bamboo flakes,petal,and velvet ball.Conversely,polyhalite in the 1000~1700 cm layer originates from epigenetic replacement.The layers with the highest carnallite content in the northeast Senie Lake are located at 1000~1700 cm and the upper 300 cm,providing valuable reference for selecting target regions for liquefaction in the next step.Furthermore,the 300~500 cm layer,characterized by the highest content of epigenetically replaced polyhalite currently forming,offers crucial materials and insights for subsequent polyhalite development and research.

关 键 词：钾盐矿物 杂卤石 沉积特征 别勒滩 察尔汗盐湖 

分 类 号：P619.211[天文地球—矿床学]