老挝万象海夏峰钾盐矿床水不溶矿物及其对沉积环境的约束  

Insoluble minerals of potash deposits in Haixiafeng mining area of Vientiane,Laos: Constraints on their sedimentary environment

作　　者：赵雪 陈忠[1] 石国成 唐启亮[2] 李雯霞[2] 张西营[2] ZHAO Xue;CHEN Zhong;SHI Guocheng;TANG Qiliang;LIWenxia;ZHANG Xiying(Faculty of Land and Resources Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,Qinghai,China;Qinghai Nuclear Geology,Xining 810008,Qinghai,China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093 [2]中国科学院青海盐湖研究所青海省盐湖地质与环境重点实验室,青海西宁810008 [3]青海省核工业地质局,青海西宁810008

出　　处：《中国地质》2023年第1期170-180,共11页Geology in China

基　　金：国家自然科学基金项目(41602086)资助。

摘　　要：【研究目的】老挝钾盐矿床是世界上重要的钾盐矿床之一,开展该矿床钾盐析出阶段沉积环境研究对于深入理解钾盐成矿作用具有重要意义。【研究方法】钾盐矿层中的水不溶矿物比可溶盐类矿物保存了更多的原始信息,是研究成矿卤水演化的重要载体。本文以老挝万象盆地海夏峰矿区ZK16钻孔为研究对象,利用镜下鉴定、XRD及SEM等方法对该钻孔钾盐矿层的水不溶矿物开展了系统研究。【研究结果】分析结果表明,水不溶物中的主要矿物为硬石膏、方硼石、水氯硼钙石、石英、白云石、菱镁矿、方解石、白云母等,其中以硬石膏、方硼石是主要的水不溶矿物。自生石英及碎屑白云母的存在及其分布特征指示了钾盐在沉积过程中不同程度地受到陆相水体的影响。【结论】综合研究揭示,研究区钾盐沉积可以分为波动沉积、浅水沉积、稳定沉积和改造作用等4个不同阶段。This paper is the result of mineral exploration engineering.[Objective]The potash deposit in Laos is one of the most important potash deposits in the world. To carry out studies of the sedimentary environment during the precipitation of potassium minerals is very significant for a deep understanding of the mineralization of potash deposits here. [Methods]The insoluble minerals in the potash seams, which can retain more original information than soluble salts, is an important carrier for studying the evolution of ore-forming brine. Systematic studies on insoluble minerals in borehole ZK16 from the Haixiafeng mining area of the Vientiane Basin of Laos were conducted through microscopic identification, XRD, and SEM. [Results]Analysis results show that the insoluble materials mainly include anhydrite,boracite, hilgardite, quartz, dolomite, magnesite, calcite, and muscovite, in which anhydrite and boracite are dominant minerals. The existence and distribution characteristics of authigenic quartz and clastic muscovite reveal that continental waters have affected potash deposits to different degrees during deposition. [Conclusions]Comprehensive studies show that the process of potassium salt deposition in the study area can be divided into four distinct stages: fluctuation deposition stage, shallow water deposition stage,stable deposition stage, and reworking stage.

关 键 词：钾盐 水不溶矿物 沉积环境 卤水演化 钾盐矿床勘查工程 海夏峰矿区 老挝 

分 类 号：P612[天文地球—矿床学]