老挝龙湖矿区ZK309孔泥岩层矿物学与地球化学特征  

The Mineralogy and Geochemistry Characters of Mudstone Strata in ZK309 Hole,Longhu Diggings,Laos

作　　者：韩元红[1,2] 马海州[1] 张西营[1,2] 袁小龙[1,2] 范惠萍 杜仲谋 

机构地区：[1]中国科学院青海盐湖研究所,青海西宁810008 [2]中国科学院研究生院,北京100039 [3]青海盐湖工业股份有限公司,青海格尔木816000 [4]青海盐湖三元钾肥股份有限公司,青海格尔木816000

出　　处：《盐湖研究》2012年第1期1-8,15,共9页Journal of Salt Lake Research

基　　金：国家自然科学基金项目(40903014);国家重点基础研究发展计划项目(2011CB403004)

摘　　要：老挝龙湖钾盐矿区是呵叻高原钾盐矿在老挝境内最主要的钾盐矿区之一,ZK309钻孔是龙湖矿区打穿最好、取样最完整和最典型的钻孔之一,通过对该钻孔盐岩上覆碎屑层的地层、矿物、元素的分析,得出泥岩层作为成盐沉积旋回中的一部分,其矿物元素变化和与其接触的下伏盐层的类型、特征等密切相关。同一旋回中自下而上泥岩颜色由青灰色变为红色,明显表现出沉积环境由还原性转变为氧化性。盐类矿物在垂向上表现出自下而上的淡化序列。矿物和元素在103～107 m处的突变显示盐岩沉积后期曾明显有水流体的淋滤作用,通过微量元素含量等的分析,该水流体表现为偏向淡水的淡水、海水混合水。碳酸盐矿物组合及含量显示当时可能有高Mg流体的活动。将粘土矿物组合与中国其它海相和陆相盆地粘土矿物组合相比较,得出粘土矿物组合与海相更相似,加上绿泥石含量较高,初步推测粘土矿物可能来源于海相沉积环境。Longhu Diggings is one of the most important potash deposits in Khorat Plateau, Laos, ZK309 hole is one of the most representative holes in this area, it is a perfect penetrated drilling where we have got complete mud rock samples. In light of analysing the upper clasolite strata, minerals and elements, mudstone as one of the cycle of sedimentation of diagenesis, we concluded that minerals and elements in mudstone are bound up with the type and character of below salt stratum. The changing regularity of saline minerals in vertical direction accord with the depositional environment that change from low salinity to high salinity. The saltation of minerals and elements located in 103 - 107 metres indicates that the fluid e- luviation had taken place during the late consolidation stage of rock salt sedimentation. It is easy to concluse that the fluids were water with low salt content and mixture of little seawater and much freshwater by analysing the minerals and elements. In terms of distributions and contents of and carbonate minerals, we concluded that there were high magnesian fluids, we had the composition of clay minerals of mudstone compared with other facies and land facies basin of China, and concluded it leaning towards sea facies. Additionally, it has more chlorite, we speculated that it may be from ocean environment.

关 键 词：老挝龙湖 钾盐矿区 泥岩 矿物学 地球化学 沉积相 

分 类 号：P588.2[天文地球—岩石学]