北羌塘盆地热觉茶卡盐湖地球化学特征及矿床成因

发布时间：2018-02-08 21:34

本文关键词： 北羌塘热觉茶卡盐湖地球化学特征成矿物质来源成矿模式　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：西藏北部是我国现代盐湖主要的分布区之一,同时也是世界上最早发现和利用的盐湖矿产闻名产地,其远景资源量及潜在经济价值较大。热觉茶卡盐湖位于西藏高原腹地,是一个现代盐湖矿床,主要受龙木错-双湖缝合带及其附近次一级深大断裂的控制形成硫酸盐型盐湖。本文详细的研究了热觉茶卡盐湖周边各时代的地层、沉积岩及构造等地质背景,矿床特征,不同时代、不同类型的沉积岩以及河水、泉水中成盐元素的含量,初步探讨了热觉茶卡盐湖矿床的成矿物质来源和成矿模式。热觉茶卡湖盆地区出露地层包括晚二叠系热觉茶卡组、早三叠系康鲁组和康南组,侏罗系布曲组、雀莫错组和索瓦组以及第四系冲洪积物,岩浆岩出露较少,主要岩性为砾岩、砂岩和碳酸盐岩。本区经历过板块碰撞和新构造运动两次重大构造事件,形成了一系列断裂,构造格局复杂。地球化学研究表明:热觉茶卡盐湖矿床的钾、锂品位较好,已达到小型规模,有实际开采价值。通过对沉积岩、河水、泉水和湖水的水化学分析表明盐湖成矿物质具有多来源性;两条河流和泉对热觉茶卡盐湖成盐成矿起到重要控制作用;盐湖的蒸发浓缩造成离子在湖中分布不均匀。另外,锶同位素研究表明泉水中的盐类物质可能来源于夏里组和索瓦组。通过对热觉茶卡地区区域地质,矿床地质,地球化学背景研究,笔者认为:热觉茶卡地区的热液活动使成盐物质活化并运移至地表或近地表赋存,热觉茶卡盐湖形成以后,经热水系统的水-岩相互作用、地表和近地表岩石风化淋滤,由流水携至湖中,经过漫长的汇聚和湖水蒸发浓缩,形成热觉茶卡盐湖矿床。
[Abstract]:Northern Tibet is one of the main distribution areas of modern salt lakes in China, and it is also the world's earliest famous source of salt lake mineral resources, which has great potential resources and potential economic value. The salt lake is located in the hinterland of Tibet plateau. It is a modern salt lake deposit, which is mainly controlled by the Longmuco-Shuanghu suture zone and its subprimary deep faults to form the sulfate salt lake. In this paper, the strata around the Jiejiechaka salt lake are studied in detail. Geological background such as sedimentary rocks and structures, characteristics of deposits, contents of salt-forming elements in different ages, types of sedimentary rocks and rivers and springs, The source of ore-forming material and metallogenic model of the Rejiaocha Ka-salt lake deposit are preliminarily discussed. The exposed strata in the Rejiaocha Lake basin area include the late Permian Rejiaocha Kaka formation, the early Triassic Kanglu formation and Kangnan formation, the Jurassic Buqu formation, the early Triassic Kanglu formation, the early Triassic Kanglu formation and the Jurassic Buqu formation. There are few magmatic rocks exposed in the Kemoco formation, Suowa formation and Quaternary alluvial deposits, and the main lithology is conglomerate, sandstone and carbonate rocks. The area has experienced two major tectonic events of plate collision and neotectonic movement, resulting in a series of faults. The geochemical study shows that the potassium and lithium grade of the Jiejiechaka salt lake deposit is good, which has reached a small scale and has practical exploitation value. The hydrochemical analysis of spring water and lake water shows that the ore-forming materials of salt lake are multi-source, the two rivers and springs play an important role in controlling the formation of salt and ore-forming, the evaporation and concentration of salt lake lead to the uneven distribution of ions in the lake. The strontium isotopic study indicates that the salt material in the spring water may originate from the Xiali formation and the Suowa formation. Through the study of the regional geology, deposit geology and geochemical background of the Rejiaocha area, The author believes that the hydrothermal activity in the area of Techa Kar makes the salt-forming substances active and transported to the surface or near the surface, and after the formation of the Takeka salt lake, through the water-rock interaction of the hot water system, the rocks on the surface and near the surface are weathered and leached. Carried by income into the lake, after a long gathering and water evaporation and concentration, the Jiejiechaka salt lake deposit was formed.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P619.211

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