青海昆仑河地区钨矿床流体包裹体特征及矿床成因
发布时间：2018-10-23 07:28
【摘要】：青海昆仑河地区地处东昆仑造山带昆南增生杂岩带内,区内近年来发现了以铜金山、二道沟为代表的钨矿床。本文在野外地质调查的基础上,结合岩矿鉴定、流体包裹体分析测试等室内研究,分析了区内两个典型钨矿床的地质特征、流体包裹体特征,厘定了矿床类型,探讨了矿床成因以及成矿作用过程。铜金山钨多金属矿体产于蚀变大理岩中。矿石中金属矿物主要为白钨矿,次为黄铜矿、方铅矿、辉铜矿、辉银矿、斑铜矿、黝锡矿等;非金属矿物主要为石英、透闪石,次为蛇纹石、方解石等。矿石组构主要为自形-半自形粒状结构、交代残余结构,稀疏浸染状构造。成矿与硅化、透闪石化关系密切。成矿作用可分为:Ⅰ.透闪石-石英-白钨矿阶段、Ⅱ.石英-硫化物-白钨矿阶段和Ⅲ.方解石-滑石阶段,其中Ⅰ、Ⅱ阶段为主成矿阶段。主成矿阶段均主要发育气液水两相包裹体,少见CO_2-H_2O包裹体。Ⅰ阶段流体包裹体均一温度为中高温、中低盐度,Ⅱ阶段为中低温、中低盐度。两个阶段的流体均属H_2O-NaCl-CH_4±CO_2体系。二道沟钨矿体由含矿石英脉组成,产于千枚岩、板岩中。矿石中金属矿物主要为白钨矿,硫化物少见。白钨矿主要产于石英脉内及两侧围岩中。矿石组构主要为自形-半自形粒状结构、交代残余结构,浸染状构造。主成矿阶段石英和白钨矿中发育气液水两相包裹体、CO_2-H_2O包裹体,偶见含子矿物三相包裹体、熔融包裹体。成矿流体属高温、高-中-低盐度共存的H_2O-NaCl-CH_4-N2-CO_2体系,具有岩浆热液特点。成矿过程中发生过流体不混溶作用。铜金山钨多金属矿床为交代岩型钨矿床,其形成与中高温含矿流体渗滤交代大理岩有关。流体中Ca~(2+)浓度增大、pH值升高、温度下降,导致白钨矿结晶沉淀。二道沟钨矿床为热液脉型钨矿床,其形成与高温含矿热液充填有关。成矿过程中流体发生不混溶作用,使CO_2逸出流体相,pH值升高,导致白钨矿结晶沉淀。
[Abstract]:The Kunlun River area in Qinghai is located in the southern Kunnan accretive complex belt of the East Kunlun orogenic belt. In recent years, the tungsten deposits represented by Tongjinshan and Erdaogou have been discovered in the area. On the basis of field geological investigation, combined with laboratory studies such as rock ore identification, fluid inclusion analysis and testing, the geological characteristics and fluid inclusion characteristics of two typical tungsten deposits in the area are analyzed, and the deposit types are determined. The genesis and metallogenic process of the deposit are discussed. The Tongjinshan tungsten polymetallic ore body occurs in altered marble. The main metallic minerals in ore are scheelite, chalcopyrite, galena, chalcopyrite, pyroxene, porphyrite, tetrahedrite and so on, while the non-metallic minerals are mainly quartz, tremolite, serpentine, calcite and so on. The ore fabric mainly consists of the granular structure of automorphism and hemiautomorphism, the metasomatic residual structure and the sparse disseminated structure. Mineralization is closely related to silicification and tremolysis. The mineralization can be divided into: 鈪，
本文编号：2288501
[Abstract]:The Kunlun River area in Qinghai is located in the southern Kunnan accretive complex belt of the East Kunlun orogenic belt. In recent years, the tungsten deposits represented by Tongjinshan and Erdaogou have been discovered in the area. On the basis of field geological investigation, combined with laboratory studies such as rock ore identification, fluid inclusion analysis and testing, the geological characteristics and fluid inclusion characteristics of two typical tungsten deposits in the area are analyzed, and the deposit types are determined. The genesis and metallogenic process of the deposit are discussed. The Tongjinshan tungsten polymetallic ore body occurs in altered marble. The main metallic minerals in ore are scheelite, chalcopyrite, galena, chalcopyrite, pyroxene, porphyrite, tetrahedrite and so on, while the non-metallic minerals are mainly quartz, tremolite, serpentine, calcite and so on. The ore fabric mainly consists of the granular structure of automorphism and hemiautomorphism, the metasomatic residual structure and the sparse disseminated structure. Mineralization is closely related to silicification and tremolysis. The mineralization can be divided into: 鈪，
本文编号：2288501
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