中文摘要:东莫扎抓铅锌矿床位于青藏高原羌塘地体东北缘，是“三江”北段铅锌铜银多金属成矿带中的典型代表，对该矿床地质特征和成因类型的研究有助于理解区域铅锌铜银多金属成矿规律，对区域找矿具有重要意义。笔者通过详细的矿区地质考察、系统的矿石光薄片显微镜下鉴定和矿石中方解石的碳、氢、氧同位素分析测试，概述了东莫扎抓铅锌矿床的地质特征和成矿流体的碳、氢、氧同位素组成特征。东莫扎抓铅锌矿床矿体呈似层状展布，产状严格受到矿区逆冲断层的控制，赋矿围岩为上三叠统结扎群波里拉组灰岩和下-中二叠统开心岭群尕迪考组灰岩，发育强白云石化和弱硅化，矿物组合简单，主要为闪锌矿+方铅矿+黄铁矿+白云石+方解石+重晶石，矿石结构以皮壳状、草莓状等胶状结构和他形粒状结构为主，矿石构造为浸染状、角砾状、团块状和脉状。矿石中方解石的δ13CV-PDB值、δ18OV-SMOW值和δDV-SMOW值分别为-1.8‰～+3.3‰、+6.1‰～+24.6‰和-137‰～-53‰，计算得到成矿流体的δ18O流体值为-0.5‰～+13.8‰。研究结果表明，东莫扎抓铅锌矿床的成矿流体主要来自盆地封存热卤水和大气降水，金属物质可能由区域流体在长距离迁移过程中通过与碳酸盐岩地层相互作用，以及淋滤含矿地层底部的火山岩而得来，成矿过程中伴随着碳酸盐岩的溶解作用，可能存在有机质的参与。据此，笔者将东莫扎抓矿床归为发育在碰撞造山带中受逆冲推覆断裂构造控制的类MVT铅锌矿床，并初步建立了东莫扎抓铅锌矿床的构造控矿模型。
Abstract:Located in the eastern and northern margins of the Tibetan orogenic belt, the Dongmozhazhua ore deposit is a Pb-Zn deposit discovered in the Pb-Zn-Cu_Ag ore bel t within the “Three Rivers" region and represents a typical type of hydrotherma l deposits in the thrust-nappe system. A study of this deposit is helpful to the understanding of ore-forming regularity of the regional Pb-Zn-Cu-Ag ore belt and also to the search for new deposits in this region. Based on detailed field wor k, systematic thin section observation of ores and analysis of C, H and O istopi c compositions in calcites, the authors give a general description of geological features of this Pb-Zn deposit as well as C, H and O istopic characteristics of the ore fluid. In this deposit, ore bodies exist in the stratoid form and are c ontrolled by thrust faults. The host rocks are limestone in Bolila Formation of Late Triassic Jiezha Group and in Gadikao Formation of Early-Middle Permian Kaix i nling Group, with strong dolomitization and weak silicification. Minerals are ra ther simple and consist of sphalerite, galena, pyrite, calcite, dolomite and barite. The important ore textures are colloforms such as framboid and crust and xenom orphic grains, and the ore structures are in disseminated, brecciated, veinlike and lumpy forms. The δ13CV-PDB,δ18OV-SMOW and δDV-SMOW values of calcites are respectively from -1.8‰ to +3.3‰, +6.1‰ to +24.6‰ and -137‰ to -53‰, and the δ18OH2O values of the ore fluid are from -0.5‰ to +13.8‰. According to this study, the aut hors point out that the ore-forming fluid of this deposit was derived mainly from the pent-up water in the basin and partly from the hydrothermal fluid, the metals might have come from carbonate str ata in the basin and igneous strata under the host rocks, and the dissolutio n of some host rocks and the participation of organic matters might have occurred during the ore-forming process. On such a basis, the authors have classified the Dongmozhazhua Pb-Zn deposit as a MVT-like Pb-Zn deposit which is controlled by the thrust-nappe system in the orogenic belt. In addition, a structural control model for the ore depo sit has been established.
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基金项目:“十一五”国家科技支撑计划项目课题八（2006BAB01A08）和课题四（2006BAB01A04）、国家973项目(2009CB421007)、国土资源大调查项目 (1212010818096)、中央级公益性科研院所基本科研业务费专项资金 (K0802)、国家基础研究计划973项目 (2002CB412600)、南京大学内生金属矿床成矿机制研究国家重点实验室资金(13-7-5）、东华理工大学核资源与环境教育部重点实验室 (081206)和中国博士后科学基金（20070420418）
引用文本：
刘英超,杨竹森,侯增谦,田世洪,王召林,宋玉财,薛万文,鲁海峰,王富春,张玉宝,朱 田,俞长 捷,苏嫒娜,李真真,于玉帅.2009.青海玉树东莫扎抓铅锌矿床地质特征及碳氢氧同位素地球化学研究[J].矿床地质,28(6):770~784杨竹森,侯增谦,田世洪,王召林,宋玉财,薛万文,鲁海峰,王富春,张玉宝,朱 田,俞长 捷,苏嫒娜,李真真,于玉帅.2009.Geology and hydrogen, oxygen and carbon isotope geochemistry of Dongmozhaz hua Pb-Zn ore deposit, Yushu area, Qinghai Province[J].Mineral Deposits28(6):770~784
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