投稿时间：2015-12-22
修订日期：2016-12-24
网络发布日期：2017-03-11
中文摘要:西藏冈底斯成矿带拉抗俄斑岩铜钼矿床位于西藏特提斯构造域拉萨地块东段中南部，是近年来青藏高原地质大调查项目评价的重点矿床之一。文章在钻孔地质编录的基础上，依据矿物组合、脉体穿切关系的不同，划分了3个成矿阶段：早阶段、中阶段以及晚阶段，成矿中阶段为主成矿阶段。根据包裹体室温下的相态充填度特征以及是否含有子矿物，可将其分为3大类：液相包裹体（Ⅰ）、气相包裹体（Ⅱ）和含子晶多相包裹体（Ⅲ）。成矿早阶段流体包裹体主要为Ⅰ、Ⅱ和Ⅲ类包裹体，均一温度集中在260~400℃之间，w（NaCleq）为2.1%~39.4%；成矿中阶段的流体包裹体主要为Ⅰ、Ⅱ和Ⅲ类包裹体，具有典型的沸腾包裹体组合，均一温度集中在280~360℃，w（NaCleq）为2.2%~37.1%；成矿晚阶段流体包裹体主要为Ⅰ类包裹体，均一温度集中在220~280℃，w（NaCleq）为3.6%~5.6%，显示包裹体均一温度及盐度呈递减趋势。成矿流体是中高温、中高盐度，且富含成矿元素的NaCl-H2O体系流体。矿床形成的压力为（100±10）MPa，形成深度为（3.7±0.4）km。激光拉曼探针分析结果表明，流体包裹体液相成分主要为H2O，气相成分含有CO2；子矿物有黄铜矿、磁铁矿、赤铁矿、石膏、黄铁矿、金红石、长石等。成矿早阶段，岩浆房发生流体出溶；成矿中阶段，岩浆流体发生减压沸腾和不混溶作用。综上所述，温度降低、压力减小、pH值的增加以及氧化还原电位的变化是造成拉抗俄矿床成矿元素沉淀的主要因素。
Abstract:Located in central and southern part of east Lhasa block in the Tibetan Tethys tectonic domain, the Lakang'e porphyry Cu-Mo deposit in the Gangdese metallogenic belt is one of the key deposits in the Tibetan Plateau for geological survey evaluation in recent years. On the basis of drilling core logging and according to the vein types and crosscutting relationships, the authors divided the mineralization in the Lakang'e deposit into three stages:early ore-forming stage, main ore-formaing stage and late ore-forming stage. Fluid inclusions at Lakang'e can be classified into type Ⅰ(liquid phase inclusions), Ⅱ(vapour phase inclusions) and Ⅲ(daughter mineral-bearing fluid inclusions). The early ore-forming stage has mainly type Ⅰ, Ⅱand Ⅲ inclusions, characterized by homogenization temperatures 260~400℃, w(NaCleq) 2.1%~39.4%; the main ore-forming stage has mainly type Ⅰ, Ⅱand Ⅲ inclusions, characterized by homogenization temperatures 280~360℃, w(NaCleq) 2.2%~37.1%; the late ore-forming stage has mainly type Ⅰinclusions, characterized by homogenization temperatures 220~280℃, w(NaCleq) 3.6%~5.6%,respectively, which suggests that the temperature and salinity decrease from early to late stage. The ore-forming fluid is the NaCl-H2O system of rich ore-forming elements, middle-high temperature and middle-high salinity. The formation pressure of deposit is (100±10) MPa, and the formation depth is (3.7±0.4) km. The laser Raman spectroscopic analysis reveals that H2O is the main component in liquid, there exist minor amounts of CO2 in vapors, and daughter minerals are mainly chalcopyrite, magnetite, hematite, gypsum, pyrite, rutile and feldspar. The exsolution of magma chambers occurs at the early ore-forming stage; the initiation of boiling and immiscibility occurs at the main ore-forming stage. The major factors influencing the participation of ore-forming elements in the Lakang'e deposit are decreasing temperature and pressure, increasing pH and variation of oxidation-reduction potential.
keywords:geochemistry fluid inclusion magmatic-hydrothermal fluid Lakang'e porphyry Cu-Mo deposit Gangdese Tibet
文章编号：
中图分类号：P618.41;P618.65
文献标志码：
基金项目:本文由公益性行业专项（编号：201511022-02；201511017）、国家自然科学基金项目（编号：41302060）和中国地质科学院基本科研业务费（编号：YYWF201608）联合资助
引用文本：
唐攀,陈毓川,唐菊兴,郑文宝,冷秋锋,林彬.2017.西藏拉抗俄斑岩铜钼矿床流体包裹体研究[J].矿床地质,36(1):68~82TANG Pan,CHEN YuChuan,TANG JuXing,ZHENG WenBao,LENG QiuFeng,LIN Bin.2017.A study of fluid inclusions from Lakang'e porphyry Cu-Mo deposit in Tibet[J].Mineral Deposits36(1):68~82
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