投稿时间：2015-12-05
修订日期：2016-12-30
网络发布日期：2017-03-11
中文摘要:黑尖山Fe-Cu（-Au）矿床位于新疆东天山阿齐山-雅满苏岛弧带。黑尖山矿体赋存于上石炭统马头滩组火山岩和火山碎屑岩中。根据脉体穿切关系和矿物共生组合类型，可将黑尖山的矿物生成顺序划分为7个阶段，分别为铬铁矿阶段（Ⅰ）、绿帘石蚀变阶段（Ⅱ）、磁铁矿阶段（Ⅲ）、黄铁矿阶段（Ⅳ）、铜（金）阶段（Ⅴ）、后期脉阶段（Ⅵ）和表生蚀变阶段（Ⅶ）。阶段Ⅰ以在磁铁矿的核部出现铬铁矿为特征；阶段Ⅱ主要为绿帘石化；阶段Ⅲ为Fe矿化，以磁铁矿与角闪石共生为主，伴有少量钾长石化；阶段Ⅳ以石英-黄铁矿-磁黄铁矿±黄铜矿为共生矿物组合；阶段Ⅴ为Cu（-Au）矿化，以石英-黄铜矿-赤铁矿和黄铜矿-银金矿-绿泥石脉为特征；阶段Ⅵ主要为后期的热液脉体；阶段Ⅶ主要出现一些铜的表生矿物。磁铁矿阶段（Ⅲ）和铜（金）阶段（Ⅴ）分别为黑尖山的Fe和Cu（-Au）矿化阶段。H、O同位素研究结果显示：黑尖山在Fe矿化之前，大量晚石炭世海水与黑尖山矿区围岩在基性岩浆所产生的区域热作用下发生反应，形成大面积的绿帘石蚀变（阶段Ⅱ：δ18Ofluid=6.3‰~7.8‰，δDfluid=-12.3‰~-7.3‰）；Fe矿化主要受高温（约590℃）的岩浆热液控制（阶段Ⅲ磁铁矿、石英和阳起石的δ18Ofluid分别为8.8‰，9.5‰~9.7‰和8.9‰~9.3‰；阳起石的δDfluid=-102.5‰~-87.6‰），并受其他因素（围岩及围岩中残留海水和有机质）的影响；外来的低温盆地卤水可能是形成硫化物和Cu（-Au）矿化的主要控制因素；后期大气降水的加入与大量后期热液脉体的形成相关（阶段Ⅵ：δ18Ofluid=1.4‰~3.5‰；δDfluid=-76.1‰~-57.2‰）。黑尖山Fe-Cu（-Au）矿床在蚀变、矿化共生组合和成矿流体来源等方面与安第斯中生代IOCG型矿床相似，且黑尖山矿床Fe和Cu（-Au）矿化阶段成矿流体的显著不同可能是东天山阿齐山-雅满苏岛弧带其他Fe-Cu矿床的普遍特征，从而区别于典型矽卡岩型和海相火山岩型矿床。
Abstract:The Heijianshan Fe-Cu (-Au) deposit is located in the Aqishan-Yamansu island arc belt of the Eastern Tianshan, Xinjiang. The Heijianshan deposit is hosted in volcanic rocks and volcaniclastic rocks of the Late Carboniferous Matoutan Formation. Based on the cutting relationships of veins and mineral assemblages, the authors divided the paragenetic sequence of Heijianshan into seven stages:chromite stage (Ⅰ), epidote alteration stage (Ⅱ), magnetite stage (Ⅲ), pyrite stage (Ⅳ), Cu (-Au) stage (Ⅴ), late veins (Ⅵ) and supergene alteration stage (Ⅶ). Stage Ⅰ is characterized by the occurrence of chromite in the core of magnetite, while stage Ⅱ is mainly composed of epidote alteration. Fe mineralization in stage Ⅲ occurs as magnetite coexisting with amphibole with minor K-feldspar alteration. Stage Ⅳ is characterized by mineral assemblage of quartz-pyrite-pyrrhotite±chalcopyrite. Stage V is dominated by Cu (-Au) mineralization, which is characterized by veins of quartz-chalcopyrite-hematite and chalcopyrite-electrum-chlorite. Stage Ⅵ is mainly composed of late hydrothermal veins, and stage Ⅶ occurs predominantly as supergene Cu minerals. The magnetite stage Ⅲ and Cu (-Au) stage V are Fe and Cu (-Au) ore-forming stages at Heijianshan, respectively. Hydrogen and oxygen isotopes show that large amounts of Late Carboniferous seawater interacted with the host rocks in Heijianshan to form the epidote alteration (stage Ⅱ:δ18Ofluid=6.3‰~7.8‰, δDfluid=-12.3‰~-7.3‰) with the enhancement of regional heat by basic magma. Fe mineralization was mainly controlled by the high temperature (~590℃) magmatic-hydrothermal fluids (stage Ⅲ δ18Ofluid values of magnetite, quartz and actinolite are 8.8‰, 9.5‰~9.7‰ and 8.9‰~9.3‰, respectively; δDfluid values of actinolite are from -102.5‰ to -87.6‰) and influenced by other factors, such as host rocks, residual seawater and organic materials in host rocks. Sulfides and Cu (-Au) mineralization might have predominantly been controlled by the low temperature basinal brines. Afterwards, the meteoric water was mixed with the ore-forming fluids to form abundant late hydrothermal veins (stage Ⅵ:δ18Ofluid=1.4‰~3.5‰; δDfluid=-76.1‰~-57.2‰). The Heijianshan Fe-Cu (-Au) deposit is similar to the Central Andean IOCG deposits in alteration, mineralization paragenesis, and sources of ore-forming fluids. Meanwhile, the remarkably different ore-forming fluids for Fe and Cu (-Au) mineralization in the Heijianshan Fe-Cu (-Au) deposit may be common characteristics for the Fe-Cu deposits in the Aqishan-Yamansu island arc belt of the Eastern Tianshan, which is different from the typical skarn and submarine volcanic-hosted deposits in this region.
keywords:geochemistry paragenesis isotope geochemistry Aqishan-Yamansu island arc belt IOCG deposit Xinjiang
文章编号：
中图分类号：P618.31;P618.41;P618.52
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基金项目:本文得到国家重点基础研究发展计划973项目（编号：2014CB440802、2014CB448000）、中国科学院创新交叉团队合作项目（编号：Y433131A07）和新疆重大基础研究项目（编号：201330121）联合资助
引用文本：
赵联党,陈华勇,张莉,张增杰,李登峰,张维峰,陆万俭,杨骏,闫学录.2017.新疆黑尖山Fe-Cu (-Au)矿床氢氧同位素特征及其地质意义[J].矿床地质,36(1):38~56ZHAO LianDang,CHEN HuaYong,ZHANG Li,ZHANG ZengJie,LI DengFeng,ZHANG WeiFeng,LU WanJian,YANG JunTao,YAN XueLu.2017.H-O isotope characteristics and geological significance of Heijianshan Fe-Cu (-Au) deposit in Eastern Tianshan, Xinjiang[J].Mineral Deposits36(1):38~56
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