投稿时间：2014-01-06
修订日期：2014-05-15
网络发布日期：2014-09-15
中文摘要:包古图地区是新疆西准噶尔重要的金矿集区之一，根据矿床地质和矿化类型，可将区内金矿化分为2类：以阔个沙也金矿床（包古图金矿Ⅰ~Ⅳ号点）为代表的石英脉型金矿化，产于部分中酸性斑岩体周边地层中，赋矿围岩为下石炭统包古图组凝灰质砂岩、凝灰岩等，围岩蚀变以硅化、绢云母化、黄铁矿化、毒砂化和碳酸盐化为主，矿体为黄铁矿-石英脉型、辉锑矿-石英脉型和自然砷-石英脉型或石英网脉型/蚀变岩型，受NE向断裂控制，与矿区密集分布的中酸性脉岩伴生，主要矿物组合为黄铁矿-毒砂-自然砷-辉锑矿-自然金-银金矿，矿化元素组合为Au-As-Sb，是中酸性斑岩系统热液演化晚期的产物；另一类金矿化产于中酸性斑岩与下石炭统火山-沉积地层的接触带中，以包古图金矿Ⅺ号点为代表，矿体为石英-硫化物脉型，矿物组合为黄铁矿-毒砂-自然铋-辉铋矿-自然金-黄铜矿，是斑岩系统热液演化较早期的产物。结合已有研究资料，可将区内金矿床的成矿模型总结如下：斑岩岩浆系统演化晚期分异出含Au-Cu-Bi-As-Sb的岩浆热液，在岩体内部形成斑岩型铜矿化，岩体与围岩接触带形成高温石英-硫化物脉型Au-As-Bi矿化，部分含矿热液随中酸性岩脉向外围迁移，并逐渐与大气水混合，最终在NE向断裂中形成石英脉型Au-As-Sb矿化。基于此成矿模型，认为包古图地区金矿找矿工作的重点应该放在中酸性斑岩体与围岩接触带和斑岩体外围NE向断裂（中酸性脉岩）密集分布区，尤其是As-Sb、As-Bi化探异常叠加区。矿床地质和地球化学特征对比显示，包古图金矿成矿系统与侵入岩有关的金矿成矿系统非常相似。
Abstract:The Baogutu area is one of the important gold concentration areas in western Junggar, North Xinjiang. There are more than ten gold ore spots and one porphyry copper deposits with Cu reserves of 0.11 Mt in Baogutu area. Two types of gold mineralization have been recognized in Baogutu: quartz vein type ore hosted in NE-trending faults with intermediate-acidic vein rocks (type-a), sulfide vein type ore hosted in radial fracture accompanied by intermediate-acidic porphyry (type-b). The Kuogeshaye gold deposit is a representative deposit of type-a. Wall rocks are tuffaceous sandstone and tuff in Lower Carboniferous Baogutu Formation, with silicification, sericitization, pyritization, arsenopyritization and carbonatization. The orebody is composed of pyrite-quartz vein, native arsenic-quartz vein, stibnite-quartz vein and disseminated quartz stockwork, with a major mineral assemblage of pyrite-arsenopyrite-native arsenic-stibnite-native gold-electrum. Baogutu gold ore district Ⅺ is a representative of type-b. It is located in the contact zone between porphyry and volcanic-sedimentary rocks, hosted in Lower Carboniferous Xibeikulasi Formation and controlled by a NE-trending radial fracture associated with porphyry. The orebody is mainly composed of pyrite, arsenopyrite, native bismuth, bismuthinite, native gold and chalcopyrite, with small amounts of pyrrhotite and quartz. Two types of gold mineralization in Baogutu area are closely related to intermediate-acidic magmatism in space and time. It is noted that gold mineralization in Baogutu is always associated with As-Sb or As-Bi mineralization, and hence it is worthwhile to pay special attention to the geochemical anomaly areas of As-Sb and As-Bi in further exploration. The Baogutu gold mineralization system is very similar to the intrusion-related gold system in geological and geochemical characteristics.
keywords:geology geological characteristics mineralization regulation gold deposit Baogutu western Junggar
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中图分类号：P618.51
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基金项目:本文受到国家自然科学基金项目（41203032）、科技部国际科技合作项目（2010DFB23390）、大陆动力学国家重点实验室自主研究项目和“三秦学者”学术团队联合资助
引用文本：
安芳,朱永峰,魏少妮,郑波.2014.新疆包古图地区金矿床地质特征及成矿模型研究[J].矿床地质,33(4):761~775AN Fang,ZHU YongFeng,WEI ShaoNi,ZHENG Bo.2014.Geology and metallogenic model of gold ore deposits in Baogutu area, Western Junggar, Xinjiang[J].Mineral Deposits33(4):761~775
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