投稿时间：2013-01-30
修订日期：2013-10-30
网络发布日期：2014-10-23
中文摘要:新疆西准噶尔包古图地区斑岩型铜矿化发育，蚀变矿化特征随岩体不同存在显著差异。文章通过岩石学、矿相学和微量元素地球化学的方法，重点研究了Ⅲ号和Ⅴ号岩体的矿化特征和成矿元素迁移规律。结果表明：Ⅲ号岩体矿化中等，以黄铁矿、磁黄铁矿和黄铜矿为主，呈浸染状，硫化物脉少见；Ⅴ号岩体内部及其与围岩接触带产出大型铜矿床，金属矿物主要有黄铁矿、黄铜矿和辉钼矿，呈浸染状和细脉-网脉状分布。Ⅲ号岩体角闪石英闪长岩形成于岩浆-热液过渡阶段，与石英（花岗）闪长岩对比显示，挥发分出溶过程中，Cs、Rb、Ba、Th、U迁移进入挥发相，稀土元素稳定未迁移，Cu、Bi显著富集，Mo和Sb被流体迁移带走，形成热液矿化。Ⅴ号岩体钾化和硅化样品代表了不同的流体作用阶段，与未蚀变样品对比显示，在钾化阶段Nb、Ta、Zr、Hf性质稳定，轻稀土元素发生显著迁移，在硅化阶段轻稀土元素富集；重稀土元素在岩浆-热液演化过程保持稳定。Cu、Mo和Bi在钾化作用阶段富集成矿，Zn和Sb则主要在晚期石英脉中富集。
Abstract:Porphyry copper deposits are well developed in Baogutu area, west Junggar, Xinjiang. Different intrusions show remarkable difference in alteration and mineralization features. The authors studied emphatically the mineralization and ore-forming elements migration in intrusive body Ⅲ and Ⅴ by means of petrology, ore microscopy and trace element geochemistry. Intrusion Ⅲ has experienced a medium degree of mineralization, with plenty of disseminated pyrite, pyrrhotite and chalcopyrite and minor sulfide veins. Intrusion Ⅴ has large-size porphyry copper deposits within the rock body or along its contact zone with wall rocks, containing plenty of chalcopyrite, pyrite and molybdenite,with disseminated and veinlet structure. Amphibole-quartz diorite from intrusion Ⅲ crystallized in the transition process from magma to hydrothermal solution, during which Cs, Rb, Ba, Th and U migrated into volatiles, REE was immobile, Cu and Bi were obviously concentrated, and Mo and Sb moved away with the fluid, producing hydrothermal mineralization. A comparative study of potassic altered samples, silicified samples and fresh samples from intrusion Ⅴ indicates that Nb, Ta, Zr, Hf remained immobile during the potassic alteration while LREE moved until silicification. HREE remained stable during the whole magmatic-hydrothermal process. Cu, Mo and Bi precipitated during potassic alteration, whereas Zn and Sb were concentrated in the late stage quartz veins.
keywords:geology elements migration hydrothermal alteration porphyry copper deposit Baogutu Xinjiang
文章编号：
中图分类号：P618.41
文献标志码：
基金项目:本文得到国家自然科学基金项目（41203032）和国际科技合作项目（2010DFB23390）联合资助
引用文本：
魏少妮,朱永峰,安芳.2014.新疆包古图地区斑岩型铜矿化特征和成矿元素迁移规律初探[J].矿床地质,33(1):165~180WEI ShaoNi,ZHU YongFeng,AN Fang.2014.Mineralization and elements migration characteristics of porphyry copper deposits in Baogutu area, Xinjiang[J].Mineral Deposits33(1):165~180
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