投稿时间：2014-03-19
修订日期：2014-10-06
网络发布日期：2014-12-30
中文摘要:多不杂富金斑岩铜矿床是班公湖-怒江成矿带第一个勘查评价出的大型斑岩铜矿床。文章在对矿区野外地质编录及室内镜下鉴定的基础上,对矿床蚀变与脉体系统进行了详细研究。结果表明,矿区发育典型斑岩铜矿蚀变系统,且分带性非常明显,从斑岩体内部向外具有钾硅酸盐化带(外缘叠加泥化蚀变与绢云母化蚀变)→绢英岩化带(大部分叠加有泥化蚀变)→青磐岩化带→角岩化带的分带特征。根据穿插关系、矿物组合及蚀变晕等特征可划分出21种脉体,早期形成的脉体包括在钾硅酸盐化带发育的磁铁矿细脉(M型脉共1种)、石英±钾长石±黑云母±磁铁矿±黄铜矿±黄铁矿脉(A型脉共8种)以及具有矿物组合分带特征的石英±磁铁矿±黑云母+钾长石+黄铜矿+黄铁矿脉(EB型脉共2种),中期形成的脉体包括主要在绢英岩化与泥化叠加带发育的石英±黄铜矿±黄铁矿±辉钼矿±石膏脉(B型脉共5种),晚期形成的脉体包括主要在青磐岩化带发育的石英±黄铁矿±黄铜矿±石膏±方解石脉(D型脉共5种),以A、B、D型脉最为发育。与矿化密切相关的蚀变带主要是钾硅酸盐化带、绢英岩化与泥化叠加带,与矿化密切相关的脉体主要为A型脉及B型脉。与国内外典型矿床相比,多不杂矿床蚀变模式及矿物组合与"二长岩"模式相似。多不杂矿床从内部的钾硅酸盐化带至外部的青磐岩化带均发育大量磁铁矿,且在青磐岩化带发育大量无矿石膏网脉,此是多不杂矿床的独有特色。
Abstract:The Duobuza gold-rich porphyry copper deposit is the first large porphyry copper deposit discovered in the Bangong Co-Nujiang River metallogenic belt . The authors conducted a detailed research on alterations and veins of the deposit based on detailed field geological survey and indoor microscopic identification. The results show that the deposit develops typical alteration systems of porphyry copper deposit and obvious zoning composed from the interior to the exterior of the porphyry of potassium silicified zone (with the superposition of argillic alteration and sericite alteration at the edge)→phyllic zone (with the superposition of argillic alteration ) →propy- litization zone →hornfels zone. According to the cutting and offsetting relationships, mineral assemblages and alteration halos, twenty one vein types were identified. The early stage contains magnetite veins (M type veins), quartz ± K-feldspar ± biotite ± magnetite ± chalcopyrite ± pyrite veins (A type veins) and quartz ± magnetite ± K-feldspar + biotite + chalcopyrite + pyrite veins (EB type veins) which were formed in the potassium silicified zone mostly. The mid-stage contains quartz ± pyrite ± chalcopyrite ± molybdenite ± gypsum veins (B type veins) which were formed in the superimposed alteration zone with phyllic and argillic alteration. The late stage contains quartz ± pyrite ± chalcopyrite ±gypsum± calcite veins (D type veins) which were formed in the propylitization zone. A, B and D type veins are especially well developed. Potassium silicified alteration and phyllic alteration are closely related to the ore-forming process, and A and B type veins are closely associated with the mineralization. The alteration model of the Duobuza deposit is similar to the "monzonite" model in contrast with typical deposits abroad. The Duobuza deposit develops a large quantity of magnetites from the potassium silicified zone to the propylitization zone and a lot of gypsum stockworks in the propylitization zone, which constitutes the unique features of the Duobuza deposit.
文章编号：
中图分类号：P618.41
文献标志码：
基金项目:本文得到青藏专项优选项目(编号: 12120113037400)、国家自然科学基金项目(编号: 41172077)及国家重点基础研究发展规划"973"项目(编号: 2011CB403103)联合资助
引用文本：
张志,陈毓川,唐菊兴,李玉彬,高轲,王勤,李壮,李建力.2014.西藏多不杂富金斑岩铜矿床蚀变与脉体系统[J].矿床地质,33(6):1268~1286ZHANG Zhi,CHEN YuChuan,TANG JuXing,LI YuBin,GAO Ke,WANG Qin,LI Zhuang,LI JianLi.2014.Alteration and vein systems of Duobuza gold-rich porphyry copper deposit, Tibet[J].Mineral Deposits33(6):1268~1286
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