西藏甲玛铜多金属矿富矿体特征  

Geological Features of the Ore Shoots from the Jiama Copper-Polymetallic Deposit in Tibet

作　　者：张志[1] 唐菊兴[2] 郑文宝[1] 应立娟[2] 姚晓峰[3] 杨毅[1] 胡正华[1] 唐晓倩[1] 

机构地区：[1]成都理工大学,四川成都610059 [2]中国地质科学院矿产资源研究所,北京100037 [3]中国地质大学,北京100083

出　　处：《地质与勘探》2013年第1期9-18,共10页Geology and Exploration

基　　金：国家自然科学基金项目(编号41172077);国家重点基础研究发展规划"973"项目(编号2011CB403103)联合资助

摘　　要：甲玛铜多金属矿是冈底斯成矿带内产出的超大型斑岩-矽卡岩型矿床之一,是西藏藏中有色金属工业的重要开发对象。本文根据矿区308个钻孔的成矿元素化学分析结果圈定富矿体,其中,主矿种铜圈定品位为1%,共生矿种钼圈定品位为0.1%,共生矿种铅圈定品位为1%,共生矿种锌圈定品位为0.8%。通过其平面分布特征分析发现,甲玛矿区富矿体以钻孔ZK1616-ZK3216为中心,从北东往南西形成Mo→Cu→Pb+Zn的富矿体分带特征;通过其剖面特征分析发现,甲玛矿区富矿体主要呈层状、块状、透镜状、树枝状等产出,其大多产于矽卡岩内,少部分产于斑岩体内,而角岩中基本未见富矿体。矿区铜厚大富矿体的矿物组合主要为斑铜矿+黄铜矿+硅灰石+石榴子石+石英,其蚀变主要可见矽卡岩化、硅化、绿帘石化、绿泥石化等;钼厚大富矿体主要矿物组合为辉钼矿+斜长石+钾长石+石英-辉钼矿+石榴子石+硅灰石+石英,其蚀变主要可见矽卡岩化、硅化、泥化、钾化等。The Jiama copper-polymetallic deposit is one of the most significant ore deposits for the nonferrous metal development in central Tibet, and is also a superlarge porphyry-skarn type deposit occurred in the Gangdise copper metallogenic belt. Based on element chemical analysis results of 308 drill holes, this paper delineates ore shoots according to high grades of each element, taking 1% , 0.1% , 1% , and 0.8% as the determination grade of the main mineral Cu and coexisting minerals Mo, Pb, Zn, respectively. According to the horizontal distribution features of the ore shoots in the Jiama copper- polymetallic deposit, there exists the zoning of Mo--~Cu^Pb ＋Zn from northeast to southwest with ZK1616-ZK3216 as the center. Geological profiles in- dicate that most of ore shoots occur in skarn rocks, and few ore shoots occur in porphyry rocks, while no ore shoots occur in the hornfels. The ore shoots display stratiform, massive, lenticular and arborization textures. The mineral assemblages in Cu ore shoots are mainly bornite ＋ chalcopyrite ＋ wollastonite ＋ garnet ＋ quartz, with the major alteration types as skarnized ＋ silieifieation ＋ epidotization ＋ chloritization. The mineral assemblages of Mo ore shoots are molybdenite ＋ plagioelase ＋ potash feldspar ＋ quartz-molybdenite ＋ garnet ＋ wollastonite ＋ quartz, and the main alteration types are skarnized ＋ silici- fication ＋ mudding ＋ potassic alteration.

关 键 词：甲玛铜多金属矿 斑岩-矽卡岩型矿床 富矿体 分带特征 矿物组合西藏 

分 类 号：P618[天文地球—矿床学]