冈底斯驱龙斑岩铜-钼矿区外围矽卡岩型铜矿的分布、特征及深部找矿意义  

Distributions and Characters of Zhibula-Langmujiaguo Skarn Cu Deposits Environing the Qulong Porphyry Cu-Mo Deposit and Their Implications for Ore-Search Towards the Deep Subsurface

作　　者：肖波[1,2] 秦克章[1] 李光明[1] 李金祥[1] 陈雷[1,2] 赵俊兴[1,2] 范新[1,2] 

机构地区：[1]中国科学院矿产资源研究重点实验室,中国科学院地质与地球物理研究所,北京100029 [2]中国科学院研究生院,北京100049

出　　处：《地质与勘探》2011年第1期43-53,共11页Geology and Exploration

基　　金：国家自然科学基金项目(40772066);西藏巨龙铜业有限公司和国家十一五科技支撑计划冈底斯成矿课题编号(2006BA01A04)的联合资助

摘　　要：世界范围内,巨型斑岩型矿床外围通常发育有同时代且具有成因联系的矽卡岩-脉状金属矿床;二者往往互为找矿标志,共同组成斑岩成矿系统。形成于印度-欧亚大陆后碰撞背景,与中新世adakitic质侵入岩有关的冈底斯斑岩Cu-Mo矿床成矿带已成我国重要的矿产基地。位于冈底斯中段的驱龙巨型斑岩Cu-Mo矿床(>1000MtCu)是我国目前最大的铜矿床,在其外围南部及东南部,分布着知不拉、朗姆家果两个矽卡岩型Cu矿;矽卡岩及矿体走向近东西,向北陡倾,矿体深部向驱龙斑岩矿床延伸。成矿时代上,知不拉与驱龙完全一致;同时知不拉与朗姆家果具有极其相似的矿床地质特征、矽卡岩矿物组成和矿化类型,硫化物组合均为黄铜矿、黄铁矿、斑铜矿和辉铜矿;矽卡岩中的石榴石主要是具有韵律生长环带的钙铁榴石(Ca3Fe2Si3O12)为主,少量的钙铝榴石(Ca3Al2Si3O12);从矽卡岩的产状推断二者可能相连成一体。最新的钻探揭示在朗姆家果矽卡岩矿床的深部出现驱龙斑岩矿床中的花岗闪长岩和黑云母二长花岗岩,表明它们是同一期岩浆-成矿作用的产物。在冈底斯带上斑岩型矿床外围有利区域寻找矽卡岩型矿床将极大的拓展找矿思路和空间。Giant porphyry Cu systems host the most widely distributed mineralization types at convergent plate boundaries,including porphyry deposits centered on intrusions,skarn and superjacent high-and intermediate-sulfidation epithermal deposits.While the giant Miocene Qulong porphyry Cu-Mo deposit,which formed in the Gangdese post-collision orogenic belt of southern Tibet,now,is thought to be the largest porphyry-type deposit in China,and with confirmed Cu ~ 10Mt and Mo ~0.5Mt,at least.Two contemporary skarn Cu deposits are located adjacently,the Zhibula and Langmujiaguo sharn deposits.The skarn deposits share exactly similar geological,mineralogical features：garnets with obvious oscillatory growth zoning are mainly andradite（Ca3Fe2Si3O12）and minor grossularite（Ca3Al2Si3O12）;sulfides are chalcopyrite,pyrite,bornite,and chalcocite.These skarn deposits have obvious close temporal and spatial relations to the Qulong porphyry deposit,and the recent exploration work at the Langmujiaguo skarn deposit found that the same Miocene granodiorite and biotite monozogranite in the Qulong porphyry deposit were intruded under the skarks.So the porphyry deposit and the skarn deposits might result from the same ore-forming system.The features of porphyry Cu systems and the closely adjacent skarn deposits need to be taken into account during planning and exploration.

关 键 词：斑岩成矿系统 驱龙斑岩Cu-Mo矿 知不拉-朗姆家果矽卡岩Cu矿床 冈底斯 

分 类 号：P618.2[天文地球—矿床学]