西藏甲玛矽卡岩型铜多金属矿体地质特征  

Geological Characteristic of Jiama Skarn-type Cu-polymetallic Ore Body in Tibet

作　　者：白云[1,2] 陈毓川[3] 唐菊兴[3] 骆毓燕[4] 覃瑜[1] 

机构地区：[1]四川省冶金地质勘查局成都地质调查所,四川成都610023 [2]成都理工大学地球科学学院,四川成都610059 [3]中国地质科学院矿产资源研究所,北京100037 [4]四川大学工商管理学院,四川成都610064

出　　处：《矿业研究与开发》2011年第4期1-3,21,共4页Mining Research and Development

基　　金："十一五"国家科技支撑计划项目(2006BAB01A01);青藏专项项目(1212010818089);中国黄金集团重点勘探项目;技术开发项目(E0804)

摘　　要：甲玛矿床为西藏冈底斯成矿带中段东部一重要的斑岩-角岩-矽卡岩复合型铜多金属矿床,为始新世末-中新世造山后伸展走滑体制下中酸性岩浆侵入活动的产物。矿体主要是以矽卡岩型铜钼铅锌(金、银)矿体、角岩型铜钼矿体和斑岩型铜钼(金、银)矿体形式存在。主矿体分布于晚侏罗世多底沟组与早白垩世林布宗组的层间扩容空间中,为一典型的矽卡岩型矿体,但具与斑岩有关的典型的Cu-Mo-Au-Ag-Pb-Zn元素组合特征。矿石矿物以黄铜矿、斑铜矿、辉钼矿、黝铜矿和辉铜矿等为主,矿石具稀疏浸染状、细脉浸染状构造和自形粒状、半自形粒状结构。成矿元素在走向上具地表东段以Cu+Mo和Cu为主,西段以Pb和Cu+Pb+Zn为主的分布规律,垂向上由浅部向深部出现了Pb+Zn(Au+Ag)→Pb+Zn(Cu+Au+Ag)向Cu(Mo+Au+Ag)→Cu+Mo+(Au+Ag)→Mo的演化序列,构成了一个完整的与岩浆作用有关的成矿元素分带、矿石矿物分带规律。建议在今后的找矿勘探中应以成矿系列理论为指导,建立"斑岩-角岩-矽卡岩型"三位一体的勘查模型,重点寻找深部和外围隐伏的斑岩型铜多金属矿,则古郎地段找矿潜力巨大。Jiama deposit is a typical porphyry - homfels - Skarn type Cu - polymetallic deposit in the middle east of Gangdise metallogenie belt in Tibet, China, the formation of jiama deposit related with the acid dykes and granite porphyry of Himalayan. The orebody is mainly concerned with copper- molybdenum- Lead - Zinc （ gold - silver） of skarn - type, copper - molybde- num of hornfels - type, copper - molybdenum （ gold - silver） of porphyry - type. The main orebody of Jiama copper - polymetal- lic ore deposit distributes in the expansion space between layers of Late Jurassic Duodigou Formation and Early Cretaceous Lin- buzong Formation, which is a typical skarn orebody, but has asso- ciation character of typical elements of Cu - Mo - Au - Ag - Pb -Zn. The ore minerals are mainly about chalcopyrite, bornite, molybdenite, tetrahedrite and chalcoeite with sparse dissemina- ted and veinlet - disseminated granular - like structure and self -shaped- subhedral granular structure. The metallogenie ele- ment zoning includes Pb ＋ Zn（ Au ＋ Ag） ---,Pb ＋ Zn （ Cu ＋ Au ＋ Ag）---~Cu（Mo ＋ Au ＋ Ag） ----~Cu ＋ Mo ＋ （ Au ＋ Ag） ---~Mo as a complete metallogenic element zoning and the ore mineral zoning related to magmatism. It was suggested that under the guide of nletallogenic series theory, the following exploration should establish the exploration model of ＂porphyry - hornfels - skarns＂ , the emphasis of exploration should be on searching deep and peripheral hidden porphyry Cu -polymetallic deposit, and the ore -prospecting potential in Gulang district is tremendous.

关 键 词：斑岩型矿体 矽卡岩型矿体 角岩型矿体 矿体地质 特征 元素分带 冈底斯成矿带 西藏 

分 类 号：P57[天文地球—矿物学]