陕西柞山地区穆家庄铜矿稀土元素地球化学特征  

Rare element geochemistry of the Mujiazhuang copper deposit in the Zhashan area,Shaanxi

作　　者：朱华平[1] 张德全[1] 刘平 陈连红 

机构地区：[1]中国地质科学院矿产资源研究所 [2]西北有色地质勘查局,陕西西安710054

出　　处：《中国地质》2004年第1期85-90,共6页Geology in China

基　　金：中国地质调查局国土资源大调查项目(200110200101);西北有色地质勘查局人才基金联合资助。

摘　　要：尽管秦岭泥盆系铅锌金多金属成矿带成矿作用均与热水喷流沉积作用有关,柞山地区却有别于凤太地区,具有独特的铜矿成矿背景。本文通过对矿床的岩、矿石稀土元素地球化学研究,认为浸染状贫铜矿石和近矿围岩的稀土组成和配分曲线基本一致,表明浸染状贫铜矿石代表了泥盆纪时期热水沉积事件所形成的含少量硫化物的热水沉积岩初步富集的产物,泥盆纪时期形成了穆家庄铜矿的初始矿源层。围岩中的层纹状硅质岩可能代表了泥盆纪时期的热水沉积岩性质。块状富矿石的稀土组成代表了广泛的陆陆碰撞造山运动所产生的流体热液作用的结果,它既就地改造了初始矿源层,而且从异地可能带来了部分成矿物质,在合适的构造部位改造富集成矿。穆家庄铜矿的成因为改造型的。Although mineralization in the Devonian lead-zinc-gold polymetallic metallogenic belt in Qinling is related to hydrothermal exhalation-sedimentation.The Zhashan area is distinguished from the Fengtai area in its having a distinctive copper metallogenic setting.REE geochemical studies of rocks and ores in the Mujiazhuang copper deposit show that the REE compositions and distribution patterns of disseminated lean copper ores and near-ore country rocks are essentially consistent,suggesting that the disseminated lean copper ores represent the product of primary concentration of hydrothermal sedimentary rocks with small amount of sulfide formed by the hydrothermal sedimentary event during the Devonian.During this period the primary source bed of the Mujiazhuang copper deposit formed.Laminated siliceous rocks in country rocks might represent the nature of the Devonian hydrothermal sedimentary rocks.The REE composition of massive rich ores represents the result of fluid hydrothermal activity resulting from extensive continent-continent collisional orogeny.The hydrothermal activity not only modified the primary source bed in situ but also may have brought part of ore substances from other places and deposited them;the deposit was then subjected to modification and concentration at the appropriate structural site.Mujiazhuang copper deposit should be of modified origin.

关 键 词：铜矿 稀土元素 元素地球化学 改造型矿床 秦岭 

分 类 号：P59[天文地球—地球化学]