云南巍山—永平碰撞造山带走滑拉分盆地铜金多金属矿成矿流体系统:稳定同位素特征及热液来源  

Stable isotope characteristics and origin of ore-forming fluids in copper-gold polymetallic deposits within strike-slip pull-apart basin of Weishan-Yongping continental collision orogenic belt,Yunnan Province,China

作　　者：王勇[1] 侯增谦[1] 莫宣学[2] 董方浏[1] 毕先梅[2] 曾普胜[1] 

机构地区：[1]中国地质科学院矿产资源研究所 [2]中国地质大学,北京100083

出　　处：《矿床地质》2006年第1期60-70,共11页Mineral Deposits

基　　金：中国地质调查局国土资源大调查综合研究项目(20001020026003)资助

摘　　要：云南巍山—永平矿集区位于兰坪走滑拉分盆地南段,有铜金多金属中、小型矿床及矿化点140余处,盆地发育和成矿作用与印度—亚洲板块碰撞密切相关。为了探索该矿集区成矿热液的来源,研究了该区成矿流体的稳定同位素特征。区内成矿流体系统可分为紫金山子系统与公郎弧子系统。公郎弧子系统内铜钴矿床成矿流体的δD为-83.8‰^-69‰,δ18O为4.17‰~10.45‰,δ13C为-13.6‰~3.7‰,成矿流体主要来源于岩浆水及地层水。紫金山子系统内金、铅锌、铁矿床成矿流体的δD为-117.4‰^-76‰,δ18O为5.32‰~9.56‰,δ13C为-10.07‰^-1.5‰;锑矿成矿流体的δD为-95‰^-78‰,δ18O为4.5‰~32.3‰,δ13C为-26.4‰^-1.9‰,成矿流体来源于地层水以及岩浆水。受印度板块与亚洲板块碰撞造山作用的影响,在该盆地内,成矿流体自南西向北东大规模迁移过程中,先形成温度、盐度较高的公郎弧子系统,随着流体向北东推进,温度、盐度逐渐降低,流体成分发生变化,演变为紫金山子系统。More than 140 middle-small size deposits or mineral occurrences occur in the Weishan-Yongping ore concentration area located in the southern part of the typical Lanping strike-slip and pull-apart basin which has plenty of mineral resources derived from the collision between Indian plate and Asian plate. The ore-forming fluid system in Weishan-Yongping ore concentration area can be divided into two subsystems, namely, Zijinshan subsystem and Gonglang arc subsystem. The ore-forming fluids of Cu, Co deposits in Gonglang arc fluid subsystem have δD values between -83.8‰ and - 69‰, δ^18O between 4.17‰ and 10.45‰, and δ^13C between - 13.6‰ and 3.7‰, suggesting that the ore-forming fluids of Cu, Co deposits were derived mainly from magmatic water and partly from formation water. The ore-forming fluids of Au, Pb, Zn, Fe deposits in Zijinshan subsystem have δD values between - 117.4‰ and - 76‰, δ^18O between 5.32‰ and 9.56‰, and δ^13C between - 10.07‰ and - 1.5‰. The ore-forming fluids of Sb deposits in Zijinshan ore-forming fluid subsystem have δ^D values between - 95‰ and - 78‰, δ^18O between 4.5‰ and 32.3‰, and δ^13C between - 26.4‰ and - 1.9‰. Hence, the ore-forming fluids in Zijinshan subsystem must have been derived mainly from formation water and partly from magmatic water. Affected by the collision between Indian plate and Asian plate, ore-forming fluids in Weishan- Yongping basin migrated considerably from southwest to northeast. At first, the Gonglang arc subsystem with high temperature and high salinity was formed. With the development of the ore-forming fluids, the Zijinshan subsystem with lower temperature and salinity was subsequently formed.

关 键 词：地球化学 成矿流体系统 流体包裹体 稳定同位素 碰撞造山 巍山-永平矿集区 云南省 

分 类 号：P618.41[天文地球—矿床学] P618.51[天文地球—地质学]