西藏班公湖-怒江成矿带西段钠木钦金多金属矿地质特征及成因

THE NAMUQIN GOLD-POLYMETALLIC DEPOSIT IN WESTERN BANGONGHU-NUJIANG METALLOGENIC BELT,TIBET:Geology and Genesis

钠木钦金多金属矿位于西藏班公湖-怒江成矿带西段,区域成矿以铜、金、铁矿为主.研究认为,钠木钦铜矿体受中二叠世下拉组地层与早白垩世中酸性侵入岩接触带——夕卡岩控制,而金矿体则主要受近东西向断裂构造控制,铜矿成矿类型为夕卡岩型,金矿成矿类型为构造蚀变岩型,成矿时代为早白垩世.矿区Ⅰ、Ⅱ、Ⅲ号矿体的深部及Ⅱ号铜矿体的西部还具有较大的找矿空间.对矿区矿床特征的研究发现,钠木钦矿与区域上的尕尔穷等矿床具有较为相似的地质背景及成矿特征,但也有其独特之处.

The Namuqin gold-polymetallic deposit is located in the western section of Bangonghu-Nujiang metallogenic belt in Tibet,with regional mineralization dominated by copper,gold and iron. The study indicates that the copper orebodies in Namuqin deposit are controlled by skarn in the contact zone between the Middle Permian Xiala Formation and Early Cretaceous acid-intermediate intrusive rocks,while the gold orebodies are mainly controlled by the near E-Wtrending fault. The metallogenesis of copper and gold are skarn type and structural altered rock type respectively,with the ore-forming age of Early Cretaceous. The deep of Nos. Ⅰ,Ⅱ and Ⅲ orebodies and west of No. Ⅱ copper orebody in the orefield still have great prospecting potential. Study shows that the Namuqin deposit shares similar geological background and metallogenic characteristics with Garqiong deposit in the region,but also with special features.