红旗岭镁铁-超镁铁岩侵入体及铜镍硫化物矿床的成岩成矿机制

红旗岭铜镍矿床地处华北地台与吉黑地槽系接触带--辉发河断裂北侧.区内出露30多个镁铁-超镁铁质岩体,其中1、7号超镁铁岩体中赋存铜镍硫化物矿(床)体.含矿岩体分相明显,各类岩石均具堆积结构.铜镍矿体呈似板状、脉状、透镜状及囊状赋存于超镁铁岩体底部橄榄辉岩相中.岩石学和地球化学研究表明,7号岩体形成以流动分异为主,1号岩体为重力分异;原始岩浆属拉斑玄武质,块状矿石系压滤作用产物,后续岩浆的补给和混合补充了成矿物质,硫化物不混溶程度受挥发分制约,矿床属岩浆深部熔离分异成因,成矿时代为印支期.

The Forming Mechanisms of Hongqiling Mafic and Ultramafic Intrusive Bodies and Cu- Ni Sulfide Deposits

The Hongqiling Cu-Ni ore deposit is located to the northern flank of a contacting zone(the Huifahe fault systems) between the North China platform and the Jilin-Heilongjiang syncline system.There are over 30 mafic and ultramafic intrusions in the area and Cu-Ni sulfide ore bodies were found in No.1 and No.7 ultramafic intrusive bodies which exhibit obvious zoning and cumulate texture.Cu-Ni ore bodies,being in the shape of plate,vein and pocket,were found in the olivine-pyroxenite facies at the base of the ultramafic intrusions.Petrological and geochemical studies indicate No.7 intrusion was formed mainly by flow differentiation while the No.1 intrusion by gravity differentiation;the source of magmas are of tholeiitic origin while the mass-ores are of the products of pressure injecting;the addition and mixing of later magmas introduced more ore-forming materials;the degree of immiscibility of sulfides was controlled by volatile components.This Cu-Ni mineral deposit was derived from deep magma segregation with the ore-forming age at Indosinian period.