滇西北羊拉大型铜矿床深部高品位锑矿体的发现及意义

Discovery of High Grade Antimony Orebody in the Depth of Yangla Large Cu Deposit,Northwest Yunnan,China,and its Geological Significance

金沙江成矿带矿产资源以铜、铅、锌矿为主,之前尚未发现具有经济价值锑矿床。云南羊拉铜矿床为该成矿带内的代表性大型铜多金属矿床,近期在其深部新发现高品位锑矿体,在金沙江铜多金属成矿带内属首次报道。该类锑矿体主要呈似层状和不规则脉状及团块状产出,空间形态严格受NE向断裂及其节理裂隙的控制。已控制的锑矿体长约300 m,厚3~15 m,矿石品位变化范围为11.14%~21.17%,局部富集地段矿石品位可达45.75%,初步估算新发现锑矿体可达到中型矿床规模。研究表明,该矿床锑矿成矿作用与铜矿成矿作用差异明显,对新发现锑矿体和已知铜矿体的成因联系研究,不仅可以丰富完善羊拉铜矿床成矿理论,亦可开拓矿区深部与外围锑资源地质勘探的思路。

Mineral resources in the Jinshajiang metallogenic belt are predominated by Cu,Pb,and Zn,and no antimony deposits have been found yet.The Yangla Cu deposit is a representative large Cu-polymetallic deposit in the belt.Recently,high-grade antimony orebodies have been discovered at the depth of the Linong ore section,the Yangla Cu deposit,which is the first report in the Jinshajiang Cu-polymetallic metallogenic belt.The antimony orebodies are mainly stratified,irregular veined and clumped,and their spatial morphology is strictly controlled by NE-trending fracture zone and joints.This newly discovered antimony orebody was about 300 m in length and 3 m to 15 m in thickness.The antimony grades of the ores vary from 11.14%to 21.17%,and can be as high as 45.75%locally.The antimony reserves of the newly discovered antimony orebodies can reach the scale of medium-sized ore deposit.Our preliminary study shows that the antimony mineralization is obviously different from copper in the Yangla deposit.The study of the genetic relationship between antimony and copper can enrich the metallogenic theory of the Yangla Cu deposit,and broaden the geological exploration ideas of antimony in the depth and periphery of the Yangla mining district as well.