藏东芒康地区巴达金(铜)多金属矿床的发现及找矿意义

The Discovery of the Bada Gold(Copper)Polymetallic Deposit in the Mangkang Area of Eastern Tibet and Its Prospecting Significance

芒康地区位于藏东玉龙-芒康斑岩铜多金属成矿带上,找矿潜力巨大。但由于工作程度低,多年来找矿效果不佳,区内急需新的找矿模型指导。近年来在本区新发现了与富碱斑岩有关的巴达大型金(铜)多金属矿床。本文在前人工作基础上,根据野外地质调查和室内镜下观察,研究总结出巴达矿床垂向矿化蚀变分带特征:以含矿石英二长斑岩为中心,由地表向深部蚀变分带依次划分为硅化+碳酸盐化带→粘土化+碳酸盐化带→硅化+粘土化+碳酸盐化带→青磐岩化+弱硅化+黄铁绢英岩化带;由地表向深部矿化分带依次划分为铜(银、铅)矿→褐铁矿→铅(银)矿→金(铜)矿。另外,在矿床地表分散流、铅矿物重砂异常重叠区域及附近新发现了7种直接找矿标志,总结出区内找矿突破的巴达金(铜)多金属矿找矿模型,并预测该矿床深部可能存在斑岩型金(铜)多金属矿床,同时在矿区外划分出2处找矿靶区,为今后巴达矿区外围找矿和本区勘查工作提供了重要参考。

The Mangkang region is located in the Yulong-Mangkang porphyry copper polymetallic metallogenic belt in eastern Tibet,which has a great prospecting potential.However,the low exploration degree has led to poor prospecting results,making it critical to build a new prospecting model.The Bada large-scale gold(copper)polymetallic deposit associated with alkali-rich porphyry was recently identified in this area.Based on previous research,this study conducted field geological surveys and indoor microscopic observations to determine the vertical mineralized alteration zonation of this deposit.Centered by mineralized quartz monzonite porphyry,the alteration can be divided into silicification+carbonation zone→clayification+carbonation zone→silicification+clayification+carbonation zone→propylitization+weak silicification+beresitization zone from the surface to the bottom.From the surface to the depth,the mineralization zoning reveals copper(silver,lead)ore→limonite→lead(silver)ore→gold(copper)ore.Furthermore,seven new direct prospecting marks were determined in the region with overlapping surface of dispersion flow and lead placer anomalies and its neighboring area,and a prospecting model was established for the Bada gold(copper)polymetallic deposit as a prospecting breakthrough in this area.In the deep section of the deposit,a porphyry-type gold(copper)polymetallic deposit is expected to be discovered.Two prospecting targets were also delineated around the deposit perimeter.This research provides vital reference for prospecting in the periphery of the Bada mining area,as well as suggestions for prospecting in the region.