山西义兴寨金矿床铁塘硐隐爆角砾岩筒地质特征、形成时代和找矿方向  

Geological characteristics,geochronology,and prospecting direction of the Tietangdong cryptoexplosive breccia pipe in the Yixingzhai Gold Deposit,Shanxi Province

作　　者：白晓明 Bai Xiaoming(Mineral Exploration Institute,Zijin Mining Group Co.,Ltd.)

机构地区：[1]紫金矿业集团股份有限公司矿产地质勘查院

出　　处：《黄金》2022年第12期9-18,共10页Gold

基　　金：中央级公益性科研院所基本科研业务费项目(KK2104);紫金矿业集团股份有限公司科研项目(HE2102)。

摘　　要：义兴寨金矿床累计探明金储量超过91 t,是目前山西省最大的金矿床,矿区发育石英脉型、蚀变斑岩型和蚀变角砾岩型等3种矿体。其中,蚀变角砾岩型矿体产于4个隐爆角砾岩筒中,以铁塘硐隐爆角砾岩筒为最大,其成矿潜力和找矿方向是矿山企业关注的焦点。针对铁塘硐隐爆角砾岩筒,通过详细野外地质调查和岩性编录工作,厘定其形成过程包括:下部无矽卡岩角砾岩化阶段(Ⅰ)、霏细岩和上部块状矽卡岩阶段(Ⅱ)、方解石-镜铁矿(-石榴子石)脉阶段(Ⅲ)、含矽卡岩角砾的岩浆胶结角砾岩阶段(Ⅳ)、石英斑岩脉阶段(Ⅴ)、石英-硫化物脉阶段(Ⅵ)。铁塘硐隐爆角砾岩筒上部矽卡岩段与霏细岩具有成因联系,二者形成于138~139 Ma。在铁塘硐隐爆角砾岩筒中,有霏细岩产出的角砾岩地段是重点勘探目标。The proven gold reserve accumulates over 91 t in the Yixingzhai Gold Deposit,and it is the largest gold deposit in Shanxi Province.3 types of ore bodies develop in the district,including quartz vein type,altered porphyry type,and altered breccia type.Altered breccia-type mineralization is hosted by 4 cryptoexplosive breccia pipes.The Tietangdong cryptoexplosive breccia pipe is the largest one,and the potential for mineralization and further exploration of which are important issues for mine enterprise.Based on detailed outdoor geological survey and lithology logging in the Tietangdong cryptoexplosive breccia pipe,this study figures out its formation process,which includes:no skarn breccia stage in the lower part(Ⅰ),felsite and massive skarn stage in the upper part(Ⅱ),calcite-specularite(-garnet)vein stage(Ⅲ),magmatic breccia stage with skarn fragments(Ⅳ),quartz porphyry dikes stage(Ⅴ)and quartz-sulfide vein stage(Ⅵ).There are genetic connections between the skarn section and the felsite in the upper Tietangdong cryptoexplosive breccia pipe.Both formed at 138-139 Ma.The breccia section where felsite occurs is an important prospecting target in the Tietangdong cryptoexplosive breccia pipe.

关 键 词：隐爆角砾岩筒 石榴子石 U-PB定年 矽卡岩 义兴寨金矿床 

分 类 号：TD11[矿业工程—矿山地质测量]