四川阿坝地区刷马金矿床地质地球化学特征及成因探讨

Geochemistry and Ore Genesis of the Shuama Gold Deposit in Aba,Sichuan Province

通过对刷马地区地质构造、矿床时空演化以及水系沉积物、土壤、岩石地球化学特征的综合研究,结合地质背景和区域地质环境,认为刷马地区金矿床赋存于上三叠统侏倭组变质石英砂岩中,严格受北西向的韧-脆性剪切带控制,与金矿化有关的蚀变主要有黄铁矿化、硅化、碳酸盐化、毒砂化和黄铜矿化,1∶20万、1∶5万水系沉积物和1∶1万土壤均显示有Au、As、Sb、Hg的地球化学组合异常,1∶20万水系沉积物异常显示Au矿矿田范围,1∶5万水系沉积物异常显示矿区位置,而1∶1万土壤异常与矿体展布基本一致,异常带稳定连续、规模大,异常展布受控于韧-脆性剪切带,是有利的Au成矿区,具有巨大的找矿潜力,其矿床类型初步判定为微细浸染型金矿床(卡林型金矿)。

By the comprehensive study of geological structure,space-time evolution and geochemical surveys of stream sediment,soil,rock of the mineral deposits in the Shuama area,combined with geological background and regional geological environment in the area,it is considered that the Shuajinsi-Maerkang gold deposits in the Upper Triassic Zhuwo Group metamorphic quartz sandstone are strictly controlled by the northwest ductile-brittle shear zones,and gold-related alterations are mainly pyritization,silicification,carbonation,and arsenopyritization and chalcopyritization. Stream sediment and soil surveys have also shown that Au,As,Sb,Hg geochemical anomalous assemblage,1：200000 stream sediment anomaly shows the scope of Au deposits,1：50000 stream sediment anomaly shows mine locations,while the 1：10000 soil anomaly is basically the same as the direction of the deposit,the anomaly zone is continuously stable on a large scale,abnormal distribution is controlled by the ductile-brittle shear zone,it has a great ore potential for gold deposits. The deposit type of the study area are discussed according to the regional metallogenic conditions and evolution of mineralization,classified as the micro-disseminated gold deposit.