甘肃大店沟金矿床金矿物的赋存状态及成因研究  

Study on Occurrence State and Genesis of Gold Mineral in the Dadiangou Gold Deposit,Gansu Province

作　　者：司明扬 刘家军[1,2] 张斌 曹瑞荣[3] 来召 樊荣 于谦 杜佰松 SI Mingyang;LIU Jiajun;ZHANG Bin;CAO Ruirong;LAI Zhao;FAN Rong;YU Qian;DU Baisong(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Beijing),Beijing 100083,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;Gansu Zhongjin Gold Mining Co.,Ltd.,Longnan 742400,Gansu,China;China National Gold Group Co.,Ltd.,Beijing 100011,China)

机构地区：[1]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]甘肃中金黄金矿业有限责任公司,甘肃陇南742400 [4]中国黄金集团有限公司,北京100011

出　　处：《黄金科学技术》2025年第1期19-31,共13页Gold Science and Technology

基　　金：中国黄金集团地质有限公司项目“西秦岭地区李子园—大店沟一带金矿床成矿规律与找矿预测研究”;国家自然科学基金项目“北秦岭丰北河—杨斜矿集区金—钨矿床共生与共生机制”(编号:42272095)联合资助。

摘　　要：为研究大店沟金矿床金的赋存状态及成因,采用反光显微镜和电子探针等技术手段对样品进行了观察和分析,明确矿石物质组成及金矿物的赋存状态,进而探讨其成因机制。将大店沟金矿床成矿阶段划分为黄铁矿—石英阶段(阶段Ⅰ)、石英—铁白云石—硫化物—碲铋化物阶段(阶段Ⅱ)和石英—方解石阶段(阶段Ⅲ)3个阶段。金矿物的赋存方式有裂隙金、粒间金和包裹金,且以裂隙金为主。尽管金矿物的粒度以显微极微粒金(0.0050~0.0002 mm)占主要地位,但显微中粒金与显微细粒金工艺粒度占比较高,其对选矿方法和磨矿细度的选择具有一定的指示作用。金矿物的成色多数在900以上,这与金银比值较高的成矿流体和中低温的成矿温度有关。研究结果为认识大店沟金矿的区域成矿规律提供了理论依据。The Dadiangou gold deposit,located in the Longnan region of Gansu Province,represents a typical orogenic gold deposit that has been discovered in recent years.The occurrence statusof gold significantly influences the development and utilization of these deposits,as well as the choice of metallurgical techniques for gold ore processing.To enhance the understanding of the gold occurrence within the Dadiangou deposit,this study utilizes a comprehensive array of investigative methodologies,including field surveys,reflective microscopy,and electron probe microanalysis.The findings suggest that the gold ore types at the Dadiangou gold deposit can be categorized into two primary types:Quartz vein typeand altered rock type.The gold within these ores predominantly exists as independent minerals,with the primary gold-bearing minerals being pyrite,chalcopyrite,galena,and quartz.The principal gold mineral is gold mineral,with minor occurrences of electrum and sylvanite.Gold particles within the ore manifest in four distinct forms:Fissure-filling,intergranular,inclusion,and interlocking.However,Fissure-filling has been identified as the predominant type.The particle size of gold is primarily extra micro-particulate(0.0050~0.0002 mm,42.03%)and micro-particulate(0.010~0.005 mm,28.26%).Although micro-medium to fine grains are less,abundant,they contribute significantly to the overall resource grade due to their higher area content,accounting for 76.53%.The fineness of gold is predominantly above 900,which may be attributed to the combined influence of ore-forming fluids with a high gold-to-silver ratio and ore-forming temperatures that are medium to low.

关 键 词：金矿物 赋存状态 金成色 成矿阶段 大店沟金矿 西秦岭造山带 

分 类 号：P618.51[天文地球—矿床学]