陕西双王金矿床矿化富集规律对成矿构造的指示意义  

The Regularity of Gold Enrichment and Its Implications to Metallogenic Tectonics in Shuangwang Gold Deposit,Shaanxi Province

作　　者：宫勇军[1] 姚书振[1] 谭满堂[2] 曹瑞荣 程建军 

机构地区：[1]中国地质大学资源学院,湖北武汉430074 [2]中国地质调查局武汉地质调查中心,湖北武汉430205 [3]陕西太白黄金矿业有限责任公司,陕西宝鸡721607

出　　处：《地球科学（中国地质大学学报）》2016年第2期189-198,共10页Earth Science-Journal of China University of Geosciences

基　　金：全国危机矿山接替资源找矿项目(No.20089939);中央高校基本科研业务费专项资金(No.2012029138)

摘　　要：双王金矿床是秦岭地区大型的危机矿山之一,找矿工作是当务之急,但其成因类型特殊,人们对其成矿构造的演化过程和控矿机制尚存在争议.以该矿床KT5矿体为例,研究了角砾岩体、断裂裂隙和金品位的空间分布关系,并结合趋势面分析,探讨了金矿化富集规律及其对成矿构造的指示意义.矿床地质特征及对矿区内基性岩墙的测年结果表明其成矿时代为印支期.在印支期秦岭造山过程中的NS向主压应力背景下,成矿断裂早期右行斜向剪切作用奠定了角砾岩带的雏形;断裂中期活动引发的地震及伴生液压致裂作用,使矿区内形成了角砾岩主体和断裂裂隙系统,主成矿阶段角砾岩化作用减弱,断裂裂隙持续发育,并作为流体运移和成矿的主要通道和有利部位,使金的矿化富集呈面状展布,断裂裂隙带的产状变化是金沉淀的重要影响因素;晚期构造应力转换为近EW向拉伸,近NS向基性岩墙群侵位并受到成矿流体的改造.Shuangwang gold deposit is one of the largest crisis mines in Qinling area with special genetic type,and it is urgent for us to undertake prospecting.But different scholars have some controversy over the evolution of the metallogenic tectonic as well as over the ore-controlling mechanism in this deposit.This paper studies the relationship of spatial distribution among the breccia bodies,fractures and fissures,and gold grade taking KT5 ore body in the deposit for an example.The regularity of gold enrichment and its implications to metallogenic tectonics are discussed,combined with trend surface analysis.According to mineralization characteristics and the age of the mafic dyke swarms in the mine area,it is suggested that the ore-forming process happened mainly in Indosinian.Under the compressive stress from north to south during Indosinian orogenesis in Qinling area,two sides of the metallogenic fault sheared obliquely with rightward contortion in the early stage,which formed the rudiment of breccia belt.In the intermediate stage,earthquake and associated hydraulic fracturing,which were induced along with the fault movement,produced the main breccia bodies together with fractures and fissures;in the gold mineragenetic process,the brecciation trailed off,while the fractures and fissures developed continuously,and they played important roles of the main pathway as well as advantaged ore-forming space for metallogenic fluid,so the gold enrichment revealed planar distribution,and the change of the fractures and fissures occurrence was the basic factor that resulted in Au precipitation.In the late stage,the extension changed to east-west,and the mafic dyke swarms intruded in the setting,which were altered by metallogenic fluid.

关 键 词：矿化富集 角砾岩体 成矿构造 双王金矿床 矿床地质 

分 类 号：P613[天文地球—矿床学]