陕西凤太矿集区丝毛岭金矿床成矿时代的Ar-Ar年龄证据  

Evidence of Ar-Ar Age for the Metallogenic Epoch of Simaoling Gold Deposit in Fengxian-Taibai Ore Cluster of Shaanxi

作　　者：王义天[1] 李霞[1,2] 王瑞廷 刘协鲁 胡乔青[1] 李建华 王长安 汶博 温深文 王胜利 

机构地区：[1]中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点实验室,北京100037 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]西北有色地质勘查局地质勘查院,陕西西安710054 [4]西北有色地质勘查局717总队,陕西宝鸡721012

出　　处：《地球科学与环境学报》2014年第3期61-72,共12页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(41372089);中国地质调查局地质大调查项目(1212011220869);"十一五"国家科技支撑计划项目(2006BAB01A11);中央级公益性科研院所基本科研业务费专项资金项目(K0801)

摘　　要：丝毛岭金矿床位于陕西凤太多金属矿集区的西北部,产于NWW向脆-韧性剪切构造带中,矿体赋存于丝毛岭向斜北翼上泥盆统星红铺组的斑点状铁白云质粉砂质千枚岩。金矿化类型包括蚀变岩型和石英脉型两种,成矿过程可划分为早、中、晚3个阶段。对其早期成矿阶段热液蚀变形成的绢云母开展40 Ar/39 Ar测年研究,获得其坪年龄为(211.9±1.5)Ma,指示其成矿作用始于211.9Ma左右,即晚三叠世。结合前人有关区域地质与多金属成矿作用的研究成果,认为丝毛岭金矿床与凤太矿集区中的八卦庙-柴蚂、双王等金矿床一样,都属于造山型金矿床,它们是中、晚三叠世—早侏罗世时期位于东古特提斯构造域中的南秦岭碰撞造山带大规模构造-岩浆-流体活动的产物。Simaoling gold deposit,located in the northwest of Fengxian-Taibai polymetallic ore cluster,Shaanxi,develops within a NWW-trending brittle-ductile shear tectonic belt,and orebodies are hosted in the speckled ankerite-bearing silty phyllite of Upper Devonian Xinghongpu Formation,which occurs in the north limb of Simaoling syncline. The types of Gold mineralization include altered rock and quartz vein,and the ore-forming process can be divided into early,middle and late stages.The 40 Ar/39 Ar dating method was used to study the sericiteformed by hydrothermal alteration in the early ore-forming stage.The plateau age of sericite is（211.9±1.5）Ma,which indicates that the mineralization of Simaoling gold deposit starts in Later Triassic（about 211.9 Ma）.By integrating the present results with the regional geology and polymetallic mineralization,the Simaoling,Baguamiao-Chaima,Shuangwang gold deposits in Fengxian-Taibai ore cluster are orogenic,and are produced from Middle and Late Triassic to Early Jurassic by the large-scale tectonism,magmatism and fluid activity of South Qinling collisional oreogen,belonging to East Paleo-Tethys tectonic regime.

关 键 词：金矿床 热液蚀变 绢云母 40Ar/39Ar测年 凤太矿集区 古特提斯构造域 

分 类 号：P611.1[天文地球—矿床学]