黑龙江老祚山金矿区片麻状花岗岩锆石U-Pb年龄、Hf同位素特征及其地质意义  

ZIRCON U-Pb AGE AND Hf ISOTOPIC CHARACTERISTICS OF THE GNEISSIC GRANITES IN LAOZUOSHAN GOLDFIELD OF HEILONGJIANG PROVINCE:Geological Implication

作　　者：寇林林[1] 张朋[1] 陈江[1] 赵岩[1] 王筱筝 毕中伟[1] KOU Lin-lin;ZHANG Peng;CHEN Jiang;ZHAO Yan;WANG Xiao-zheng;BI Zhong-wei(Shenyang Center of China Geological Survey,Shenyang 110034,China;Core and Sample Center of Natural Resources,Sanhe 065201,Hebei Province,China)

机构地区：[1]中国地质调查局沈阳地质调查中心,辽宁沈阳110034 [2]中国地质调查局自然资源实物地质资料中心,河北三河065201

出　　处：《地质与资源》2020年第3期239-245,共7页Geology and Resources

基　　金：国家自然科学基金“变质地体中内生金矿成矿模式研究——以辽东裂谷猫岭金矿为例”(41502093);中国地质调查局项目“东北地区区域成矿规律与总结”(121201103000150020).

摘　　要：黑龙江老柞山金矿床是佳木斯地块中北部的大型热液叠加夕卡岩型矿床.对矿区东矿带赋矿片麻状花岗岩进行了LA-ICP-MS的U-Pb定年和Hf同位素分析,共获得3组年龄,分别为697.1±8.0、703.0±8.8和484.7±2.7 Ma.其中前2组为捕获的锆石年龄,暗示佳木斯地块南缘可能存在新元古代的结晶基底.第三组锆石年龄代表片麻状花岗岩结晶年龄.锆石原位Hf同位素测试显示,片麻状花岗岩的εHf(t)值为-2.4^+3.6,TDM2为1620~1390 Ma,指示片麻状花岗岩原岩可能是中元古代陆壳物质重熔.结合区域构造演化,认为片麻状花岗岩可能形成于晚泛非—早加里东期的碰撞造山作用,是麻山群深熔岩浆结晶作用的产物.The Laozuoshan gold deposit in Heilongjiang Province is a large hydrothermal superimposed skarn deposit in the north-central of Jiamusi block.Three groups of age,697.1±8.0,703.0±8.8,and 484.7±2.7 Ma respectively,are acquired through the LA-ICP-MS U-Pb dating and Hf isotope analysis of gneissic granites in the east ore belt of orefield,among which the former two are the age of captured zircons,suggesting that there might be Neoproterozoic crystalline basement in the south margin of Jiamusi block,and the latter represents the crystallization ages of gneissic granites.The zircon Hf isotope tests show that theεHf(t)ranges from-2.4 to+3.6,with TDM2 of 1620-1390 Ma,indicating that the protolith of gneissic granite may be the derived from the remelting of Mesoproterozoic continental crust material.Combined with the regional tectonic evolution,it is believed that the gneissic granite was possibly formed by the late Pan-African-early Caledonian collision-orogeny as the product of anatectic magma crystallization of Mashan Group.

关 键 词：锆石U-PB定年 HF同位素 片麻状花岗岩 老柞山金矿床 黑龙江省 

分 类 号：P588.12[天文地球—岩石学] P597[天文地球—地质学]