嫩江-黑河构造带中花岗质糜棱岩的确定及地质意义  

DETERMINATION AND GEOLOGICAL IMPLICATION OF THE GRANITIC MYLONITE IN NENJIANG-HEIHE TECTONIC BELT

作　　者：汪岩[1,2] 杨晓平 那福超[1,2] 张广宇[1,2] 康庄[1,2] 刘英才[1,2] 张文龙 毛朝霞[1,2] 

机构地区：[1]沈阳地质矿产研究所 [2]中国地质调查局沈阳地质调查中心,辽宁沈阳110034 [3]黑龙江省地质调查研究总院齐齐哈尔分院,黑龙江哈尔滨150036

出　　处：《地质与资源》2013年第6期452-459,共8页Geology and Resources

基　　金：中国地质调查局"黑龙江省1/5万嫩北农场;石头沟子;山河农场;科洛幅区域地质调查"项目(1212010881213)资助

摘　　要：在二连-贺根山-扎兰屯构造带北东向延伸的嫩江-黑河构造带中,从前人划分的新开岭群变质地层中厘定出一变质变形的侵入体,岩性以花岗质糜棱岩为主,具有高硅、富钾特征.该岩体铕普遍弱负异常到局部正异常;有明显的P、Ti、Nb负异常;Nb/La为0.02～0.4,Nb/Ta为0.19～16.22,具壳源深熔岩浆特点.锆石LA-ICP-MS U-Pb年龄结果表明,该岩体形成于324.5±2.1 Ma,遭受糜棱岩化的变质时间为184±1 Ma,应为兴安地块与松嫩-张广才岭地块于早石炭世沿嫩江-黑河一线碰撞拼贴的产物,同时表明嫩江-黑河构造带具漫长而复杂的演化历史.In the Nenjiang-Heihe tectonic belt,which is the northeastward extension of the Erenhot-Hegenshan-Zhalantun tectonic belt,a metamorphosed and deformed intrusive body is identified in the metamorphic stratum of former Xinkailing group.The rock is lithologically dominated by granitic mylonite,with high silicon and rich potassium,generally weak negative anomaly to locally positive anomaly of Eu,notable P,Ti and Nb negative anomalies,with Nb/La ratio of 0.02-0.4 and Nb/Ta ration of 0.19-16.22,showing the characteristics of crustal anatectic magma.The zircon LA-ICP-MS U-Pb age testing results show that the rock formed at 324.5 ± 2.1 Ma,with mylonitized metamorphism time of 184 ± 1 Ma.The granitic mylonite is the product of collision-collage of the Xingan and Songnen massifs along the Nenjiang-Heihe in Early Carboniferous.It is also suggested that the Neniiang-Heihe tectonic belt experience a long and complex evolution history.

关 键 词：花岗质糜棱岩 锆石LA-ICP-MS U-PB年龄 早石炭世 嫩江-黑河构造带 黑龙江省 

分 类 号：P588.33[天文地球—岩石学]