Raohe granitic plutons in Wandashan, northeast China show evidence of syn-tectonic magmatic emplacement. The dark minerals and K-feldspar phenocrysts are aligned parallel to the NNE-trending magmatic flow lineation. The lenticular dioritic xeno⁃liths are arranged horizontally, characterized by long axis parallel to the magmatic flow lineation with sinistral shearing. Boudin quartz veins are also well developed in the plutons. All of these features indicate that the plutons were affected by sinistral strike-slip shearing in the process of magmatic intrusion and emplacement. Thus, the Raohe granite was formed in a sinistral strike slip environment which underwent syn-tectonic magmatic flow. The Raohe granite was emplaced at 121±1Ma and 119±1Ma, as shown by LA-ICP-MS zircon U-Pb dating. The wall rock gabbro and the syenite veins and diabase dikes that intruded in the Raohe pluton were ana⁃lyzed by zircon U-Pb dating, with the yielded ages being 160±1Ma, 109±2Ma and 124±1Ma, respectively. According to the charac⁃teristics of inherited zircon age data in these samples, the ages of wall rock gabbro are quite concentrated with no relict zircon ages, whereas the granite and the dikes have inherited zircon age data from Archean to Jurassic. These age data combined with the regional geology might indicate that the Wandashan block had completed the subduction collage before 120Ma, and the Wandashan granitic plutons were formed in sinistral strike slip motion of intracontinental deformation as the syn-tectonic emplacement.%分布于中国东北完达山地区的饶河花岗岩岩体中暗色矿物和斑晶钾长石定向排列，呈北北东走向，其中透镜状闪长质捕掳体近水平排列，局部具有左行剪切的特点。岩体中发育石香肠状石英脉，表明岩体在侵位过程中受到左行剪切作用的影响或制约。对出露的花岗岩进行LA-ICP-MS锆石U-Pb定年，获得年龄121±1Ma和119±1Ma，表明该岩浆流动形成于早白垩世。同时对围岩辉长岩、侵入岩体中的正长岩脉和辉绿岩脉进行锆石U-Pb年龄分析，分别获得160±1Ma、109±2Ma、124±1Ma的年龄结果。根据各样品中继承锆石的特征，围岩辉长岩的年龄数据很集中，不存在古老锆石的年龄信息。岩浆流动岩体及岩脉中都有太古宙、元古宙等各时代的锆石年龄数据，可能表明完达山地区在约120Ma之前已完成古太平洋板块的俯冲拼贴，饶河岩体形成于走滑环境下的陆内变形，为同构造侵入岩。
展开▼
