Emplacement age of the Tahe granite and its constraints on the tectonic nature of the Ergun block in the northern part of the Da Hinggan Range  

作　　者：GE Wenchun WU Fuyuan ZHOU Changyong Abdel Rahman A. A. 

机构地区：[1]College of Earth Sciences, Jilin University, Changchun 130061, China [2]Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

出　　处：《Chinese Science Bulletin》2005年第18期2097-2105,共9页

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.40372038 and 40325006);National Oil Gas Special Project(Grant No.XQ-2004-07).

摘　　要：Large-scale granitic plutons are exposed in the Ergun block in the northern part of the Da Hinggan Range, but their emplacement age and petrogenesis remain un-known. Of these plutons, the Tahe pluton is composed mainly of porphyritic syenogranite and monzogranite, with minor hornblende alkali feldspar granite and gabbro, which have affinities to post-orogenic granitoids. Laser-ablation Induc-tively Coupled Plasma Mass-spectroscope (LA-ICP-MS) analysis shows that the major rock types of the Tahe pluton formed at 494-480 Ma ago, indicating its emplacement in the Early Paleozoic. It is concluded, therefore, that the colli-sion between the Ergun and the Xing’an blocks ended in Early Paleozoic. Considering the geochronological data of the plutons in the adjacent areas, the Early Paleozoic evolu-tionary history of the Ergun block is similar to the central Mongolia and the Tuvino blocks in Mongolia, and the Ergun block should be a part of the accretionary continental mar-gin in the southern Siberian Craton.Large-scale granitic plutons are exposed in the Ergun block in the northern part of the Da Hinggan Range, but their emplacement age and petrogenesis remain unknown. Of these plutons, the Tahe pluton is composed mainly of porphyritic syenogranite and monzogranite, with minor hornblende alkali feldspar granite and gabbro, which have affinities to post-orogenic granitoids. Laser-ablation Inductively Coupled Plasma Mass-spectroscope （LA-ICP-MS） analysis shows that the major rock types of the Tahe pluton formed at 494- 480 Ma ago, indicating its emplacement in the Early Paleozoic. It is concluded, therefore, that the collision between the Ergun and the Xing＇an blocks ended in Early Paleozoic. Considering the geochronological data of the plutons in the adjacent areas, the Early Paleozoic evolutionary history of the Ergun block is similar to the central Mongolia and the Tuvino blocks in Mongolia, and the Ergun block should be a part of the accretionary continental margin in the southern Siberian Craton.

关 键 词：锆石 花岗岩 岩石学 成分结构 深成岩体 

分 类 号：P588.121[天文地球—岩石学]