西拉木伦河缝合带北侧二叠纪砂岩碎屑锆石LA-ICP-MS U-Pb年代学及其构造意义  

LA-ICP-MS U-Pb Dating of Detrital Zircons from the Permian Sandstones in North Side of Xar Moron River Suture Belt and Its Tectonic Implications

作　　者：韩国卿[1,2] 刘永江[1] 温泉波[1] 李伟[1] 吴琳娜[1,3] 赵英利[1] 丁凌[1,4] 赵立敏[1] 梁琛岳[1] 

机构地区：[1]吉林大学地球科学学院,吉林长春130061 [2]萨尔茨堡大学地质与地理系 [3]冀东油田勘探开发研究院,河北唐山063004 [4]中国冶金地质总局第一地质勘查院,河北燕郊101601

出　　处：《地球科学（中国地质大学学报）》2011年第4期687-702,共16页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学重点基金项目(No.40739905);博士点基金项目(No.200801830041);国家油气专项(No.2009GYXQ12);中国石油化工股份有限公司科技开发项目(No.G0800-06-ZS-327);国家留学基金建设高水平大学公派研究生项目(No.2008617114)

摘　　要：研究区位于西拉木伦河缝合带北侧,地理位置位于内蒙古东部草原区、大兴安岭南段,构造部位介于苏尼特左旗-锡林浩特-西乌珠穆沁旗南缝合线和西拉木伦河缝合带之间,是讨论华北地块北缘与其北侧地块拼贴过程的关键地区.通过对西拉木伦河缝合带北侧克什克腾旗(简称克旗)和林西地区二叠纪砂岩进行碎屑锆石LA-ICP-MS U-Pb年代学研究,认为克旗地区原中二叠世"哲斯组"可能为一套晚二叠世甚至早三叠世沉积.克旗、林西地区二叠纪的沉积物源主要来自其北侧的苏尼特左旗-锡林浩特-西乌旗南的岩浆弧,并有华北板块北缘物源混入,华北板块北缘与其北侧地块应在晚二叠世林西组沉积时期已经开始碰撞,导致林西地区林西组沉积具有南北两侧混合物源特征,板块碰撞的最终闭合的时间应在250 Ma左右.The study area is geographically located in the northern side of Xar Moron River suture belt in the eastern Inner Mongolia and the southern Da Hingg＇an Mountains and tectonically between the Sonidzuoqi-Xilinhot-southern Xi Ujimqin suture belt and Xar Moron River suture belt. It＇s a key area for the study on the collision process between the northern margin of North China Plate and the blocks to the north. The detrital zircons from Permian sandstones in Hexigten Banner （Keqi for short） and Linxi areas in the northern side of Xar Moron River suture belt have been dated by LA-ICP-MS U-Pb method. The dating results suggest that the previous Mid-Permian ＂Zhesi＂ Fm. is probably a Late Permian or even Early Triassic sedimentary sequence. The provenance of the Permian sediments in Keqi and Linxi areas is mainly from Sonidzuoqi-Xilinhot-sourthern Xi Ujimqin magma arc in the north, and partly from the northern margin of North China Plate. It is indicated that the collision between the northern margin of North China Plate and the blocks to the north had started in Late Permian during the Linxi Fm.depositing, the Permian sediments＇ provenance in Linxi and Keqi areas mixed those from the north and south, and the final closure time was about 250 Ma.

关 键 词：缝合带 砂岩 锆石 地质年代学 构造学 

分 类 号：P597[天文地球—地球化学]