大兴安岭南段幸福之路组新认识及区域对比  

New understanding of the Xingfuzhilu Formation in the southern part of the Greater Khingan Mountains and a correlation with the neighboring areas

作　　者：郑月娟[1,2] 张德军[1,2] 苏飞[1,2] 张海华[1,2] 张健[1,2] 陈树旺[1,2] ZHENG Yuejuan;ZHANG Dejun;SU Fei;ZHANG Haihua;ZHANG Jian;CHEN Shuwang(Shenyang Center,China Geological Survey,Shenyang 110034,Liaoning,China;Northeast S&T Innovation Center,China Geological Survey,Shenyang 110034,Liaoning,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]中国地质调查局东北地质科技创新中心,辽宁沈阳110034

出　　处：《地质通报》2023年第2期201-214,共14页Geological Bulletin of China

基　　金：中国地质调查局项目《松辽盆地北部及外围石炭—二叠系油气地质调查》(编号:DD20190097);国家自然科学基金项目《中国东北二叠纪安加拉植物群演替》(批准号:31670215)。

摘　　要：晚二叠世—中三叠世是中亚造山带东段构造演化过程中承上启下的关键地质时期,涉及古亚洲洋的最终闭合、沉积环境剧变等重大地质问题。重新实测了晚二叠世—早三叠世幸福之路组一段、二段的建组剖面,运用同位素测年和孢粉化石综合研究的方法,结合野外观察及前人资料,提出对幸福之路组沉积序列的新认识:幸福之路组为以红层出现作为划分标志的一套砂泥岩夹火山岩沉积,原划为幸福之路组一段的砾岩时代晚于原二段、三段,时代不老于中三叠世,不宜划入幸福之路组。研究区上二叠统与下三叠统为连续沉积,晚二叠世晚期盆地边缘开始出现红层沉积(幸福之路组),同时期盆地中心仍为灰黑色、灰绿色砂泥岩沉积(林西组上部),林西组上部与幸福之路组下部为同时异相沉积。结合区域地质特征推测,晚二叠世—早三叠世,研究区处于整体隆升阶段,古亚洲洋应闭合于早三叠世之后。It is an important period for the tectonic evolution of the eastern segment of the Central Asia Orogenic Belt during the Late Permain to Middle Triassic,which involes the final closure of the Paleo-Asian Ocean and the sharp changes of sedimentary environment.The stratotype of the 1st and 2nd Members of the Xingfuzhilu Formation was reinvestigated by the authors.Based on the sporopollen fossils and isotopic ages,combined with previous studies and field investigation,this paper offers some new understanding on the sedimentary succession of Xingfuzhilu Formation.Late Permian-Early Triassic Xingfuzhilu Formation which uses red-bed features as a divided point,is consisted of sand shale and pyroclastic rocks.The conglomerate which were considered as part of the lower member of xingfuzhilu Formation is actually younger than the middle triassic.In this case,this conglometrate should be not be classified as members of xingfuzhilu formation anymore.The sedimentary environment of the Upper part of Linxi Formation and Xingfuzhilu Formation is contemporaneous heterotopic facies.However,the lacustrine sediments of Linxi Foumation were deposited at the center of the basin while the red-bed of Xingfuzhilu Formation were deposited at the edge of the basin respectively.According to the above results and regional data,the study area is overall upper uplift during the period from Late Permain to Middle Triassic.It leads to the conclusion that the the final closure time of the Paleo-Asian Ocean is after Early Triassic.

关 键 词：晚二叠世—早三叠世 大兴安岭 幸福之路组 沉积序列 地质调查工程 

分 类 号：P534.46[天文地球—古生物学与地层学] P534.51[天文地球—地质学]