Sedimentary features and sequence stratigraphy of the successions around the Carboniferous-Permian boundary in the Ordos Basin:links to glacial and volcanic impacts  

作　　者：Zhong-Shuai Hou Shi-Yue Chen Zhao Liang 

机构地区：[1]Hebei Key Laboratory of Strategic Critical Mineral Resources,Hebei GEO University,Shijiazhuang 050031,China [2]Interdisciplinary Science Research Institute,Hebei GEO University,Shijiazhuang 050031,China [3]School of Geosciences,China University of Petroleum,Qingdao 266580,China

出　　处：《Journal of Palaeogeography》2023年第3期358-383,共26页古地理学报（英文版）

基　　金：Science and Technology Research Project for University in Hebei Province (QN2022060);National Preresearch Funds of Hebei Geo University in 2023(QN202307);Opening Foundation of Hebei Key Laboratory of Strategic Critical Mineral Resources (HGUSCMR2120);National Science and Technology Major Project of China (2016ZX05006-007)

摘　　要：The sedimentary successions around the Carboniferous-Permian boundary(CPB)in the Ordos Basin were investigated using extensive outcrop,borehole,well logging,thin section,and geochemistry data to study sedimentary and sequence stratigraphic responses to glaciation and volcanism in paleotropical transitional strata.Within the studied interval,five distinct lithofacies have been identified,including bauxite,coal,and carbonaceous shale(No.8+9 coal seams),sandstone(Qiaotou),limestone(Baode),and mudstone,which can be classified into three lithofacies associations.The most complete lithofacies associ-ation is composed of bauxite,coal,carbonaceous shale,sandstone,limestone/mudstone or their combinations from the bottom to the top,while coal and carbonaceous shale,as well as sandstone,are absent locally,resulting in the formation of the other two types of lithofacies associations.The occurrence of bauxite in-dicates shelf exposure and weathering,the occurrence of coal and carbonaceous shale indicates swampiness of the shelf,and the occurrence of sandstone reveals river rejuvenation;all of these are thought to be sedimentary responses to the transcontinental glacier expansion in Gondwana around the CPB.The presence of limestone and mudstone indicates carbonate platform and lagoon deposition,respectively,in the context of the earliest Asselian transgression caused by volcanism-induced glacier melting.The lithofacies associations record the regressive-transgressive cycles that occurred because of glaciation and volcanism near the CPB.The top surface of bauxite can be used as a sequence boundary,while the lowstand systems tract consists of the No.8+9 coal seams and the Qiaotou sandstone,and the transgressive systems tract consists of the overlying Baode limestone and laterally equivalent mudstone.The lowstand systems tract,which contains source rock and hydrocarbon reservoirs,and the overlying transgressive systems tract,which serves as cap rock,form an excellent source-reservoir-seal combination.

关 键 词：GLACIATION VOLCANISM Incised valley Sequence stratigraphy Ordos basin 

分 类 号：P534.4[天文地球—古生物学与地层学]