内蒙古南部晚二叠世同生变形构造与陆缘裂陷  

Late Permian Syngenetic Deformation Structures and Epicontinental Faulted Depression in Southern Inner Mongolia

作　　者：田树刚[1] 张永生[2] 翟大兴[2] 宫月萱 TIAN Shu-gang;ZHANG Yong-sheng;ZHAI Da-xing;GONG Yue-xuan(Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037;Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037;Chinese Academy of Geological Sciences,Beijing 100037)

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质科学院矿产资源研究所,北京100037 [3]中国地质科学院,北京100037

出　　处：《地球学报》2018年第2期144-154,共11页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:41472027;41572098);中国地质调查局地质调查项目(编号:1212011120927)联合资助~~

摘　　要：内蒙南部林西县至正镶白旗林西—正镶白旗地区晚二叠世地层中,发现类型繁多的同生变形构造。除前人报道的滑卷层理、滑塌褶皱、滑塌砾岩和浊积砂砾岩以外,还有本文首次发现的大量球状体,包括滚动纺锤体、叠加滑卷球核、砾核滚动球、砂质滚动球和泥质滚动球。形态结构、成分组成和地层分布研究表明,这些构造形体均属重力成因和形成在陆棚—斜坡上。不同类型的构造形体可以组成来源演变序列,显示重力作用的加强,如滑卷层理通过"叠加滑卷"变成滑卷叠加球核,再通过"滚动粘结"变成滚动球体。它们形成和保存都受特定环境因素控制,因此各自具有特殊指相意义。大量同生变形构造出现,反映沿华北板块北缘出现陆棚、斜坡和深水海槽环境,证明晚二叠世兴—蒙海槽再次裂开,并形成"林西—九台裂陷带"。Various Late Permian syngenetic deformation structures were found in the Linxi–Zhengxiangbai Banner area,southern Inner Mongolia.In addition to convolute beddings,slump folds and slump breccia reported by previous researchers,a lot of roll spheroids were firstly discovered by the authors,which included roll spindles,over-convolute cores,spheroids with breccia cores,sandy spheroids and muddy spheroids.A study of shapes,textures,compositions and strato-spreading shows that these structures were all formed under the gravitation on land-shelf and slop.In addition,individuals of different kinds could make up the same original series that reflects strengthening of gravity activities,e.g.,convolute beddings changed to over-convolute cores through‘over-convoluting’,and then to roll spheroids by‘roll-pasting’.Due to their formation,rolling and stop are all controlled by specified conditions,so each kind of them serves as excellent facies-indicating marks.The existence of many syngenetic deformation structures prove that the Xingan–Inner Mongolia sea-trough experienced breakup again in the Late Permian,and land-shelf,steep-slop and deep-trough occurred along the north margin of Huabei Platform,where the Linxi–Jiutai faulted depression zone was formed.

关 键 词：内蒙南部 晚二叠世 同生变形构造 陆棚—斜坡 陆缘裂陷 

分 类 号：P534.46[天文地球—古生物学与地层学] P548[天文地球—地质学]