内蒙古达茂旗满都拉地区早二叠世生物地层划分对比再研究

Further Study on Biostratum Division and Correlation of Early Permian Epoch of Mandula Area ofDamaoqi,Inner Mongolia

满都拉地区早二叠世各类古生物化石丰富，曾被古生物学家、学者多次研究。本次１∶５万区调，分队再次进行了生物地层划分对比研究，并以类为标准确立该区地层层序，将其划分为两个单位：下部Ｍｏｎｏｄｉｅｘｏｄｉｎａ延限带，上部Ｃｏｄｏｎｏｆｕｓｉｅｌａ－Ｓｃｈｗａｇｅｒｉｎａ组合带。珊瑚划分了三个组合带，自下而上为：Ｐｌｅｒｏｐｈｙｌｕｍｃｒａｓｏｓｅｐｔａｔｕｍ－Ｔａｃｈｙｌａｓｍｚｈｅｓｉｅｎｓｅ组合带，Ｐｓｅｕｄｏｗａａｇｅｎｏｐｈｙｌｕｍｖｅｓｉｃｕｌｏｓｕｍ－Ｄｉｐｈｙｃａｒｉｎｏｐｈｙｌｕｍ组合带，Ｗａａｇｅｎｏｐｈｙｌｕｍｓｔｅｒｅｏｓｅｐｔａｔｕｍ－Ｗｅｎｔｚｅｌｅｌａ组合带。腕足类、苔藓虫类、海绵类等则分别进行了生态组合讨论。尤其是对腕足类，通过对其在区域上的产出层位及在测区赋存层位的对比，认为在哲斯组沉积时期，北极动物群与特提斯动物群在该地区已经混生，由于其个体生存环境的差异，不同的属种分别赋存于不同的岩相中，显示出明显的生态环境特征，进而划分了浅滩相：Ｓｐｉｒｉｆｅｒｅｌａ－Ｋｏｃｈｉｐｒｏｄｕｃｔｕｓ－Ｙａｋｏｖｌｅｖｉａ组合及礁相：Ｓｔｒｅｐｔｏｒｈｙｎｃｈｕｓ－Ｈｅｍｉｐｔｙｃｈｉｎａ－Ｒ?

Different kinds of palaeobiology fossils where occurred in Early Permian Epoch of Mandula area,Inner Mongolia are very rich.Which have been researched many times by paleontologists.During 1∶50000 regional geological servey,it was further studied on biostratum’s division and correlation and established the area of stratigrphic sequence with fusulinids standard which have divided into two units:under part is Monodiexodina range-zone and upper part is Codonofusiella-Schwagerina assemblage-zone.Anthozoa can be divided into three assemblage-zone from under to upper: Plerophyllum crassoseptatum-Tachylasm zhesiense,Pseudowaagenophyllum vesiculosum-Diphycarinophyllum and Waagenophyllum stereoseptatum-Wentzelella assemblage-zone.Brachiopoda bryozoa and porifera are discussed respectively,especially the brachiopoda fossils of correlation region and surveyed area of horizon.It was thought that North Pole and Tethys fauma had mixed during sediment of Zhesi formation time,but single fossils have different existing environment and all kinds of genus and species occurence in different appearance out ecotope characteristics to rock facies,so that divided into shoal facies: Spiriferella-Kochiproductus-Yakovlevia and reef facies: Streptorhynchus-Hemiptychina-Richthofenia assemblage.