Study On The Carbonate Microfacies And Foraminifera Distribution Close To P-T Boundary At Xianfeng Mining Area

Biological mass extinctions of the late Permian and Triassic early biological recovery is history’s greatest phanerozoic life change, witnessed the huge change of Marine ecosystem structure, at the same time also promotes the transformation to modern biota Paleozoic biota.Biological extinction pattern at the end of the Permian is now one of the hot issues of paleontology research. Through detailed study of carbonate sedimentation and paleontological characteristics,we can identify carbonate sedimentary history of global or local environment.A total of seven sedimentary subfaces are identyfied included Carbonate slope facies, rimmed carbonate platform phase two sedimentary phase; high-energy bioclastic shoal, within the confines of the gentle slope, open domestic gentle slope,open sea slope, peat swamp facies, restricted platform facies, open platform and twenty-six micro facies.Identification of the foraminifera 18 genera and 72 species,statistical analysis showed that mainly species of glomospira, hemigordius, nodosaria and Pachyphloia, such as.Through the statistical analysis of a variety of biological, P-T biological combination is divided into dasycladales- shell of foraminifera, coal plants, recovery combined biological, small Ostracoda, benthic organisms and calcareous microbialites,residual biota, wide habitat biota and ostracod biology group eight biological assemblage zone.found the 236-5 layer appeared at the end of the Permian trilobite-dasycladacean biota, after all extinct. According to the contrast, the P-T boundary of the ZK1501 hole is confined to the 3-4 cm above the bottom of the 236-4 layer, while the corresponding ZK17503 hole is located in the k9-13 layer.