Abstract: Carbonate platform-basin facies developed during the early Triassic Feixianguan Formation in the northwestern margin of the Upper Yangtze. The study of rock structure and structure under the microscope can be a special feature of the early Triassic after the Late Permian mass extinction event. The sedimentary environment and biological resuscitation studies provide intuitive evidence. Four field profiles of the Lower Triassic Feixianguan Formation across the open platform, platform margin, and pre-platform slope-basin multiphase belt in the northwestern Upper Yangtze are selected, and common slices are systematically sampled and made. Based on this, rocks of different profiles The type, mineral composition, rock structure, structure, paleontology, diagenesis, etc. were systematically displayed, and photomicrographs of the system were provided. The study can provide basic materials for the early Triassic paleoclimate, paleoenvironment, paleontology recovery, etc., and the study of sedimentary differentiation of different facies in this period after the Permian global extinction. Basic data support.
Keywords: northwest margin of Upper Yangtze; Lower Triassic Feixianguan Formation; carbonate rock; biological extinction; micro-atlas