Abstract: The late Ordovician is a crucial period in the long geological history, during which carbonate rocks deposited recorded the changes of the earth’s epigenetic environment, laying the foundation for the study of the extinction events at the end of Ordovician. In this study, we collect and identify the late Ordovician carbonate thin section images by biological polarizing microscope. The study area includes Kelpin of northwest Tarim and Yichang area of South China. The stratigraphic age involved the Sandbian-Katian, and the identification content was fossil fragments， with the sampling interval of 0.5–2 m and 0.2–0.3 m. The dataset can be compared with the data of late Ordovician studies in other regions, provide more details for subsequent studies on the paleoceanographic and paleoenvironmental of the Ordovician, and establish the spatial variation model of carbonate rocks deposited in the late Ordovician.
Keywords: Upper Ordovician; Northwest Tarim; Middle Yangtze region; carbonate; fossil fragment