华南板块吴家坪组顶部穿时性:来自牙形石新证据OACHSSCD

The Late Permian represents a critical transitional interval in geological history,marked by the end-Guadalupian extinction event and the subsequent Permian-Triassic mass extinction.These events coincided with profound changes in global biodiversity,ecosystem structure,and paleoenvironmental conditions.The well-developed marine successions of the South China Block provide exceptional sedimentary records for investigating the patterns and processes of biotic extinction and environmental perturbation during this interval.The Jingshan section in Hubei province preserves a continuous marine succession spanning the Middle Permian to Lower Triassic,comprising in ascending order the Wujiaping Formation(limestone),the Dalong Formation(interbedded chert and mudstone with chocolate-colored tuff at its base),and the Daye Formation(shale).This study focuses on the Wujiaping-Changhsingian boundary interval in this section,employing high-resolution conodont biostratigraphy to refine the regional depositional age of the upper Wujiaping Formation.Although no diagnostic conodonts were recovered from the Dalong and Daye formations,abundant conodont faunas were obtained from the top of the Wujiaping Formation,yielding six species assignable to two genera,including Clarkina dukouensis,C.asymmetrica,C.guangyuanensis,C.liangshanensis,C.transcaucasica,and Hindeodus typicails.Biostratigraphic correlation places the top of the Wujiaping Formation carbonates within the Clarkina guangyuanensis Zone,thereby providing new chronostratigraphic constraints for regional stratigraphic correlation and for the study of Late Permian bio-environmental events.