New Progress in the Biostratigrphic Correlation of the Cambrian Series 2 Stage 4 in Jianhe, Guizhou

The Cambrian System is divided into 4 series and 10 stages internationally. So far, only Global Standard Stratotype Sections and Points (GSSPs) of 3 series and 6 stages have been defined, making it the most lagging system in the Phanerozoic. In recent years, some progress has been made in the research on the GSSP of the Cambrian Stage 4 in China. Zhao et al. identified three trilobite zones of Oryctocarella duyunensis, Oryctocarella duyunensis - Arthricocephalus chauveaui, and Protoryctocephalus arcticus from the bottom to the top in the Balang Formation and Tsinghsutung Formation of the Cambrian System in Jianhe, Guizhou. The Jiaobang section, only ~ 2 km away from the Wuliu - Zengjiayan section (the stratotype section for defining the base of Cambrian Miaolingian Series and Wuliuan Stage), was proposed as a candidate GSSP for the Cambrian Stage 4 based on the first appearance datum (FAD) of the oryctocephalid trilobite A. chauveaui orO. duyunensis. However, due to the higher occurrence level of A. chauveaui or O. duyunensis in North Greenland, some scholars have different opinions on using these two species as the FAD to define the GSSP of the Cambrian Stage 4. Recently, through the analysis and correlation of the range and evolution characteristics of O. duyunensis, A. chauveaui, and P. arcticus in both Jianhe and Greenland, it is believed that the Eoagnostus roddyi - Oryctocarella duyunensis zone of Greenland can correlate to the Protoryctocephalus arcticus zone of South China. Through the correlation of the oryctocephalid trilobite zones in South China and Greenland, combined with the biostratigraphy of Redlichia, it can provide information for establishing a precise stratigraphic correlation framework and determining the GSSP of Cambrian Stage 4.