The Cambrian SPICE event in Yongshun area, Hunan Province, and its significance for stratigraphic correlation

Abstract：An analysis of thirty-eight C/O stable isotopic samples collected from the Wangcun section in the Cambrian slope facies of Yongshun area within Hunan Province shows that there is a carbon isotope abnormal event, i.e., the SPICE event. The event shows remarkable positive shift of stable carbon isotopes, whose value increases from 0.69‰ at the top of Huaqiao Formation to the peak of 3.05‰ in the middle of Chefu Formation, and then decreases gradually to 0.67‰ in the middle of Bitiao Formation. The event was genetically not only related to the upwelling and the fast burial of organic materials but also to the weathering of carbonate rocks. Due to its extensive correlativity, this event is of great significance for stratigraphic correlation, especially for the correlation of strata in the restricted platform.