Journal Article

Global and regional controls on carbon-sulfur isotope cycling during SPICE event in south China

JIN, Chensheng, LEI, Lidan, TAN, Xianfeng, GLUYAS, Jon, CHEN, Hongjin, LUO, Long, ZHANG, Zihu, WANG, Jia, CHEN, Qing, LI, Meng

2023

Overview

The positive S-isotopic excursion of carbonate-associated sulfate (δ 34S CAS) is generally in phase with the Steptoean positive carbon isotope excursion (SPICE), which may reflect widespread, global, transient increases in the burial of organic carbon and pyrite sulfate in sediments deposited under large-scale anoxic and sulphidic conditions. However, carbon-sulfur isotope cycling of the global SPICE event, which may be controlled by global and regional events, is still poorly understood, especially in south China. Therefore, the δ 13C PDB, δ 18O PDB, δ 34S CAS, total carbon (TC), total organic carbon (TOC) and total sulfate (TS) of Cambrian carbonate of Waergang section of Hunan Province were analyzed to unravel global and regional controls on carbon-sulfur cycling during SPICE event in south China. The δ 34S CAS values in the onset and rising limb are not obviously higher than that in the preceding SPICE, meanwhile sulfate (δ 34S CAS) isotope values increase slightly with increasing δ 13C PDB in rising limb and near peak of SPICE (130-160 m). The sulfate (δ 34S CAS) isotope values gradually decrease from 48.6‰ to 18‰ in the peak part of SPICE and even increase from 18‰ to 38.5% in the descending limb of SPICE. The abnormal asynchronous C-S isotope excursion during SPICE event in the south China was mainly controlled by the global events including sea level change and marine sulfate reduction, and it was also influenced by regional events such as enhanced siliciclastic provenance input (sulfate), weathering of a carbonate platform and sedimentary environment. Sedimentary environment and lithology are not the main reason for global SPICE event but influence the δ 13C PDB excursion-amplitude of SPICE. Sea level eustacy and carbonate platform weathering probably made a major contribution to the δ 13C PDB excursion during the SPICE, in particularly, near peak of SPICE. Besides, the trilobite extinctions, anoxia, organic-matter burial and siliciclastic provenance input also play an important role in the onset, early and late stage of SPICE event.

• Publisher: Higher Education Press,Springer Nature B.V
• Subject: Anoxia / Anoxic sediments / Cambrian / Cambrian period / Carbon / Carbon cycle / Carbon isotopes / carbonate platform weathering / Carbonates / China / Cycles / Earth and Environmental Science / Earth Sciences / Fossil animals / hypoxia / isotopes / Lithology / Marine invertebrates / Organic carbon / Platforms (geology) / provenance / Pyrite / Research Article / Sea level / sea level change / Sea level changes / Sediments / sulfate isotope excursion / Sulfate reduction / Sulfates / Sulfur / Sulfur isotopes / Sulphate reduction / Sulphur / terrigenous matter / Total organic carbon / transitional slope environment / Waergang section / Weathering