Deglacial volcanism and reoxygenation in the aftermath of the Sturtian Snowball Earth.

ABSTRACT: The Cryogenian Sturtian and Marinoan Snowball Earth glaciations bracket a nonglacial interval during which Demosponge and green-algal biomarkers first appear. To understand the relationships between environmental perturbations and early animal evolution, we measured sulfur and mercury isotopes from the Datangpo Formation from South China. Hg enrichment with positive Δ¹⁹⁹Hg excursion suggests enhanced volcanism, potentially due to depressurization of terrestrial magma chambers during deglaciation. A thick stratigraphic interval of negative Δ³³S_py indicates that the nonglacial interlude was characterized by low but rising sulfate levels. Model results reveal a mechanism to produce the Δ³³S anomalies down to -0.284‰ through Rayleigh distillation. We

SUBMITTER: Li M 

PROVIDER: S-EPMC10482342 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature