Sulfate triple-oxygen-isotope evidence confirming oceanic oxygenation 570 million years ago.

ABSTRACT: The largest negative inorganic carbon isotope excursion in Earth's history, namely the Ediacaran Shuram Excursion (SE), closely followed by early animal radiation, has been widely interpreted as a consequence of oceanic oxidation. However, the primary nature of the signature, source of oxidants, and tempo of the event remain contested. Here, we show that carbonate-associated sulfate (CAS) from three different paleocontinents all have conspicuous negative ¹⁷O anomalies (Δ'¹⁷O_CAS values down to -0.53‰) during the SE. Furthermore, the Δ'¹⁷O_CAS varies in correlation with its corresponding δ³⁴S_CAS and δ¹⁸O_CAS as well as the carbonate δ¹³C_carb, decreasing initially followed by

SUBMITTER: Wang H 

PROVIDER: S-EPMC10354052 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature