The evolution of the ediacaran sulfur cycle: A paired sulfate-pyrite δ^(34)S approach

An anomalous enrichment in marine sulfate δ^(34)S_(SO4) is preserved in globally-distributed latest Ediacaran – early Cambrian strata. The proximity of this anomaly to the Ediacaran-Cambrian boundary and the associated evolutionary radiation has invited speculation that the two are causally related. Here we present a high resolution record of paired sulfate (δ^(34)S_(SO4)) and pyrite (δ^(34)S_(pyr)) from sediments of the Ara Group, Sultanate of Oman. An enrichment in δ^(34)S_(pyr) coincides with the interval of enriched δ^(34)S_(SO4), beginning at ca. 550 million years ago (Ma) and continuing through at least ca. 540 Ma.