Oxygenated Mesoproterozoic lake revealed through magnetic mineralogy.

ABSTRACT: Terrestrial environments have been suggested as an oxic haven for eukaryotic life and diversification during portions of the Proterozoic Eon when the ocean was dominantly anoxic. However, iron speciation and Fe/Al data from the ca. 1.1-billion-year-old Nonesuch Formation, deposited in a large lake and bearing a diverse assemblage of early eukaryotes, are interpreted to indicate persistently anoxic conditions. To shed light on these distinct hypotheses, we analyzed two drill cores spanning the transgression into the lake and its subsequent shallowing. While the proportion of highly reactive to total iron (Fe_HR/Fe_T) is consistent through the sediments and typically in the range taken to be equivocal between anoxic and oxic conditions, magnetic experiments and petrograph

SUBMITTER: Slotznick SP 

PROVIDER: S-EPMC6304936 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature