Geobiology of the Proterozoic Eon

Iron formations: A global record of Neoarchaean to Palaeoproterozoic environmental history

“…All available data that constrain the marine landscape in the midProterozoic ocean are consistent with only locally developed euxinic conditions along productive continental margins (e.g., in oxygen-minimum zones) or within intracratonic basins (Scott et al, 2008;Poulton et al, 2010;Planavsky et al, 2011;Lyons et al, 2012;Reinhard et al, 2013). The emerging consensus is that the redox state of the deep ocean was spatially and temporally variable during the mid-Proterozoic but was generally at a low oxidation state (e.g., Planavsky et al, 2011).…”

Carbonate rocks and related facies with vestiges of biomarkers: Clues to redox conditions in the Mesoproterozoic ocean

“…In addition, Lyons et al (2012Lyons et al ( , 2014 stressed that euxinia definitely was part of the Mesoporoterozoic oceans but that the environments of euxinia may have been limited to marginal marine settings. Sperling et al (2014) provided evidence for the presence of free oxygen in the Mesoproterozoic Arlan Member basinal calcareous shale in Russia, further supporting Proterozoic redox heterogeneity.…”

The impact of marine nutrient abundance on early eukaryotic ecosystems

“…In the ocean interior, particulate F I G U R E 1 Summary of key late Proterozoic changes in the microfossil (a), molecular biomarker (b), and inorganic geochemical (c, d) records. (a) Approximate first appearance of major fossil groups and interval of major eukaryotic diversification summarized from (Butterfield, 2000;Cohen, Knoll, & Kodner, 2009;Hofmann, 1976;Knoll, 2011Knoll, , 2014Lyons, Reinhard, Love, & Xiao, 2012;Porter et al, 2003;Xiao & Laflamme, 2008). (b) Maximum ratio of steranes (a molecular biomarker for eukaryotic algae) to hopanes (a molecular biomarker for bacteria) from organic geochemical records following (Brocks et al, 2017;Isson et al, 2018), where open circles denote undetectable sterane abundance.…”