Different geochemical analysis and iron extraction from the Bravo Lake Formation, Nunavut in Canada ...

• Main Authors: Partin, C A, Bekker, A, Planavsky, Noah J, Lyons, Timothy W
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2017
• Subjects: Canada; Nunavut
• Online Access: https://dx.doi.org/10.1594/pangaea.874891; https://doi.pangaea.de/10.1594/PANGAEA.874891

The composition of seawater changed dramatically during the initial rise of atmospheric oxygen in the earliest Paleoproterozoic, but the emerging view is that atmosphere-ocean system did not experience an irreversible transition to a well-oxygenated state. Instead, it has been suggested that the oxygen content of the atmosphere-ocean system decreased considerably after ca. 2.06 billion years ago (Ga), which resulted in a crash in marine sulfate concentrations. The end of the deposition of major granular iron formations at ca. 1.85 Ga has been linked either to the development of extensive euxinic conditions along continental shelves or a decrease in hydrothermal flux. The record of oceanic redox state is not well constrained for the period between ca. 2.06 Ga, the end of the Lomagundi positive carbon isotope excursion, and ca. 1.88 Ga when major granular iron formations appeared. We address this gap by presenting new iron-speciation, major and trace element data, as well as sulfur, organic carbon, and ... : Supplement to: Partin, C A; Bekker, A; Planavsky, Noah J; Lyons, Timothy W (2015): Euxinic conditions recorded in the ca. 1.93Ga Bravo Lake Formation, Nunavut (Canada): Implications for oceanic redox evolution. Chemical Geology, 417, 148-162 ...