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Trace metals as paleoredox and paleoproductivity proxies: An update
Abstract This paper is a synthesis of the use of selected trace elements as proxies for reconstruction of paleoproductivity and paleoredox conditions. Many of the trace elements considered here showExpand
The rise of oxygen in Earth’s early ocean and atmosphere
The rapid increase of carbon dioxide concentration in Earth’s modern atmosphere is a matter of major concern. But for the atmosphere of roughly two-and-half billion years ago, interest centres on aExpand
Low Mid-Proterozoic atmospheric oxygen levels and the delayed rise of animals
Low oxygen limited the rise of animals Oxygen levels in Earth's early atmosphere had an important influence on the evolution of complex life. Planavsky et al. analyzed the isotopic signature ofExpand
A Whiff of Oxygen Before the Great Oxidation Event?
High-resolution chemostratigraphy reveals an episode of enrichment of the redox-sensitive transition metals molybdenum and rhenium in the late Archean Mount McRae Shale in Western Australia.Expand
Mo–total organic carbon covariation in modern anoxic marine environments: Implications for analysis of paleoredox and paleohydrographic conditions
[1] Sedimentary molybdenum, [Mo]s, has been widely used as a proxy for benthic redox potential owing to its generally strong enrichment in organic-rich marine facies deposited under oxygen-depletedExpand
Evidence for oxygenic photosynthesis half a billion years before the Great Oxidation Event
The early Earth was characterized by the absence of oxygen in the ocean–atmosphere system, in contrast to the well-oxygenated conditions that prevail today. Atmospheric concentrations first rose toExpand
Low marine sulphate and protracted oxygenation of the Proterozoic biosphere
Progressive oxygenation of the Earth's early biosphere is thought to have resulted in increased sulphide oxidation during continental weathering, leading to a corresponding increase in marineExpand
Tracing the stepwise oxygenation of the Proterozoic ocean
Biogeochemical signatures preserved in ancient sedimentary rocks provide clues to the nature and timing of the oxygenation of the Earth’s atmosphere. Geochemical data suggest that oxygenationExpand
A critical look at iron paleoredox proxies: New insights from modern euxinic marine basins
Enrichments in reactive iron occur under euxinic marine conditions, that is, where dissolved sulfide is present in the water column. These enrichments result primarily from the export of remobilizedExpand
Late Archean Biospheric Oxygenation and Atmospheric Evolution
High-resolution geochemical analyses of organic-rich shale and carbonate through the 2500 million-year-old Mount McRae Shale in the Hamersley Basin of northwestern Australia record changes in bothExpand