16 Good Golly, Why Moly? THE STABLE ISOTOPE GEOCHEMISTRY OF MOLYBDENUM

Kendall, B. E.; Dahl, Tais W.; Anbar, Ariel D.

doi:10.1515/9783110545630-017

Cited by 23 publications

(36 citation statements)

References 208 publications

(597 reference statements)

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“…The absence of this isotope fractionation indicates little Archean seawater sulfate and implies anoxic air. Using similar arguments of O 2 -sensitive weathering, transport, and fractionation, isotopes of Cu (76), Cr (77), Fe (78), U (79), Mo [e.g., (80,81)], and Se (82) indicates an anoxic Archean atmosphere.…”

Section: Archean Atmospheric Gasesmentioning

confidence: 99%

The Archean atmosphere

2020

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The atmosphere of the Archean eon—one-third of Earth’s history—is important for understanding the evolution of our planet and Earth-like exoplanets. New geological proxies combined with models constrain atmospheric composition. They imply surface O2 levels <10−6 times present, N2 levels that were similar to today or possibly a few times lower, and CO2 and CH4 levels ranging ~10 to 2500 and 102 to 104 times modern amounts, respectively. The greenhouse gas concentrations were sufficient to offset a fainter Sun. Climate moderation by the carbon cycle suggests average surface temperatures between 0° and 40°C, consistent with occasional glaciations. Isotopic mass fractionation of atmospheric xenon through the Archean until atmospheric oxygenation is best explained by drag of xenon ions by hydrogen escaping rapidly into space. These data imply that substantial loss of hydrogen oxidized the Earth. Despite these advances, detailed understanding of the coevolving solid Earth, biosphere, and atmosphere remains elusive, however.

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Section: Archean Atmospheric Gasesmentioning

confidence: 99%

The Archean atmosphere

2020

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“…For example, Cl exhibits the Figure 2. The terrestrial isotopic variation vs. the relative mass difference for non-traditional stable isotopes covered in this volume (Anderson et al 2017; Barnes and Sharp 2017;Blum and Johnson 2017;Dauphas et al 2017;Elliott and Steele 2017;Kendall et al 2017;Moynier et al 2017;Nielsen et al 2017;Penniston-Dorland et al 2017;Poitrasson 2017;Qin and Wang 2017;Rouxel and Luais 2017;Stueken 2017;Teng 2017). The Dm i−j = m i − m j , where i and j represent the two isotopes that are used to report the isotopic variation, with i > j. second largest isotopic variation, which is due to kinetic isotope fractionation during volcanic degassing (Barnes and Sharp 2017).…”

Section: Introductionmentioning

confidence: 99%

Non-Traditional Stable Isotopes: Retrospective and Prospective

Teng

Dauphas

Watkins

2017

Reviews in Mineralogy and Geochemistry

196

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“…Redox conditions exert complex controls on Mo isotope fractionation in marine sediments (for a recent review, see Kendall et al, 2017). Whereas Mo adsorption to manganese oxides in oxic water column conditions yields light  98/95 Mo isotopic values of ~-0.7‰ that reflect a large ~3‰ fractionation from seawater molybdate ( 98/95 Mo ≈ + 2.3‰) (Barling et al, 2001;Siebert et al, 2003Siebert et al, , 2006Barling andAnbar, 2004, Wasylenki et al, 2008), sediments formed in euxinic water column conditions frequently precipitate with  98/95 Mo close to that of seawater (Arnold et al, 2004;Neubert et al, 2008).…”

Section: Introductionmentioning

confidence: 99%