Continuously increasing δ 98 Mo values in Neoarchean black shales and iron formations from the Hamersley Basin

Kurzweil, Florian; Wille, Martin; Schoenberg, Ronny; Taubald, Heinrich; Kranendonk, Martin J. Van

doi:10.1016/j.gca.2015.05.009

Cited by 50 publications

(21 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nitrate was likely scarce in all parts of the mid-Archean ocean, including shallow waters (Stüeken et al, 2015a), consistent with very low levels of atmospheric oxygen at this time (Pavlov and Kasting, 2002;Kurzweil et al, 2013;Lyons et al, 2014). Surface water nitrate levels may have increased in the late Archean with the onset of low levels of oxidative weathering and enhanced oxygenation of the surface ocean (Siebert et al, 2005;Wille et al, 2007;Kendall et al, 2010;Stüeken et al, 2012;Zerkle et al, 2012;Gregory et al, 2015;Kurzweil et al, 2015). In the Ghaap Group in South Africa (2.67-2.52 Ga), bulk δ 15 N bulk values have a mean of +4.6 ± 2.0 ‰ and show no systematic variation between different facies, which include shallow-water microbialites and deeper-water siliciclastic sediments (Godfrey and Falkowski, 2009).…”

Section: Mesoproterozoic Nitrate Minimummentioning

confidence: 81%

“…For example, the appearance of free O 2 as early as 2.8 Ga (reviewed by Farquhar et al, 2011) in microbial mats and marine surface waters (Lalonde & Konhauser 2015, Olson et al 2013 probably spurred the radiation of nitrifying bacteria (Godfrey and Falkowski, 2009) because locally enhanced crustal weathering (Anbar et al, 2007;Wille et al, 2007;Reinhard et al, 2009;Czaja et al, 2010;Kendall et al, 2010;Stüeken et al, 2012;Gregory et al, 2015;Kurzweil et al, 2015) would have led to a greater influx of trace metals such as Fe, Cu, and Mo. Higher O 2 levels combined with increasing micro-nutrient availability would have facilitated the oxidation of ammonium to nitrite and nitrate (reviewed by Buick, 2007;Godfrey and Glass, 2011).…”

Section: Precambrian Nitrogen Cyclingmentioning

confidence: 99%

See 1 more Smart Citation

Spatial and temporal trends in Precambrian nitrogen cycling: A Mesoproterozoic offshore nitrate minimum

Koehler

Stüeken

Kipp

et al. 2017

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Section: Mesoproterozoic Nitrate Minimummentioning

confidence: 81%

Section: Precambrian Nitrogen Cyclingmentioning

confidence: 99%

Spatial and temporal trends in Precambrian nitrogen cycling: A Mesoproterozoic offshore nitrate minimum

Koehler

Stüeken

Kipp

et al. 2017

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

“…The presence of transient authigenic enrichments or isotopic fractionation of redox‐sensitive elements has been reported within Archaean‐aged rocks deposited up to 600–800 Myr prior to the GOE amidst a backdrop of evidence for an otherwise anoxic atmosphere (e.g. Anbar et al., ; Crowe et al., ; Eroglu, Schoenberg, Wille, Beukes, & Taubald, ; Frei, Gaucher, Poulton, & Canfield, ; Kurzweil, Wille, Schoenberg, Taubald, & Van Kranendonk, ; Olson, Kump, & Kasting, ; Reinhard, Raiswell, Scott, Anbar, & Lyons, ; Riding, Fralick, & Liang, ; Satkoski, Beukes, Li, Beard, & Johnson, ; Wille et al., ). Some of these signatures are attributed to localised oxygenation in restricted shallow marine oxygen “oases,” whereas others call for atmospheric O 2 in terrestrial environments at levels high enough to oxidise reduced minerals (e.g.…”

Section: Introductionmentioning

confidence: 99%

Chromium geochemistry of the ca. 1.85 Ga Flin Flon paleosol

2016

View full text Add to dashboard Cite

Fractionation of stable Cr isotopes has been measured in Archaean paleosols and marine sedimentary rocks and interpreted to record the terrestrial oxidation of Cr(III) to Cr(VI), providing possible indirect evidence for the emergence of oxygenic photosynthesis. However, these fractionations occur amidst evidence from other geochemical proxies for a pervasively anoxic atmosphere. This study examined the Cr geochemistry of the ca. 1.85 Ga Flin Flon paleosol, which developed under an atmosphere unambiguously oxidising enough to quantitatively convert Fe(II) to Fe(III) during pedogenesis. The paleosol shows an extreme range in Cr isotope composition of 2.76 ‰ δ Cr. The protolith greenstone (δ Cr: -0.23 ‰), the deepest weathering horizon (δ Cr: -0.15 to -0.23 ‰) and a residual corestone in the upper paleosol (δ Cr: -0.01 ‰) all exhibit Cr isotopic compositions comparable to unaltered igneous rocks. The most significant isotopic fractionation is preserved in the areas influenced by oxidative subaerial weathering (i.e. increase in Fe(III)/Fe(II)) and the greatest loss of mobile elements. The uppermost paleosol horizon is both Cr and Mn depleted and offset to significantly Cr-enriched compositions (δ Cr values between +1.50 and +2.38 ‰), which is not easily modelled with the oxidation of Cr(III) and loss of isotopically heavy Cr(VI). Instead, the currently preferred model for these data invokes the open-system removal of isotopically light aqueous Cr(III) during either pedogenesis or subsequent hydrothermal/metamorphic alteration. The Cr enrichment would then represent the preferential dissolution or complexation of isotopically light aqueous Cr(III) species (enhanced by lower pH conditions and possibly the presence of complexing ligands) and/or the residual signature from preferential adsorption of isotopically heavy Cr(III). Both scenarios would contradict the widely held assumption that only redox reactions of Cr can generate large magnitude isotopic fractionations and, if substantiated, non-redox isotope effects would complicate the conclusive fingerprinting of ancient atmospheric O from Cr isotope data alone.

show abstract

“…The record of the rise of free oxygen in Earth's atmosphere stimulates vigorous scientific debate, particularly as more sensitive geochemical proxies for oxygen have emerged during recent years. Even though the Great Oxidation Event (GOE) between about 2.42 to 2.33 Gy ago Farquhar et al, 2000;Gumsley et al, 2017;Hannah et al, 2004;Luo et al, 2016;Pavlov and Kasting, 2002) marks the first significant global rise of atmospheric oxygen above 10 -5 of the present atmospheric level (PAL) (Farquhar et al, 2000), there are several indications for global (Crowe et al, 2013;Frei et al, 2009) or at least local accumulation of free oxygen hundreds of millions of years earlier, causing oxidative cycling of redox-sensitive elements (Anbar et al, 2007;Duan et al, 2008;Eroglu et al, 2015;Kendall et al, 2010;Kurzweil et al, 2015;Planavsky et al, 2014;Wille et al, 2007). In a largely anoxic world, it was necessary to increase the oxygen production and to decrease the oxygen consumption by reducing species to ultimately gain a net production of oxygen.…”

Section: Introductionmentioning

confidence: 99%

Depth-dependent δ13C trends in platform and slope settings of the Campbellrand-Malmani carbonate platform and possible implications for Early Earth oxygenation

Eroglu

Zuilen

Taubald

et al. 2017

Precambrian Research

Self Cite

View full text Add to dashboard Cite

Depth-dependent δ 13 C trends in platform and slope settings of the Campbellrand-Malmani carbonate platform and possible implications for Early Earth oxygenation, Precambrian Research (2017), doi: http:// dx. AbstractThe evolution of oxygenic photosynthesis is widely seen as the major biological factor for the profound shift from reducing to slightly oxidizing conditions in Earth's atmosphere during the Archean-Proterozoic transition period. The delay from the first biogenic production of oxygen and the permanent oxidation of Earth's atmosphere during the early Paleoproteorozoic Great Oxidation Event (GOE) indicates that significant environmental modifications were necessary for an effective accumulation of metabolically produced oxygen. Here we report a distinct temporal shift to heavier carbon isotope signatures in lagoonal and intertidal carbonates (δ 13 C carb from -1.6 to +0.2 ‰, relative to VPDB) and organic matter (δ 13 C org from about -40 to -25 ‰, relative to VPDB) from the 2.58-2.50 Gy old shallow-marine Campbellrand-Malmani carbonate platform (South Africa). This indicates an increase in the burial rate of organic matter caused by enhanced primary production as well as a change from an anaerobic to an aerobic ecosystem. Trace element data indicate limited influx of reducing species from deep open ocean water into the platform and an increased supply of nutrients from the continent, both supporting primary production and an increasing oxidation state of the platform interior. These restricted conditions allowed that the dissolved inorganic carbon (DIC) pool in the platform interior developed differently than the open ocean. This is supported by coeval carbonates from the marginal slope setting, which had a higher interaction with open ocean water and do not record a comparable shift in δ 13 C carb throughout the sequence. We propose that the emergence of stable shallow-water carbonate platforms in the Neoarchean provided ideal conditions for the evolution of early aerobic ecosystems, which finally led to the full oxidation of Earth's atmosphere during the GOE. Keywords: Neoarchean carbonate platform; oxygen oasis; carbon isotopes; rare earth elements; carbonate diagenesis Highlights • Carbon cycle of Neoarchean carbonate platform and potential oxygen oasis • Carbon isotopes reveal a shift to aerobic biosphere and increasing oxidation state • Rare earth element patterns reveal decrease in open ocean water influx • Rimmed margin architecture was crucial for evolution of aerobic ecosystems

show abstract

Continuously increasing δ 98 Mo values in Neoarchean black shales and iron formations from the Hamersley Basin

Cited by 50 publications

References 89 publications

Spatial and temporal trends in Precambrian nitrogen cycling: A Mesoproterozoic offshore nitrate minimum

Spatial and temporal trends in Precambrian nitrogen cycling: A Mesoproterozoic offshore nitrate minimum

Chromium geochemistry of the ca. 1.85 Ga Flin Flon paleosol

Depth-dependent δ13C trends in platform and slope settings of the Campbellrand-Malmani carbonate platform and possible implications for Early Earth oxygenation

Contact Info

Product

Resources

About