Relationships between Fe redistribution and Po2 during mineral dissolution under low O2 conditions

Sugimori, Hirokazu; Kanzaki, Yoshiki; Murakami, Takashi

doi:10.1016/j.gca.2012.01.001

Cited by 19 publications

(17 citation statements)

References 61 publications

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“…1 clearly indicates that the calculated /-P O 2 relationships are essentially the same between the present study (curves) and Yokota et al (2013) (open symbols). Because Yokota et al (2013) have already confirmed the validity of their model by the consistency of the /-P O 2 relationships between the model estimates and mineral dissolution results (Sugimori et al, 2012), the present model is also valid for the calculation of the /-P O 2 relationship. By assuming steady-state weathering, the present model can avoid complicated assumptions (e.g., primary mineral distribution within a weathering profile) and time-consuming calculations (e.g., the Fe(II) concentration calculations for a number of layers in one weathering profile) which are necessary for the model by Yokota et al (2013).…”

Section: Formulation For the Calculation Of /supporting

confidence: 62%

“…Fe(II)-bearing primary minerals such as biotite and chlorite release Fe(II) in solution by weathering. Depending on weathering conditions such as Fe(II) oxidation kinetics and water flow rate, some portion of the dissolved Fe(II) is oxidized to Fe(III), which will form Fe(III)-(oxyhydr)oxides and remain in the weathering profile (e.g., Murakami et al, 2004Murakami et al, , 2011Sugimori et al, 2008Sugimori et al, , 2009Sugimori et al, , 2012 because of the low solubility of Fe(III) (e.g., Stefánsson, 2007). The remaining (unoxidized) portion of the dissolved Fe(II) flows out of the profile and/ or forms Fe(II)-bearing smectite that will remain in the weathering profile (Rye and Holland, 2000;Murakami et al, 2004) depending on weathering conditions.…”

Section: P O 2 Estimation Methodsmentioning

confidence: 99%

“…Note that Fe(II) oxidation can be assumed to dominantly occur in the porewater (k[Fe(II)] in Eq. (2)) (cf., Sugimori et al, 2009Sugimori et al, , 2012. Therefore, structural (White and Yee, 1985) and heterogeneous (Tamura et al, 1980) Fe(II) oxidations are not included in either Eqs.…”

Section: Formulation For the Calculation Of /mentioning

confidence: 99%

See 2 more Smart Citations

Estimates of atmospheric O2 in the Paleoproterozoic from paleosols

Kanzaki

Murakami

2016

Geochimica et Cosmochimica Acta

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Section: Formulation For the Calculation Of /supporting

confidence: 62%

Section: P O 2 Estimation Methodsmentioning

confidence: 99%

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Estimates of atmospheric O2 in the Paleoproterozoic from paleosols

Kanzaki

Murakami

2016

Geochimica et Cosmochimica Acta

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“…2(a)). Using similar reasoning, Sugimori et al (2012) observed that some Fe(II) that were released from olivine were oxidized and precipitated as Fe(III) oxides/hydroxides. The line g & 3.8 can be ascribed to high-spin Fe(III) ions held in the inner-sphere in octahedral sites with rhombic symmetry (Guskos et al 2002;Carbone et al 2005;Mota et al 2009).…”

Section: X-ray Diffractometrymentioning

confidence: 86%

Interaction of forsterite-91 with distilled water and artificial seawater: a prebiotic chemistry experiment

Souza¹,

Carneiro²,

Baú³

et al. 2013

International Journal of Astrobiology

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In the present work, the interactions between forsterite-91 with distilled water and forsterite-91 with artificial seawater were studied at two pHs (2.0 and 8.0) using different techniques. A large increase in pH was observed for samples incubated at an initially acidic pH (2.0) due to the dissolution of forsterite-91 in distilled water and artificial seawater. Thus, in acidic hydrothermal vents, an increase in the amount of hydrocarbons and magnetite should be expected due to the release of Fe(II). The pH PZC decreased and the pH IEP increased when forsterite-91 was treated with distilled water and artificial seawater. The ions from the artificial seawater had an effect on zeta potential. Scanning electron microscopy (SEM) images and X-ray diffractograms showed halite in the samples of forsterite-91 mixed with artificial seawater. The presence of halite or adsorption of ions on the surface of forsterite-91 could affect the synthesis of magnetite and hydrocarbons in hydrothermal vents, due to a decrease in the dissolution rates of forsterite-91. The dissolution of forsterite-91 yields low concentrations of Fe(III) and Mn(II) as detected by electron paramagnetic resonance (EPR) spectroscopy. Microanalysis of forsterite-91 showed a higher amount of Mn, with an oxidation that was likely not + II, as Mn in supernatant solutions was only detected by EPR spectroscopy after mixing with artificial seawater at pH 2.0. As Fe(III) and Mn(II) are catalyst constituents of magnetite and manganese oxide, respectively, their presence is important for synthesis in hydrothermal vents. Etch pits were observed only in the forsterite-91 sample mixed with distilled water at pH 8.0. Na, Cl, S, Ca and K were detected in the samples mixed with artificial seawater by SEM-EDS. Si, Mg, Fe and Al were detected in almost all supernatant samples due to forsterite-91 dissolution. Cr was not dissolved in the experiments, thus Cr in the mineral could serve as an effective catalyst for Fischer Tropsch Types (FTT) reactions in hydrothermal vent systems. X-ray diffractograms of the original forsterite-91 also showed peaks arising from zeolites and clinochlore. After the samples were treated with artificial seawater, X-ray diffractograms showed the dissolution of zeolite. Experiments should be performed in the natural environment to verify the potential for zeolites to act as a catalyst in hydrothermal vents.

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“…Potentially, this explains why non‐linear olivine dissolution rates are not typically reported. However, experiments by Sugimori, Kanzaki, and Murakami (), which specifically focused on whether or not Fe 2+ oxidation affects olivine dissolution rates, suggest that Fe 3+ oxide precipitates do not affect bulk dissolution rates. Potentially, the discrepancy between the results of this study and those of Sugimori et al.…”

Section: Discussionmentioning

confidence: 99%

The kinetics of siderophore‐mediated olivine dissolution

et al. 2019

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Silicate minerals represent an important reservoir of nutrients at Earth's surface and a source of alkalinity that modulates long‐term geochemical cycles. Due to the slow kinetics of primary silicate mineral dissolution and the potential for nutrient immobilization by secondary mineral precipitation, the bioavailability of many silicate‐bound nutrients may be limited by the ability of micro‐organisms to actively scavenge these nutrients via redox alteration and/or organic ligand production. In this study, we use targeted laboratory experiments with olivine and the siderophore deferoxamine B to explore how microbial ligands affect nutrient (Fe) release and the overall rate of mineral dissolution. Our results show that olivine dissolution rates are accelerated in the presence of micromolar concentrations of deferoxamine B. Based on the non‐linear decrease in rates with time and formation of a Fe3+‐ligand complex, we attribute this acceleration in dissolution rates to the removal of an oxidized surface coating that forms during the dissolution of olivine at circum‐neutral pH in the presence of O2 and the absence of organic ligands. While increases in dissolution rates are observed with micromolar concentrations of siderophores, it remains unclear whether such conditions could be realized in natural environments due to the strong physiological control on microbial siderophore production. So, to contextualize our experimental results, we also developed a feedback model, which considers how microbial physiology and ligand‐promoted mineral dissolution kinetics interact to control the extent of biotic enhancement of dissolution rates expected for different environments. The model predicts that physiological feedbacks severely limit the extent to which dissolution rates may be enhanced by microbial activity, though the rate of physical transport modulates this limitation.

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Relationships between Fe redistribution and Po2 during mineral dissolution under low O2 conditions

Cited by 19 publications

References 61 publications

Estimates of atmospheric O2 in the Paleoproterozoic from paleosols

Estimates of atmospheric O2 in the Paleoproterozoic from paleosols

Interaction of forsterite-91 with distilled water and artificial seawater: a prebiotic chemistry experiment

The kinetics of siderophore‐mediated olivine dissolution

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