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Title: One possible source of mass-independent fractionation of sulfur isotopes in the Archean atmosphere of Earth

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1415305
Grant/Contract Number:
AC02-05CH11231
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Geochimica et Cosmochimica Acta
Additional Journal Information:
Journal Volume: 204; Journal Issue: C; Related Information: CHORUS Timestamp: 2018-01-02 04:29:00; Journal ID: ISSN 0016-7037
Publisher:
Elsevier
Country of Publication:
United States
Language:
English

Citation Formats

Babikov, Dmitri, Semenov, Alexander, and Teplukhin, Alexander. One possible source of mass-independent fractionation of sulfur isotopes in the Archean atmosphere of Earth. United States: N. p., 2017. Web. doi:10.1016/j.gca.2017.01.029.
Babikov, Dmitri, Semenov, Alexander, & Teplukhin, Alexander. One possible source of mass-independent fractionation of sulfur isotopes in the Archean atmosphere of Earth. United States. doi:10.1016/j.gca.2017.01.029.
Babikov, Dmitri, Semenov, Alexander, and Teplukhin, Alexander. Mon . "One possible source of mass-independent fractionation of sulfur isotopes in the Archean atmosphere of Earth". United States. doi:10.1016/j.gca.2017.01.029.
@article{osti_1415305,
title = {One possible source of mass-independent fractionation of sulfur isotopes in the Archean atmosphere of Earth},
author = {Babikov, Dmitri and Semenov, Alexander and Teplukhin, Alexander},
abstractNote = {},
doi = {10.1016/j.gca.2017.01.029},
journal = {Geochimica et Cosmochimica Acta},
number = C,
volume = 204,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2017},
month = {Mon May 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.gca.2017.01.029

Citation Metrics:
Cited by: 2works
Citation information provided by
Web of Science

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  • Experimental evidence is presented which demonstrates a chemically produced, mass-independent isotopic fractionation of oxygen. The effect is thought to result from self-shielding by the major isotopic species /sup 16/O/sub 2/, but other possible mechanisms such as molecular symmetry cannot be ruled out. In a three-isotope plot, the experimentally produced fractionation line is essentially equal in slope to the observed carbonaceous chondrite mixing line. The implications for the early history of the solar system are discussed.
  • Mass independent fractionation (MIF) has been a very interesting topic in the field of inorganic isotope chemistry, in particular, geo- and cosmo- chemistry. In the present work, we studied the isotope fractionation of Ni(II) and Pb(II) ions in complex formation with chelating reagent EDTA. To obtain clear results on the mass dependence of the isotope fractionation, we have conducted long-distance ion exchange chromatography of Ni(II) and Pb(II), using chelate complex reagent EDTA. The results apparently show that the isotope fractionation in Ni complex formation system is governed by the mass dependent rule. On the other hand the isotope fractionation inmore » the Pb complex system is governed by the mass independent rule or the nuclear volume effect.« less
  • Recent experiments have shown that in the oxygen isotopic exchange reaction for O({sup 1}D) + CO{sub 2} the elastic channel is approximately 50% that of the inelastic channel [Perri et al., 2003]. We propose an analogous oxygen atom exchange reaction for the isoelectronic O({sup 1}D) + N{sub 2}O system to explain the mass-independent isotopic fractionation (MIF) in atmospheric N{sub 2}O. We apply quantum chemical methods to compute the energetics of the potential energy surfaces on which the O({sup 1}D) + N{sub 2}O reaction occurs. Preliminary modeling results indicate that oxygen isotopic exchange via O({sup 1}D) + N{sub 2}O can accountmore » for the MIF oxygen anomaly if the oxygen atom isotopic exchange rate is 30-50% that of the total rate for the reactive channels.« less
  • Both the Indus River and the Witwatersrand basin contain sand with grains of detrital uraninite. Because this mineral is easily oxidized, its presence in Archean strata as a detrital particle has been used as evidence for a low-oxygen atmosphere before 2.5 Ga. However, its presence in modern sand from the Indus River system has been used to argue that detrital uraninite does not provide information about the oxygen concentration of Earth's early atmosphere. Petrographic and chemical study of sand from these two sources reveals differences that suggest the modern Indus sand cannot be used as an analog for the Archeanmore » Witwatersrand occurrences. The Witwatersrand quartzites are depleted in Ca, Mg, and Na, indicating that the original sand from which they formed had been subjected to intense weathering. The chemical index of alteration (CIA), a commonly used indicator of degree of weathering, yields an average value of about 0.80 for Witwatersrand quartzites, comparable to modern tropical streams such as the Orinoco that drain deeply weathered terrains under tropical conditions (CIA=0.75). In contrast, the CIA for Indus sand is 0.45, indicating virtually no chemical weathering. The significance of Archean quartz-pebble conglomerates is not just that they contain unstable detrital phases like uraninite and pyrite, but that these particles are associated with rocks whose compositions suggest intense weathering. These conglomerates must have been subjected to intense weathering under tropical conditions, either in their source area or at the site of deposition, and the preservation of minerals like uraninite such conditions is indeed strong evidence for a low-oxygen atmosphere.« less