Redox conditions on small bodies, the moon and mars

    Research output: Chapter in Book/Report/Conference proceedingChapter

    51 Citations (Scopus)

    Abstract

    The current state of knowledge regarding redox conditions of rocks from asteroidal bodies (as represented by various classes of meteorites), the Moon and Mars is discussed here. In the case of the differentiated meteorite parent bodies, the redox conditions range over at least six orders of magnitude (from ~5 log units below the Iron-Wustite buffer to slightly above it) and are determined in large part by the compositions of the undifferentiated precursor materials that accreted to form these parent bodies. Lunar basalts record oxygen fugacities ranging from close to the Iron-Wustite (IW) buffer to ~2 log units below it. The current best estimate of the oxygen fugacity of the lunar mantle is ~ 1 log unit below IW. Martian crustal rocks represented by the Shergottite-Nakhlite-Chassignite group of meteorites record a wide range of oxygen fugacities. The basaltic shergottites range from slightly below the IW buffer to ~2 log units above it, whereas the cumulate nakhlites (and chassignites) are relatively oxidized (-3-4 log units above the IW buffer). Following early metal-silicate and crust-mantle differentiation on Mars, the depleted martian mantle is likely to have been reduced (close to the IW buffer or slightly lower). Metasomatism and secondary (hydrous) alteration are likely to have produced silicate reservoirs on Mars that are relatively more oxidized (most likely ≥3 log units above the IW buffer). The redox conditions on the other terrestrial planets (Mercury and Venus) are not well constrained. Based on the limited information from remote spacecraft and telescopic observations of surface rocks on these planets, it is inferred that silicate reservoirs on Mercury are highly reduced; those on Venus are likely to be somewhat more oxidized than on Mercury, possibly similar to the lower mantle of Earth.

    Original languageEnglish (US)
    Title of host publicationOxygen in the Solar System
    PublisherDe Gruyter Mouton
    Pages493-510
    Number of pages18
    ISBN (Electronic)9781501508509
    ISBN (Print)9780939950805
    DOIs
    StatePublished - Nov 15 2018

    Fingerprint

    redox conditions
    Moon
    Mars
    iron
    fugacity
    meteorite
    silicate
    parent body
    Venus
    oxygen
    lunar mantle
    Mercury (planet)
    shergottite
    rock
    mantle
    lower mantle
    cumulate
    metasomatism
    spacecraft
    planet

    ASJC Scopus subject areas

    • Earth and Planetary Sciences(all)

    Cite this

    Wadhwa, M. (2018). Redox conditions on small bodies, the moon and mars. In Oxygen in the Solar System (pp. 493-510). De Gruyter Mouton. https://doi.org/10.2138/rmg.2008.68.17

    Redox conditions on small bodies, the moon and mars. / Wadhwa, Meenakshi.

    Oxygen in the Solar System. De Gruyter Mouton, 2018. p. 493-510.

    Research output: Chapter in Book/Report/Conference proceedingChapter

    Wadhwa, M 2018, Redox conditions on small bodies, the moon and mars. in Oxygen in the Solar System. De Gruyter Mouton, pp. 493-510. https://doi.org/10.2138/rmg.2008.68.17
    Wadhwa M. Redox conditions on small bodies, the moon and mars. In Oxygen in the Solar System. De Gruyter Mouton. 2018. p. 493-510 https://doi.org/10.2138/rmg.2008.68.17
    Wadhwa, Meenakshi. / Redox conditions on small bodies, the moon and mars. Oxygen in the Solar System. De Gruyter Mouton, 2018. pp. 493-510
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