Geochemistry and mineralogy of a feldspathic lunar meteorite (regolith breccia), Northwest Africa 2200

Hiroshi Nagaoka, Yuzuru Karouji, Tomoko Arai, Mitsuru Ebihara, Nobuyuki Hasebe

    Research output: Contribution to journalArticle

    5 Citations (Scopus)

    Abstract

    The lunar meteorite Northwest Africa (NWA) 2200 is a regolith breccia with a ferroan feldspathic bulk composition (Al2O3=30.1wt.%; Mg#=molar 100×Mg/(Mg+Fe)=59.2) and low Th content (0.42μg/g). Lithologically, NWA 2200 is a diverse mixture of lithic and glassy clasts, mineral fragments, and impact glass spherules, all embedded in a dark glassy matrix. NWA 2200 contains some feldspathic brecciated rock components (ferroan anorthositic granulitic breccia, poikiloblastic granulitic breccia, and glassy melt breccia with an intersertal texture). The bulk compositions of these brecciated components indicate they are derived from ferroan troctolitic or noritic anorthosite lithologies (bulk Al2O3=26-30wt.%; bulk FeO/MgO>1.0). The bulk composition of NWA 2200 is more ferroan and feldspathic than the Apollo feldspathic regolith samples and feldspathic lunar regolith meteorites, and is also more depleted in incompatible elements (e.g., rare earth elements) than Apollo 16 feldspathic regolith samples. We conclude that NWA 2200 originated from a location different to the Apollo landing sites, and may have been sourced from the ferroan KREEP-poor highlands, "KREEP" materials are enriched in such elements as potassium (K), rare earth elements (REE), phosphorus (P).

    Original languageEnglish
    Pages (from-to)241-259
    Number of pages19
    JournalPolar Science
    Volume7
    Issue number3-4
    DOIs
    Publication statusPublished - 2013

    Fingerprint

    lunar meteorite
    geochemistry
    mineralogy
    regolith
    breccia
    rare earth elements
    rare earth element
    spherule
    anorthosite
    clast
    meteorite
    glass
    lithology
    highlands
    potassium
    texture
    rocks
    Africa
    melt
    minerals

    Keywords

    • Ferroan anorthosite
    • Geochemistry
    • Lunar meteorite
    • Mineralogy

    ASJC Scopus subject areas

    • Earth and Planetary Sciences(all)
    • Aquatic Science
    • Ecology, Evolution, Behavior and Systematics
    • Ecology

    Cite this

    Geochemistry and mineralogy of a feldspathic lunar meteorite (regolith breccia), Northwest Africa 2200. / Nagaoka, Hiroshi; Karouji, Yuzuru; Arai, Tomoko; Ebihara, Mitsuru; Hasebe, Nobuyuki.

    In: Polar Science, Vol. 7, No. 3-4, 2013, p. 241-259.

    Research output: Contribution to journalArticle

    Nagaoka, Hiroshi ; Karouji, Yuzuru ; Arai, Tomoko ; Ebihara, Mitsuru ; Hasebe, Nobuyuki. / Geochemistry and mineralogy of a feldspathic lunar meteorite (regolith breccia), Northwest Africa 2200. In: Polar Science. 2013 ; Vol. 7, No. 3-4. pp. 241-259.
    @article{c308b5a186714547a6e6f90ae94834d0,
    title = "Geochemistry and mineralogy of a feldspathic lunar meteorite (regolith breccia), Northwest Africa 2200",
    abstract = "The lunar meteorite Northwest Africa (NWA) 2200 is a regolith breccia with a ferroan feldspathic bulk composition (Al2O3=30.1wt.{\%}; Mg#=molar 100×Mg/(Mg+Fe)=59.2) and low Th content (0.42μg/g). Lithologically, NWA 2200 is a diverse mixture of lithic and glassy clasts, mineral fragments, and impact glass spherules, all embedded in a dark glassy matrix. NWA 2200 contains some feldspathic brecciated rock components (ferroan anorthositic granulitic breccia, poikiloblastic granulitic breccia, and glassy melt breccia with an intersertal texture). The bulk compositions of these brecciated components indicate they are derived from ferroan troctolitic or noritic anorthosite lithologies (bulk Al2O3=26-30wt.{\%}; bulk FeO/MgO>1.0). The bulk composition of NWA 2200 is more ferroan and feldspathic than the Apollo feldspathic regolith samples and feldspathic lunar regolith meteorites, and is also more depleted in incompatible elements (e.g., rare earth elements) than Apollo 16 feldspathic regolith samples. We conclude that NWA 2200 originated from a location different to the Apollo landing sites, and may have been sourced from the ferroan KREEP-poor highlands, {"}KREEP{"} materials are enriched in such elements as potassium (K), rare earth elements (REE), phosphorus (P).",
    keywords = "Ferroan anorthosite, Geochemistry, Lunar meteorite, Mineralogy",
    author = "Hiroshi Nagaoka and Yuzuru Karouji and Tomoko Arai and Mitsuru Ebihara and Nobuyuki Hasebe",
    year = "2013",
    doi = "10.1016/j.polar.2013.09.001",
    language = "English",
    volume = "7",
    pages = "241--259",
    journal = "Polar Science",
    issn = "1873-9652",
    publisher = "Elsevier",
    number = "3-4",

    }

    TY - JOUR

    T1 - Geochemistry and mineralogy of a feldspathic lunar meteorite (regolith breccia), Northwest Africa 2200

    AU - Nagaoka, Hiroshi

    AU - Karouji, Yuzuru

    AU - Arai, Tomoko

    AU - Ebihara, Mitsuru

    AU - Hasebe, Nobuyuki

    PY - 2013

    Y1 - 2013

    N2 - The lunar meteorite Northwest Africa (NWA) 2200 is a regolith breccia with a ferroan feldspathic bulk composition (Al2O3=30.1wt.%; Mg#=molar 100×Mg/(Mg+Fe)=59.2) and low Th content (0.42μg/g). Lithologically, NWA 2200 is a diverse mixture of lithic and glassy clasts, mineral fragments, and impact glass spherules, all embedded in a dark glassy matrix. NWA 2200 contains some feldspathic brecciated rock components (ferroan anorthositic granulitic breccia, poikiloblastic granulitic breccia, and glassy melt breccia with an intersertal texture). The bulk compositions of these brecciated components indicate they are derived from ferroan troctolitic or noritic anorthosite lithologies (bulk Al2O3=26-30wt.%; bulk FeO/MgO>1.0). The bulk composition of NWA 2200 is more ferroan and feldspathic than the Apollo feldspathic regolith samples and feldspathic lunar regolith meteorites, and is also more depleted in incompatible elements (e.g., rare earth elements) than Apollo 16 feldspathic regolith samples. We conclude that NWA 2200 originated from a location different to the Apollo landing sites, and may have been sourced from the ferroan KREEP-poor highlands, "KREEP" materials are enriched in such elements as potassium (K), rare earth elements (REE), phosphorus (P).

    AB - The lunar meteorite Northwest Africa (NWA) 2200 is a regolith breccia with a ferroan feldspathic bulk composition (Al2O3=30.1wt.%; Mg#=molar 100×Mg/(Mg+Fe)=59.2) and low Th content (0.42μg/g). Lithologically, NWA 2200 is a diverse mixture of lithic and glassy clasts, mineral fragments, and impact glass spherules, all embedded in a dark glassy matrix. NWA 2200 contains some feldspathic brecciated rock components (ferroan anorthositic granulitic breccia, poikiloblastic granulitic breccia, and glassy melt breccia with an intersertal texture). The bulk compositions of these brecciated components indicate they are derived from ferroan troctolitic or noritic anorthosite lithologies (bulk Al2O3=26-30wt.%; bulk FeO/MgO>1.0). The bulk composition of NWA 2200 is more ferroan and feldspathic than the Apollo feldspathic regolith samples and feldspathic lunar regolith meteorites, and is also more depleted in incompatible elements (e.g., rare earth elements) than Apollo 16 feldspathic regolith samples. We conclude that NWA 2200 originated from a location different to the Apollo landing sites, and may have been sourced from the ferroan KREEP-poor highlands, "KREEP" materials are enriched in such elements as potassium (K), rare earth elements (REE), phosphorus (P).

    KW - Ferroan anorthosite

    KW - Geochemistry

    KW - Lunar meteorite

    KW - Mineralogy

    UR - http://www.scopus.com/inward/record.url?scp=84897080659&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84897080659&partnerID=8YFLogxK

    U2 - 10.1016/j.polar.2013.09.001

    DO - 10.1016/j.polar.2013.09.001

    M3 - Article

    AN - SCOPUS:84897080659

    VL - 7

    SP - 241

    EP - 259

    JO - Polar Science

    JF - Polar Science

    SN - 1873-9652

    IS - 3-4

    ER -