@article{oai:nipr.repo.nii.ac.jp:00010058,
 author = {Nagaoka, Hiroshi and Karouji, Yuzuru and Ara, iTomoko and Ebihara, Mitsuru and Hasebe, Nobuyuki and Nagaoka, Hiroshi and Karouji, Yuzuru and Ara, iTomoko and Ebihara, Mitsuru and Hasebe, Nobuyuki},
 issue = {3},
 journal = {Polar science, Polar science},
 month = {Sep},
 note = {The lunar meteorite Northwest Africa (NWA) 2200 is a regolith breccia with a ferroan feldspathic bulk composition (Al_2O_3 = 30.1 wt.%; Mg^# = molar 100 × Mg/(Mg + Fe) = 59.2) and low Th content (0.42 μg/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 Al_2O_3 = 26–30 wt.%; 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)., 本論文では、月隕石Northwest Africa (NWA) 2200に対し、化学的、岩石鉱物学的研究を行い、その起源について考察した。NWA 2200は、月の斜長岩地殻に由来するレゴリス角礫岩である。含まれる斜長岩石片の組成は、アポロ16号サイトで回収された斜長岩ferroan anorthosite (FAN)のものとよく似ている。また、それらの組織は多様に変成を受けており、月表層での複雑な衝突史を物語っている。一方でNWA 2200の全岩化学組成は、どのアポロ回収レゴリス試料とも大きく異なり、トリウムや希土類元素のような液相濃集元素が枯渇し、FeO/MgO比が高い。これらの特徴から、この月隕石はFANに近い組成をもつものの、アポロ着陸点とは異なるレゴリス地域を起源としていることがわかった。},
 pages = {241--259},
 title = {Geochemistry and mineralogy of a feldspathic lunar meteorite (regolith breccia), Northwest Africa 2200},
 volume = {7},
 year = {2013}
}