The Grove Mountains (GRV) 021663 meteorite was collected from the Grove Mountains region of Antarctica. The meteorite is composed primarily of olivine (Fa(5.4)), orthopyroxene (Fs(4.7)Wo(3.0)), chromian diopside (En(53.6)Fs(2.4)Wo(44)), troilite, kamacite, and plagioclase (Ab(74.5)Or(4)An(21.5)). Minor phases include schreibersite and K-feldspar. The meteorite is highly weathered (W3) and weakly shocked (S2). We determine a whole rock oxygen isotopic composition of delta(18)O = 7.50 parts per thousand, delta(17)O = 3.52 parts per thousand. Comparisons of these data with other primitive achondrites have resulted in the reclassification of this meteorite as a member of the winonaite group. The occurrences of troilite, metal, and schreibersite in GRV 021663 indicate that these minerals were once completely molten. Euhedral inclusions of pyroxene within plagioclase further suggest that these may have crystallized from a silicate melt, while the depletion of plagioclase, metal, and troilite indicates that GRV 021663 could represent a residuum following partial melting on its parent asteroid. Trace element distributions in silicate minerals do not, however, confirm this scenario. As with other winonaite meteorites, the formation of GRV 021663 probably relates to brecciation and mixing of heterogeneous lithologies, followed by varying degrees of thermal metamorphism on the parent body asteroid. Peak metamorphic conditions may have resulted in localized partial melting of metal and silicate mineralogies, but our data are not conclusive.

Publication name	METEORITICS & PLANETARY SCIENCE　Volume: 46 　Issue: 9 　Pages: 1329-1344　 Published: SEP 2011
Author(s)	Li, Shijie; Wang, Shijie; Bao, Huiming; Miao, Bingkui; Liu, Shen; Coulson, Ian M.; Li, Xiongyao; Li, Yang
Corresponding author	WANG Shijie  wangshijie@vip.skleg.cn  Chinese Acad Sci, Inst Geochem, Guiyang 550002, Peoples R China

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