Lunar Meteorite: Northwest Africa 482

Northwest Africa 482 appears very fresh, with a shiny fusion crust and flow lines.  Clasts are visible through the fusion crust. Photo credit: Jim Strope
It has some nice regmaglypts. Photo credit: Jim Strope
Sawn face of NWA 482, with melt veins. Photo credit: Jim Strope
Lab samples. Photo credit: Randy Korotev
from The Meteoritical Bulletin, No. 85

Northwest Africa 482

(Northwestern Africa)
Purchased: 2001 January 10
Mass: 1015 g (1 piece)

Lunar meteorite (impact melt breccia)

History: A 1015 g stone was purchased on 2001 January 10 in Alnif, Morocco, by Michael Farmer. The exact location of find is unknown but it is possibly in Algeria. The stone is complete, oriented, and appears relatively unweathered.

Classification and mineralogy (A. Rubin and P. Warren, UCLA, and D. Kring and I. Daubar, UAz): texture is typical of a crystalline impact melt breccia (polymict) with highland affinities; glassy and vesicular melt veins and melt pockets indicate shock subsequent to compaction by an impact event; plagioclase, An95.7Ab4.09Or0.17 (n = 136, UAz); olivine, Fo65-68 (average Fo66) with FeO/MnO = 88 ± 7 g/g (UCLA); olivine Fo68.4 with FeO/MnO = 93.9 ± 7.7 g/g (range: 78.7 to 111) (n = 51, UAz); pyroxene, Fs25Wo17 with nearly uniform Mg/(Mg+Fe) = 67-68 mol% and FeO/MnO = 51 ± 6 g/g (n = 10, UCLA); pyroxene, Wo10.3- 51En32.6-63.9Fs42.6-14.2, mean Mg/(Mg+Fe) = 68 mol%, FeO/MnO = 52 ± 8 g/g (n = 28, UAz); glassy melt veins occur in both UCLA and UAz samples; a 0.1 mm vein (UCLA) has SiO2 = 44.3 wt.%, Na2O = 0.3 wt.%, Al2O3 = 30.0 wt.%, FeO = 3.6 wr.%, MgO = 3.9 wt.%, CaO = 17.3 wt.%, and TiO2 = 0.3 wt.%, which may approximate the bulk meteorite composition.

Specimens: Half of the main mass is with Farmer; type specimens, 24 g, UCLA, and 18 g, UAz.

Randy Says…

NWA 482 is one of the most beautiful of lunar meteorites. It is a crystalline impact-melt breccia, which is one of the less common breccia types among lunar meteorites. Compositionally, it is a typical feldspathic lunar meteorite.

More Information

Meteoritical Bulletin Database

NWA 482

References

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