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Lunar Meteorite

Northwest Africa 482

Morocco/Algeria

 

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          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)

 

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It has some nice regmaglypts.

(photo credit: Jim Strope)

 

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Sawn face of NWA 482, with melt veins
(photo credit: Jim Strope)

 

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Randy’s samples

(photo credit: Randy Korotev)

 

from The Meteoritical Bulletin, No. 85, Meteoritics & Planetary Science 36, A293–A322 (2001)

Northwest Africa 482

(Northwest Africa)
Purchased: 2001 January 10
Mass: 1015 g

Lunar meteorite (impact melt breccia) 

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 ap-pears 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…

It's one of the most beautiful lunar meteorites. It's one of the few crystalline impact-melt breccias. Compositionally, it’s a typical feldspathic lunar meteorite.

 

More Information

Meteoritical Bulletin Database

NWA 482

References

Calzada-Diaz A., Joy K. H., Crawford I. A., and Nordheim T. A. (2015) Constraining the source regions of lunar meteorites using orbital geochemical data. Meteoritics & Planetary Science 50, 214-228.

Consolmagno G. J., Russell S. S., and Jeffries T. E. (2004) An in–situ study of REE abundances in three anorthositic impact melt lunar highland meteorites (abstract). Lunar and Planetary Science XXXV, abstract no. 1370, Lunar and Planetary Institute.

Daubar I. J., Kring D. A., Swindle T. D., and Jull A. J. T. (2002) Northwest Africa 482: A crystalline impact-melt breccia from the lunar highlands, Meteoritics & Planetary Science 37, 1797-1814.

Hidaka H. and Yoneda S. (2013) Isotopic studies of radiogenic and neutron-captured REE of lunar meteorites (abstract). 76th Annual Meeting of the Meteoritical Society, abstract no. 5042.

Joy K. H., Burgess R., Ruzie L, and Clay P. L. (2014) Composition, age and regolith history of feldspathic lunar meteorites (abstract). 77th Annual Meeting of the Meteoritical Society, abstract no. 5345.

Korotev R. L. (2005) Lunar geochemistry as told by lunar meteorites. Chemie der Erde 65, 297–346.

Korotev R. L., Jolliff B. L., Zeigler R. A., Gillis J. J., and Haskin L. A. (2003) Feldspathic lunar meteorites and their implications for compositional remote sensing of the lunar surface and the composition of the lunar crust, Geochimica et Cosmochimica Acta 67, 4895-4923.

Korotev R. L., Irving A. J., and Bunch T. E. (2008) Keeping up with the lunar meteorites – 2008 (abstract). In Lunar and Planetary Science XXXIX, abstract no. 1209, 39th Lunar and Planetary Science Conference.

Lorenzetti S., Busemann H., and Eugster O. (2005) Regolith history of lunar meteorites. Meteoritics & Planetary Science 40, 315-327.

Macke R. J., Kiefer W. S., Britt D. T., and Consolmagno G. J. (2010) Density, porosity and magnetic susceptibility of lunar rocks (abstract). In Lunar and Planetary Science XLI, abstract no. 1252, Lunar and Planetary Institute.

Macke R. J., Britt D. T., and Consolmagno G. J. (2011) Density, porosity and magnetic susceptibility of achondritic meteorites. Meteoritics & Planetary Science 46, 311-326.

Nishiizumi K. (2003) Exposure histories of lunar meteorites (abstract). In Evolution of Solar System Materials: A New Perspective from Antarctic Meteorites, p. 104, National Institute of Polar Research, Tokyo.

Nishiizumi K. and Caffee M. W. (2001) Exposure histories of lunar meteorites Dhofar 025, 026, and Northwest Africa 482 (abstract), Meteorit. Planet. Sci. 36, A148-A149, 64th Annual Meeting, Meteoritical Society.

Puchtel I.S., Walker R.J., Kring D.A., and James O.B. (2007) Further study of 187Os/188Os and highly siderophile element systematics of lunar impact melt rocks (abstract). In Lunar and Planetary Science XXXVIII, abstract no. 2040, 38th Lunar and Planetary Science Conference.

Puchtel I. S., Walker R. J., James O. B., and Kring D. A. (2008) Osmium isotope and highly siderophile element systematics of lunar impact melt breccias: Implications for the late accretion history of the Moon and Earth. Geochimica et Cosmochimica Acta 72, 3022–3042.

Takeda H., Yamaguchi A., Otsuki M., Hiroi T., Ohtake M., and Kato M. (2010) Mineralogical interpretation on the feldspathic highlands of the Moon on the basis of some feldspathic lunar meteorites (abstract). 73th Annual Meeting of the Meteoritical Society, abstract no. 5060. Lunar and Planetary Institute.

Warren P. H. and Kallemeyn G. W. (2001) New lunar meteorite Northwest Africa 482: An anorthositic impact melt breccia with low KREEP content (abstract), Meteorit. Planet. Sci. 36, A220, 64th Annual Meeting, Meteoritical Society.

Warren P. H., Ulff-Møller F., and Kallemeyn G. W. (2005) “New” lunar meteorites: Impact melt and regolith breccias and large-scale heterogeneities of the upper lunar crust. Meteoritics &.Planetary Science 40, 989–1014.

 

 

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Prepared by
: Randy L. Korotev
 
Department of Earth and Planetary Sciences
Washington University in St. Louis

Please don't contact me about the meteorite you think you've found until you read this and this.


e-mail
korotev@wustl.edu

Last revised: 8-Oct-2015