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Lunar Meteorite

Northwest Africa 5000

Morocco

 

Northwest Africa 5000. Lower right image: 19 cm across. Click on image for enlargement.
(photo credit: by Greg Hupé)

 

 

A big slice of NWA 5000. Click on image for enlargement (big).
(photo credit: Randy Korotev)

 

Close-up of lab samples. Notice the large, rusted metal grain. Millimeter ticks for scale. Click on image for enlargement.
(photo credit: Randy Korotev)

 

Photomicrographs of a thin section of NWA 5000, plane polarized light (left) and cross-polarized light (right). Scale bar is 1 mm. Click on image for enlargement.
(photo credit: Axel Wittmann)

 

from The Meteoritical Bulletin, No. 93, Meteoritics & Planetary Science 43, 571–632 (2007)

Northwest Africa 5000

 

Morocco
Find: 2007 July
Mass: 11,528 g

Achondrite (lunar, feldspathic breccia)

History: Found in July 2007 in southern Morocco and provided to Adam Hupé in October 2007 by a Moroccan dealer.

Physical characteristics: A single, large cuboidal stone (11.528 kg) with approximate dimensions 27 cm × 24 cm × 20 cm. One side (which appears to have been embedded downward in light brown mud) has preserved regmaglypts and is partially covered by translucent, pale greenish fusion crust with fine contraction cracks. Abundant large beige to white, coarse-grained clasts up to 8 cm across (some of which have been eroded out on exterior surfaces of the stone, likely by eolian sand blasting) and sparse black, vitreous clasts up to 2 cm across (containing irregular small white inclusions) are set in a dark gray to black, partially glassy breccia matrix. One partially eroded clast exposed on an exterior surface contains both the coarse grained beige lithology and the more resistant black, vitreous lithology in sharp contact.

Petrography: (A. Irving and S. Kuehner, UWS) Almost monomict fragmental breccia dominated by Mg-suite olivine gabbro clasts consisting predominantly of coarse-grained (0.5-2 mm) calcic plagioclase, pigeonite (some with fine exsolution lamellae), and olivine with accessory merrillite, Mg-bearing ilmenite, Ti-bearing chromite, baddeleyite, rare zirconolite, silica polymorph, K-feldspar, kamacite, and troilite. Some gabbro clasts have shock injection veins composed mostly of glass containing myriad fine troilite blebs and engulfed mineral fragments. Black, vitreous impact melt clasts consist of sporadic, small angular fragments (apparently surviving relics) of gabbro and related mineral phases in a very fine grained, non-vesicular, ophitic-textured matrix of pigeonite laths (up to 20 microns long × 2 microns wide) and interstitial plagioclase with tiny spherical grains of kamacite, irregular grains of schreibersite and rare troilite.

Mineral composition and geochemistry: Gabbro clasts: plagioclase (An96.1-98.0Or<0.1), pigeonite (Fs32.0-64.5Wo6.7-13.1; FeO/MnO = 51.1-62.0), olivine in different clasts range from Fa23.9-24.2, Fa40.4 to Fa58.8 (with FeO/MnO = 81-100), chromite [(Cr/(Cr + Al) = 0.737, Mg/(Mg + Fe) = 0.231, TiO2 = 5.9 wt%], ilmenite (4.1 wt% MgO). Bulk composition: (R. Korotev, WUSL) INAA of 6 subsamples gave mean values of 5.3 wt% FeO and 0.4 ppm Th.

Classification: Achondrite (lunar, feldspathic breccia). Specimens: A total of 40.2 g of sample, two polished mounts and one large polished thin section are on deposit at UWS. A. Hupé hold the main mass.

 

Randy Says…

At 11.5 kg, it is one of the biggest lunar meteorites. It is mineralogically and texturally unique among feldspathic lunar meteorites. It contains large fragments of metal, apparently from an iron meteorite.

 

More Information

Meteoritical Bulletin Database

NWA 5000

References

Arai T., Yamamoto A., Ohtake M., Matsunaga T., Haruyama J., Hiroi T., Sasaki S., and Matsui T. (2011) Lunar crustal mineralogy inferred from lunar meteorites and Kaguya data (abstract). The 34rd Symposium on Antarctic Meteorites, p. 3-4, Tokyo.

Arai T., Hiroi T., Sasaki S., and Matsui T. (2013) Origin of the lunar crust inferred from mineralogy and reflectance spectra of lunar meteorites (abstract). In 44th Lunar and Planetary Science Conference, abstract no. 1016.

Artemieva N. (2014) NWA 5000 — One of a kind? (abstract). 77th Annual Meeting of the Meteoritical Society, abstract no. 5231.

Grange M. L. Norman M. D., and Assis Fernandes V. (2016) Clues to the origin of gabbroic lunar meteorite Northwest Africa 5000. 47th Lunar and Planetary Science Conference, abstract no. 1784.

Grange M. L., Norman M. D. and  Bennett V. (2016) A Possible 4.1–4.2 Ga impact event recorded in lunar meteorite Northwest Africa 5000 (abstract). 79th Annual Meeting of the Meteoritical Society, abstract no. 6300.

Fernandes V. A. (2009) 40Ar-39Ar age for gabbroic lunar meteorite Northwest Africa 5000 (abstract), Goldschmidt Conference Abstracts 2009, A365.

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.

Humayun M. & Irving A. (2008) Impactor metal in gabbroic lunar meteorite Northwest Africa 5000. Goldschmidt Conference Abstracts 2008, Geochimica et Cosmochimica Acta 72, 12S, p. A402.

Irving A. J., Kuehner S. M., Korotev R. L., Rumble D. III, and Hupé A. C. (2008) Petrology and bulk composition of large lunar feldspathic leucogabbroic breccia Northwest Africa 5000 (abstract). In Lunar and Planetary Science XXXIX, abstract no. 2186, 39th Lunar and Planetary Science Conference.

Korotev R. L (2013) Siderophile elements in brecciated lunar meteorites (abstract). In Lunar and Planetary Science XLIV, abstract no. 1028.

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.

Korotev R. L., Jolliff B. L., and Zeigler R. A. (2010) On the origin of the moon’s feldspathic highlands, pure anorthosite, and the feldspathic lunar meteorites(abstract). In Lunar and Planetary Science XLI, abstract no. 1440, 41st Lunar and Planetary Science Conference.

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.

Nagurney A. B., Treiman A. H., and Spudis P. D. (2016) Petrology, bulk composition, and provenance of meteorite Northwest Africa 5000. 46th Lunar and Planetary Science Conference, abstract no. 1103.

 

Nishiizumi K., Caffee M. W., Vogel N., Wieler R., Leclerc M. D., and Jull A. J. T. (2009) Exposure history of lunar meteorite Northwest Africa 5000 (abstract). In Lunar and Planetary Science XL, abstract no. 1476, 40th Lunar and Planetary Science Conference.

 

 

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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: 28-June-2016