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Lunar Meteorite

Northwest Africa 6687

Morocco

 

lm_nwa_6687_5192s.jpg

Lab sample of Northwest Africa 6687. Click on image for enlargement.Thanks to Norbert Classen for the sample.
(photo credit: Randy Korotev)

 

from The Meteoritical Bulletin, No. 100

Northwest Africa 6687

(Northwest Africa)
Find: 2010
Mass: 42.4 g

Lunar (feldspathic breccia)

History: Found in Morocco in 2010 and purchased from the finder by G. Tomelleri.

Physical characteristics: A single black stone (42.4 g) lacking fusion crust. The interior is dark gray and displays several small white clasts.

Petrography: (V. Moggi Cecchi, S. Caporali, G. Pratesi, MSP) The overall texture consists of coarse-grained inclusions set in a fine-grained matrix. The matrix contains isolated mineral clasts, mainly consisting of augite, plagioclase and olivine, and a fine grained mineral debris enclosed within a dark, partly glassy and vesicular matrix. The large coarse grained inclusions consist of elongated plagioclase and clinopyroxene crystals set in a glassy matrix. Opaque phases are represented by ilmenite, ulvospinel and chromite.

Geochemistry: Olivine (Fa33.7-49.2, Fe/Mn=108, n=20, Cr=1500 ppm, Mn=3100 ppm), augite (Fs23.8.5-31.2En24.9-30.0Wo27.3-30.0Al-px 13.9-19.5; FeO/MnO mean=65.6; V=400 ppm; Ca=0.61 afu), plagioclase (An83.4Or0.8; K = 0.008 afu); Oxygen isotopes: (I. Franchi, R. Greenwood, OU) δ17O = 3.58, δ18O = 6.84, Δ17O = 0.02 per mil.

Classification: Achondrite (lunar, feldspathic breccia).

Specimens: 9.5 g sample is on deposit at MSP.

 

Randy SaysÖ

Northwest Africa 6687 is described as a feldspathic breccia above. With 16% FeO, however, this meteorite is one of the least feldspathic of the brecciated lunar meteorites. Compositionally, itís a 2:1 mixture of mare basalt and KREEP impact-melt breccia. In that regard, itís most similar to the Apollo 12 soil and unlike any other lunar meteorite.

 

More Information

Meteoritical Bulletin Database

NWA 6687

References

 

Korotev R. L., Irving A. J., and Bunch T. E. (2012) Keeping Up With the Lunar Meteorites ó 2012 (abstract). In Lunar and Planetary Science XLIII, abstract no. 1152, 43rd 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: 22-November-2016