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Lunar Meteorite

Northwest Africa 6578

Morocco

 

Northwest Africa 6578. Click on image for enlargement.
(photo credit: Ted Bunch)

 

NWA 6578 sawn face. Click on image for enlargement.
(photo credit: Ted Bunch)

 

NWA 6578 in the lab
(photo credit: Randy Korotev)

 

from The Meteoritical Bulletin, No. 99

Northwest Africa 6578

Morocco
Find: 2010
Mass: 1638 g

Lunar meteorite (feldspathic breccia)

History: A tan to gray 1638 g stone was purchased in Morocco by Adam Aaronson in 2010.

Physical characteristics: Surface is deeply etched in some places from desert wind abrasion, and the gray colored areas show remnant, translucent fusion crust.

Petrography: (T. Bunch and J. Wittke, NAU; A. Irving and S. Kuehner, UWS): A fine-grained (<0.5 mm, mean grain size = 0.125 mm) partially annealed ultracataclastite (crushed matrix occupies > 90 vol%). The rock is an anorthosite based on the mineral modes of (vol%): anorthite 90, pigeonite 6, olivine 2, metal and FeS2. Numerous fine-grained (<0.02 mm) micrographic-textured patches contain pigeonite + olivine + plagioclase ± FeS and are roughly flow-oriented. In addition, glassy shock melt veins are sub parallel to the apparent flow direction. A few elongated clusters of vermiform taenite (<0.05 mm) are interspersed with micrographic intergrowths.

Geochemistry: Plagioclase, An94-96.3; pigeonite, Fs27.7-33.4Wo12.4-14, (FeO/MnO = 73-98); olivine, Fa21.7-44 (FeO/MnO = 78-90); taenite Ni = 9.8-16.7 wt. %. Shock melt glass (avg. of 3 in wt%) is SiO2 = 45.2, Al2O3 = 28.8, CaO = 18.9, FeO = 3.86, MgO = 2.12, Na2O = 0.4, TiO2 = 0.47, MnO = 0.18.

Classification: Achondrite (lunar, granulitic anorthositic breccia). This meteorite is one of the most feldspar-rich lunar specimens (rivaling some Apollo samples), but is texturally unique.

Specimens: A total of 20.2 g is on deposit at NAU. Mr. Adam Aaronson holds the main mass.

 

Randy Says…

Northwest Africa 6578 Is a highly feldspathic granulitic breccia.

 

More Information

Meteoritical Bulletin Database

NWA 6578

References

 

Korotev R. L., Irving A. J., and Bunch T. E. (2012) Keeping Up With the Lunar Meteorites — 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: 14-Oct-2015