Lunar Meteorite: Northwest Africa 8182

Two slices of Northwest Africa 8182. Photo credit: Matt Morgan
A slice of NWA 8182 in hand. Photo credit: Matt Morgan
Two views of a lab sample of NWA 8182.  Thanks to Carl Agee for the sample. Photo credit: Randy Korotev

from The Meteoritical Bulletin, No. 103

Northwest Africa 8182 (NWA 8182)

(Northwest Africa)
Purchased: 2013
Mass: 15.6 g (1 piece)

Classification: Lunar meteorite (feldspathic breccia)

History: Purchased by Matt Morgan in 2013, reportedly found in Algeria.

Physical characteristics: Single stone, complete, dome shaped, remnants of brown-black fusion crust. Saw cut reveals a range of clast and fragmental feldspar sizes set in dark fine grained matrix, dark gray shock melt veins throughout.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows two main types of breccia: 1) cataclastic breccia with densely packed olivine, pyroxene and plagioclase fragments and abundant vesiculated shock melt veins, 2) feldspathic breccia with primarily fragmental plagioclase set in a very fine-grained matrix. Chromite, ilmenite, zircon, phosphate, silica, and sulfide observed.

Geochemistry: C. Agee and N. Muttik, UNM). Olivines are fairly uniformly Mg-rich, olivine Fa36.5±7.1, Fe/Mn=99±10, n=31. Some plagioclase has relatively high albite content, An93.4±2.2Ab6.2±1.9Or0.4±0.3, range An89.1-96.3, n=12. This specimen appears to have three distinct clinopyroxene populations, likely representing at least three lithologic types: 1) Mg-rich clinopyroxene, Fs32.8±12.3Wo18.6±8.0, Fe/Mn=57±9, n=17; 2) Fe-rich clinopyroxene, Fs51.0±7.9Wo24.3±6.7, Fe/Mn=72±5, n=15; 3) hedenbergite, Fs53.1Wo41.6, Fe/Mn=89 + Fs-rich pigeonite, Fs81.0Wo13.0, Fe/Mn=63.

Classification: Achondrite (lunar meteorite). Feldspathic breccia.

Specimens: A total of 3.5 g, including a probe mount, is on deposit at UNM. MtMorgan holds the main mass.

Randy Says…

Northwest Africa 8182 is a moderately mafic, KREEP-bearing feldspathic breccia. 

More Information

Meteoritical Bulletin Database

NWA 8182

References

Korotev R. L. and Irving A. J. (2015) Keeping up with the lunar meteorites – 2015. 46th Lunar and Planetary Science Conference, abstract no. 1942.

Korotev R. L. and Irving A. J. (2021) Lunar meteorites from northern Africa. Meteoritics & Planetary Science, 206–240. 

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