Lunar Meteorite: Northwest Africa 8701

from The Meteoritical Bulletin, No. 103

Northwest Africa 8701 (NWA 8701)

Mali
Purchased: 2014 September
Mass: 72 g (1 piece)

Lunar meteorite (feldspathic breccia)

History: Purchased by Stefan Ralew in September 2014 in Erfoud, Morocco.

Physical characteristics: Single stone (72 g) lacking fusion crust and composed of angular, mostly whitish clasts in a very dark gray matrix with some crosscutting veins of vesicularglass.

Petrography: (A. Irving and S. Kuehner, UWS) Fragmental olivine-poor breccia composed of mineral clasts in a finer matrix. Minerals include anorthite, pigeonite, orthopyroxene, augite, ilmenite and merrillite, along with rare olivine, Cr-armalcolite and kamacite.

Geochemistry: Orthopyroxene (Fs_27.0Wo_2.6; FeO/MnO = 70, N = 1), ferroan pigeonite (Fs_53.0Wo_16.8, FeO/MnO = 65, N = 1), pigeonite (core Fs_26.5Wo_19.8; FeO/MnO = 54; rim Fs_71.6Wo_25.2; FeO/MnO = 85), augite (Fs_23.4Wo_41.0, FeO/MnO = 58, N = 1), olivine (Fa_30.4, FeO/MnO = 92; Fa_11.3, FeO/MnO = 117, N = 2), plagioclase (An_96.1-96.5Or_0.1-0.5, N = 2).

Bulk composition: (R. Korotev, WUSL) INAA of subsamples gave the following mean abundances (in wt.%) FeO 5.2, Na₂O 0.44; (in ppm) Sc 11.8, La 6.0, Sm 2.5, Eu 0.85, Yb 2.3, Lu 0.32, Th 1.7.

Classification: Lunar (feldspathic fragmental breccia). This specimen contains much less olivine than most lunar feldspathic breccias, but some of the olivine that is present is very magnesian.

Specimens: 14.4 g including one polished endcut at UWB; main mass with Ralew.

Randy Says…

Northwest Africa 8701 is a KREEP-bearing feldspathic lunar meteorite. The B sample (above), which appears glassier,  is more mafic and has 3x greater concentrations of KREEP elements than A and C.  Unnamed 64 is intermediate; it does not have a name because it was not classified (no type specimen).

More Information

Meteoritical Bulletin Database

NWA 8701

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.