Northwest Africa 8701 (NWA 8701)
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 (Fs27.0Wo2.6; FeO/MnO = 70, N = 1), ferroan pigeonite (Fs53.0Wo16.8, FeO/MnO = 65, N = 1), pigeonite (core Fs26.5Wo19.8; FeO/MnO = 54; rim Fs71.6Wo25.2; FeO/MnO = 85), augite (Fs23.4Wo41.0, FeO/MnO = 58, N = 1), olivine (Fa30.4, FeO/MnO = 92; Fa11.3, FeO/MnO = 117, N = 2), plagioclase (An96.1-96.5Or0.1-0.5, 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.
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.
Meteoritical Bulletin Database
Korotev R. L. and Irving A. J. (2021) Lunar meteorites from northern Africa. Meteoritics & Planetary Science, 206–240.