Northwest Africa 11077 (NWA 11077)
Lunar meteorite (feldspathic breccia)
History: Purportedly found near Adrar, Algeria in October 2016, and purchased by Darryl Pitt in November 2016 from a dealer in Mauritania.
Physical characteristics: A single medium gray stone (1139.7 g) lacking fusion crust but exhibiting a shiny desert patina on exterior surfaces. Very sparse, small whitish clasts are visible within a dominant very fine grained, vesicular matrix.
Petrography: (A. Irving and S. Kuehner, UWS) Extremely fine-grained breccia consisting mainly of very tiny mineral grains plus devitrified glass (some with swirly texture visible in thin section) plus sparse lithic clasts, which are themselves melt rocks with intersertal texture and sparse relict clasts. Minerals large enough to be quantitatively analyzed are anorthite, olivine and subcalcic augite; accessory minerals include kamacite, troilite and minor barite.
Geochemistry: Olivine (Fa15.9-39.7, FeO/MnO = 73-77, N = 4), subcalcic augite (Fs20.1Wo34.1, FeO/MnO = 40), plagioclase (An96.1-96.8Or0.3-0.1, N = 2).
Bulk composition: (R. Korotev, WUSL) INAA of subsamples gave the following mean abundances (in wt.%) FeO 3.7, Na2O 0.40; (in ppm) Sc 7.4, Ni 160, La 3.1, Sm 1.45, Eu 0.80, Yb 1.1, Lu 0.15, Hf 1.1, Th 0.41. Magnetic susceptibility log χ (× 10-9 m3/kg) = 2.38.
Classification: Lunar (feldspathic vitric regolith breccia).
Specimens:20.4 g including one polished thin section at UWB; remainder with DPitt.
Compositionally, Northwest Africa 11077 is a typical feldspathic lunar meteorite. It is is compositionally indistinguishable from the NWA 10141 clan, but the textures are very different. This one is very fined grained.
Meteoritical Bulletin Database
Korotev R. L. and Irving A. J. (2021) Lunar meteorites from northern Africa. Meteoritics & Planetary Science, 206–240.