Lunar Meteorite: Northwest Africa 10404
|from The Meteoritical Bulletin, No. 104 |
Northwest Africa 10404 (NWA 10404)
Classification: Lunar meteorite (feldspathic breccia)
History: Purchased by Darryl Pitt in May 2015 from a dealer in Ouarzazate, Morocco.
Physical characteristics: A single stone (229 g) lacking fusion crust. Interior slices exhibit angular mineral clasts plus rounded colorless, brownish and greenish glassy objects in gray, partly vesicular matrix
Petrography: (A. Irving and S. Kuehner, UWS) Vitric fragmental breccia composed of angular to rounded lithic clasts plus mineral clasts of anorthite, olivine, pigeonite, orthopyroxene, subcalcic augite, augite and rare Ti-chromite, troilite and taenite in a partly vitreous matrix. Some lithic clasts are fine grained, plagioclase-phyric crystalline lithologies, but many consist of partly-devitifried glass with bulk compositions intermediate between those of anorthite, olivine and low-Ca pyroxene. The latter consist of isotropic cores (colorless to pale brown in thin section) mantled by aggregates rich in polycrystalline, spherulitic birefringent crystallites within zones parallel to clast margins and constituting ~50% of clast volumes.
Geochemistry: Olivine (Fa26.4; Fa47.2, FeO/MnO = 77-84, N = 2), orthopyroxene (Fs37.6Wo3.2, FeO/MnO = 64), pigeonite (Fs21.1-25.9Wo15.5-11.3, FeO/MnO = 59-60, N = 2), subcalcic augite (Fs21.9Wo32.2, FeO/MnO = 51), augite (Fs20.0Wo37.9, FeO/MnO = 46), plagioclase (An96.1-97.0Or0.0, N = 3).
Bulk composition: (R. Korotev, WUSL) INAA of subsamples gave the following mean abundances (in wt.%) FeO 3.8, Na2O 0.36; (in ppm) Sc 6.8, La 4.2, Sm 2.0, Eu 0.83, Yb 1.5, Lu 0.21, Th 0.74.
Classification: Lunar (feldspathic vitric regolithic breccia).
Specimens: 20.61 g including one polished thin section at UWB; main mass with DPitt.
Compositionally, Northwest Africa 10404 is a KREEP-bearing feldspathic lunar meteorite. It’s unusually glassy and vesicular.
Meteoritical Bulletin Database
Hahn T. Jr., Jin Z., Wittmann A., Bose M., and Irving A. (2020) Volatiles in magnesian glasses occurring in lunar feldspathic breccia Northwest Africa 10404. 51st Lunar and Planetary Science Conference, abstract no. 2627.
Korotev R. L. and Irving A. J. (2016) Not quite keeping up with the lunar meteorites – 2016. 47th Lunar and Planetary Science Conference, abstract no. 1358.
Korotev R. L. and Irving A. J. (2021) Lunar meteorites from northern Africa. Meteoritics & Planetary Science, 206–240.
Kuehner S. M., Wittmann A., Korotev R. L., Carpenter P., Macke R. J., Britt D. T., Irving A. J., and Pitt D. (2016) Petrologic, chemical and physical characterization of unique lunar vitric regolith breccia Northwest Africa 10404. 47th Lunar and Planetary Science Conference, abstract no. 2246.
Will P., Maden C., and Busemann H. (2016) Noble gases in recently found hot and cold desert lunar meteorites. 79th Annual Meeting of the Meteoritical Society, abstract no. 6548.
Will P., Busemann H., Riebe M. E. I., and Maden C. (2019) Regolith history of six lunar regolith breccias derived from noble gas elemental and isotopic abundances. 82nd Annual Meeting of the Meteoritical Society, abstract no. 6494.
Wittmann A., Korotev R. L., Kuehner S. M., and Irving A. J. (2016) The origin and processing of magnesian glass in lunar meteorite Northwest Africa 10404. 79th Annual Meeting of the Meteoritical Society, abstract no. 6025.