Abar al’ Uj 012 (AaU 012)
Ash Sharqiyah, Saudi Arabia
Lunar meteorite (feldspathic breccia)
History: Found by Edwin Gnos, Beda Hofmann, Khalid al Wagdani, Ayman Majoub, Abdulaziz Solami, Siddiq Habibullah, Maruan Al Bokari during a search for meteorites on January 31, 2012.
Physical characteristics: Medium gray stone with a total mass of 122.78 g. The wind-ablated meteorite consists of two fitting fragments, with masses of 104.5 and 18.27 g, respectively. Fusion crust is absent. Contains black, white and red mineral and lithic clasts (up to 6 mm) embedded in a very fine-grained matrix. Vesicles are abundant. Some vesicles and thin cracks are filled with terrestrial mineral assemblages.
Petrography: (B. Hofmann NMBE; M. Mészáros NMBE/Bern) Clast-rich impact-melt breccia, consisting of partly resorbed mineral clasts (up to 1 mm) and subrounded/rounded lithic clasts (up to 6.8 mm) set in a very fine-grained, well-crystallized impact-melt matrix. Most common mineral clasts are plagioclase with minor pyroxene and olivine. The lithic clast population is dominated by anorthositic breccias. Rare clasts of igneous rocks and a single basalt clast were observed. Vesicles (up to 3.0 mm diameter) are abundant. Shock features (polycrystalline grains, mosaicism, recrystallization) were observed in pyroxenes, olivine and plagioclase. Trace mineral phases are troilite, FeNi-metal, spinel (pleonast), SiO2 and terrestrial alteration products (carbonates, celestine, Fe-hydroxides).
Geochemistry: (N. Greber, M. Mészáros, Bern) Mineral composition: feldspar (n=46): An93.4-97.7 Or0.0-1.6; olivine (n=7): Fa28.4-35.3, Fe/Mn=95.7; orthopyroxene (n=1): Wo3.6 Fs25.2, Fe/Mn=52.8; clinopyroxene (n=10): Wo5.1-40.6 Fs12.8-36.9, Fe/Mn=89.9. Bulk analysis (ICP/ICPMS): Al2O3=28.9 wt%, FeO=5.0 wt%, Sc=8 ppm, Sm=1.2 ppm, Th=0.5 ppm. Oxygen isotopes: (R. Greenwood, OU): ?18O=5.46 permil, ?17O=2.86 permil ?17O=0.018 permil.
Classification: Lunar feldspathic impact-melt breccia.
Specimens: Type material (25.1 g) and 3 polished thin sections at MHNGE, main mass at SGS.
AaU 012 is a typical feldspathic lunar meteorite, but one that is not compositionally identical to any of the many others.
Meteoritical Bulletin Database
Mészáros M., Hofmann B. A., Korotev R. L., Gnos E., Greber N., and Greenwood R. C. (2014) Petrology and geochemistry of lunar meteorite Abar al’ Uj 012. 77th Annual Meeting of the Meteoritical Society, abstract no. 5008.
Mészáros M., Hofmann B. A., Lanari P., Korotev R. L., Gnos E., Greber N. D., Leya I., Greenwood R. C., Jull A. J. T., Al-Wagdani K., Mahjoub A., Al-Solami A. A., and Habibullah S. N. (2016) Petrology and geochemistry of feldspathic impact-melt breccia Abar al’ Uj 012, the first lunar meteorite from Saudi Arabia. Meteoritics & Planetary Science 51, 1830-1848.
Mészáros M., Leya I., and Hofmann B. A. (2016) Noble gases in the two lunar meteorites AaU 012 and Shişr 166. 79th Annual Meeting of the Meteoritical Society, abstract no. 6129.
Mészáros M., Leya I., and Hofmann B. A. (2017) Cosmic-ray exposure histories of the lunar meteorites AaU 012 and Shişr 166. Meteoritics & Planetary Science 82, 2040–2050.