Lunar Meteorite: Northwest Africa 16366
| from The Meteoritical Bulletin, No. 112 Northwest Africa 16366 (NWA 16366)(Northwestern Africa) Lunar meteorite (anorthosite) History: Reportedly found in August 2023 in Western Sahara. Petrography: (K. Metzler, IfP): Light-colored mafic rock, dominated by plagioclase, with small amounts of pyroxene and olivine. It shows solid-state recrystallisation and some internal brecciation on the sub-mm scale. Point counting on the investigated thin section revealed ~83 vol% plagioclase, ~14 vol% pyroxene and ~3 vol% olivine. Pyroxene grains show exsolution lamellae on the submicron scale. Plagioclase has been partly transformed to maskelynite. Glassy shock melt veins and melt pockets occur. Accessories are Cr-spinel, Ilmenite, and troilite. Geochemistry: Mineral compositions and geochemistry: Mean olivine composition: Fa39.6±0.8 (Fa37.9-40.5); mean Fe/Mn (at.): 110; n=14. Mean pyroxene composition: Fs29.3±1.6Wo13.8±2.9 (Fs27.0-32.0Wo10.1-18.4); mean Fe/Mn (at.): 59; n=14. Plagioclase An96.6±0.7Or0.1±0.1 (An95.4-97.9Or0.0-0.3); n=18. Classification: Lunar rock, based on high Fe/Mn values in olivine and pyroxene, and high An values in plagioclase. Gabbroic anorthosite due to modal amounts of plagioclase, pyroxene, and olivine. Specimens: 20 g at IfP. Main mass with Aliyen Faidalah. |
| Randy Says… I have not studied Northwest Africa 16366. On the basis of the stated modal mineral abundance, the rock is not “mafic” and not a gabbro; it is a noritic or gabbroic anorthosite according to the recommended classification system of Stöffler et al (1980). |
More InformationMeteoritical Bulletin Database NWA 16366 |