Lunar Meteorite: Northwest Africa 13974
|from The Meteoritical Bulletin, No. 110
Northwest Africa 13974 (NWA 13974)
Classification: Lunar meteorite (feldspathic breccia)
History: Multiple complete individuals ranging in size from 1 – 800 g were found in the Western Sahara. Adam Aaronson purchased the samples in Temara in 2021.
Physical characteristics: Exterior of the 20% of the samples is light orangish-gray in color and shows voids, some of which are circular in profile. The cut face shows the interior is darker grey and shows a brecciated texture. Other samples found on the surface are reported to have a shiny black wind-ablated exterior.
Petrography: Description and classification (A. Love, App) Sample is a complex breccia composed of rounded to irregular-shaped, mm-sized lithic and anhedral mineral clasts surrounded by a melt matrix. Lithic clasts include: anorthosite, norite, troctolite, brecciated and shock melted clasts. Mineral clasts are dominantly anorthite with minor zoned olivine. Matrix areas within the thin section show some regions with flow-textured glass and fine vesicles. Additional minerals are: <1vol% FeNi grains, chromite, ilmenite, sulfide, secondary barite and calcite.
Geochemistry: (A. Love, App) Olivine (Fa29.1±6.8, Fe/Mn=66-92, n=29); low Ca pyroxene (Fs21.3±3.2Wo4.4±0.5, Fe/Mn=49-55, n=7); pigeonite (Fs24.4±4.0Wo9.0±3.9, Fe/Mn=48-59, n=13); high Ca Pyroxene (Fs11.7±2.1Wo38.6±6.3, Fe/Mn=40-47, n=4); plagioclase (An97.2±0.7Or0.1±0.1, n=18).
Classification: lunar (feldspathic melt breccia A-S3, low weathering). Textures and mineral compositions (Fe/Mn ratios for Olivine and pyroxene and An content of plagioclase) indicate sample is a melt breccia of lunar origin.
Specimens: Aaronson holds 7889 g comprising the 800 g main mass and additional samples. David Sherman holds 684 g and J. Sinclair holds an additional 166 g. A 40 g specimen is held at the Moroccan ministry of Mines and Environment in Rabat. A 20.2 g type specimen, a polished mount and thin section are on deposit at App.
I have not studied NWA 13974.
Meteoritical Bulletin Database