Lunar Meteorite: Northwest Africa 14992

from The Meteoritical Bulletin, No. 111

Northwest Africa 14992 (NWA 14992)

(Northwestern Africa)
Purchased: 2022
Mass: 158 g (1 piece)

Lunar meteorite (basalt)

History: Reportedly found in 2021 and purchased by Ziyao Wang in 2022 from a meteorite dealer in Mauritania.

Physical Characteristics: Single stone with irregular brown exterior surface, no fusion crust present. Fresh broken surface shows a fine-grained mix of gray and light brown grains, with abundant shiny fine grained maskelynite, and some small dark shock melt veins. Unbrecciated.

Petrography: (C. Agee, UNM) Backscatter electron and reflected light microscope images show igneous-zoned olivines and pyroxenes. The modal abundance ratio of olivine to pyroxene is approximately 1:3. Maskelynite makes up approximately 25% of the modal mineralogy. Minor phases include Ti-Cr spinel, Ti-magnetite, ilmenite, troilite, taenite, and kamacite. A prominent shock melt vein was present in the deposit sample microprobe mount.

Geochemistry: (A. Ross and C. Agee, UNM) Olivine Fa_53.7±10.1, Fe/Mn=103±10, n=10; clinopyroxene Fs_40.2±12.4Wo_23.7±7.1, Fe/Mn=64±8, n=20; maskelynite An_88.0±2.1Ab_11.5±1.9, n=7. Quench melt SiO₂=44.0±0.6, TiO₂=2.0±0.1, Cr₂O₃=0.48±0.04, Al₂O₃=10.5±1.8, MgO=8.0±0.7, FeO=20.8±1.3, MnO=0.24±0.03, CaO=10.6±0.4, Na₂O=0.45±0.05, (all wt%, 30 micron defocused beam), n=4. Clinopyroxene shows Fe-enrichment trends that are continuous from Mg-augite and Mg-pigeonite to subcalcic-ferroaugite/ferropigeonite.

Classification: Lunar (mare basalt). Based on the TiO₂ content of quench melt this is meteorite is a low-Ti mare basalt (Giguere et al. 2000).

Specimens: 21 g including a probe mount on deposit at UNM, WangZ holds the main mass.

Randy Says…

I have not studied NWA 14992.

Li and Jiang (2023): “The preliminary [petrographic] results show that NWA 14526 and NWA 14992 probably belong to a pair of low-titanium mare basalts, and they are closely related to NWA 10597.” NWA 10597 is a pair to NWA 4734. I doubt that NWA 14992 is paired or launch paired with NWA 032/10597, which have distinct fusion crusts (as do their launch pairs, the LAP 02205 clan), while NWA 14992 does not have a fusion crust.

More Information

Meteoritical Bulletin Database

NWA 14992

References

Giguere T. A., Taylor G. J., Hawke B. R., abd Lucey P. G. (2000) The titanium contents of lunar mare basalts. Meteoritics & Planetary Science, 35, 193-200.

Li P. and Jiang Y. (2023) Mineral chemistry of two new mare basalts Northwest Africa (NWA) 14526 and NWA 14992. 86th Annual Meeting of the Meteoritical Society, abstract no. 6249.