Northwest Africa 14657 (NWA 14657)

(Northwest Africa)

Purchased: 2021

Classification: Lunar meteorite (feldspathic breccia)

History: Purchased by Edwin Thompson in early 2021 from a meteorite dealer in Adrar, Algeria. Subsequently acquired in May 2021 by Cascadia as part of a trade.

Physical characteristics: Single stone with nearly absent fusion crust.

Petrography: (D. Sheikh, H. Babst, Cascadia) Sample displays a brecciated texture composed of lithic clasts (most mm-sized, up to ~1 cm), mineral clasts, and isolated mineral fragments set within a fine-grained matrix containing glassy melt pockets and fractures. Various anorthositic clast lithologies (ferroan anorthosite, magnesian-suite anorthosite, and hyper-ferroan, as found in ALHA 81005, Dhofar 302, Dhofar 081, and NEA 001 by Gross et al. (2014) were identified in this sample. Accessory phases include ilmenite, apatite, silica, troilite, ülvospinel (some Cr-bearing), and Fe-Ni metal. Some plagioclase grains have been transformed into maskelynite.

Geochemistry: Olivine (Fa_34.1±8.1, range Fa_19.9-40.4, Fe/Mn=87±6, n=26), Low-Ca Pyroxene (Fs_24.3±6.0Wo_3.2±1.1, range Fs_16.6-29.8Wo_0.3-4.5, Fe/Mn=51±4, n=12), Pigeonite (Fs_40.3±11.8Wo_13.5±5.7, range Fs_22.2-58.4Wo_5.6-23.4, Fe/Mn=55±5, n=17), Augite (Fs_22.4±8.0Wo_35.2±5.7, range Fs_11.4-36.0Wo_27.2-44.8, Fe/Mn=51±8, n=7), Calcic Plagioclase (An_96.5±0.7, range An_94.9-97.7, n=45); Ferroan anorthosite clasts (Mg#=64.2±2.1, An_96.7±0.3, n=3), Magnesian-suite anorthosite clast (Mg#=80.8, An_95.9, n=1), Hyper-ferroan clasts (Mg#=37.4±5.8, An_96.8±0.7, n=2).

Classification: Lunar (feldspathic fragmental breccia)

Specimens: Cascadia holds 149.8 g (main mass) in two pieces, in addition to 1 polished thin section; 11.6 g at UAb.