Northwest Africa 15483 (NWA 15483)

(Northwest Africa)

Purchased: 2022 Oct

Classification: Lunar meteorite (basaltic breccia)

History: Purchased by Ziyao Wang in October 2022 from a dealer in Agadir, Morocco.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Complex breccia composed of sparse lithic basalt clasts plus diverse mineral clasts of olivine, exsolved pigeonite, low-Ca pyroxene, unexsolved pigeonite (zoned to ferropigeonite), subcalcic augite, augite, fayalite, calcic plagioclase, anorthite and rare andesine in a fine grained matrix containing kamacite, ilmenite, troilite, merrillite, silica polymorph (as rounded and elongate blebs), zircon and baddeleyite. Lithic clasts have intergranular textures and consist predominantly of zoned clinopyroxene and anorthite with relatively low but varying amounts of accessory troilite and oxide phases. Elongate sinuous portions of the matrix are glassy and vesicular, and exhibit flow banding with enclosed relict mineral grains.

Geochemistry: Olivine (Fa_23.1-39.7, FeO/MnO = 83-101; Fa_62.0, FeO/MnO = 110; N = 7), low-Ca pyroxene (Fs_25.8Wo_4.7, FeO/MnO = 60), pigeonite (Fs_23.9-24.0Wo_11.7-15.7, FeO/MnO = 46-55, N = 2), ferropigeonite (Fs_57.6-60.0Wo_17.9-16.1, FeO/MnO = 58-72, N = 2), subcalcic augite (Fs_28.1-38.0Wo_30.4-27.5, FeO/MnO = 55-58, N = 2), augite (Fs_34.8Wo_39.8, FeO/MnO = 68), low-Ca pyroxene hosts (Fs_50.4-62.8Wo_3.2-6.1, FeO/MnO = 68-72, N = 3), subcalcic augite exsolution lamellae (Fs_28.9-38.0Wo_36.7-28.8, FeO/MnO = 68-76, N = 2), augite exsolution lamella (Fs_35.7Wo_40.6, FeO/MnO = 81), fayalite (Fa_87.5-92.7, FeO/MnO = 82-95, N = 2), calcic plagioclase (An_88.8Or_0.3), anorthite (An_95.3-97.7Or_0.1, N = 5), andesine (An_42.7Or_2.2).

Classification: Lunar basaltic breccia (regolithic).

Specimens: 15 g including a polished slice and a polished mount at UWB; remainder with WangZ.