Northwest Africa 3160

Morocco

Find: July 2005

Achondrite (lunar, mare basalt breccia)

History: In July 2005, A. and G. Hupé purchased three broken stones with a total weight of 34 g from a Moroccan dealer in Erfoud, Morocco.

Physical Characteristics: The largest stone (28 g) has a partial thin weathered fusion crust.

Petrography: (R. Zeigler and R. Korotev, WUSL; A. Irving and S. Kuehner, UWS) The large specimen consists almost entirely of a fine-grained, olivine-phyric basalt clast with minor attached breccia matrix and appears to be part of a larger, coarse-grained, polygenic breccia. The two small stones are pieces of the breccia. The basalt contains phenocrysts of euhedral to subhedral olivine (~0.1–0.9 mm) and minor chromite (<0.1 mm).

Geochemistry: Olivine phenocrysts are zoned, with cores typically Fo_55–70 and rims extending to ~Fo₄₀ with FeO/MnO ratios of 91–105. The groundmass has spinifex olivine (Fo₂₉) and skeletal pyroxene (En_37–39Wo_11–13; FeO/MnO = 71–75) set in a fine-grained matrix of pyroxene (En_35–39Wo_20–23), olivine (~Fo₂₂), and glass. The breccia lithology is a fragmental breccia consisting primarily of olivine (Fo_6–82) and pyroxene (En_1–68Wo_9–39Fs_16–83), with minor amounts of plagioclase (An_82–97) and trace silica; hedenbergite-fayalite-silica symplectite (after former pyroxferroite), and Fe-Ti-Cr oxides.

Classification: Achondrite (lunar, mare basalt breccia). Note: These samples may be paired with NWA 2727.

Specimens: A 4.8 g type specimen and one polished thin section are on deposit at UWS. A 2.1 g specimen is on deposit at WUSL. AHupé holds the main mass.