Northwest Africa 11281 (NWA 11281)

Morocco

Purchased: 2007

Classification: Ordinary chondrite (L6, melt breccia)

History: The meteorite was purchased in 2007 from a meteorite dealer in Erfoud, Morocco

Physical characteristics: The main mass has no visible fusion crust and red-brown staining across its surface.

Petrography: (C. Herd, UAb) Cut surfaces reveal a light-gray interior with red-brown staining along fractures. About 2/3 of the thin section investigated is matrix, consisting of very fine-grained (10-50 μm) euhedral olivine and pyroxene crystals with interstitial plagioclase and disseminated sulfide grains. Clasts within this material are 200-1000 μm across and consist of microcrystalline pyroxene and olivine; similar sulfide and Fe-Ni metal clasts are also present. The remaining ~1/3 of the thin section consists of relict chondrules set in a dark, very fine-grained matrix rich in sulfide blebs. Chondrules are poorly delineated (indicative of petrologic type 6), although textures (such as BO) are preserved. Shock effects include strong mosaicism and recrystallization. Most Fe-Ni metal appears to have been replaced by terrestrial oxidation. No ringwoodite is evident, although the presence of wadsleyite cannot be ruled out.

Geochemistry: Geochem: (C. Herd, UAb) Olivine and pyroxene compositions in matrix and relict chondrules are indistinguishable from one another, within uncertainties. Olivine Fa_24.3±1.1 (n=29); Low-Ca Pyroxene Fs_19.8±1.4Wo_2.1±0.9 (n=17).

Classification: L-melt breccia

Specimens: Type specimen of 22.5 g, including one thin section, is at UAb. Main mass at JTESM.