Northwest Africa 11000 (NWA 11000)

Morocco

Purchased: 2015 April

Classification: Ordinary chondrite (H4)

History: Specimen was purchased in April 2015 in Morocco by S. Tutorow, who holds the main mass.

Physical characteristics: The type specimen is brown in color with an uneven surface and no evident fusion crust. Observation of the slab show a high abundance of metal grains, with the largest grain measuring ~1 cm in length. An igneous clast is present in the thin section.

Petrography: (E. Ferguson, UWO) The largest chondrule size is ~2 mm in diameter, and smallest chondrule size <0.1 mm ranging from well delineated rounded and sub-rounded chondrules to irregular or sub-angular in shape. Porphyritic olivine pyroxene (POP) chondrules dominate. Radial pyroxenes and small (<0.5mm) barred olivine (BO) chondrules were also found. Chondrules vary in size from <0.1mm to ~0.5mm. The specimen contains abundant metal grains with a modal abundance of ~10 vol%. Iron-nickel oxides are abundant and make up a network of irregularly shaped grains. Fe-Ni oxidation is evident around the edges of these grains and throughout the sample, however there is little evidence of silicate weathering. Secondary feldspar grains are <20 μm in size.

Geochemistry: (EMPA) Olivine Fa_18.6±0.9 (n=10), low-Ca pyroxene Fs_14.0±4.1Wo_0.8±0.4 (n=10), high-Ca pyroxene Fs_8.4±1.8Wo_34.0±5.1 (n=5).

Specimens: 33.0 g type specimen, including polished mount and thin section at UWO. The remaining mass is with S. Tutorow.