Northwest Africa 2085

Morocco

Found 2003 October

Ordinary chondrite (L melt rock)

A 2.7 kg single stone was purchased in Rissani, Morocco. Description and classification (T. Bunch and J. Wittke, NAU): exceptional melt rock: centimeters-size L chondrite clasts are surrounded by crystallized melt. The melt contains oblate to round, eutectic-textured, masses (up to 2.5 mm) of taenite metal set in troilite. The metal/troilite complexes show strong flow alignment in a matrix of tabular to equant olivine (< 0.8 mm), which has no apparent preferred orientation, and SiO₂-rich glass, in addition to small, recrystallized chondrite fragments. Melt olivine, Fa_{22.8 (22.1 – 23.8)}; taenite, Ni = 15.4 wt%, range, 13.6 – 16.1 wt%; troilite, Ni = 0.42 wt%; glass, SiO₂ = 74.6 wt%, FeO = 3.6 wt%. Clast chondrules and matrix are partially recrystallized from shock effects; olivine, Fa_{22.2 – 23.9}; orthopyroxene, Fs_18–19.9Wo_1.4-2.0. Shock level, S4 to S6; weathering grade, W1/2. Specimens: type specimen 88.5 g, and one thin section, NAU; main mass, MFarmer.