Northwest Africa 2061

Morocco

Found 2003

Achondrite (eucrite)

A 135 g very fresh and fully crusted complete stone was purchased in Erfoud, July 2003. Classification and mineralogy (T. Bunch and J. Wittke, NAU): unbrecciated, porphyritic basalt with long (up to 9 mm) phenocrysts of low-Ca pyroxenes set in a matrix of smaller pyroxenes and blocky to acicular plagioclase. Clots (3 to 8 mm in dia.) of low-Ca pyroxene phenocrysts set in radiating bundles of plagioclase (variolitic texture) are distributed throughout the specimen. Main mass, low-Ca pyroxene phenocrysts are zoned from cores of Fs_29.8Wo_4.9 to pigeonite rims of Fs₄₉Wo₁₂; Fe/Mn = 29.8 and 37.2, respectively. Small inclusions of metal (Ni =0.05 to 0.25 wt %) are sparsely distributed. Blocky to acicular plagioclase is An_83.7Or₂ with a small compositional range. All plagioclase, regardless of size and morphology, contains FeO up to 0.97 wt. %. Clot pyroxene cores are Fs_42.9Wo₂₈ (Fe/Mn = 35.6) and rims are Fs_49.2Wo_25.1 (Fe/Mn = 36.1). Very fresh with no apparent weathering; shock level, low shock. Specimens: type sample, 21.7 g, NAU; main mass, Boswell.