Northwest Africa 3333 (NWA 3333)      

Morocco

Found: May 2005

Classification: Lunar basaltic fragmental breccia

History: Fabien Kuntz purchased a 33 g specimen from a Moroccan dealer. The original main mass was broken into at least 5 pieces and distributed to several dealers.

Physical characteristics: A partially weathered blackish-brown fusion crust was present on the specimen. Cut and polished surfaces on two different specimens reveal a coarsely brecciated texture, while a third specimen exhibits three different lithologies.

Petrography: (R. Zeigler, WUSL) The specimen examined consists of one basalt clast (1.5 cm) and one clast of cumulus olivine gabbro (1.2 cm) set in a fragmental breccia matrix. The basalt consists of phenocrysts composed of large zoned olivine and smaller chromite set in a fine-grained matrix of spinifex olivine, skeletal pyroxene, and glass. The gabbro (vol%) is 50% olivine, 35% pyroxene, and 15% plagioclase. A vein of black shock melt separates the cumulate clast from the fragmental breccia. The breccia is composed predominantly of pyroxene and olivine clasts, with minor plagioclase, and trace silica, Fe-Ti-Cr oxides, troilite, chromite, ilmenite, FeNi, apatite, and RE-merrillite.

Geochemistry: Mineral compositions and geochemistry: Matrix pyroxene and olivine is Fs_17–65Wo_12–29En_8-61 and Fa_40–95; plagioclase clasts are An_86–95Or_<2. Olivine in the basalt is zoned (Fo_47–72). Mineral compositions in the olivine cumulate are Fo₆₈, Fs₆₃Wo₁₅ and Fs₅₂Wo₃₂, and An₉₂Or_1. Fe/Mn = 85–110 (olivine) and 40–77 (pyroxene). Bulk composition: (R. Zeigler and R. Korotev, WUSL) The basalt (TiO₂ = 0.8%, FeO = 21%, MgO = 14%, Th = 1.4 µg/g) is compositionally similar to that of NWA 3160; the cumulate olivine gabbro (TiO₂ = 0.4%, FeO = 20%, MgO = 27%, Th = 1.2 µg/g) is similar to NWA 773 and 2977. All lithologies are characterized by low concentrations of Na₂O (= 0.15 ± 0.06%) and Eu (= 0.4 ± 0.2 ppm) compared to other lunar basalts. The oxygen isotope composition (I. A. Franchi, R. C. Greenwood, OU) is consistent with lunar origin (δ¹⁷O = 2.94, δ¹⁸O = 5.59, Δ¹⁷O = 0.032).

Classification: Achondrite (lunar basaltic fragmental breccia). The specimen is part of the NWA 773/2700/2727/2977/3160 pairing group.

Specimens: A mass of 6.55 g is on deposit at DuPont and 0.4 g (neutron irradiated) and one thin section at WUSL.