Martian meteorite (basaltic shergottite)

A 63g complete and partially crusted stone found near Lakhbi, Algeria was purchased from a Moroccan dealer in 2003 September . The ellipsoidal stone has an average width of 30 mm, with a 1 to 3 mm thick weathering rind; Classification and mineralogy

(J. Wittke and T. Bunch, NAU; A. Irving and S. Kuehner, UWS): olivine-orthopyroxene-phyric basaltic rock. Subhedral to euhedral, dark brown olivine phenocrysts (up to 2.2 mm long)

are strongly zoned from cores of Fa15.7 to rims of Fa47.9, and subhedral to euhedral, prismatic orthopyroxene phenocrysts (up to 2.1 mm long) have cores as magnesian as Fs17.7Wo2.5, surrounded

by irregularly zoned mantles with both pigeonite and augite, and pigeonite rims as ferroan as Fs39.0Wo12.5. The groundmass consists mainly of zoned pigeonite (Fs30Wo6.5 to Fs40Wo13) intergrown

with maskelynite (zoned from cores of Ab25.5Or0.1 to rims of Ab36.5Or1.1) and small grains of relatively ferroan olivine (Fa47.6-58.1). Accessory minerals include Ti-chromite (Al/(Al+Cr)

= 13.8-28.3), chromite, ilmenite, Cr-ulvöspinel, pyrrhotite (commonly in parallel growth with ilmenite), merrillite, rare chlorapatite, and rare fayalite (which occurs as a reaction rim on

groundmass pigeonite in contact with ilmenite or pyrrhotite). Trapped melt inclusions in olivine contain aluminous diopside, amphibole(?), pleonaste, chromite, merrillite and glass. Large,

prismatic orthopyroxene phenocrysts exhibit preferred orientation; olivine phenocrysts are weakly oriented and tend to occur in clusters. Textures and mineral compositions are similar to those

in olivine-orthopyroxene-phyric shergottite NWA 1195, but the olivine cores in NWA 2046 are more magnesian (Irving et al., 2004). Specimens: type specimen, 12.2 g, and one polished thin

section, NAU;

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