Abstract
The Lafayette meteorite is a calcium-rich achondrite composed predominantly of cumulus clinopyroxene (Wo 39En 39Fs 22) with minor iron-rich olivine (Fa 66) and rare interstitial feldspar (Or 4Ab 62An 34-Or 22Ab 65An 13). The opaque oxide minerals are magnetite-ilmenite intergrowths, an apparently homogenous Cr-rich (Cr 2O 3 ∼ 7 wt.%) titaniferous magnetite, and discrete ilmenite. Pyrite, the major sulfide mineral, occasionally displays lamellar intergrowths of marcasite that appear to be of primary origin. Troilite occurs as inclusions in ilmenite or interstitial to the silicate minerals. Bulk chemical composition of the glass in the fusion crust is comparable with that of the Nakhla meteorite. The glass contains abundant skeletal crystals of magnetite, as well as very rare, zoned magnetite grains with rims enriched in Mg and depleted in Ti relative to the cores. Although no brecciation is visible in the Lafayette meteorite, the presence of deformed twin lamellae in the clinopyroxene indicates some deformation has occurred.
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