Northwest Africa 8142 (NWA 8142)

(Northwest Africa)

Purchased: 2010

Classification: Ordinary chondrite (L5, melt breccia)

History: Three mostly crusted stones weighing 12 g were found and purchased in Agadir in 2009. Greg Catterton acquired the sample from a meteorite prospector in 2010.

Physical characteristics: Black shiny fusion crust covers 95% of the rounded ellipsoidal stones. Fusion crusted surfaces display contraction cracks.

Petrography: (A. Love, App): Sample is light greenish-gray and displays a brecciated macro-texture composed of clasts of very fine-grained (<20 μm), porphyritic-textured melt embaying areas and clasts of recrystallized chondritic rock. Melt is composed of ~19 μm zoned and unzoned, euhedral olivine grains with 205-305 μm melted and partially melted olivine phenocrysts and 0.2 - 1.3 mm rounded nodules of cellular-textured FeNi and FeS set within a silicate glass. Chondritic rock is composed of: ~400 μm angular clasts of metamorphosed chondritic material, 300 μm mineral grains and few relict chondrules (~605 μm) set within a recrystallized matrix of clastic debris.

Geochemistry: Chondritic lithology Fa_23.5±0.9 (N=7), Fs_19.9±0.6 (N=6), An_12.2±2.0 (N=5). Unmelted phenocrysts Fa_24.3±0.7 (N=5). Microporphyry Fa_11.7±5.1 (N=18)

Classification: L5 Impact melt rock

Specimens: 2.4 g and 2 polished thin sections are on deposit at App