Northwest Africa 7032 (NWA 7032)

Morocco

Found: Oct 2011

Classification: Martian meteorite (Shergottite)

History: A small stone was found in October 2011 in southern Morocco and purchased from a Moroccan dealer in Zagora in November 2011 by Luc Labenne.

Physical characteristics: A single very fresh, irregular ellipsoidal stone (85 g) coated by black fusion crust and naturally broken on one side revealing the interior. The specimen resembles a terrestrial microgabbro, and consists of larger black, yellow-green and clear, limpid grains along with small opaque grains.

Petrography: (A. Irving and S. Kuehner, UWS): Medium grained (to 0.9 mm) igneous assemblage of olivine (~40 vol.%), two types of clinopyroxene (~35 vol.%) and maskelynite (~20 vol.%), plus accessory chromite (with variable Ti contents), ilmenite, pyrrhotite and rare Mg-merrillite. Shocked plagioclase has been completely converted to maskelynite. All of the constituent minerals exhibit very limited compositional variation.

Geochemistry: Olivine (Fa_45.7-46.1, Fe/Mn=49-51), pigeonite (Fs_26.6Wo_15.7, Fe/Mn=30), subcalcic augite (Fs_23.7Wo_25.3, Fe/Mn=28), plagioclase (An_55.2-58.5Or_1.7-1.5). Oxygen isotopes (R. Tanaka, OkaU): analyses of acid-washed subsamples by laser fluorination gave, respectively δ¹⁷O = 2.681, 2.577; δ¹⁸O = 4.599, 4.423; Δ¹⁷O = 0.259, 0.248 per mil.

Classification: Achondrite (Martian, shergottite). This specimen is unlike most other shergottites in being coarser grained (microgabbroic), and in containing minerals with a high degree of compositional homogeneity.

Specimens: A total of 17.0 g of type material, one polished thin section and a polished mount are on deposit at UWS. The remaining material is held by Labenne.