Northwest Africa 11106 (NWA 11106)

Morocco

Purchased: February 2016

Classification: Iron meteorite (IAB-MG)

History: According to the seller, a single large specimen were found in a place called Souhada, close to Lmahbes (El Mahbes).

Physical characteristics: The main mass has a dark brown exterior with patches of rusty red and light brown, and is irregular in shape.

Petrography: Polished and etched surfaces show kamacite grains up to 4 cm across with an equilibrated (120 junction) texture and containing schreibersite up to 1.5 cm in longest dimension. Neumann lines are evident. Veins of iron oxides extend into the interior along grain boundaries. No fusion crust or heat-affected zone was observed.

Geochemistry: ICP-MS data, using sample of North Chile (Filomena) as standard (C. Herd and G. Chen UAb): Ni = 6.8, Co = 0.49 (both wt%); Ir <0.015, Ga = 67, Ge = 219, W = 0.6, Re <0.008, Os <0.04, Cu = 155, Ru = 3.0, Pd = 2.6, Pt = 3.1 (all μg/g).

Classification: (C. Herd, UAb): IAB-MG, although concentrations of Re, Ir, W and Pt seem to be anomalously low. Similar to IAB-MG irons such as La Serena or Zaffra (Wasson and Kallemeyn, 2002).

Specimens: Type specimen consisting of a 73.6 g representative slice and numerous small fragments (from <0.1 g to 22.6 g) at UAb. Main mass with Kuntz.