Toufassour                 29°39’.135 N, 07°44’.958 W

Toufassour, Tata, Morocco

Find: 16 November 2007

Mesosiderite

History: A small impact structure about 3 m in diameter was found in the vicinity of the village of Toufassour (Tata, Morocco). A number of stones have been collected since 2003 by nomads and sold to dealers in Erfoud. In particular two stones totaling 3 kg and a number of fragments were sold by one nomad, but the most significant mass (an ~70 kg stone) was found by a woman hunting for meteorites. More recently many small stones were collected by Moroccan scientists (IZU. Agadir) around the impact structure: Three pieces of 61.0, 15.5 and 13.1 grams and fragments ranging 1 to 5 grams, totaling about 320 grams. Total mass exceeds ~73.3 kg.

Physical characteristics: The fusion crust is absent and the surface appears dark brown. Larger nodules of metal protrude here and there, and larger inclusions of silicates are seen, as greenish spots. Many of the smaller specimens were rich in metal, the phase, which best resisted weathering.

Petrography: (A. Ibhi and H. Nachit, IZU, and A. Jambon, O. Boudouma and D. Badia, UPVI) Mode (wt%): kamacite and (minor) sulfide, (partly oxidized) = 27, pyroxene = 56, plagioclase = 20, silica = 5, and chromite = 0.9. Rutile and schreibersite are also present.

Mineral compositions and geochemistry (EMPA): Pyroxene FeO/MnO = 27, En₇₀Fs₂₆Wo₄ to En₅₉Fs₃₃Wo₈. Chromite Cr/(Cr + Al) = 0.76. Plagioclase Ab₇, An₉₃. Kamacite, Ni = 6%. Merrillite contains significant amounts of MgO.

Classification: Mesosiderite. Moderately to significantly weathered, depending on the grain size.

Type specimens: 2 polished thin sections and 89.6 g at IZU, one polished thin section and 22 g at UPVI. An anonymous dealer holds 300 g.