Ben Kesbes 002        30.567347, 4.960781

Ouargla, Algeria

Find: 2020

Classification: Martian meteorite (Shergottite)

History: Two stones 12.12 g and 8.12 g were purchased from Aziz Zad in August 2020, an Algerian meteorite dealer, were reportedly found by a nomad on May 13, 2020, about 160 km south of the city of Ouargl. A third stone 9.07 g was purchased from Fabien Kuntz in January 2020 and was also reportedly found in the same location (in Algeria in the Ouargla area). In this classification we determined, through SEM and EMPA analyses of the three stones, that they are petrologically and geochemically identical.

Physical characteristics: Three individual stones, 12.12 g, 9.07 g, 8.12 g, all covered with fresh, shiny black fusion crust. Visually all three stones are identical in appearance.

Petrography: (C. Agee, UNM) The two major phases in this meteorite are clinopyroxene and maskelynite. Ubiquitous minor phases are merrillite, apatite, titanomagnetite, ilmenite and troilite. The clinopyroxene has a modal abundance of approximately 60%, with significant core to rim zoning observed in backscattered electron images indicating an igneous crystallization trend with Mg-rich pigeonite cores, mantled by augite, and rimmed with ferropigeonite. Clinopyroxene average grain size is approximately 300-500 μm. Maskelynite has modal abundance of approximately 30%, most grains are thin and elongate with maximum length ~1 mm.

Geochemistry: (C. Agee, UNM) Clinopyroxene Fs_52.0±21.4Wo_22.0±8.9, core to rim range Fs_32.6Wo_17.7(Mg-pigeonite) – Fs_24.7Wo_38.7 (augite) – Fs_86.0Wo_12.6 (ferropigeonite), Fe/Mn=36±4, n=20; maskelynite An_51.3±3.7Ab_46.6±2.5Or_2.1±1.3, n=7. Oxygen isotopes (K. Ziegler, UNM): 3 acid-washed fragments analyzed by laser fluorination gave δ¹⁸O= 4.865, 4.900, 4.820; δ¹⁷O= 2.810, 2.826, 2.814; Δ¹⁷O= 0.241, 0.239, 0.269 (linearized, all per mil, TFL slope=0.528).

Classification: Evolved pyroxene-phyric basalt, clinopyroxene compositional zoning trends are similar to QUE 94201. Paired with NWA 12522, NWA 12550, and NWA 12960.

Specimens: 5.87 g plus a polished thin section on deposit at UNM, Michael Doran holds three stones described above.