Dhofar 019

Oman

Found 2000 January 24

Martian basalt (shergottite)

A brownish gray stone weighing 1056 g was found in the desert.  Mineralogy and classification (M. Nazarov and M. Ivanova, Vernad; L. A. Taylor, UTenn): fusion crust absent; meteorite is a doleritic rock consisting of subhedral grains (0.2–0.5 mm) of pigeonite (Wo_{9–1 5} En_40–70, Fe/Mn = 20–40 at), augite (Wo_30–40 En_40–55), olivine (Fo_25–60, Fe/Mn = 50–60 at), and feldspar (An_36–68) converted to maskelynite; olivine has higher Fe/Mg than that of coexisting pyroxenes, as it is in nakhlites; mineral modes (approximate  volume percent) are pyroxene = 65, maskelynite = 25, and olivine = 10, with accessory silica, K-rich feldspar, whitlockite, chlorapatite, chromite, ilmenite, titanomagnetite, magnetite, and pyrrhotite; secondary phases are calcite, gypsum, smectite, celestite, and Fe hydroxides; shock features include fracturing and mosaicism, maskelynite, and rare impact-melt pockets; extensive terrestrial weathering present mainly as carbonate veins crosscutting the meteorite, however, there are smectite–calcite–gypsum "orangettes" replacing maskelynite, which are similar to those in Allan Hills 84001 and could be of martian origin; bulk chemistry close to Shergotty, with light rare earth elements strongly depleted.  Specimens:  type specimens, 113, 4, and 2 g, and two thin sections, Vernad; main mass with anonymous finder.