Dhofar 309

Oman

Found 2002 January 14

Lunar meteorite (anorthositic impact melt breccia)

A grey, partly fusion-crusted 81.3 g stone was found in the Dhofar region of Oman. Classification and mineralogy (S. Demidova, Vernad; G. Kurat, NHMV): the meteorite is a clast-poor impact melt breccia; mineral fragments and lithic clasts are embedded in a matrix of devitrified glass. The clast population is dominated by granulite clasts of mainly anorthositic and troctolitic composition; fragments of possible pristine rocks and single mineral fragments are less common. Mineral compositions: plagioclase An_93–98Or_0.1–0.4; olivine Fo_75–89 (atomic Fe/Mn ≈ 79); orthopyroxene En_80–86Wo_2–5; clinopyroxene En_46–82Wo_5–46; accessory minerals are Ti-poor chromite and Cr-pleonaste, ilmenite (4–9 wt% MgO), troilite, and FeNi metal. The composition (wt%) of the impact melt matrix is MgO 6.2, CaO 16.1, Al₂O₃ 29.1, SiO₂ 44.3, FeO 3.1; terrestrial weathering is not significant, although celestite and calcite are present in cracks. Dhofar 309 is different in texture and mineral chemistry from Dhofar 081/280, 302, 303, 305, 306, 310 found nearby. However, the meteorites may be paired. Specimens: 16.5 g plus two thin sections, Vernad; main mass with anonymous finder.