Mount DeWitt 12007 (DEW 12007)        77°14.153’S, 158°2.218’E

Antarctica

Found: 2013 Jan 3

Classification: Lunar meteorite

History: A single unweathered stone was found on a blue ice patch during the XXVIII PNRA expedition, 2012-2013 (in collaboration with KOREAMET). Nine additional distinct meteorites were found in the same icefield.

Physical characteristics: Fresh, oblate (7 × 3 × 3 cm) stone of 94.2 g. 7% of the external surface is covered by a dark brown vesicular fusion crust. The remaining surface shows abundant mm-sized white and pale gray clasts embedded in a dark gray fine-grained matrix.

Petrography: (A. Collareta and L. Folco, DST-PI) Breccia consisting of numerous crystal fragments (pyroxene, plagioclase, olivine, silica polymorphs), plagioclase-rich clasts, gabbroic clasts, impact melt particles, rare basaltic and mingled breccia clasts. Clasts are embedded in a very fine crystal-rich matrix, which contains vesicular glassy veins and agglutinates. Main minerals are plagioclase, pyroxene (pigeonite and augite), olivine, Ti-bearing chromite, Cr-bearing ulvöspinel, ilmenite, troilite, minor silica polymorphs, baddeleyite, tranquillityite, and tiny FeNi-metal grains.

Geochemistry: (M. Gemelli, M. D’Orazio, A. Collareta, DST-PI) Pigeonite Fs_42.3±10.7Wo_13.5±3.5, Fe/Mn=63±11, n=19; augite Fs_41.1±12.3Wo_28.8±4.6, Fe/Mn=66±9, n=14, plagioclase An_92.1±3.6Ab_7.6±3.5Or_0.3±0.1, n=13, fayalitic olivine Fa_90.6±2.0, Fe/Mn=90±2, n=4, forsteritic olivine Fa_41.5±6.0, Fe/Mn=94±2, n=3. All analyses by EPMA. Bulk Fe/Mn = 65 by HHXRF. Oxygen isotopes done by laser fluorination (A. Pack, UGött): δ¹⁸O = 6.05, δ¹⁷O = 3.13, Δ¹⁷O = -0.071 (all permil).

Classification: Lunar (mingled regolithic breccia)

Specimens: 47.5 g endcut (type specimen) at MNA-SI, 46.7 g endcut at KOPRI.