Lunar Meteorite: Dhofar 2122

Dhofar 2122 in the field. Photo credit: Beda Hofmann
Photomicrograph of a thin section of Dhofar 2122. Note the numerous rusty metal grains. Image credit: Beda Hofmann

from The Meteoritical Bulletin, No. 110

Dhofar 2122 (Dho 2122)

Zufar, Oman
Find: 2018 February 10
Mass: 62.843 g (3 pieces)

Lunar (feldsp. breccia)

History: Three fragments were found in close proximity during a search for meteorites.

Physical characteristics: Three grey fragments with rusty specks and light clasts, maximum dimensions of 5.5, 3 and 2 cm, irregular surface, no fusion crust preserved.

Petrography: (J. Pape, E. Gnos, B. Hofmann) The sample shows a complex brecciated texture with rock and mineral clasts up to 5 mm embedded in a fine-grained matrix. Feldspar grains and feldspar-rich clasts are partly transformed to maskelynite. Most feldspar, olivine and pyroxene grains are highly fractured, show fine-grained recrystallization and irregular and undulatory extinction. The sample contains mm-sized mafic clasts of fine-grained olivine, pigeonite and Cr-spinel mineral assemblages. Several roundish pockets appear mostly black in polarized transmitted light, contain variable mineral inclusions, and are interpreted to mostly consist of glass. The largest mineral/rock clasts are up to 3 mm. Additional observed phases are troilite, grains of Fe-Ni metal up to 0.5 mm and Cr-spinel. Common veins of terrestrial calcite. Medium weathering.

Geochemistry: (J. Pape) Olivine composition: Fa30.9±10.2 (range Fa21.4-52.8), Fe/Mg = 0.5±0.3, Fe/Mn = 83.4±7.7 (N = 18), two Fe-rich olivine analyses give Fa92.2±1.2 (N = 2). Low-Ca pyroxene composition (pigeonite or orthopyroxene): Fs27.8±5.1Wo9.5±5.5 (range Fs20.6-38.1Wo2.9-22.3), Fe/Mg = 0.5±0.1 and Fe/Mn = 50.7±4.5 (N = 19). Plagioclase composition: An96.0±1.9Or0.4±0.3 (range An89.0-98.1Or0.1-1.0) (N = 24). Bulk concentrations (pXRF, N = 3): FeO = 7.92±0.34 wt%, MnO 0.11±0.01 wt%, Cr = 1330±80 ppm, Ni = 156±47 ppm; FeO/MnO = 72.

Classification: Based on petrography and mineral compositions this is a lunar feldspathic breccia. Strongly shocked, medium weathering.

Specimens: 15.6 g and one polished thin section at NMBE. Main mass: MHTO.

Randy Says…

Dhofar 2122 was found 3.4 km west of the find location of the Dhofar 925 clan and 6.6 km east of Dhofar 1527. Both these meteorites are rich in FeNi metal (especially Dhofar 1527) and have 7.5-8.0% FeO. All 3 of these meteorites may be paired. Dhofar 489, however, is not part of the pair group. It is a member of the Dhofar 303 clan – highly feldspathic and troctolitic.

More Information

Meteoritical Bulletin Database

Dhofar 2122