Lunar (KREEP-rich? impact melt breccia)
History: This meteorite was found in the desert of Oman.
Physical characteristics: Five brownish to dark green stones weighing 106.5 g in total, with no fusion crust were located within two meters of each other.
Petrography (Ivanova M. A., Lorenz C. A., and Nazarov M. A., Vernad): This meteorite is an impact melt breccia containing lithic clasts, mineral fragments, glassy spherules, granulites and melt breccias embedded in a fine-grained melt matrix. The breccia is polymict; matrix/clasts ratio varies from sample to sample of the meteorite. The lithic clast population includes anorthosites, gabbros, olivine gabbronorites, gabbro-norites and norites. KREEPy and mare basalt clasts are present. The size range of the clasts is 0.02–8 mm; major minerals are pyroxene and feldspar; minor minerals are olivine, silica, chromite, ilmenite, Ca-phosphate, troilite and FeNi metal.
Geochemistry (Ivanova M. A. and Kononkova N. N. (Vernad): Feldspar is An73–96Ab3.7–24.8; clinopyroxene En2.6–69.5Wo5.6–42.8 (Fe/Mn = 64 at.), orthopyroxene En60.8–77.1Wo1.2–4.1 (Fe/Mn = 69 at.), olivine Fo39.9–72.2 (Fe/Mn = 93 at.); ilmenite (MgO 5.5 wt%); FeNi metal (Ni 8.0 wt%; Co 0.6 wt%). Average glassy matrix composition (wt%): SiO2 49.6; TiO2 1.76; Al2O3 17.4; Cr2O3 0.20; FeO 10.7; MnO 0.15; MgO 7.16; CaO 11.1; Na2O 0.88; K2O 0.76; P2O5 0.84.
Classification: Lunar (KREEP-rich impact melt breccia) with minor weathering.
Type specimens: A total of 21.8 g and two thin sections are on deposit at Vernad. An anonymous buyer holds the main mass of the meteorite.
Dhofar 1442 is described above as containing glassy spherules. By definition, the rock is therefore a regolith breccia, not an impact-melt breccia (Stöffler et al., 1980).
Dhofar 1442 has higher concentrations of geochemically incompatible elements (K, P, Zr, REE, Th, U, etc.) than any lunar meteorite except SaU 169. It also has higher concentrations of incompatible elements than any lunar regolith sample, Apollo or meteorite.
Meteoritical Bulletin Database
Demidova S. I., Nazarov M. A., Anosova M. O., Kostitsyn Y. A., Brandstätter F., and Ntaflos Th. (2012) U-Pb dating of zircons from the Dhofar 1442 lunar meteorite. 43rd Lunar and Planetary Science Conference, abstract no. 1090.
Demidova S. I., Nazarov M. A., Anosova M. O., Kositsyn Yu. A., Ntaflos Th., and Brandstätter F. (2014) U–Pb Zircon dating of the lunar meteorite Dhofar 1442. Petrology 22 (1), 1–16.
Korochantseva E. V., Buikin A. I., Hopp J., Korochantsev A. V., and Trieloff M. (2016) 40Ar-39Ar results of lunar meteorites Dhofar 025, 280, 309, 730, 733, 1436, 1442, SaU 449, NWA 6888. 79th Annual Meeting of the Meteoritical Society, abstract no. 6317.
Korotev R. L. (2011) Lunar meteorites from Antarctica and Oman. 74th Annual Meeting of the Meteoritical Society, abstract no. 5073.
Korotev R. L. (2012) Lunar meteorites from Oman. Meteoritics & Planetary Science 47, 1365-1402.
Korotev R. L. (2017) Update (2012–2017) on lunar meteorites from Oman. Meteoritics & Planetary Science52, 1251-1256.
Korotev R. L, Zeigler R. A., Jolliff B. L., Irving A. J., and Bunch T. E. (2009) Compositional and lithological diversity among brecciated lunar meteorites of intermediate iron composition. Meteoritics & Planetary Science 44, 1287-1322.
Stöffler D., Knöll H.-D., Marvin U. B., Simonds C. H., and Warren P. H. (1980) Recommended classification and nomenclature of lunar highlands rocks-a committee report. In Proceedings Conf. Lunar Highlands Crust (eds. J. J. Papike and R. B. Merrill), 51-70, Pergamon Press.
Xu L., Lin Y. T., Hofmann B. A., Gnos E., and Ouyang Z. Y. (2012) The origin of metal particles in lunar meteorites. 75th Annual Meeting of the Meteoritical Society, abstract no. 5247.
Yang J., Lin Y. T., Joy K. H., and Chen B. (2019) The petrogenesis of very low-Ti mare basaltic clasts in lunar meteorite Dhofar 1442. 82nd Annual Meeting of the Meteoritical Society, abstract no. 6258.
Zeigler R. A., Korotev R. L., and Jolliff B. L. (2011) Petrography and geochemistry of lunar meteorite Dhofar 1442. 42nd Lunar and Planetary Science Conference, abstract no. 1012.
Zhou Q., Zeigler R. A., Yin Q.-Z., Korotev R. L., Jolliff B. L., Amelin Y., Marti K., Wu F. Y., Li X. H., Li Q. L., Lin Y. T., Liu Y., and Tang G. Q. (2012) U-Pb dating of zircons and phosphates in lunar meteorites, acapulcoites and angrites. 43rd Lunar and Planetary Science Conference, abstract no. 1554.
Zhou Q., Yin Q. Z., Zeigler R., Korotev R., Jolliff B., Wu F. Y., Li X. H., Li Q. L., Liu Y., Tang G. Q. and Li C. L. (2015) U-Pb dating of phosphates in lunar meteorite Dhofar 1442. 46th Lunar and Planetary Science Conference, abstract no. 1771.