Lunar Meteorite: Dhofar 1673, 1983, & 1984

from The Meteoritical Bulletin, No. 101

Dhofar 1673

Zufar, Oman
Found: 2011 January
Mass: 15.1 g (1 piece)

Lunar meteorite (feldspathic breccia)

Petrography: (P. Strickland, UAb) Dominated by ferroan anorthosite and less frequent gabbroic clasts embedded in two distinct matrices. Olivine is rare and occurs in small amounts as fine grains. Ferroan anorthosite clasts are frequently seen with poikilitic pigeonite and augite, and some gabbro clasts have ophitic textures. The anorthosite clasts are embedded in a devitrified fine-grained matrix and fragment-rich feldspathic glassy impact melt matrix. A preferred orientation of clasts can be seen within these matrices. Clast sizes range from 0.05-1 mm, excluding the crystalline clasts which range up to 1.3 mm. Other fragments consist of dark fine-grained impact-melt breccias and microporphyritic impact-melt breccias. High alumina, silica-poor (HASP) glass spherules range from 50 to 500 µm and seem to be mainly associated with the fine-grained matrix. Very few fractures are present, indicating low shock deformation. Minimal presence of calcite veins and oxidation indicate low weathering grade.

Geochemistry: (C. Herd and P. Strickland, UAb) Olivine Fa_47.3±6.6 (n=10); low-Ca pyroxene Fs_43.3±4.6Wo_31.2±7.7 (n=16); augite Fs_40.2±11.1Wo_31.2±7.7 (n=27); plagioclase An_96.2±1.2 (n=29); Ti-Cr-Spinel (all wt%) TiO₂=21.6, Al₂O₃=3.92, Cr₂O₃=20.0, FeO=50.1, MgO= 1.6; HASP Glass (all wt%) SiO₂=39.9-45.6, Al₂O₃=27.5-34.0.

Classification: Achondrite, Lunar Feldspathic Regolith Breccia. Classified as a regolith breccia rather than a fragmental breccia based on the presence of HASP glass spherules, as was observed in the mature regolith breccia QUE 93069 (Warren et al., 2005).

Specimens: 7.1 g type specimen, including polished thin section, are on deposit at UAb. Remainder at SQU.

from The Meteoritical Bulletin, No. 103

Dhofar 1983

Zufar, Oman
Found: 2011 January
Mass: 56.3 g (1 piece)

Lunar meteorite (feldspathic breccia)

Physical characteristics: Dark brown fusion crust with an orange tint covers the sample. Fracture surfaces have light orange colourations due to minor weathering. Cut section shows a clast-rich gray interior with white and gray clasts ranging from 0.5 to 10 mm in diameter. There are no obvious signs of oxidation of the interior with the exception a single orange veinlet.

Petrography: (P. Strickland and C. Herd, UAb). Petrographic microscope examination of thin section. Dominated by ferroan anorthosite and less frequent gabbroic clasts embedded in two distinct matrices. Melt breccia clasts up to 1 cm across are present, as are much smaller mineral fragments of pyroxene and less commonly, olivine. Glassy spherules approximately 100 µm are also present. Clasts and spherules are embedded in either a lighter, devitrified fine-grained matrix, or a less abundant, darker, glassy melt matrix. A preferred orientation of clasts is not observed. Very few fractures are present, indicating low shock deformation. Minimal presence of calcite veins and oxidation indicate low weathering grade.

Geochemistry: EPMA examination of carbon-coated thin sections (C. Herd and P. Strickland, UAb; T. Theye, UStutt; P. Hill, UWO): Olivine Fa_20.0-45.8 (n=28); low-Ca pyroxene Fs_16.2-82.4Wo_2.6-19.3 (n=30); augite Fs_10.3-57.8Wo_17.6-43.6 (n=26); plagioclase An_90.6-98.3 (n=53).

Bulk composition: (R. Korotev, WUSL): INAA of subsamples give mean abundances of (in wt.%) FeO 5.6, Na₂O 0.369, CaO 15.2, and (in ppm) Sc 11.7, La 2.3, Sm 1.17, Eu 0.79, Yb 1.01, and Th 0.37. Oxygen isotopic composition (A. Ali and N. Banerjee, UWO): δ¹⁷O = 2.6±0.3 ‰, δ¹⁸O = 5.1±0.5 ‰, Δ¹⁷O = -0.03±<0.01 ‰ (n=2; unleached specimens).

Classification: Achondrite, lunar feldspathic regolith breccia.

Specimens: 11.4 g type specimen, including polished thin section and 0.3 g bulk powdered sample, are on deposit at UAb. A 0.55 g slice of the type specimen was used for INAA by Korotev. Remainder at SQU.

from The Meteoritical Bulletin, No. 103

Dhofar 1984

Zufar, Oman
Found: 2011 January
Mass: 32.1 g (1 piece)

Lunar meteorite (feldspathic breccia)

Petrography: (S. Bell and C. Herd, UAb). Petrographic microscope examination of thin section. A clast-rich breccia with a clastic, fine-grained matrix composed mainly of plagioclase. Clasts range in size from 50 to 600 µm, and are dominated by impact breccias, cataclastic ferroan anorthosite, and rarer basaltic clasts. The latter consist of subophitic, Mg-Fe zoned augite and An-rich plagioclase; one such clast also contains part of a larger Fo₆₉ olivine phenocryst. Fragments of plagioclase and rarer pyroxene and olivine are also present, as are glassy clasts. A preferred orientation of clasts is not observed. Very few fractures are present, indicating low shock deformation. Minimal presence of calcite veins and oxidation indicate low weathering grade.

Geochemistry: EPMA examination of carbon-coated thin sections (C. Herd and S. Bell, UAb; T. Theye, UStutt): olivine Fa_21.3-43.3 (n=7); pyroxene Fs_13.9-69.7Wo_10.8-40.9 (n=17); plagioclase An_93.6-97.0 (n=15).

Bulk composition: (R. Korotev, WUSL): INAA of subsamples give mean abundances of (in wt.%) FeO 5.26, Na₂O 0.372, CaO 15.4, and (in ppm) Sc 11.32, La 2.8, Sm 1.35, Eu 0.79, Yb 1.10, and Th 0.41.

Classification: Achondrite, lunar feldspathic fragmental breccia.

Specimens: 7.2 g type specimen, including polished thin section and 2.4 g bulk powdered sample, are on deposit at UAb. A 0.36 g slice of the type specimen was used for INAA by Korotev. Remainder at SQU.

Randy Says…

The three stones that were found together, distant from other Dhofar stones. The meteorite is a basalt-bearing (minor) feldspathic lunar meteorite.

More Information

Meteoritical Bulletin Database

Dhofar 1673 | 1983 | 1984

Map

Schematic Map of  Find Locations of  Lunar Meteorite from Oman

References

Hill P. J. A., Osinski G. R., Banerjee N. R., Ali A., Korotev R. L. , and Nasir S. (2015) Petrography and geochemistry of lunar meteorite Dhofar 1983. 46th Lunar and Planetary Science Conference, abstract no. 2612.

Hill P. J. A., Osinski G. R., Banerjee N. R., Ali A., Korotev R. L., and Nasir S. (2015) Petrography and geochemistry of lunar meteorite Dhofar 1673. 46th Lunar and Planetary Science Conference, abstract no. 2644.

Hill P. J. A., Osinski G. R., Banerjee N. R., Korotev R. L., Nasir S. J., Herd C. D. K. (2018) Petrography and geochemistry of lunar meteorites Dhofar 1673, 1983, and 1984. Meteoritics & Planetary Science 54, 300-320.

Korotev R. L. (2017) Update (2012–2017) on lunar meteorites from Oman. Meteoritics & Planetary Science 52, 1251-1256.

All Korotev data on Omani lunar meteorites.

Korotev R. L. and Irving A. J. (2013) Keeping up with the lunar meteorites – 2013. 44th Lunar and Planetary Science Conference, abstract no. 1216.

Korotev R. L. and Irving A. J. (2015) Keeping up with the lunar meteorites – 2015. 46th Lunar and Planetary Science Conference, abstract no. 1942.