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Lunar Meteorite: Dhofar 287

Oman


A sawn face of Dhofar 287. The smallest divisions on the scale are 1 mm apart. The bottom 95% of the stone is crystalline mare basalt, the "A" lithology (rock type) of Anand et al. (2003). The darker portion on top is regolith breccia, the "B" lithology of Demidova et al. (2003). The division between the two lithologies is sharp. One interpretation (and one that also applies to NWA 773) is that the meteorite is a regolith breccia, the A lithology is a very large clast, and smaller clasts of the basalt (A lithology) occur in the breccia (B lithology). This interpretation is consistent with the point made regarding ALHA 81005 (Fig. C) that the lunar regolith, and breccias derived there from, are fractal objects. Photo courtesy of Dr. Mikhail Nazarov of the Laboratory of Meteorites, Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow.
  
A small slab of the basalt(A) lithology.
The tick marks on the scales are spaced at 1 mm increments. Click on image for enlargement. (Photos by Randy Korotev)

from The Meteoritical Bulletin, No. 85, Meteoritics & Planetary Science 36, A293-A322 (2001)

Dhofar 287

18°24.2'N 54°08.8'E
Oman
Found 2001 January 14

Lunar meteorite (Low-Ti, olivine-pyroxene mare basalt breccia)  A dark gray, 154 g black stone without fusion crust was found in the Dhofar region of Oman, 400 m from Dhofar 025. Classification and mineralogy (M. Nazarov, Vernad; L. Taylor, UTenn): contains two adjacent lithologies, mare basalt (95 vol%) and regolith breccia (5 vol%). Basaltic portion: consists of olivine (Fo70-45) and minor augite (Wo30-40 En38-45) phenocrysts (up to 1 mm) set in a subophitic, fine-grained (50-100 µm) groundmass composed of plagioclase (An85-75) and pyroxene (Wo10-25En2-50), with accessory pyroxferroite, K-Ba feldspar, apatite, ilmenite, Ti-rich chromite, ulvöspinel, baddeleyite, silica, tranquillityite, troilite, Fe-Ni metal, and a fayalite + K-rich glass mesostasis; shock veins and impact melt pockets are present; plagioclase is totally converted to maskelynite; mineral modes (vol%) are pyroxene = 49, maskelynite = 26, olivine = 18, opaques = 4, impact melt = 2; whole-rock TiO2 content = 2.8 wt%; Fe/Mn = 75; a prominent negative Eu anomaly is present; similar in composition to Apollo 12 mare basalts, but distinctly higher in Na and incompatible elements. Regolith breccia portion: clast-rich, with numerous lithic and mineral grains (up to 1 mm) cemented by fine-grained mineral fragments (<100 µm) and minor impact melt; dominated by low-Ti and VLT mare basalt lithologies; minor highland material probably present; lithic clasts are fine- grained, vitrophyric, granular to ophitic, basaltic rocks and impact melt breccias; mineral fragments dominated by pyroxene, olivine, and plagioclase; glass fragments and spherules also occur; plagioclase, An98-66; olivine, Fo80-25; pyroxenes highly variable, Wo5-40En2-80; main accessories are silica, fayalite, pyroxferroite, K-rich glass, apatite, ilmenite, Ti-rich chromite, ulvöspinel, troilite, and FeNi metal. Specimens: 32 g and two thin sections, Vernad; main mass with anonymous finder.

More Information

Meteoritical Bulletin Database

Dhofar 287

Map

Schematic Map of the Find Locations of the Dhofar Lunar Meteorites

References

Anand M., Misra K., Taylor L. A., Nazarov M. A., Clayton R. N., and Mayeda T. K. (2002) Apparently KREEPy lunar meteorite Dhofar 287a: The residual melt tapped from a fractionating magma chamber (abstract), Lunar and Planetary Science 33, CD-ROM no. 1635, Lunar and Planetary Institute, Houston.

Anand M., Taylor L. A., Nazarov M. A., and Patchen A. (2003) Petrologic comparisons of lunar mare basalt meteorites Dh-287A and NWA 032 (abstract), Lunar and Planetary Science 34, CD-ROM #1787, Lunar and Planetary Institute, Houston.

Anand M., Taylor L. A., Misra K. C., Demidova S. I., and Nazarov M. A. (2003) KREEPy lunar meteorite Dhofar 287A: A new lunar mare basalt, Meteorit. Planet. Sci. 38, 485-499.

Demidova S., Nazarov M. A., Anand M., and Taylor L. A. (2002) Clast population of lunar regolith breccia Dhofar 287B (abstract), Lunar and Planetary Science 33, CD-ROM no. 1290, Lunar and Planetary Institute, Houston.

Demidova S. I., Nazarov M. A., Anand M., and Taylor L. A. (2003) Lunar regolith breccia Dhofar 287B: A record of lunar volcanism, Meteorit. Planet. Sci. 38, 501–514.

Korotev R. L. (2005) Lunar geochemistry as told by lunar meteorites. Chemie der Erde 65, 297–346.

Korotev R. L. and Zeigler R. A. (2007) Keeping up with the lunar meteorites (abstract). In Lunar and Planetary Science XXXVIII, abstract no. 1340, Lunar and Planetary Institute, Houston.

Korotev R. L., Irving A. J., and Bunch T. E. (2008) Keeping up with the lunar meteorites – 2008 (abstract). In Lunar and Planetary Science XXXIX, abstract no. 1209, 39th Lunar and Planetary Science Conference, Houston.

Taylor L. A., Nazarov M. A., Demidova S. I., and Patchen A. (2001) Dhofar 287: A new lunar mare basalt from Oman abstract, 64th Annual Meteoritical Society Meeting, CD-ROM no. 5106.

Shih C.-Y., Nyquist L. E., Reese Y., Wiesmann H., Nazarov M.A., and Taylor L.A. (2002) The chronology and petrogenesis of the mare basalt clast from lunar meteorite Dhofar 287: Rb-Sr and Sm-Nd isotopic studies (abstract), Lunar and Planetary Science 33, CD-ROM no. 1344, Lunar and Planetary Institute, Houston.

Chemical Classification

Overview | Dhofar 287 | Basaltic Lunar Meteorites

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Prepared by:

Randy L. Korotev

Department of Earth and Planetary Sciences
Washington University in St. Louis

Please don't contact me about the meteorite you think you’ve found until you read this and this.

e-mail: korotev@wustl.edu

Last revised: 08-Feb-2008