Lunar Meteorite: Yamato 983885

Yamato Mountains, Antarctica

Yamato 983885 (290 g). Photo credit: Kojima and Imae, (2001)

Lab samples of Yamato 983885. The bottom sample (2 sides) is 4 mm in longest dimension. Photo credit: Randy Korotev

from Meteorite Newsletter, vol. 10, No. 2, 2001

Yamato 983885 (Y-983885)

Dimensions (cm): 8.4 x 5.4 x 5.2

Found: 1999-January-11
Mass: 289.71 g (1 piece)
Weathering: A Fracturing: B

Lunar Anorthositic Breccia

Macroscopic description (Kaiden H.). It is a rounded stone with some thin yellowish green fusion crust. Angular white to gray clasts (up to 3 mm in size), white crystalline plagioclases, pyroxenes and dark grains set in a dark fine-grained matrix.

Petrographic Description (Kaiden H.). A thin section (71-1) shows a polymict breccia containing polymineralic and monomineralic clasts (up to 1.2 mm in size) set in a dark brown clastic matrix. Most of larger clasts are polymineralic, frequently composed of calcic plagioclase pyroxene and olivine, less commonly plagioclase and olivine, or plagioclase alone. Smaller clasts are dominantly mineral fragments of plagioclase, with some pyroxenes and olivines. Glass spherules, up to 0.3 mm in diameter, are also observed. EPMA analyses show a pyroxene composition range of En14-85Fs12-55Wo2-40; a plagioclase range of An89-98; and an olivine range of Fo32-36. The average FeO/MnO ratios of pyroxenes (64) indicates that this rock is lunar rock. The oxygen isotopic composition (analyzed by Clayton and Mayeda) of a bulk rock sample that is δ18O=+5.65, δ 17=+2.89, Δ17O=-0.05, also indicates that the meteorite is lunar origin.

Randy Says…

Yamato 983885 is basalt- and KREEP-bearing  feldspathic breccia.

More Information

Meteoritical Bulletin Database

Yamato 983885

Map: NIPR Location Map

References

Arai T. (2003) Yamato 983885: Lunar highland breccia with alkali anorthosite. Evolution of Solar System Materials: A New Perspective from Antarctic Meteorites, 7-8.

Arai T., Otsuki M., Ishii T., Mikouchi T., and Miyamoto M. (2004) Mineralogy of Yamato 983885 lunar polymict breccia with alkali-rich and Mg-rich rocksLunar and Planetary Science XXXV, abstract no. 2155.

Arai T., Otsuki M., Ishii T., Mikouchi T., and Miyamoto M. (2005) Mineralogy of Yamato 983885 lunar polymict breccia with KREEP basalt, a high-Al basalt, a very low-Ti basalt and Mg-rich rocksAntarctic Meteorite Research 18, 17-45.

Arai S., Terada K., Arai T., Hidaka H., and Sano Y. (2008) Ion microprobe U-Pb dating of the Yamato-983885 lunar meteorite. 71st Annual Meeting of the Meteoritical Society, abstract no. 5074.

Kaiden H. and Arai T. (2006) Ion microprobe REE analyses of the Yamato 983885 lunar meteorite69th Annual Meeting of the Meteoritical Society, abstract no. 5385.

Kaiden H. and Kojima H. (2002) Yamato 983885: A second lunar meteorite from the Yamato 98 collection, Antarctic Meteorites XXVII, 49-51.

Kaiden H. and Kojima H. (2002) Yamato 983885: A new lunar meteorite found in AntarcticaLunar and Planetary Science XXXIII, abstract no. 1958.

Karouji Y., Arai T., and Ebihara M. (2006) Chemical composition of another KREEP-rich lunar regolith breccia Yamato 983885. In Lunar and Planetary Science XXXVII, abstract no. 1919.

Kojima H. and Imae N. (2001) Meteorite Newsletter 10(2), 1.

Korotev R. L. (2005) Lunar geochemistry as told by lunar meteoritesChemie der Erde 65, 297-346.

Korotev R. L., Irving A. J., and Bunch T. E. (2008) Keeping up with the lunar meteorites – 2008Lunar and Planetary Science XXXIX, abstract no. 1209Korotev 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 compositionMeteoritics & Planetary Science 44, 1287-1322.

Mahajan R. R. (2015) Lunar meteorite Yamato-983885: Noble gases, nitrogen and cosmic ray exposure historyPlanetary and Space Science 117, 24-34.

Miura Y. N., Arai T., Karouji Y., and Ebihara M. (2006) Noble gases in the lunar meteorite Yamato 983885, a KREEP-rich lunar regolith breccia. Antarctic Meteorites XXX, 67-68.

Warren P. H. and Bridges J. C. (2004) Lunar meteorite Yamato-983885: A relatively KREEPy regolith breccia not paired with Y-791197. 67th Annual Meteoritical Society Meeting, abstract no. 5095.

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