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Lunar Meteorite: Yamato 983885

Antarctica, Yamato Mountains

Yamato 983885.  The scale cube is 1 cm on each side. 
Photo from Kojima H. and Imae N. (2001).		  
Fragments of Yamato 983885.  The scale to the lower left has millimeter tick marks.
Yamato 983885 is a regolith breccia.  This fragment is about 4 mm in longest dimension.


It's compositionally unique.
  

 

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

Yamato 983885

Sample Name: Yamato 983885 Location: JARE IV Nunataks
Dimensions (cm): 8.4 x 5.4 x 5.2 Weight (g): 289.71
Weathering: A Fracturing: B

Meteorite Type: 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 d18O=+5.65, d17=+2.89, D17O=-0.05, also indicates that the meteorite is lunar origin.

More Information

Antarctic Meteorite Research Center | National Institute of Polar Research

Meteoritical Bulletin Database

Yamato 983885

Map

NIPR Location Map

References

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

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

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 rocks (abstract). In Lunar and Planetary Science XXXV, abstract no. 2155, Lunar and Planetary Institute, Houston.

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 rocks. Antarct. Meteorite Res. 18, 17–45.

Kaiden H. and Arai T. (2006) Ion microprobe REE analyses of the Yamato 983885 lunar meteorite (abstract). 69th Annual Meeting of the Meteoritical Society, abstract no. 5385. Lunar and Planetary Institute, Houston.

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

Kaiden H. and Kojima H. (2002) Yamato 983885: A second lunar meteorite from the Yamato 98 collection (abstract), Antarctic Meteorites XXVII, 49–51, National Institute of Polar Research, Tokyo.

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

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

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.

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.

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

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 (abstract). In Antarctic Meteorites XXX, 67-68, National Institute of Polar Research, Tokyo.

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

Chemical Classification

Overview | Yamato 983885

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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: 23-Oct-2009