Lunar Meteorite: Calcalong Creek

Slices of Calcalong Creek. Photo credits: Robert Haag (left) and David Kring (right)
Two (?) slices of Calcalong Creek. Note the vesicular fusion crust. Photo credit: Jim Strope
Two sides of a 0.25-g slice of Calcalong Creek. Millimeter ticks. Photo credit: Luc Labenne
Outside and inside of a 0.21-g piece of Calcalong Creek. Note the vesicular fusion crust. Thanks to Dolores Hill for the sample. Image credit: Randy Korotev
Photomicrograph of a thin section (field of view: 1.1 cm across). Most of the clasts are grains of plagioclase and pyroxene. Image credit: Dolores Hill (Figure 1a from Hill & Boynton, 2003). There are no vesicles in the interior of the meteorite.

from The Meteoritical Bulletin, no. 71

Calcalong Creek

Wiluna District, Western Australia, Australia
Found: after 1960
Mass: 19 g (1 piece)

Lunar meteorite

History: A stone of 19 g was found by an Aborigine meteorite hunter in the Millbillillie strewnfield.

Physical Characteristics: It has a complete fusion crust, the interior shows a microbreccia with white angular clasts in a dark matrix (impact melt breccia, calculated from the bulk analysis: 50% anorthosite, 20% KREEP, 15% Luna- 16 type low-Ti mare basalt and 15% Sc-Cr-V components).

Information and analysis: Fe/Mn = 73-78, KREEP pattern of REE, Dolores H. Hill, Lunar Planetary Laboratory, University of Arizona, Tucson AZ 85726, USA. See also, D. H. Hill, W. V. Boynton and R. A. Haag, Nature, 1991, in press.

Specimens: The main mass is with Robert Haag, P. O. Box 27527, Tucson, AZ 85726, USA

Randy Says…

Because Calcalong Creek is a regolith breccia, it has a vesicular fusion crust, as do some lunar meteorites from Antarctica. The vesicles form from release of solar-wind implanted gases during the heating melting of the exterior associated with atmospheric entry.

The meteorite is compositionally distinct from Lynch 002, the only other lunar meteorite from Australia, but similarly rich in incompatible elements like Th.  The two Australian lunar meteorites were found 859 km apart.

More Information

Meteoritical Bulletin Database

Calcalong Creek

References

Hill D. H. and Boynton W. V. (2003) Chemistry of the Calcalong Creek lunar meteorite and its relationship to lunar terranes. Meteoritics & Planetary Science 38, 595-626.

Hill D. H., Boynton W. V., and Haag R. A. (1991) A lunar meteorite found outside the Antarctic. Nature 352, 614-617.

Hill D. H., Marvin U. B., and Boynton W. V. (1995) Clasts from the Calcalong Creek lunar meteorite. Lunar and Planetary Science XXVI, 605-606.

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.

Pernet-Fisher J. F., Nottingham M., Curran N. M. , and Joy K. H. (2020) Cosmic-ray exposure histories of Th-rich lunar regolith breccias. 51st Lunar and Planetary Science Conference, abstract no. 1376.

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