Lunar Meteorite: Kalahari 008 & 009 (paired stones)

Botswana

Thin section of Kalahari 008. Photo credit: Addi Bischoff

Kalahari 009 (13.5 kg), with a bright 1-cm cube for scale. Photo credit: Addi Bischoff

Lab sample of Kalahari 008, the feldspathic stone. The scale ticks are spaced at 1 mm. Thanks to Addi Bischoff for the sample. Photo credit: Randy Korotev

Lab sample of Kalahari 008, the basaltic stone. Thanks to Addi Bischoff for the sample. Photo credit: Randy Korotev

From The Meteoritical Bulletin, No. 89

Kalahari 008

Kalahari, Botswana
Found: 1999 September
Mass: 598 g (1 piece)

Lunar meteorite (feldspathic regolith breccia)

A single stone of 598 g was found in September 1999 by an anonymous finder in front of a sand dune within the Kalahari desert. The rock is an anorthositic breccia having typical clasts of lunar highland breccias (e.g., feldspathic crystalline melt breccias, granulitic lithologies, cataclastic anorthosites etc.) embedded within a well-lithified matrix. An impact melt spherule indicates that this rock derives from the regolith. The regolith origin is also supported by the finding of solar wind implanted rare gases (L. Schultz, Mainz).

Classification and mineralogy (Anna Sokol and Addi Bischoff, Mün): olivine, Fa63±18; pyroxene Fs42±10; plagioclase An85-98. The shock stage of the rock is S4, the weathering grade is W1. Oxygen isotopic composition: δ18O = +6.52;δ17O = +3.32; Δ = -0.07‰ (R. N. Clayton, UChic);

Concentrations of selected elements (XRF or INAA; H. Palme, G. Weckwerth, Köln) in wt.%: Al: 14.68; Si: 20.73; Mg: 2.68; Fe: 3.5; Ca: 11.1.

Specimen: Type specimen, 20g and polished thin section, Mün; main mass, anonymous finder.

From The Meteoritical Bulletin, No. 89

Kalahari 009

Kalahari, Botswana
Found: 1999 September
Mass: 13,500 g

Lunar meteorite (basaltic fragmental breccia)

A single stone of about 13.5 kg was found in September 1999 by an anonymous finder in front of a sand dune within the Kalahari desert, roughly 50 m apart from Kalahari 008. The rock is different from the Kalahari 008 anorthositic breccia. It has a heavily brecciated texture and is basaltic in composition. The sample does not contain solar wind implanted rare gases (L. Schultz, Mainz).

Classification and mineralogy (Anna Sokol and Addi Bischoff, Mün): olivine, Fa50-99.9 (mostly Fa80-95); pyroxene is highly variable (Fs22-67 En10-64 Wo6-41); plagioclase An86-96 (very few plagioclase have more albitic composition, An70-80). The shock stage of the rock is S4; the weathering grade is W1; however, calcite veins are present.

Oxygen isotopic composition: δ18O = +6.87‰; δ17O = +3.45‰ (R. N. Clayton, UChi);

Concentrations of selected elements (XRF or INAA; H. Palme, G. Weckwerth, Köln; Münker, Mün) in wt.%: Al: 6.76; Mg: 5.14; Fe: 12.47; Ca: 7.66. Zr/Hf = 30.2 and Nd/Ta= 17.4.

Specimens: type specimen, 20 g and polished thin section, Mün; main mass, anonymous finder.

Randy Says…

This is a unique, if not bizarre, meteorite.

It’s the only lunar meteorite from Botswana. The two stones are reported to have been found 50 meters apart.

Cosmic-ray exposure data support the hypothesis that the stones are paired. Their trip from the Moon to the Earth is the shortest ever measured in a lunar meteorite, 230 ± 90 years.

As rocks, the two stones are totally different. Kalahari 008 is a  feldspathic breccia (4.7 % FeO) with little or no evidence for a component of clastic basalt. Kalahari 009 is a brecciated “basalt” (monomict, 16.4% FeO) with no petrographic evidence for a component of clastic anorthosite. As a lunar “basalt,” Kalahari 009 is unique in having very low concentrations of incompatible elements.

There is some subtle compositional evidence, however, that the two stones are “related” and I suspect that the basaltic breccia is (1) not derived from a “mare” (or cryptomare basalt), (2) contains a chemical component of the feldspathic breccia, and (3) that both are derived from nonmare rocks (Korotev, 2017).

If someone had walked into my office with either of these stones, I’d have told them that it wasn’t a meteorite.  I just does not look like a meteorite.

More Information

Meteoritical Bulletin Database

Kalahari 008 | 009

References

Anand M., Tartèse R., Barnes J. J., Starkey N. A., Franchi I. A., and Russell S. S. (2013) Abundance, distribution, and isotopic composition of water in the Moon as revealed by basaltic lunar meteorites44th Lunar and Planetary Science Conference, abstract no. 1957.

Calzada-Diaz A., Joy K. H., Crawford I. A., and Nordheim T. A. (2015) Constraining the source regions of lunar meteorites using orbital geochemical dataMeteoritics & Planetary Science 50, 214-228.

Calzada-Diaz A., Joy K. H., and Crawford I. A. (2016) Investigation of lunar meteorites potentially sourced from cryptomare regions. 47th Lunar and Planetary Science Conference, abstract no. 2075.

Cohen B. A. (2005) More impact-melt clasts in feldspathic lunar meteorites. 68th Annual Meeting of the Meteoritical Society, abstract no. 5314.

Cohen B. A. (2008) Lunar meteorite impact melt clasts and lessons learned for lunar surface samplingLunar and Planetary Science XXXIX, abstract no. 2532.

Fernandes V.A., Burgess R., Bischoff A., Sokol A. K., and Haloda J. (2007) Kalahari 009 and North East Africa 003: Young (<2.5 ga) lunar mare basalts. Lunar and Planetary Science XXXVIII, abstract no. 1611.

Fernandes V.A., Sokol A., Burgess R., Bischoff A., Schultz T., Münker C. (2007) Kalahari 009: One of the oldest lunar mare basalts – Chronology, chemical and petrological composition, and source regionAmerican Geophysical Union, Fall Meeting 2007, abstract id. V23B-1441.

Fritz J. (2012) Impact ejection of lunar meteorites and the age of Giordano BrunoIcarus 221, 1183-1186.

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

Korotev R. L. (2017) Is lunar meteorite Kalahari 009 brecciated nonmare basalt or impact melt? 80th Annual Meeting of the Meteoritical Society, abstract no. 6034.

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

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 compositionMeteoritics & Planetary Science 44, 1287-1322.

Nishiizumi K., Welten K. C., and Bischoff A. (2005) Kalahari 008/009 – The shortest exposure age of all meteorites. 68th Annual Meeting of the Meteoritical Society, abstract no. 5270.

Schulz T., Sokol A. K., Palme H., Weckwerth G., Münker C., and Bischoff A. (2007) Chemical composition and Lu-Hf age of the lunar mare basalt meteorite Kalahari 009. 70th Annual Meeting of the Meteoritical Society, abstract no. 5151.

Shih C.-Y., Nyquist L. E., Reese Y. D., and Bischoff A. (2008) Sm-Nd and Rb-Sr isotopic studies of meteorite Kalahari 009: An old VLT mare basaltLunar and Planetary Science XXXIX, abstract no. 2165.

Snape J. F., Curran N. M., Whitehouse M. J., Nemchin A. A, Joy K. H., Hopkinson T., Anand M., Bellucci J. J., Kenny G. G. (2018) Ancient volcanism on the Moon: Insights from Pb isotopes in the MIL 13317 and Kalahari 009 lunar meteoritesEarth and Planetary Science Letters 502, 84-95.

Sokol A. K. and Bischoff A. (2005) Mineralogy of the Lunar Meteorites Kalahari 008 and Kalahari 009. 68th Annual Meeting of the Meteoritical Society, abstract no. 5059.

Sokol A. K., V. A. Fernandes, T. Schulz, A. Bischoff, R. Burgess, R. N. Clayton, C. Münker, K. Nishiizumi, H. Palme, L. Schultz, G. Weckwerth, K. Mezger, and M. Horstmannaan (2008) Geochemistry, petrology and ages of the lunar meteorites Kalahari 008 and 009: New constraints on early lunar evolutionGeochimica et Cosmochimica Acta 72, 4845-4873.

Sokol A. K. and Bischoff A. (2005) Meteorites from BotswanaMeteoritics & Planetary Science 40, Suppl., A177-A184.

Tartese R., Anand M., Joy K. H., Franchi I. A. (2014) H and Cl isotope characteristics of apatite in brecciated lunar meteorites NWA 4472, NWA 773, SaU 169 and Kalahari 009. 77th Annual Meeting of the Meteoritical Society, abstract no. 5085.

Terada K., Anand M., Sokol A. K., Bischoff A., and Sano Y. (2007) Cryptomare magmatism 4.35 Gyr ago recorded in lunar meteorite Kalahari 009Nature 450, 849-853.

Terada K., Sasaki Y., Oka Y., Tanabe A., Fujikawa N., Tanikawa S., Sano Y., Anand M., and Taylor L. A. (2008) Ion microprobe U-Pb dating of phosphates in lunar basaltic meteoritesLunar and Planetary Science XXXIX, abstract no. 1681.