MAC 88105 - Lunar Meteorite

Lunar Meteorite: MacAlpine Hills (MAC) 88104 & 88105 (paired stones)

Antarctica

MAC 88104 and MAC 88105 were found a few minutes apart. This is the bigger stone, MAC 88105. The fusion crust on the 663-gram meteorite is evident in this view. The small cube in the corner is 1 cm on each side.
(From NASA photo S89-38379. All of the images here were scanned from photographs in which the colors had shifted. These images have all been color-balanced so that the near face of the 1-cm cube is neutral gray.)

61-gram MAC 88104.
(From NASA photo S89-38376)

MAC 88104 after it was broken for sampling in the Astromaterials Curation Laboratory at the NASA Johnson Space Center in Houston. Each subsample receives its own subnumber.
(From NASA photo S89-38377)

Sawn face of MAC 88105 (from NASA photo S89 47066). The meteorite is a regolith breccia, i.e., it is composed of compacted regolith or "soil." Several large, angular clasts are visible in this view.

Photos from the field
(photos by R. L. Korotev)

The field team (Robbie Score, Monica Grady, and Scott Sandford) near the collection site.

Blue ice, with the MacAlpine Hills in the background.

MAC 88105 is one of the biggest lunar meteorite stones from Antarctica.

Randy saw the stones in the field!

Listed in The Meteoritical Bulletin, No. 76, Meteoritics 29, 100-143 (1994)

Amended classification from
Antarctic Meteorite Newsletter, Vol. 12, No. 3, 1989 (PDF p. 21)

MAC 88104, MAC 88105

Weight (g): 61.2; 662.5
Dimensions (cm): 4 x 4.5 x 2.5; 11 x 7.5 x 6.5
Location: MacAlpine Hills; MacAlpine Hills
Field No.: 5757; 5759
Weathering: A/Be; A/Be
Fracturing: A/B; A/B

Meteorite Type: Anorthositic Breccia

Macroscopic Description: Roberta Score

MAC88104 and MAC88105 are paired fragments of a polymict breccia. Both specimens have thin gray-green fusion crust which covers approximately 30% of the exterior surface. The other exterior surfaces are dark gray and weathered, with numerous clasts and vugs where clasts have been plucked out by weathering. A minute amount of evaporite minerals is evident in the minor cracks in the fusion crust. The interior is blue gray and mostly fine-grained, but glassy in some areas. Veins of dark vesicular glass surround some clasts, but do not transect any clasts. The meteorite contains abundant angular feldspathic clasts and fine-grained gray, black and beige clasts. The largest clast exposed (1.5 x 1 cm) is fine-grained and anorthositic, with scattered mafic minerals. Other clasts are medium-grained and more mafic.

Thin Section (MAC88104,7; 88105,6) Description: Brian Mason

The sections show a microbreccia of small (up to 0.3 mm) mineral grains, and clasts (up to 3 mm across), in a translucent to semi-opaque brown glassy matrix. The mineral grains are almost all plagioclase, except for a few olivines and pyroxenes; two pink spinel grains and one minute grain of metal or metal-sulfide were seen in 88105,6. Some of the clasts consist almost entirely of dark-brown semi-opaque glass; others show small plagioclase laths with interstitial glass; some are plagioclase-rich with minor olivine or pyroxene. Microprobe analyses show that the plagioclase is almost pure anorthite (Na₂O 0.3-0.5%, K₂O less than 0.1%). Olivine composition is variable, Fa_10-34; most of the pyroxene is Ca-poor, averaging Wo₆Fs₂₅, but some more Ca-rich grains were analysed; the FeO/MnO ratio is very high, 50-80, characteristic of lunar material. The composition of the glassy matrix is somewhat variable, but averages (weight percent): SiO₂, 45, Al₂O₃ 28, FeO 6.3, MgO 4.7, CaO 16, Na₂O 0.36, TiO₂ 0.32, MnO 0.11, K₂O less than 0.1. The meteorite is an anorthositic microbreccia, almost certainly of lunar origin.

Oxygen Isotopic Composition: Robert Clayton

The oxygen isotopic composition of MAC88105 is d¹⁸O = 5.5, d¹⁷O = 2.7, which falls within the group of previously analyzed lunar meteorites and Apollo lunar rocks.

Thermoluminescence Data: Derek Sears

The measured natural TL values for MAC88104 and MAC88105 are 2.4 +/- 0.3 and 2.9 +/- 0.3 krad at 250 degrees C, respectively. This compares with Steve Sutton's values of 0.75, 1.7, and 0.5 krad for ALHA81005, YAMATO-791197, and YAMATO-82192, respectively, and with typical values for most Antarctic chondrites of 20-80 krad. These low values reflect recent heating or anomalous (non-classical) fading, observed for some lunar meteorites. (Sutton, 1985, Proc. 10th Symp. Antarctic Meteorites, 133-139: 1986, Meteoritics, 21, 520-521: 1989, personal communications).

²⁶Al Measurement: John Wacker

²⁶Al activity of MAC88105 is 19.5 ± 2.6 dpm/kg which is considerably lower than the 41-139 dpm/kg measured by Nishiizumi et al. (1988; Meteoritics 23, 294-295) in four other lunar meteorites. The low activity implies either an unreasonably old terrestrial age (>1 MY) or that the sample was heavily shielded on the moon and had a short transit time in space.

More Information

Meteoritical Bulletin Database

MAC 88104 | MAC 88105

Map

ANSMET location Map

References

Bogard D.D., Garrison D. H., and Nyquist L. E. (2000) Argon-39–argon-40 ages of lunar highland rocks and meteorites (abstract). In Lunar and Planetary Science XXXI, abstract no. 1138, Lunar and Planetary Institute, Houston.

Delano J. W. (1991) Geochemical comparison of impact glasses from lunar meteorites ALHA81005 and MAC88105 and Apollo 16 regolith 64001, Geochimica et Cosmochimica Acta 55, 3019-3029.

Eugster O. (1990) Lunar meteorite MAC88105: History derived from cosmic-ray produced and solar wind trapped noble gases (abstract). In Lunar and Planetary Science 21, p. 337-337, Lunar and Planetary Institute, Houston.

Eugster O., Burger M., Krähenbühl U., Michel Th., Beer J., Hofmann H. J., Synal H. A., Woelfli W., Finkel R. C. (1991) History of the paired lunar meteorites MAC88104 and MAC88105 derived from noble gas isotopes, radionuclides, and some chemical abundances. Geochimica et Cosmochimica Acta 55, 3139-3148.

Grier J. A., Kring D. A., and Swindle T. D. (1995) Impact melts and anorthositic clasts in lunar meteorites QUE93069 and MAC88105 (abstract). Lunar and Planetary Science 26, 513-514.

Jolliff B. L., Korotev R. L., and Haskin L. A. (1991) A ferroan region of the lunar highlands as recorded in meteorites MAC88104 and MAC88105. Geochimica et Cosmochimica Acta 55, 3051-3071.

Koeberl C., Kurat G., and Brandstätter F. (1991) MAC88105-A regolith breccia from the lunar highlands: Mineralogical, petrological, and geochemical studies. Geochimica et Cosmochimica Acta 55, 3073-3087.

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

Korotev R. L., Jolliff B. L., Zeigler R. A., Gillis J. J., and Haskin L. A. (2003) Feldspathic lunar meteorites and their implications for compositional remote sensing of the lunar surface and the composition of the lunar crust, Geochimica et Cosmochimica Acta 67, 4895-4923.

Lindstrom M. M., Schwarz C., Score R., and Mason B. (1991) MacAlpine Hills 88104 and 88105 lunar highland meteorites: General description and consortium overview. Geochimica et Cosmochimica Acta 55, 2999–3007.

Lindstrom M. M., Wentworth S. J., Martinez R. R., Mittlefehldt D. W., McKay D. S., Wang M.-s., and Lipschutz M. J. (1991) Geochemistry and petrography of the MacAlpine Hills lunar meteorites. Geochimica et Cosmochimica Acta 55, 3089-3103.

Neal C. R., L. A. Taylor, Y. Liu, and R. A. Schmitt (1991) Paired lunar meteorites MAC88104 and MAC88105: A new "FAN" of lunar petrology. Geochimica et Cosmochimica Acta 55, 3037-3049.

Nishiizumi K., Arnold J. R., Klein J., Fink D., Middleton R., Kubik P. W., Sharma P., Elmore D., and Reedy R. C. (1991) Exposure histories of lunar meteorites: ALHA81005, MAC81004, MAC81005, and Y791197. Geochimica et Cosmochimica Acta 55, 3149-3155.

Nyquist L. E., Wiesmann H., Shih C.-Y., Dasch J. (1996) Lunar meteorites and the lunar crustal Sr and Nd isotopic compositions (abstract). Lunar and Planetary Science XXVII, p. 971–972, Lunar and Planetary Institute, Houston.

Nyquist L. E., Bogard D. D., Shih C. Y., Wiesmann H. (2002) Negative e_Nd in anorthositic clasts in Yamato 86032 and MAC88105: Evidence for the LMO? Lunar and Planetary Science XXXIII, CD-ROM no. 1289, Lunar and Planetary Institute, Houston (abstr.).

Palme H., Spettel B., Jochum K. P., Dreibus G., Weber H., Weckwerth G., Wänke H., Bischoff A., and Stöffler D. (1991) Lunar highland meteorites and the composition of the lunar crust, Geochimica et Cosmochimica Acta 55, 3105-3122.

Sears D. W. G., Benoit P. H., Sears H., Batchelor J. D., and Symes S. (1991) The natural thermoluminescence of meteorites: III. lunar and basaltic meteorites, Geochimica et Cosmochimica Acta 55, 3167-3180.

Semenova A. S., Nazarov M. A., Kononkova N. N., Patchen A., Taylor L. A. (2000) Mineral chemistry of lunar meteorite Dar al Gani 400 (abstract). In Lunar and Planetary Science XXXI, abstract no. 1252, Lunar and Planetary Institute, Houston.

Taylor G. J. (1991) Impact melts in the MAC88105 lunar meteorite: Inferences for the lunar magma ocean hypothesis and the diversity of basaltic impact melts, Geochimica et Cosmochimica Acta 55, 3031-3036.

Vogt S., Fink D., Klein J., Middleton R., Dockhorn B., Korschinek G., Nolte E., and Herzog G. F. (1991) Exposure histories of the lunar meteorites: MAC88104, MAC88105, Y791197, and Y86032. Geochimica et Cosmochimica Acta 55, 3157-3165.

Warren P. H. and Kallemeyn G. W. (1991) The MacAlpine Hills lunar meteorite and implications of the lunar meteorites collectively for the composition and origin of the Moon. Geochimica et Cosmochimica Acta 55, 3123-3138.

Wentworth S. J. and McKay D. S. (1990) Lunar meteorite MAC88104/5: Petrography and glass compositions (abstract). In Lunar and Planetary Science 21, p. 1323-1324.

Yanai K. and Kojima H. (1991) Varieties of lunar meteorites recovered from Antarctica. Proc. NIPR Symp. Antarct. Meteorites 4, 70-90.

Chemical Classification

Overview | MAC 88104/88015

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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: 10-Jul-2009