|Northwest Africa 6234|
|Basic information||Name: Northwest Africa 6234|
This is an OFFICIAL meteorite name.
Abbreviation: NWA 6234
Observed fall: No
Year found: 2010
Mass: 55.7 g
This is 1 of 151 approved meteorites (plus 1 unapproved name) classified as Martian (shergottite). [show all]
Search for other: Martian meteorites
Approved 28 Dec 2010|
Revised 2 Jan 2011: Fixed weight
Writeup from MB 99:
Northwest Africa 6234 (NWA 6234)
History: A pale-colored stone found in Mali in 2009 was purchased in February 2010 by an anonymous collector.
Physical characteristics: A fine-grained, partly fusion-crusted stone (55.7 g) displaying fluted abrasion features on several sides. The fresh interior is pale gray with evenly-distributed, larger, pale-tan grains, and is crosscut by several thin, black shock veins.
Petrography: (A. Irving and S. Kuehner, UWS): Porphyritic texture, with small (0.15 to 0.35 mm) olivine phenocrysts in a finer grained groundmass composed mainly of prismatically zoned pigeonite (with rare subcalcic augite) and maskelynite with accessory ferroan olivine, chromite, titanomagnetite, ilmenite, merrillite and pyrrhotite.
Geochemistry: Olivine phenocrysts (core Fa26.1-26.5, rim Fa39.2; FeO/MnO = 47.1-56.6), pigeonite (Fs28.5-38.7Wo5.9-16.3, FeO/MnO = 30.3-38.3), augite (Fs23.3Wo35.4, FeO/MnO = 30.7), groundmass olivine (Fa47.3, FeO/MnO = 55.0), plagioclase (An52.3-55.1Or1.8-2.2). Bulk composition (M. Gellissen, XRF, Koln; C. Herd, ICPMS, UAb): powder prepared from clean cutting dust gave the following elemental abundances (in wt%): SiO2 44.7, FeO 22.6, MgO 16.3, CaO 6.4; (in ppm) La 1.3, Ce 3.1, Nd 2.0, Sm 1.1, Yb 1.2, Lu 0.17, Ni 540.
Classification: Achondrite (Martian, olivine-phyric shergottite). This specimen has essentially the same external appearance, grainsize, texture and mineral compositions as NWA 2990 and NWA 5960, and evidently is paired with those stones.
Specimens: A total of 20.0 g of type material and one polished thin section are on deposit at UWS. The remaining material is held by an anonymous collector.
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012)
UAb: 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB, T6G 2E3, Canada, Canada; Website (institutional address; updated 17 Oct 2011)
Koln: Universität zu Köln, Institut für Mineralogie und Geochemie, Zülpicher Straße 49 b, 50674 Köln, Germany (institutional address; updated 7 Nov 2015)
|References:||Published in Meteoritical Bulletin, No. 99, April 2012, MAPS 47, E1-E52 (2012) [published online only]|
This is 1 of 19 approved meteorites from Mali (plus 1 unapproved name)
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