| MetSoc Home Publications Contacts |
|
||
|
||
| Northwest Africa 11431 | |||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Basic information | Name: Northwest Africa 11431 This is an OFFICIAL meteorite name. Abbreviation: NWA 11431 Observed fall: No Year found: 2017 Country: Mauritania Mass:  524 g | ||||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 330 approved meteorites (plus 2 unapproved names) classified as Martian (shergottite). [show all] Search for other: Martian meteorites | ||||||||||||||||||||||||||||||||||
| Comments: | Approved 13 Oct 2017 | ||||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 106:
Northwest Africa 11431 (NWA 11431) Mauritania Find: 2017 Jun Classification: Martian meteorite (Shergottite) History: Found in June 2017 in Mauritania in a region directly south of the NWA 6963 strewnfield (located near Fej Arrih to the north in adjacent Morocco), and puchased by Ben Hoefnagels in July 2017 from a Moroccan dealer. Physical characteristics: A single stone (524 g) with a flat prismatic shape almost completely coated by black fusion crust. The interior is gray with evident glassy maskelynite. Petrography: (A. Irving and S. Kuehner, UWS) Medium-grained, diabasic texture. Composed predominantly of zoned clinopyroxene and maskelynite with accessory Fe-bearing merrillite, titanomagnetite, ilmenite (with rare baddeleyite inclusions), silica polymorph, fayalite and pyrrhotite. Geochemistry: Pigeonite (Fs36.2-51.6Wo8.1-12.8, FeO/MnO = 31-37, N = 4), subcalcic augite (Fs21.6-42.0Wo30.1-31.3, FeO/MnO =30-42, N = 4), fayalite (Fa85.5, FeO/MnO = 60), maskelynite (An38.4-42.3Or4.5-3.0, N = 2). The most ferroan subcalcic augite rims are notably aluminous (Al2O3 = 2.2-2.5 wt.%) and yield low oxide sums plus high cation totals indicative of the presence of minor ferric iron. Magnetic susceptibility (P. Rochette, CEREGE) log χ (× 10-9 m3/kg) = 3.22. Classification: Martian (shergottite, diabasic). This specimen has many similarities to the NWA 6963 stones and evidently comes from an extension of the same strewnfield into Mauritania. Specimens: 26.5 g including one polished thin section and one polished thick section at UWB; remainder with Mr. B. Hoefnagels. | ||||||||||||||||||||||||||||||||||
| Data from: MB106 Table 0 Line 0: |
|
||||||||||||||||||||||||||||||||||
| Institutions and collections |
CEREGE: CEREGE
BP 80
Avenue Philibert, Technopole de l'Arbois
13545 Aix-en-Provence Cedex 4
France, France (institutional address; updated 10 Jun 2023) UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012) UWB: University of Washington, Burke Museum of Natural History and Culture, Box 353010 Seattle, WA 98195, United States (institutional address; updated 9 Oct 2023) |
||||||||||||||||||||||||||||||||||
| Catalogs: |
| ||||||||||||||||||||||||||||||||||
| References: | Published in Gattacceca J., Bouvier A., Grossman J., Metzler K., and Uehara M. (2019) Meteoritical Bulletin, no. 106. Meteorit. Planet. Sci. 54 in press.
| ||||||||||||||||||||||||||||||||||
Geography:
|
Statistics: This is 1 of 232 approved meteorites from Mauritania (plus 2 unapproved names) (plus 2 impact craters) | ||||||||||||||||||||||||||||||||||