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Northwest Africa 13673 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 13673 This is an OFFICIAL meteorite name. Abbreviation: NWA 13673 Observed fall: No Year found: 2020 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 4 approved meteorites classified as Achondrite (brachinite-like). [show all] Search for other: Primitive achondrites, Ungrouped achondrites | ||||||||||||||||||||||||||||||
Comments: | Approved 19 Mar 2022 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 111:
Northwest Africa 13673 (NWA 13673) (Northwest Africa) Purchased: 2020 Sep Classification: Achondrite (brachinite-like) History: Purchased by Habib Naji in September 2020 from a dealer in Laayoune, Morocco. Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Protogranular aggregate (mean grainsize ~0.5 mm) of predominantly olivine and low-Ca pyroxene together with subordinate augite plus accessory kamacite, troilite, low-Ti chromite, merrillite, chlorapatite and minor secondary calcite. Small orthopyroxene+kamacite symplectitic intergrowths (up to 60 µm across) occur throughout the specimen. No plagioclase was found. Geochemistry: Olivine (Fa23.3-24.2, FeO/MnO = 42-48, N = 5), low-Ca pyroxene (Fs22.6-23.0Wo2.0-2.1, FeO/MnO = 31-35, N = 5), augite (Fs8.9-9.2Wo44.1-43.9, FeO/MnO = 24-26, N = 2).Oxygen isotopes (K. Ziegler, UNM); analyses of acid-washed subsamples by laser fluorination gave, respectively, δ17O 2.545, 2.444, 2.535; δ18O 5.390, 5.200, 5.382; Δ17O -0.301, -0.302, -0.307 per mil (all data linearized). Classification: Achondrite (ultramafic, brachinite-like). Brachinite-like achondrites are more magnesian, and have more opx (vs. augite)than brachinites. The olivine composition (Fa and Fe/Mn), and opx/augite abundances also support brachinite-like rather than brachinite. See Day et al. (2012) and Goodrich et al. (2017). Specimens: 23 g including one polished thin section at UWB; remainder with Mr. H. Naji. | ||||||||||||||||||||||||||||||
Bibliography: |
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Data from: MB111 Table 0 Line 0: |
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Plots: | O isotopes: | ||||||||||||||||||||||||||||||
Institutions and collections |
UNM: Institute of Meteoritics
MSC03 2050
University of New Mexico
Albuquerque NM 87131-1126
USA, United States; Website (institutional address; updated 12 Feb 2015) UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012) WUSL: Washington Univ., One Brookings Drive, St. Louis, MO 63130, United States (institutional address; updated 17 Oct 2011) UWB: University of Washington, Box 353010 Seattle, WA 98195, United States (institutional address; updated 27 Jul 2012) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 111, in preparation (2022)
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Geography: |
Statistics: This is 1 of 9116 approved meteorites from (Northwest Africa) (plus 1873 unapproved names) |