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Northwest Africa 15317 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 15317 This is an OFFICIAL meteorite name. Abbreviation: NWA 15317 Observed fall: No Year found: 2021 Country: Algeria Mass: ![]() | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 40 approved meteorites classified as Angrite. [show all] Search for other: Achondrites, Angrites | ||||||||||||||||||||||||||||||
Comments: | Approved 22 Dec 2022 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 111:
Northwest Africa 15317 (NWA 15317) Algeria Purchased: 2021 Oct Classification: Angrite History: Purportedly found in Algeria and purchased by Darryl Pitt in October 2021 from a dealer in Agadir, Morocco. Physical characteristics: A single ellipsoidal stone (299.3 g) about 40% covered by black fusion crust. Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Very fresh specimen with porphyritic dendritic texture. Larger grains (up to 1.5 mm) of compositionally-zoned Al-Ti-augite (pink with purple-brown rims in thin section) and Ca-bearing olivine plus smaller laths of anorthite are set within finer grained interstitial regions composed of intergrowths of the same phases plus kirschsteinite, troilite, ulvöspinel, silicoapatite and calcite. Geochemistry: Olivine (Fa47.7-77.7Ln2.1-8.6, FeO/MnO = 70-90, N = 6), Al-Ti-augite (Fs22.9-47.1Wo50.5-53.2, FeO/MnO = 83-134, Al2O3 5.4-8.7 wt.%, TiO2 1.9-4.7 wt.%, N = 8), kirschsteinite (Fa64.3-81.5Ln33.1-15.3, FeO/MnO = 62-74, N = 4), anorthite (An99.3-99.8Or0.0, N = 4). Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed subsamples by laser fluorination gave, respectively, δ17O=2.353, 2.457, 2.283; δ18O=4.734, 4.802, 4.529; Δ17O=-0.146, -0.079, -0.108 per mil (all data linearized, TFL slope = 0.528). Classification: Angrite (medium grained, porphyritic, dendritic). Specimens: 20.2 g including one polished thin section and one polished slice at UWB; remainder with DPitt. | ||||||||||||||||||||||||||||||
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) DPitt: Darryl Pitt, 225 West 83rd Street, New York, NY 10024, United States; Website (private address) |
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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 1270 approved meteorites from Algeria (plus 29 unapproved names) (plus 4 impact craters) |