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Northwest Africa 13432 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 13432 This is an OFFICIAL meteorite name. Abbreviation: NWA 13432 Observed fall: No Year found: 2020 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 79 approved meteorites (plus 1 unapproved name) classified as Winonaite. [show all] Search for other: Primitive achondrites, Winonaites | ||||||||||||||||||||||||||||||
Comments: | Approved 14 Oct 2020 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 109:
Northwest Africa 13432 (NWA 13432) (Northwest Africa) Purchased: 2020 Mar Classification: Primitive achondrite (Winonaite) History: Purchased by Darryl Pitt in March 2020 from a Moroccan dealer. Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Metamorphic triple grain junction texture (mean grainsize ~250 µm). Aggregate of olivine, orthopyroxene, fluoro-edenitic amphibole (as oikocrysts enclosing other mineral grains), sodic plagioclase, diopside and kamacite plus minor fluorapatite, graphite and schreibersite. Geochemistry: Olivine (Fa3.0-3.3, FeO/MnO = 16-22, N = 5), orthopyroxene (Fs 3.5-3.8Wo1.7-1.9, FeO/MnO = 12-14, N = 5), diopside (Fs1.1-1.3Wo44.8-45.8, FeO/MnO = 9-12, N = 3), plagioclase (An20.8Ab76.5Or2.6). A total of 53 WDS analyses were obtained on the fluoro-edenite amphibole: it is very homogeneous in composition throughout the studied thin section. It has a mean formula (with (OH) by difference): (Na0.836K0.101) (Ca1.749Na0.176 Fe2+0.068 Mn0.007) (Mg4.799Ti0.104Cr0.04Al0.036Fe2+0.021)(Si6.954Al1.046)O22 [F1.905(OH)0.078Cl0.016]. Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed subsamples by laser fluorination gave, respectively, δ17O 2.272, 2.016, 2.196; δ18O 5.328, 4.855, 5.196; Δ17O -0.541, -0.548, -0.548 per mil (all data linearized). Classification: Winonaite. This specimen is unusual because of the presence of fluoro-amphibole, as also observed in winonaite Hammadah al Hamra 193 (Floss et al., 2007). Specimens: 23.8 g including one polished thin section at UWB; remainder with DPitt. | ||||||||||||||||||||||||||||||
Data from: MB109 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. 109, in preparation (2020)
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Geography: |
Statistics: This is 1 of 9111 approved meteorites from (Northwest Africa) (plus 1873 unapproved names) |