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Northwest Africa 1457 | |||||||||||||||||
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Basic information | Name: Northwest Africa 1457 This is an OFFICIAL meteorite name. Abbreviation: NWA 1457 Observed fall: No Year found: 2002 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||
Classification history: |
This is 1 of 85 approved meteorites (plus 1 unapproved name) classified as Winonaite. [show all] Search for other: Primitive achondrites, Winonaites | ||||||||||||||||
Writeup![]() |
Writeup from MB 87:
Northwest Africa 1457 Morocco Purchased 2001 December Achondrite (winonaite) Seven small stones with a total weight of 52 g were purchased from a Moroccan dealer by A. and G. Hupé (xHupé) in 2001 December. Classification and mineralogy (A. Irving and S. Kuehner, UWS): medium-grained, equilibrated metamorphic texture with triple junctions among mineral grains. Abundant enstatite (Fs6Wo1.5, FeO/MnO = 15) and forsteritic olivine (Fa5, FeO/MnO = 18) with subordinate diopside (Fs2.8Wo44, FeO/MnO = 8), sodic plagioclase (Ab82Or4), Ni-poor Fe-Ni metal, troilite, schreibersite, Cr-rich chromite, and Cl-rich apatite. Daubreelite occurs as blades within some troilite grains. Rare chromite grains (up to 20 µm; 66 wt% Cr2O3; Cr/ (Cr+Al) = 0.870; Mg/(Mg+Fe) = 0.682) are associated with troilite. Grain boundaries are veined by heterogeneous Nifree iron oxides and/or hydroxides. Oxygen isotope composition (D. Rumble, CIW): analyses of two whole rock fragments by laser fluorination gave δ18O = +5.1 ± 0.1‰; δ17O = +2.3 ± 0.1‰; ∆17O = –0.40 ± 0.03‰. The texture, mineralogy and oxygen isotopic composition of this sample match the criteria for winonaites given by Benedix et al. (1998). Specimens: type specimen, 10 g, and one polished thin section, UWS; main mass, xHupé. | ||||||||||||||||
Data from: MB87 Table 8 Line 84: |
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Plots: | O isotopes: | ||||||||||||||||
Institutions and collections |
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012) CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address) xHupé: (old address—now see GHupé or AHupé) G. and A. Hupe, 2616 Lake Youngs Court SE, Renton, WA 98058., United States (private address) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 87, MAPS 38, A189-A248 (2003)
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Photos: |
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Geography: |
Statistics: This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names) |