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Northwest Africa 6474 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 6474 This is an OFFICIAL meteorite name. Abbreviation: NWA 6474 Observed fall: No Year found: 2010 Country: (Northwest Africa) Mass: 312 g | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 62 approved meteorites classified as Brachinite. [show all] Search for other: Brachinites, Primitive achondrites | ||||||||||||||||||||||||||||||
Comments: | Approved 31 Jan 2012 | ||||||||||||||||||||||||||||||
Writeup |
Writeup from MB 100:
Northwest Africa 6474 (NWA 6474) (Northwest Africa) Purchased: Sept 2010 Classification: Primitive achondrite (Brachinite) History: Purchased in 2010 September by Marc Jost from a dealer in Smara, Western Sahara. Physical characteristics: A single dark brown stone weighing 312 g. Petrography: Protogranular aggregate of olivine, clinopyroxene, zincian chromite, troilite, chlorapatite, minor intermediate plagioclase and taenite. Geochemistry: Olivine Fa35.7-36.1, Fe/Mn=71-76; clinopyroxene Fs9.8-10.0Wo45.4-46.0, Fe/Mn=33-35, Cr2O3=0.68-0.70 wt%. Oxygen isotopes (D. Rumble, CIW and R. Tanaka, OkaU): analyses of acid-washed subsamples by laser fluorination gave, respectively δ17O = 1.98, 1.943, 2.181; δ18O = 3.879, 3.829, 4.234; Δ17O = -0.064, -0.073, -0.048 per mil. Classification: Achondrite (brachinite). This specimen has textural and mineralogical similarities to NWA 4882, but differs significantly in its oxygen isotopic composition. Specimens: A total of 20.2 g and one polished thin section are on deposit at UWS. Mr. M. Jost holds the main mass. | ||||||||||||||||||||||||||||||
Data from: MB100 Table 1 Line 1387: |
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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) OkaU: Institute for Study of the Earth's Interior, Okayama University, Misasa Tottori 682-0193, Japan (institutional address) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 100, MAPS 49, E1-E101 (2014)
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Photos: |
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Geography: |
Statistics: This is 1 of 9914 approved meteorites from (Northwest Africa) (plus 1841 unapproved names) |