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Northwest Africa 8404 | |||||||||||||||||||||||
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Basic information | Name: Northwest Africa 8404 This is an OFFICIAL meteorite name. Abbreviation: NWA 8404 Observed fall: No Year found: 2014 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||
Classification history: |
This is 1 of 18 approved meteorites classified as Diogenite-olivine. [show all] Search for other: Achondrites, Diogenites, and HED achondrites | ||||||||||||||||||||||
Comments: | Approved 29 May 2014 | ||||||||||||||||||||||
Writeup![]() |
Writeup from MB 103:
Northwest Africa 8404 (NWA 8404) (Northwest Africa) Purchased: 2014 Classification: HED achondrite (Diogenite, olivine) History: Purchased by J. Wooddell from a Moroccan dealer, 2014 Feb 7, at the Tucson Gem and Mineral Show. Physical characteristics: Single stone fragment with dull moderately weathered black fusion crust covering 35% of the stone. Broken surface and saw cut reveal numerous mm-sized green crystals set in light yellow groundmass. Petrography: Microprobe examination of a polished mount shows a brecciated texture with large pyroxene grains 300-2000 μm and smaller olivine grains 100-500 μm, many grains are fragmental to cataclastic. Accessory plagioclase, iron metal, and troilite. Minor amounts of iron oxidation. Geochemistry: (C. Agee and N. Muttik, UNM) EMPA. Low Ca-pyroxene Fs25.0±0.3Wo3.3±0.3, Fe/Mn=30±1, n=13; olivine Fa26.8±0.3, Fe/Mn=49±3, n=9; plagioclase An88.2±3.0Ab11.4±2.9Or0.4±0.2, n=4. (Karen Ziegler, UNM) Oxygen isotope values of 3 acid-washed aliquots of bulk sample, 1.0, 1.7, 1.8 mg, gave δ17O = 1.510, 1.328, 1.452, δ18O = 3.477, 3.103, 3.233, Δ17O = -0.326, -0.310, -0.255 (linearized, all permil). Classification: Achondrite (Diogenite-olivine) based on the presence of approximately 25% olivine. Typical δ18O values for diogenites, however two analyses gave anomalously low values for Δ17O. Specimens: 16.1 g plus a thin section on deposit at UNM, J. Wooddell holds the remainder and a mount. | ||||||||||||||||||||||
Data from: MB103 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) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 103, MAPS 52, 1014, May 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12888/full
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Photos: |
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Geography: |
Statistics: This is 1 of 9116 approved meteorites from (Northwest Africa) (plus 1873 unapproved names) |