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Northwest Africa 8400 | |||||||||||||||||||||
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Basic information | Name: Northwest Africa 8400 This is an OFFICIAL meteorite name. Abbreviation: NWA 8400 Observed fall: No Year found: 2014 Country: Western Sahara Mass: 1026 g | ||||||||||||||||||||
Classification history: |
This is 1 of 32 approved meteorites classified as H7. [show all] Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||
Comments: | Approved 8 Aug 2014 | ||||||||||||||||||||
Writeup |
Writeup from MB 103:
Northwest Africa 8400 (NWA 8400) Western Sahara Found: 2014 Classification: Ordinary chondrite (H7) History: Found by a meteorite hunter on a 2014 Jan-Feb expedition in Western Sahara, and subsequently purchased by Darryl Pitt. Physical characteristics: Single stone with brown weathered exterior. Saw cut reveals polygonal texture of dark colored silicates and metal/sulfides. Petrography: (C. Agee, UNM) Examination of a polished mount shows intergranular texture of olivines and pyroxenes, grain size 50-500 μm, plagioclase >100 μm, ~10% metal and sulfide, numerous oxide veinlets. Geochemistry: (C. Agee and N. Muttik, UNM) Olivine Fa18.6±0.4, Fe/Mn=38±2, n=7; low Ca-pyroxene Fs16.2±0.6Wo3.3±0.5, Fe/Mn=24±1; augite Fs8.9Wo37.4, Fe/Mn=17, Cr2O3=1.3 wt%; plagioclase An28.5±2.0Ab78.3±1.2Or3.3±0.4, n=6. Oxygen isotopes (Karen Ziegler, UNM) Oxygen isotope values of 3 acid-washed aliquots of bulk sample, 1.3, 1.3, 1.1 mg, gave δ17O = 2.979, 3.056, 2.753, δ18O = 4.763, 4.947, 4.212, Δ17O = 0.464, 0.444, 0.529 (linearized, all permil). Classification: H chondrite, H7, based on oxygen isotope values that are in the H-chondrite range, absence of chondrules, recrystallized silicates, remobilized metal-sulfide, Fa and Fs values that are H-chondrite-like. Specimens: 20.5 g including a probe mount on deposit at UNM, DPitt holds the main mass. | ||||||||||||||||||||
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) 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. 103, MAPS 52, 1014, May 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12888/full
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Geography: |
Statistics: This is 1 of 286 approved meteorites from Western Sahara (plus 20 unapproved names) |