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Northwest Africa 8686 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 8686 This is an OFFICIAL meteorite name. Abbreviation: NWA 8686 Observed fall: No Year found: 2014 Country: (Northwest Africa) Mass: 376 g | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 330 approved meteorites (plus 2 unapproved names) classified as Martian (shergottite). [show all] Search for other: Martian meteorites | ||||||||||||||||||||||||||||||
Comments: | Approved 13 Dec 2014 | ||||||||||||||||||||||||||||||
Writeup |
Writeup from MB 103:
Northwest Africa 8686 (NWA 8686) (Northwest Africa) Purchased: 2014 Classification: Martian meteorite (Shergottite) History: Purchased by Aziz Habibi in Morocco, 2014. Physical characteristics: Single stone with weathered fusion crust, some light colored desert sediment coating, broken surface reveals-fine grained, light gray-green basaltic texture. Petrography: (C. Agee, UNM) Microprobe examination of a polished epoxy mount shows ~10% olivine, ~60% pyroxene, ~25% maskelynite, ubiquitous Cr-Ti-Fe oxides and troilite. Pyroxenes and olivines show igneous zonation in BSE images, heavily shocked, grain size ranges from ~50-500 μm. Geochemistry: (C. Agee and N. Muttik, UNM) EMPA. Olivine Fa49.9±4.9, Fe/Mn=55±1, n=24; pigeonite Fs31.8±4.6Wo10.1±2.2, Fe/Mn=31±2, n=36; augite Fs24.0±2.6Wo29.4±5.0, Fe/Mn=29±2, n=7; maskelynite Or3.1±0.5Ab48.5±3.0An48.3±3.4, n=12. Oxygen Isotopes, laser fluorination (K. Ziegler, UNM), analyses on 3 acid-washed aliquots, 0.9, 1.3, 1.5 mg, gave values δ17O=2.879, 2.723, 2.511, δ18O=4.984, 4.671, 4.417, Δ17O=0.247, 0.257, 0.179 (linearized, all permil). Classification: Achondrite (Martian basalt), olivine-phyric shergottite, zoned olivines and pigeonites show significant iron-enrichment trend. Specimens: 20.4 g including microprobe mount on deposit UNM, Aziz Habibi 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) |
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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 9921 approved meteorites from (Northwest Africa) (plus 1838 unapproved names) |