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Northwest Africa 12543 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 12543 This is an OFFICIAL meteorite name. Abbreviation: NWA 12543 Observed fall: No Year found: 2019 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 | ||||||||||||||||||||||||||||||
Comments: | Approved 31 Mar 2019 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 108:
Northwest Africa 12543 (NWA 12543) Northwest Africa Purchased: 2019 Classification: Primitive achondrite (Winonaite) History: Reportedly found June 2018, purchased by Zuokai Ke in February 2019 from a Moroccan meteorite dealer. Physical characteristics: Single stone, dark color, partial fusion crust on exterior. Saw-cut surfaces shows scattered fine-grained metal set in a mosaic of dark colored silicate minerals. Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows a texturally equilibrated mosaic of forsterite, enstatite, and diopside with grain size in the range 100-300 μm, many triple junctions are present. Fe-Ni metal makes up approximately 5-10% of this meteorite, most grains are 100-300 μm in diameter, there are also fine veinlets of metal or Fe-oxide throughout. No feldspar was observed. Geochemistry: (C. Agee UNM) Forsterite Fa0.6±0.1, Fe/Mn=4±1, n=6; enstatite Fs1.1±0.2Wo1.8±0.2, Fe/Mn=2±0, n=3; diopside Fs1.0±0.6Wo47.0±0.6, Fe/Mn=2±1, n=3. Oxygen isotopes (K. Ziegler, UNM): 3 acid-washed fragments analyzed by laser fluorination gave δ18O=4.662, 5.118, 5.583; δ17O=1.88, 2.12, 2.345; Δ17O=-0.582, -0.582, -0.603 (linearized, all per mil, TFL slope=0.528). Classification: Primitive achondrite (winonaite) based on presence of near-end member magnesian silicates and oxygen isotope values that coincide with the winonaite field. Specimens: 24 g including a probe mount on deposit at UNM, Zuokai Ke holds the main mass. | ||||||||||||||||||||||||||||||
Data from: MB108 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. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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Geography: |
Statistics: This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names) |