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Northwest Africa 10023 | |||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 10023 This is an OFFICIAL meteorite name. Abbreviation: NWA 10023 Observed fall: No Year found: 2014 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||
Classification history: |
This is 1 of 16 approved meteorites classified as Pallasite, PMG-an. [show all] Search for other: Main group pallasites, Metal-rich meteorites, and Pallasites | ||||||||||||||||||||||||||
Comments: | Approved 16 Mar 2015 | ||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 104:
Northwest Africa 10023 (NWA 10023) (Northwest Africa) Purchased: 2014 Classification: Pallasite (Main group, anomalous) History: Purchased from Rachid Chaoui in December 2014, reportedly found near the Moroccan/Algerian border. Physical characteristics: One piece. Polished saw cuts show angular, orange-brown-green, translucent olivine; some grains up to ~2 cm in size. Metal makes up approximately 30-40% of this meteorite. There is only minor oxidation present. Petrography: (C. Agee, UNM) The etched surface of this pallasite shows approximately 98% of the metal consisting of very fine-grained (<1 μm) plessite, whereas kamacite occurs only as a thin mantling around olivine crystals. Olivine is the only silicate phase present. Accessory schreibersite, chromite, Ni-rich sulfide, and Ca-Mg phosphates were observed. Geochemistry: (C. Agee and N. Muttik, UNM) Olivine Fa12.7±0.6, Fe/Mn=47±3, n=8; plessite Fe=84.0±1.2, Ni=15.4±0.7, Co=0.55±0.08 (all wt%), n=4; kamacite Fe=93.1±3.0, Ni=5.9±0.2, Co=0.88±0.13 (all wt%), n=4; schreibersite Fe=58.8±5.1, Ni=27.9±2.1, Co=0.22±0.00, P=14.8±0.08 (all wt%), n=2; Fe-Ni sulfide Fe=49.9, Ni=16.1, Co=0.24, S=33.9 (all wt%), n=1. Likely farringtonite Mg3(PO4)2 and stanfieldite Ca3Mg3(PO4)4 detected in EDS. Oxygen isotopes (K. Ziegler, UNM): 7 acid-washed fragments analyzed by laser fluorination gave, respectively δ18O= 3.667, 3.554, 3.167, 3.143,3.608, 3.887, 3.368; δ17O= 1.693, 1.630, 1.440, 1.458, 1.668, 1.753, 1.572; Δ17O= -0.243, -0.247, -0.232, -0.202, -0.237, -0.299, -0.206 (linearized, all per mil), mean value δ18O=3.485±0.273, δ17O=1.602±0.118, Δ17O=-0.238±.032 (TFL slope=0.528). Classification: Pallasite, PMG-an. An unusually high amount of the metal is in the form of plessite. Oxygen isotopes indicate an affinity to the pallasite main group. Specimens: 20.3 g including a probe mount on deposit at UNM, DPitt holds the main mass. | ||||||||||||||||||||||||||
Data from: MB104 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. 104, MAPS 52, 2284, Octover 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12930/full
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Geography: |
Statistics: This is 1 of 9305 approved meteorites from (Northwest Africa) (plus 1873 unapproved names) |