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Northwest Africa 12924
Basic information Name: Northwest Africa 12924
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12924
Observed fall: No
Year found: 2018
Country: Niger
Mass:help 5.7 kg
Classification
  history:
Recommended:  H5-melt breccia    [explanation]

This is 1 of 23 approved meteorites classified as H5-melt breccia.   [show all]
Search for other: H chondrites, H chondrites (type 4-7), Melted chondrites, Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 21 Nov 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12924 (NWA 12924)

Niger

Purchased: January 2018

Classification: Ordinary chondrite (H5, melt breccia)

History: Mendy Ouzillou and Dustin Dickens purchased a single 5.7 kg stone directly from a dealer in Laayoune, Morocco in January 2018.

Petrography: (C. Herd, UAb) Examination of a ~3 × 4.5 cm slice and a ~1 × 2 cm slice (later used to make the thin section) shows dark-gray rounded clasts containing metal and silicates with some microporosity, surrounded by lighter-gray microcrystalline domains which often have vein-like morphology relative to the clasts. Metal grains in the clasts are mostly <0.5 mm, but locally up to 8 mm in longest dimension. At thin section scale, the clasts consist of poorly delineated chondrules, metal and sulfides in a typical equilibrated ordinary chondrite texture. Microcrystalline domains are glassy in places, and contain fragments of the larger clasts; these are likely shock melt veins. Other shock effects include strong mosaicism in olivine.

Geochemistry: (C. Herd and L. Tunney, UAb) Data obtained by EMP examination of carbon-coated thin section, grey clasts only: Olivine Fa18.8±0.4 (n=8); Low-Ca Pyroxene Fs16.3±0.2, Wo1.3±0.2 (n=5); Feldspar Or2.5Ab81 (n=1).

Classification: Ordinary chondrite, H5-melt breccia. Likely paired with Tassedet 004.

Specimens: Type specimen of 20.1 g, including one thin section, at UAb. Mendy Ouzillou 2.85 kg, Dustin Dickens 2.85 kg.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Laayoune
Date:P January 2018
Mass (g):5700
Pieces:1
Class:H5-melt breccia
Fayalite (mol%):18.8±0.4 (n=8)
Ferrosilite (mol%):16.3±0.2 (n=5)
Wollastonite (mol%):1.3±0.2 (n=5)
Classifier:C. Herd and L. Tunney, UAb
Type spec mass (g):20.1
Type spec location:UAb
Main mass:Mendy Ouzillou, Dustin Dickens
Comments:Field number MMO-2018-3E; submitted by C. Herd
Institutions
   and collections
UAb: 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB, T6G 2E3, Canada, Canada; Website (institutional address; updated 17 Oct 2011)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Niger
Coordinates:Unknown.

Statistics:
     This is 1 of 69 approved meteorites from Niger (plus 4 unapproved names)

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