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Northwest Africa 15431
Basic information Name: Northwest Africa 15431
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 15431
Observed fall: No
Year found: 2020
Country: (Northwest Africa)
Mass:help 35 g
Classification
  history:
Recommended:  Lunar (frag. breccia)    [explanation]

This is 1 of 26 approved meteorites classified as Lunar (frag. breccia).   [show all]
Search for other: Lunar meteorites
Comments: Approved 19 Nov 2022
Writeuphelp
Writeup from MB 111:

Northwest Africa 15431 (NWA 15431)

(Northwest Africa)

Purchased: Mar 2020

Classification: Lunar meteorite (frag. breccia)

History: Meteorite was purchased by Mr. Jasper Spencer from a Moroccan dealer (Nor Eddine Azelmat) in March 2020 via e-mail. Mr. Spencer sent a 7.9 g end piece to Cascadia for classification.

Physical characteristics: Physical Characteristics: The exterior of the sample is covered with a desert varnish; no evidence of a fusion crust was visible on the end piece received by Cascadia. The cut face shows sub-angular to sub-rounded clasts in a variety of colors, including white, cream, light brown, reddish-brown to black, set in a dark brownish-gray matrix.

Petrography: (M. Hutson and A. Ruzicka, Cascadia): Sample is a breccia comprised of large (up to 3 mm in length) sub-angular to sub-rounded lithic clasts set in a matrix of finer (< 250 µm) angular clastic material. The larger clasts contain abundant glass, while the matrix contains crystalline anorthitic feldspar. Accessory phases include ilmenite, silica polymorph, armalcolite, troilite, FeNi-metal, and Ca-phosphate grains observed in x-ray maps but too small to analyze.

Geochemistry: (M. Hutson and A. Ruzicka, Cascadia): Plagioclase feldspar: Ab4.2±2.0Or0.6±0.4An95.2±2.1, N=33; Glass (in large clasts): Ab4.5±5.6Or1.2±1.4An94.3±6.0, N=21; Olivine: Fa40.1±8.9, Fe/Mn=87.2±5.0, N=9; Low-Ca pyroxene: Fs23.5±8.4Wo3.6±0.6, Fe/Mn=55.0±8.6, N=21; Pigeonite: Fs24.8±7.7Wo10.0±3.9, N=13; Augite: Fs21.8±20.6Wo40.7±9.0, N=19.

Classification: Lunar (frag. breccia). This meteorite is best described as a lunar feldspathic fragmental breccia based on texture and chemistry.

Specimens: Cascadia holds 6.9 g in two pieces, as well as a polished thin section and material in an epoxy butt; Mr. Jasper Spencer holds the main mass.

Data from:
  MB111
  Table 0
  Line 0:
Place of purchase:e-mail
Date:P Mar 2020
Mass (g):35
Pieces:1
Class:Lunar (frag. breccia)
Fayalite (mol%):40.1±8.9 (N=9)
Ferrosilite (mol%):23.5±8.4 (N=21)
Wollastonite (mol%):3.6±0.6 (N=21)
Classifier:M. Hutson and A. Ruzicka, Cascadia
Type spec mass (g):7.9
Type spec location:Cascadia
Main mass:Mr. Jasper Spencer
Comments:Lab number CML 1437; submitted by Melinda Hutson
Institutions
   and collections
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011)
Catalogs:
References: Published in Meteoritical Bulletin, no. 111, in preparation (2022)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 8777 approved meteorites from (Northwest Africa) (plus 1879 unapproved names)

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