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Northwest Africa 13474
Basic information Name: Northwest Africa 13474
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 13474
Observed fall: No
Year found: 2020
Country: Morocco
Mass:help 218 g
Classification
  history:
Recommended:  Martian (shergottite)    [explanation]

This is 1 of 260 approved meteorites (plus 1 unapproved name) classified as Martian (shergottite).   [show all]
Search for other: Martian meteorites
Comments: Approved 11 Nov 2020
Writeuphelp
Writeup from MB 109:

Northwest Africa 13474 (NWA 13474)

Morocco

Purchased: 2020 Mar

Classification: Martian meteorite (Shergottite)

History: Purportedly found in southern Morocco and purchased in Tindouf, Algeria in March 2020. David Lehman is the American agent for the owners.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Coarse grained assemblage of predominantly twinned pyroxene (low-Ca pyroxene, pigeonite and subcalcic augite) and olivine (exhibiting very limited zoning, some grains enclosed in pyroxene) together with interstitial maskelynite (~15 vol.%, some with a curvilinear lath-like habit). Accessory phases include chromite (with variable Ti/Cr), ilmenite, merrillite, pyrrhotite, pentlandite and rare baddeleyite. Melt inclusions surrounded by subradial re-expansion cracks are common in olivine grains, and have rims of aluminous clinopyroxene enclosing assemblages of K-Na-rich feldspathic glass, plagioclase, chlorapatite needles, Fe-Ni sulfides and ilmenite.

Geochemistry: Olivine (Fa43.0-45.6, FeO/MnO = 51-53, N = 6), low-Ca pyroxene (Fs24.6-25.6Wo3.5-6.4, FeO/MnO = 28-31, N = 5), pigeonite (Fs27.3-35.1Wo9.2-12.2, FeO/MnO = 27-31, N = 6), subcalcic augite (Fs17.4-20.3Wo35.1-35.5, FeO/MnO = 27, N = 3), maskelynite (An48.2-55.7Or1.7-2.6, N = 3).

Classification: Shergottite (olivine gabbroic).

Specimens: 20.3 g including one polished thin section at UWB; remainder with Mr. D. Lehman.

Data from:
  MB109
  Table 0
  Line 0:
Place of purchase:Tindouf
Date:P 2020 Mar
Mass (g):218
Pieces:1
Class:Martian (shergottite)
Shock stage:high
Weathering grade:low
Fayalite (mol%):43.0-45.6
Ferrosilite (mol%):24.6-25.6; 27.3-35.1; 17.4-20.3
Wollastonite (mol%):3.5-6.4; 9.2-12.2; 35.1-35.5
Classifier:A. Irving, UWS, and P. Carpenter, WUSL
Type spec mass (g):20.3
Type spec location:UWB
Main mass:D. Lehman
Comments:DL 1034; submitted by A. Irving
Institutions
   and collections
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012)
WUSL: Washington Univ., One Brookings Drive, St. Louis, MO 63130, United States (institutional address; updated 17 Oct 2011)
UWB: University of Washington, Box 353010 Seattle, WA 98195, United States (institutional address; updated 27 Jul 2012)
Catalogs:
References: Published in Meteoritical Bulletin, no. 109, in preparation (2020)
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 1676 approved meteorites from Morocco (plus 25 unapproved names) (plus 1 impact crater)

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