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Northwest Africa 7940
Basic information Name: Northwest Africa 7940
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7940
Observed fall: No
Year found: 2013
Country: (Northwest Africa)
Mass:help 184 g
Classification
  history:
Meteoritical Bulletin:  MB 102  (2013)  L3
Recommended:  L3    [explanation]

This is 1 of 707 approved meteorites classified as L3.   [show all]
Search for other: L chondrites, L chondrites (type 3), Ordinary chondrites, and Ordinary chondrites (type 3)
Comments: Approved 30 Dec 2013
Writeuphelp
Writeup from MB 102:

Northwest Africa 7940 (NWA 7940)

(Northwest Africa)

Purchased: 2013 Feb

Classification: Ordinary chondrite (L3)

History: Purchased by Gary Fujihara in February 2013 from a Moroccan dealer at the Tucson Gem and Mineral Show.

Petrography: (A. Irving and S. Kuehner, UWS) Well-formed, closely-packed, medium-sized (0.4-2.2 mm) chondrules. Olivine, orthopyroxene, subcalcic augite, augite, sodic plagioclase, chromite, stained kamacite and troilite.

Geochemistry: Olivine (Fa0.7-60.0; Cr2O3 in ferroan examples is 0.04-0.63 wt.%, mean 0.21±0.20 wt.%, N = 11), orthopyroxene (Fs1.0-22.1Wo0.7-0.4), subcalcic augite (Fs3.4Wo35.9), augite (Fs10.4Wo41.5).

Classification: Ordinary chondrite (L3.15). Estimation of subtype based Cr2O3 distribution in ferroan olivine per Fig. 15a of Grossman and Brearley (2005).

Specimens: 20.7 g and one polished thin section are at UWB. The remainder is held by Mr. G. Fujihara.

Bibliography:
  • Grossman J.N. and Brearley A.J. (2005) The onset of metamorphism in ordinary and carbonaceous chondrites. Meteorit. Planet. Sci. 40, 87-122. (link)
Data from:
  MB102
  Table 0
  Line 0:
Place of purchase:Tucson
Date:P 2013 Feb
Mass (g):184
Pieces:many
Class:L3
Shock stage:S2
Weathering grade:W0/1
Fayalite (mol%):0.7-60.0 (n = 13)
Ferrosilite (mol%):1.0-22.1
Wollastonite (mol%):0.7-0.4
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):20.7
Type spec location:UWB
Main mass:G. Fujihara
Comments:GF13-3; 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)
UWB: University of Washington, Box 353010 Seattle, WA 98195, United States (institutional address; updated 27 Jul 2012)
Catalogs:
References: Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
Find references in NASA ADS:
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Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Aeroliths Collection Theodossiou   
Public domain photographs:
Gary Fujihara      
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7354 approved meteorites from (Northwest Africa) (plus 1958 unapproved names)

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