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Northwest Africa 6925
Basic information Name: Northwest Africa 6925
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 6925
Observed fall: No
Year found: 2011
Country: (Northwest Africa)
Mass:help 1300 g
Classification
  history:
Meteoritical Bulletin:  MB 102  (2013)  L3.15
Recommended:  L3.15    [explanation]

This is 1 of 6 approved meteorites classified as L3.15.   [show all]
Search for other: L chondrites, L chondrites (type 3), Ordinary chondrites, and Ordinary chondrites (type 3)
Comments: Approved 6 Sep 2013
Writeuphelp
Writeup from MB 102:

Northwest Africa 6925 (NWA 6925)

Northwest Africa

Purchased: 2011 Mar

Classification: Ordinary chondrite (L3.15)

Petrography: (A. Irving and S. Kuehner, UWS) Fairly large (to 0.7 mm), well formed and relatively closely packed chondrules in a matrix containing very ferroan silicates and moderate amounts of altered metal. Minerals are olivine, orthopyroxene, clinopyroxene, with accessory altered kamacite, troilite and taenite. A single grain of Al-Ti-diopside may be an exotic component related to CAI.

Geochemistry: Olivine (Fa1.5-92.1; Cr2O3 in ferroan examples is 0.02-0.39 wt.%, mean 0.20 wt.%, s.d. 0.12 wt.%, N = 10), orthopyroxene (Fs5.1Wo0.3, Fs16.3Wo3.0), clinopyroxene (Fs8.6Wo45.4), Al-Ti-diopside (Fs0.8Wo56.9; Al2O3 19.2 wt.%, TiO2 1.5 wt.%, FeO/MnO = 67). Oxygen isotopes (R. Tanaka, OkaU): analyses of acid-washed subsamples by laser fluorination gave δ18O 5.602, 5.529; δ17O 4.062, 4.012; Δ17O 1.110, 1.098 per mil.

Classification: Ordinary chondrite (L3.15). Subtype estimated to be 3.15 based on Cr2O3 range in ferroan olivine. Estimation of subtype based on chart (Fig. 15a) in Grossman and Brearley (2005).

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:Erfoud
Date:P 2011 Mar
Mass (g):1300
Pieces:many
Class:L3.15
Shock stage:S2
Weathering grade:W2
Fayalite (mol%):1.5-92.1, n=12
Ferrosilite (mol%):5.1-16.3
Wollastonite (mol%):0.3-3.0
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):20.3
Type spec location:UWB
Main mass:G. Fujihara
Comments:GF11-4; submitted by A. Irving
Plots: O isotopes:  
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)
OkaU: Institute for Study of the Earth's Interior, Okayama University, Misasa Tottori 682-0193, Japan (institutional address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
Find references in NASA ADS:
Find references in Google Scholar:
Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Chris Spratt   
Edward Krikorian   
Jean-Michel Masson      
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7035 approved meteorites from (Northwest Africa) (plus 2000 unapproved names)

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