Meteoritical Bulletin: Entry for Northwest Africa 6925

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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: 1300 g

Classification
history:

Meteoritical Bulletin:	MB 102	(2013)	L3.15
Recommended:			L3.15 [explanation]

This is 1 of 9 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

Writeup

help

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 (Fa_1.5-92.1; Cr₂O₃ in ferroan examples is 0.02-0.39 wt.%, mean 0.20 wt.%, s.d. 0.12 wt.%, N = 10), orthopyroxene (Fs_5.1Wo_0.3, Fs_16.3Wo_3.0), clinopyroxene (Fs_8.6Wo_45.4), Al-Ti-diopside (Fs_0.8Wo_56.9; 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, Burke Museum of Natural History and Culture, Box 353010 Seattle, WA 98195, United States (institutional address; updated 9 Oct 2023)
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:

Credit	Photos
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 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names)

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