Meteoritical Bulletin: Entry for Northwest Africa 6864

header

MetSoc Home Publications Contacts

Search the Meteoritical Bulletin Database
Last update: 5 Oct 2024
Search for:	Search type:	Search limits:	Display:	Publication:
Names Text Places Classes Years	Contains Starts with Exact Sounds like	NonAntarctic Falls Non-NWAs Has strewnfield		What's new in the last:
Include past classifications in search		Has photo	Limit to approved meteorite names
Search text:

Northwest Africa 6864

Basic information

Name: Northwest Africa 6864
This is an OFFICIAL meteorite name.
Abbreviation: NWA 6864
Observed fall: No
Year found: 2011
Country: (Northwest Africa)
Mass: 2.06 kg

Classification
history:

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

This is 1 of 11 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 6864 (NWA 6864)

Northwest Africa

Purchased: 2011 Apr

Classification: Ordinary chondrite (L3.15)

Petrography: (A. Irving and S. Kuehner, UWS) Medium sized (some to 0.8 mm), closely packed and well-formed chondrules. Minerals are olivine, orthopyroxene, pigeonite, subcalcic augite, sodic plagioclase, chromite, altered kamacite, and troilite.

Geochemistry: Olivine (Fa_0.5-45.8; Cr₂O₃ in ferroan olivine grains ranges from 0.12-0.45 wt.%, mean 0.28 wt.%, s.d. 0.09 wt.%, N = 15), orthopyroxene (Fs_2.3-33.6Wo_0.5-3.4), pigeonite (Fs_18.1Wo_17.6), subcalcic augite (Fs_28.4Wo_26.3). Oxygen isotopes (R. Tanaka, OkaU): analyses of acid-washed subsamples by laser fluorination gave δ¹⁸O 5.671, 6.062; δ¹⁷O 3.649, 4.024; Δ¹⁷O 0.662, 0.830 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). L designation consistent with chondrule size, and O isotopes.

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 Apr
Mass (g):	2061
Pieces:	6
Class:	L3.15
Shock stage:	S2
Weathering grade:	W2
Fayalite (mol%):	0.5-45.8, n=17
Ferrosilite (mol%):	2.3-33.6
Wollastonite (mol%):	0.5-3.4
Classifier:	A. Irving and S. Kuehner, UWS
Type spec mass (g):	21.7
Type spec location:	UWB
Main mass:	S. Ralew
Comments:	SR11-3; 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)
Ralew: Stefan Ralew, Kunibertstraße 29, 12524 Berlin, Germany; Website (private address)

Catalogs:

References:

Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015

Find references in NASA ADS:
Find references in Google Scholar:

Geography:

Coordinates:

Unknown.

Statistics:
This is 1 of 9933 approved meteorites from (Northwest Africa) (plus 1837 unapproved names)

Direct link to this page