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Northwest Africa 6697
Basic information Name: Northwest Africa 6697
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 6697
Observed fall: No
Year found: 2010
Country: Mauritania
Mass:help 67.1 g
Meteoritical Bulletin:  MB 99  (2011)  C2-ung
Recommended:  C2-ung    [explanation]

This is 1 of 25 approved meteorites classified as C2-ung.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), and Ungrouped chondrites
Comments: Approved 10 May 2011
Writeup from MB 99:

Northwest Africa 6697 (NWA 6697)


Purchased: 2010

Classification: Carbonaceous chondrite (C2, ungrouped)

Petrography: Aqueously altered, ~35 vol% phyllosilicate-rich matrix. Chondrules lack glassy mesostasis. Opaques in the matrix are mainly iron-sulfide and magnetite. Many chondrules are surrounded by ~50 μm phyllosilicate-rich rims. Sparse metallic Fe-Ni in chondrules; metal grains are small and surrounded by sulfide and/or magnetite. Lacks coarse metal grains in chondrules and matrix. Chondrules ~800 μm (compared to 270 µm for CM chondrites). Many chondrules have irregular convoluted boundaries and abundant chondrule fragments in the matrix. Most chondrules are type-I PO and POP and a few BO. AOIs range in size from ~500 to ~1500 μm; they constitute ~2 vol.% of the rock.

Geochemistry: Oxygen isotopes (Byeon-Gak Choi, Seoul-NU): Replicate analyses of acid-washed whole rock samples by laser fluorination gave δ18O = 2.653, 2.475; δ17O = -2.525, -2.358; Δ17O = -3.923, -3.633 (all per mil).

Classification: Carbonaceous chondrite, ungrouped, petrologic grade 2. The whole-rock O-isotopic composition is on the CCAM line, indicating that the rock is not closely related to CR chondrites.

Data from:
  Table 0
  Line 0:
Place of purchase:Northwest Africa
Date:P 2010
Mass (g):67.05
Shock stage:S2
Weathering grade:W2
Fayalite (mol%):10.9±13.3 (n=15)
Ferrosilite (mol%):1.8±1.1 (n=10)
Wollastonite (mol%):1.5±1.1 (n=10)
Classifier:Alan Rubin
Type spec mass (g):16.9 g
Type spec location:UCLA
Main mass:Sean Tutorow
Comments:Submitted by Alan Rubin
Plots: O isotopes:  
   and collections
UCLA: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, United States (institutional address; updated 17 Oct 2011)
Seoul-NU: Department of Earth Science Education, Room# 13-426, Seoul National University, Seoul, Korea, 151-748, South Korea (institutional address; updated 20 Dec 2014)
References: Published in Meteoritical Bulletin, No. 99, April 2012, MAPS 47, E1-E52 (2012) [published online only]
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     This is 1 of 212 approved meteorites from Mauritania (plus 2 unapproved names) (plus 2 impact craters)

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