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Northwest Africa 6957 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 6957 This is an OFFICIAL meteorite name. Abbreviation: NWA 6957 Observed fall: No Year found: 2011 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 188 approved meteorites classified as CR2. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), and CR chondrites | ||||||||||||||||||||||||||||||
Comments: | Approved 6 Sep 2013 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 102:
Northwest Africa 6957 (NWA 6957) (Northwest Africa) Purchased: 2011 Aug Classification: Carbonaceous chondrite (CR2) History: Purchased by Gary Fujihara from a dealer in Erfoud, Morocco in 2011 August. Petrography: (A. Irving and S. Kuehner, UWS) Separated chondrules with prominent rims of altered kamacite (plus some troilite) set in a dark-brown matrix rich in cronstedtite-tochilinite. Minerals are olivine, enstatite, Cr-Al-bearing diopside, altered kamacite and troilite. Geochemistry: Olivine (predominantly highly magnesian Fa1.2-5.2, but there are compositions as ferroan as Fa67.4 in the matrix), enstatite (Fs1.3-1.8Wo0.6-4.6), diopside (Fs3.0Wo39.1; Fs1.2Wo42.9). Oxygen isotopes (R. Tanaka, OkaU): analyses of acid-washed subsamples by laser fluorination gave δ17O = -2.642, -3.316; δ18O = 0.355, -0.505; Δ17O = -2.832, -3.055 per mil. Classification: Carbonaceous chondrite (CR2). The O isotopes together with the low Fa range and presence of cronstedtite-tochilinite make this consistent with a CR. | ||||||||||||||||||||||||||||||
Data from: MB102 Table 0 Line 0: |
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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) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
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Geography: |
Statistics: This is 1 of 9370 approved meteorites from (Northwest Africa) (plus 1875 unapproved names) |