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Northwest Africa 6909 | |||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 6909 This is an OFFICIAL meteorite name. Abbreviation: NWA 6909 Observed fall: No Year found: 2009 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||
Classification history: |
This is 1 of 587 approved meteorites (plus 1 unapproved name) classified as Eucrite. [show all] Search for other: Achondrites, Eucrites, and HED achondrites | ||||||||||||||||||||||||||||
Comments: | Approved 29 Nov 2011 | ||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 100:
Northwest Africa 6909 (NWA 6909) Northwest Africa Purchased: Nov 2009 Classification: HED achondrite (Eucrite) Petrography: Dark greenish gray, compact stone with minor weathered fusion crust. Subophitic texture with blocky to lath shaped, calcic plagioclase grains partly enclosed within strongly zoned pigeonite. Accessory minerals include chromite, ulvöspinel intergrown with ilmenite, silica polymorph, troilite and Ni-free metal. Pyroxene grains have cores of relatively magnesian pigeonite (mantled by ferropigeonite) and in turn by symplectitic intergrowths of fayalite+hedenbergite+silica+ilmenite against plagioclase. Geochemistry: Pigeonite cores Fs38.4-40.7Wo7.4-8.2, FeO/MnO=27, ferropigeonite mantles Fs71.0-79.1Wo20.6-17.3, FeO/MnO=36-39, plagioclase An83.4-91.4Or0.2-0.7. Oxygen isotopes (D. Rumble, CIW): duplicate analyses by laser fluorination of acid-washed subsamples gave, respectively δ17O=1.683, 1.647; δ18O=3.647, 3.600; Δ17O= -0.236, -0.247. | ||||||||||||||||||||||||||||
Data from: MB100 Table 1 Line 1530: |
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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) CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 100, MAPS 49, E1-E101 (2014)
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Geography: |
Statistics: This is 1 of 9305 approved meteorites from (Northwest Africa) (plus 1873 unapproved names) |