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Northwest Africa 6686 | |||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 6686 This is an OFFICIAL meteorite name. Abbreviation: NWA 6686 Observed fall: No Year found: 2010 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||
Classification history: |
This is 1 of 453 approved meteorites classified as Howardite. [show all] Search for other: Achondrites, HED achondrites, and Howardites | ||||||||||||||||||||||||||
Comments: | Approved 16 Dec 2011 | ||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 100:
Northwest Africa 6686 (NWA 6686) (Northwest Africa) Purchased: 2010 Classification: HED achondrite (Howardite) History: Found by an anonymous person in Western Sahara and purchased 2010 in Erfoud by G.Tomelleri. Physical characteristics: The main mass weighs 62 g has no fusion crust. Petrography: (V. Moggi Cecchi, G. Pratesi, S. Caporali MSP): A polymict breccia consisting of diogenitic and eucritic clasts. Diogenitic clasts are composed mainly of orthopyroxene (92% by volume), with minor olivine (5%), and plagioclase (3%). Eucritic clasts are dominated by clinopyroxene, with minor orthopyroxene displaying very fine (1-2 μm width) exsolution lamellae and anorthitic plagioclase. Minor phases include ilmenite and chromite. Geochemistry: Diogenitic clasts show low-Ca pyroxene (Fs19-43En79-53Wo1-3) and olivine (Fa31-34); eucritic clasts show calcic plagioclase (An88-91), pigeonite (Fs51-47En37-36Wo12-17); exsolution lamellae in low-Ca pyroxene Fs51-33En40-29Wo9-38. Oxygen isotopes: (I. Franchi, R. Greenwood, OU) δ17O = 1.58, δ18O = 3.48, Δ17O = -0.24 per mil. Classification: Achondrite (howardite) with high degree of shock and low degree of weathering. Specimens: 12.5 g and one thin section are on deposit at MSP (MSP 5152). | ||||||||||||||||||||||||||
Data from: MB100 Table 1 Line 1482: |
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Plots: | O isotopes: | ||||||||||||||||||||||||||
Institutions and collections |
MSP: Museo di Scienze Planetarie, Via Galcianese 20/H, 59100 Prato, Italy, Italy; Website (institutional address; updated 22 Oct 2022) OU: Planetary and Space Sciences Department of Physical Sciences The Open University Walton Hall Milton Keynes MK7 6AA United Kingdom, United Kingdom (institutional address; updated 8 Dec 2011) |
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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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Photos: |
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Geography: |
Statistics: This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names) |