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| Northwest Africa 4271 | |||||||||||||
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| Basic information | Name: Northwest Africa 4271 This is an OFFICIAL meteorite name. Abbreviation: NWA 4271 Observed fall: No Year found: 2003 Country: Algeria Mass:  6 g | ||||||||||||
| Classification history: |
This is 1 of 425 approved meteorites classified as Eucrite-pmict. [show all] Search for other: Achondrites, Eucrites, and HED achondrites | ||||||||||||
| Comments: | Approved 24 Jul 2007 | ||||||||||||
| Writeup |
Writeup from MB 92:
Northwest Africa 4271 27°57'N, 7°50'W Hamada du Draa, southwest of Algeria Find: February 2003 Achondrite (eucrite, polymict) History: The meteorite found by Nomads in Hamada du Draa, southwest of Algeria. Physical characteristics: The stone displays a fine fusion crust and weighs 6 g. Petrography: (A. Seddiki, Ud'OEA and UJM; B. Moine, J.Y. Cottin, UJM; M. Denise, V. Sautter, J.P. Lorand, MNHNP). The stone has a fine to medium grained, brecciated texture containing mineral fragments of plagioclase, diogenitic pyroxenes, spinel, olivine and silica.The rock also contains some basaltic fragments displaying both ophitic and sub-ophitic textures, formed by plagioclase and pigeonite; some pigeonite grains also display augite exsolution lamellae.Diogenitic fragments are low in abundance (<10%). Mineral compositions and geochemistry: Mineral fragments: plagioclase (An88.4), diogenitic pyroxenes (En67.4-75.9, Wo2.0-3.0), spinel (cr# = 0.89), olivine (Fa67-80).Basaltic fragments: plagioclase (An85.8-93.6), pigeonite (En37.2,Wo7.7), pigeonite with augite lamellae (En39.6,Wo41.4).Oxygen isotopes: (R. Greenwood, OU) δ18O=3.34 and δ 17O=1.25, Δ17O = -0.48 (all ‰). Classification: Achondrite (eucrite, polymict); moderate shock and minor weathering. Type specimens: A total of 2.55 g of sample is on deposit at MNHNP. One thin section, one inclusion and a powder aliquot (430 mg) are on deposit at UJM. An anonymous finder holds the main mass. | ||||||||||||
| Data from: MB92 Table 2 Line 20: |
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| Plots: | O isotopes: | ||||||||||||
| Institutions and collections |
MNHNP: Museum National d'Histoire Naturelle, IMPMC-CP52, 57 rue Cuvier, 75005 Paris, France, France; Website (institutional address) 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) UJM: Université Jean Monnet, Saint-Etienne, France (institutional address) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 92, MAPS 42, 1647-1694 (2007)
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Geography:
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Statistics: This is 1 of 61 approved meteorites from Tindouf, Algeria (plus 1 impact crater) This is 1 of 1402 approved meteorites from Algeria (plus 33 unapproved names) (plus 4 impact craters) | ||||||||||||
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