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| Northwest Africa 7449 | |||||||||||||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 7449 This is an OFFICIAL meteorite name. Abbreviation: NWA 7449 Observed fall: No Year found: 2009 Country: Western Sahara Mass:  405 g | ||||||||||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 12780 approved meteorites (plus 11 unapproved names) classified as L6. [show all] Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||||||||||||||||||||||
| Comments: | Approved 21 Sep 2012 | ||||||||||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 101:
Northwest Africa 7449 (NWA 7449) 24°08’N, 13°10’W Western Sahara Found: July 2009 Classification: Ordinary chondrite (L6) History: A single, completely fusion crusted stone was found in July 2009 by a nomad in the Gour Lafkah area, Morocco. The stone was broken into three fragments by the finder and eventually sold to collector R. Lenssen by a Moroccan meteorite dealer. The combined mass of the three fragments was 314 g. After the finder was urged to look for more stones, additionally a 91 g stone was found in September or October 2009. The total known mass is 405 g. Physical characteristics: The three fragments of the stone that was found first show black fusion crust, next to a fresh, light grey to white interior. The 91 g stone found a few months later shows minor signs of weathering on the fusion crust and on a broken edge. This 91 g stone is covered by a somewhat thicker fusion crust than the first stone. Petrography: Chondrules are poorly delineated and strongly recrystallized. Plagioclase grains are up to 0.2 mm in size. Troilite shows characteristic twinning lamellae. Besides dispersed grains, chromite and ilmenite form inclusions in iron metal. Cu metal is present at troilite-iron metal contacts. Geochemistry: Electron microprobe analysis yielded olivine Fa23.3 (Fa22.2 by XRD), pyroxene Fs20.0Wo1.0. Cosmogenic radionuclides: (Patrick Weber, Laboratory for High Energy Physics, University of Bern): Gamma-spectroscopy performed in September 2009 showed the presence of the following short-lived radionuclides: 46Sc, 54Mn, 57Co, 22Na, 26Al. The 22Na/26Al activity ratio of 1.3 is in the range of recent falls. By comparison with the mean activities of 57Co, 51Cr, 54Mn and 46Sc at the time of fall of five other recent falls, a terrestrial age of 202±14 days (before Sept. 20, 2009) is estimated, indicating a fall in February or March 2009. Classification: Ordinary chondrite (L6), shock stage S3, no weathering (W0). Specimens: 27.8 g and two polished thin sections: NMBE. 371 g: R. Lenssen collection. | ||||||||||||||||||||||||||||||||||||||||
| Data from: MB101 Table 0 Line 0: |
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| Institutions and collections |
NMBE: Natural History Museum Bern
Bernastrasse 15
CH-3005 Bern
Switzerland, Switzerland; Website (institutional address; updated 2 Mar 2012) Bern: University of Bern, University of Bern, Hochschulstrasse 4, CH-3012 Bern, Switzerland (institutional address) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 101, MAPS 50, 1661, September 2015
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| Photos: |
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Geography:
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Statistics: This is 1 of 50 approved meteorites from Rio de Oro, Western Sahara This is 1 of 280 approved meteorites from Western Sahara (plus 20 unapproved names) | ||||||||||||||||||||||||||||||||||||||||
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| Revision history: |
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