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Northwest Africa 4421
Basic information Name: Northwest Africa 4421
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4421
Observed fall: No
Year found: 2006
Country: Morocco
Mass:help 250 g
Meteoritical Bulletin:  MB 93  (2008)  CO3
Recommended:  CO3    [explanation]

This is 1 of 564 approved meteorites (plus 1 unapproved name) classified as CO3.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CM-CO clan chondrites, and CO chondrites
Comments: Approved 6 Mar 2008
Revised 4 Aug 2008: final writeup
Writeup from MB 93:

Northwest Africa 4421                   ~32°19'N, ~4°4'W


Find: May 2006

Carbonaceous chondrite (CO3)

History: One sample, said to have been found in the Gourrama area in the province of Er Rachidia, Morocco, and was purchased by P. Thomas in May 2006.

Physical characteristics: A complete stone, weighing 249.73 g, entirely covered with a black, crackled fusion crust.

Petrography: (M. Bourot-Denise, MNHN). The average grain size of chondrules and chondrule fragments is around 100 µm. The largest chondrule is porphyritic and 1000 µm in diameter. Matrix is abundant, fine, and moderately altered; it is sulfide-rich (troilite, pyrrhotite, pentlandite). In the polished section studied, many CAIs and a few AOAs are present, with dimensions comparable to those of chondrules. In BSE images, 90% of the chondrules and chondrule fragments appear FeO-poor, and their olivines are not zoned. The only FeO-rich silicates are in porphyritic (type II) chondrule fragments. Opaque nodules contain metal and sulfides and are associated with magnetite. Small silicate melt pockets are blackened by tiny metal and sulfide droplets.

Geochemistry: Olivine (mean Fa23.9±22.1, range Fa0.46-55.1; Cr2O3 = 0.28, CaO = 0.25 [both in wt%]); low-Ca pyroxene (mean Fs8.5±8.2, range Fs1.4-25.6). Magnetic susceptibility (J. Gattacceca, CEREGE) log χ = 4.57 (10-9 m3/kg) is consistent with a CO carbonaceous chondrite.

Classification: Carbonaceous chondrite (CO3, estimated subtype 3.2); moderate shock and weathering.

Type specimens: A total of 20.04 g of sample (3 pieces) and one thin section are on deposit at MNHN. Thomas holds the main mass.

Submitted by: M. Bourot-Denise, MNHN.

Data from:
  Table 2
  Line 43:
Place of purchase:Found in Gourrama, Er Rachidia, Morocco
Mass (g):249.73
Type spec mass (g):30.04
Comments:32°19'N, ~4°4'W
   and collections
CEREGE: CEREGE BP 80 Avenue Philibert, Technopole de l'Arbois 13545 Aix-en-Provence Cedex 4 France, France (institutional address; updated 29 Oct 2018)
MNHN: Museum National d'Histoire Naturelle, IMPMC-CP52, 57 rue Cuvier, 75005 Paris, France, France; Website (institutional address)
References: Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008)
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Photos from the Encyclopedia of Meteorites:
Don Edwards   

     Recommended::   (32° 19'N, 4° 4'W)

     This is 1 of 62 approved meteorites from Meknès-Tafilalet, Morocco
     This is 1 of 1523 approved meteorites from Morocco (plus 22 unapproved names) (plus 1 impact crater)
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