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Northwest Africa 11577
Basic information Name: Northwest Africa 11577
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 11577
Observed fall: No
Year found: 2017
Country: Morocco
Mass:help 86 g
Meteoritical Bulletin:  MB 107  (2018)  Iron, IAB-sHL
Recommended:  Iron, IAB-sHL    [explanation]

This is 1 of 19 approved meteorites classified as Iron, IAB-sHL.   [show all]
Search for other: IAB complex irons, Iron meteorites, and Metal-rich meteorites
Comments: Approved 24 Jan 2018
Writeup from MB 107:

Northwest Africa 11577 (NWA 11577)


Purchased: 2017 Jan

Classification: Iron meteorite (IAB-sHL)

History: Reportedly found in Algeria by nomads in December 2016, subsequently sold to a Moroccan merchant in Ouarzazate, from whom it was purchased by J. Shea.

Physical characteristics: The main mass consists of two tabular specimens approximately 1 cm thick, both having dark brown exteriors.

Petrography: (C. Herd, UAb) SEM investigation of a ~2 × 3 cm polished surface reveals a well-developed Widmanstatten pattern consistent with a finest octahedrite (0.025±0.005 mm; n=16). Some areas of kamacite are coarser, and some kamacite has been replaced by terrestrial oxidation.

Geochemistry: ICP-MS data, using sample of North Chile (Filomena) as standard (C. Herd and G. Chen UAb): Ni = 12.5, Co = 0.55 (both wt%); Ir = 0.12, Ga = 17, Ge = 38, As = 24, W = 0.38, Re = 0.01, Os = 0.22, Cu = 276, Au = 2.7 (all μg/g).

Classification: (C. Herd, UAb): IAB iron, sHL subgroup according to Wasson and Kallemeyn (2002).

Specimens: Type specimen consisting of two representative slices (16.6 and 2.1 g) at UAb. Main mass with Shea.

  • Wasson J.T. and Kallemeyn, G.W. (2002) The IAB iron-meteorite complex: A group, five subgroups, numerous grouplets, closely related, mainly formed by crystal segregation in rapidly cooling melts. Geochim. Cosmochim. Acta 66 2445-2473 (link)
Data from:
  Table 0
  Line 0:
Place of purchase:Ouarzazate
Date:P 2017 Jan
Mass (g):86
Class:Iron, IAB-sHL
Shock stage:low
Weathering grade:low
Classifier:C. Herd, UAb
Type spec mass (g):18.7
Type spec location:UAb
Main mass:J. Shea
Comments:Submitted by C. Herd
   and collections
UAb: 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB, T6G 2E3, Canada, Canada; Website (institutional address; updated 17 Oct 2011)
References: Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
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     This is 1 of 1991 approved meteorites from Morocco (plus 31 unapproved names) (plus 1 impact crater)

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