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Northwest Africa 2656
Basic information Name: Northwest Africa 2656
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 2656
Observed fall: No
Year found: 2003
Country: (Northwest Africa)
Mass:help 7.5 kg
Classification
  history:
Meteoritical Bulletin:  MB 90  (2006)  Acapulcoite
Recommended:  Acapulcoite    [explanation]

This is 1 of 74 approved meteorites classified as Acapulcoite.   [show all]
Search for other: Acapulcoite-lodranite family, Acapulcoites, and Primitive achondrites
Comments: Approved 25 Jun 2006
Revised 3 Feb 2006: Revised writeup
Writeuphelp
Writeup from MB 90:

Northwest Africa 2656

Morocco or Algeria

Find: 2003

Achondrite (acapulcoite)

History: A 386 g broken stone with weathered fusion crust (part of a larger ~7.5 kg mass found in 2003) was purchased in Erfoud, Morocco, in 2004 for N. Oakes.

Petrography: (T. Bunch and J. Wittke, NAU; A. Irving, UWS) The specimen is recrystallized into homogeneous polygonal and subhedral grains with a grain size of <1 mm and a ~ equal distribution of phases.

Composition: Olivine (Fa8.0; FeO/MnO = 16–19 [n = 25]), orthopyroxene (Fs8.4Wo2.4; [n = 17]), plagioclase (An18.3– 21.0Or2.8–3.4), chromite ((Cr/Cr+Al) = 0.85; Mg/(Mg+Fe) = 0.41). Troilite, schreibersite, and kamacite are also present. Oxygen isotopes: (D. Rumble, CIW) Replicate analyses by laser fluorination gave δ17O = 1.71, 1.69; δ18O = 5.05, 5.04; ∆17O = −0.953, −0.973 (all ‰).

Classification: Achondrite (acapulcoite); low shock, moderate weathering.

Specimens: A 21 g type specimen and one polished thin section are on deposit at NAU. Oakes holds the main mass.

Data from:
  MB90
  Table 2
  Line 38:
Place of purchase:Unknown
Date:2003
Mass (g):386
Pieces:1
Class:Acp
Shock stage:Low
Weathering grade:W3
Fayalite (mol%):8
Ferrosilite (mol%):8.4
Type spec mass (g):21
Plots: O isotopes:  
Institutions
   and collections
NAU: Geology, Bldg 12 Knoles Dr Northern Arizona University, Flagstaff, AZ 86011, United States; Website (institutional address; updated 12 Apr 2012)
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012)
CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address)
Oakes: Nelson Oakes, Route 1, House 50C, Uniondale, PA 18470, United States; Website (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 90, MAPS 41, 1383-1418 (2006)
Find references in NASA ADS:
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Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
David Hardy   
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6752 approved meteorites from (Northwest Africa) (plus 2052 unapproved names)

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