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Northwest Africa 4801
Basic information Name: Northwest Africa 4801
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4801
Observed fall: No
Year found: 2007
Country: Morocco
Mass:help 252 g
Meteoritical Bulletin:  MB 94  (2008)  Angnte
Recommended:  Angrite    [explanation]

This is 1 of 51 approved meteorites classified as Angrite.   [show all]
Search for other: Achondrites, Angrites
Comments: Approved 28 Sep 2007
Writeup from MB 94:

Northwest Africa 4801


Find: May 2007

Achondrite (angrite)

History: Greg Hupé purchased the single stone in Erfoud, Morocco. The stone is broken into four pieces (total weight 252 g) and was found in Algeria in May 2007.

Physical characteristics: Friable specimen composed of relatively coarse dark reddish-brown, pale yellow-green, white and black grains, with some large white patches (polycrystalline anorthite aggregates). No fusion crust is evident.

Petrography: (A. Irving and S. Kuehner, UWS) The overall texture is granular with the presence of some polygonal grain aggregates and triple grain junctions. Grain size ranges from 0.1–1.2 mm. It is composed mostly of Al-Ti clinopyroxene and pure anorthite (some as polycrystalline aggregates up to 0.5 cm across), with sporadic large Cr-pleonaste grains (up to 200 mm across), calcic olivine, pleonaste, poikilitic merrillite and minor troilite and altered kamacite. Subhedral olivine grains are enclosed by clinopyroxene, and both these and pleonaste are surrounded by interstitial anorthite and merrillite. Pleonaste occurs as small grains throughout the specimen, but also as mantles around the large Cr-pleonaste grains, and those mantles contain abundant chadacrysts of subhedral olivine and clinopyroxene. Small cavities (2–5 μm across) within clinopyroxene contain olivine and anorthite grains. Kirschsteinite is absent, and merrillite is more abundant than in most other known angrites.

Geochemistry: Clinopyroxene (Fs11.8Wo56.9; Al2O3 = 10.6 wt%, TiO2 = 2.4 wt%, FeO/MnO = 133), olivine (Fa45.5Ln2.4, FeO/MnO = 88), spinel (Cr-pleonaste: Cr2O3 = 6.3 wt%, Cr/(Cr + Al) = 0.070, Mg/(Mg + Fe) = 0.451; pleonaste: Cr2O3 = 1.9–2.4 wt%, Cr/(Cr + Al) = 0.021–0.026, Mg/(Mg + Fe) = 0.462–0.467). Oxygen isotopes (D. Rumble, CIW): δ18O = 3.595, 3.544; δ17O = 1.809, 1.823; Δ17O = -0.082, -0.041 ‰.

Classification: Achondrite (angrite).

Specimens: A total of 20.0 g, one polished thin section and one polished mount are on deposit at UWS. GHupé holds the main mass.

Data from:
  Table 2
  Line 59:
Mass (g):252
Fayalite (mol%):45.5 (Ln2.4)
Ferrosilite (mol%):11.8
Wollastonite (mol%):56.9
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):20
Type spec location:UWS
Main mass:GHupé
Comments:Oxygen isotopes (D. Rumble, CIW): δ18O = 3.595, 3.544; δ17O = 1.809, 1.823; Δ17O = -0.082, -0.041 per mil.
Plots: O isotopes:  
   and collections
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)
GHupé: Gregory M. Hupé, 9003 Placid Lakes Blvd., Lake Placid, FL 33852, United States; Website (private address)
References: Published in Meteoritical Bulletin, no. 94, MAPS 43, 1551-1588 (2008)
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Photos from the Encyclopedia of Meteorites:
The Hupe Collection   
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Gregor H.   
Solar Anamnesis         


     This is 1 of 2082 approved meteorites from Morocco (plus 31 unapproved names) (plus 1 impact crater)

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