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Northwest Africa 4051
Basic information Name: Northwest Africa 4051
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4051
Observed fall: No
Year found: 2004
Country: (Northwest Africa)
Mass:help 828 g
Meteoritical Bulletin:  MB 91  (2007)  Eucrite
Recommended:  Eucrite    [explanation]

This is 1 of 608 approved meteorites (plus 1 unapproved name) classified as Eucrite.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 1 Sep 2006
Writeup from MB 91:

Northwest Africa 4051

Kem Kem Basin, Algeria

Find: April 2004

Achondrite (eucrite)

History: A stone with brownish-black fusion crust was purchased by a member of Moussa Minerals & Fossils, England, in 2004 from a Moroccan dealer.

Physical characteristics: The 828 g meteorite is almost entirely covered in a fusion crust. Terrestrial weathering is present in terms of charred fusion crust and calcite veins occurring throughout the rock.

Petrography: (M. Anand, NHM and OU) The rock consists of large mineral (up to 3 mm) and lithic clasts (up to 6 mm). Pyroxene and plagioclase grains dominate (usually about 100–500 µm), in a highly immature matrix of the same texture and mineral composition but smaller grain size (<100 µm). Plagioclase occurs as subangular to lath-shaped crystals. Minor phases include chromite, ilmenite, silica, iron sulfide, and Fe,Ni-rich metal.

Mineral compositions and geochemistry: EMP analysis, conducted at the NHM, of mineral phases: pigeonite (En50Wo5.2–En38Wo17.5), which is the dominant pyroxene phase containing exsolution lamellae of orthopyroxene (En47Wo2.3–En41Wo5) and in some cases of subcalcic augite = En35Wo26–En35Wo20.5. The Fe/Mn ratio in pyroxenes varies from 27 to 38. The anorthite content of plagioclase varies from An85 to An93. Chromite grains contain Al2O3 = 7–14 and TiO2 = 2–5.6 (both wt%). Ilmenite contains MgO = 0.6–1.3 and MnO = 0.8–1 (both wt%). Oxygen isotopes: (R. C. Greenwood and I. A. Franchi, OU) δ17O = 1.861, δ 18O = 3.994, Δ17O = −0.216 (all as ‰).

Classification: Achondrite (brecciated basaltic eucrite).

Type specimen: A total of 20 g is on deposit at the NHM. Moussa holds the main mass.

Data from:
  Table 2
  Line 169:
Place of purchase:Ken Kem Basin, Morocco
Date:2004 Apr
Mass (g):828
Classifier:Anand, NHM, OU
Type spec mass (g):22.5
Type spec location:NHM
Main mass:Moussa
Plots: O isotopes:  
   and collections
NHM: Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom; Website (institutional address; updated 9 Dec 2011)
OU: Planetary and Space Sciences Department of Physical Sciences The Open University Walton Hall Milton Keynes MK7 6AA United Kingdom, United Kingdom (institutional address; updated 8 Dec 2011)
Moussa: No contact information provided., United Kingdom (private address)
References: Published in Meteoritical Bulletin, no. 91, MAPS 42, 413-466 (2007)
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Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)

     This is 1 of 9825 approved meteorites from (Northwest Africa) (plus 1851 unapproved names)

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