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Northwest Africa 4468
Basic information Name: Northwest Africa 4468
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4468
Observed fall: No
Year found: 2006
Country: (Northwest Africa)
Mass:help 675 g
Classification
  history:
Meteoritical Bulletin:  MB 91  (2007)  Martian (basaltic shergottite)
Recommended:  Martian (shergottite)    [explanation]

This is 1 of 107 approved meteorites (plus 1 unapproved name) classified as Martian (shergottite).   [show all]
Search for other: Martian meteorites
Comments: Approved 28 Mar 2007
Writeuphelp
Writeup from MB 91:

Northwest Africa 4468

Northwest Africa

Find: Summer 2006

Achondrite (Martian, basaltic shergottite)

History: Found in the western part of the Sahara in summer 2006 and purchased in Laâyoune by G. Hupé in July 2006.
Physical characteristics: A single 675 g ellipsoidal stone, mostly coated by shiny black fusion crust, and broken at one end revealing the pale yellow-green interior.

Petrography: (A. Irving and S. Kuehner, UWS) Large ovoid pyroxene oikocrysts (2–10 mm across) enclosing chadacrysts of Ti-poor chromite and olivine are set in an interstitial matrix of 35% olivine, 30% clinopyroxene, 25% maskelynite (all vol%), Ti-chromite, ilmenite, merrillite, Cl-apatite (as prisms up to 0.8 mm long), and pyrrhotite. Inclusions (up to 300 µm across) surrounded by radial shock relaxation fractures occur within matrix olivine grains; some are quenched melt inclusions and others consist mainly of maskelynite. The specimen is cross-cut by sporadic, thin, dark, glassy shock veins (Irving et al. 2007).

Mineral compositions and geochemistry: Pyroxene oikocrysts are zoned from orthopyroxene cores (Fs24.5Wo4.4; FeO/MnO = 35.4) with mantles of pigeonite (Fs26.3Wo6.3; FeO/MnO = 29.4) to augite rims (Fs17.9Wo33.6; FeO/MnO = 24.9). Olivine chadacrysts (as magnesian as Fa28.8) typically become progressively more ferroan from pyroxene core to rim (up to Fa39.9). Matrix olivine (Fa40.7; FeO/MnO = 50.2), matrix clinopyroxene (Fs31.3Wo8.1, Fs19.6Wo31.3), matrix maskelynite (An38.7–54Or3.9–2.3); maskelynite in inclusions within olivine is inhomogeneous and K-Na-rich (Or52.6Ab40.7An6.7).

Classification: Achondrite (Martian, basaltic shergottite).

Type specimen: A total of 20.2 g and one large 3.8 × 2.8 cm thin section are on deposit at UWS. G. Hupé holds the main mass.

Data from:
  MB91
  Table 2
  Line 340:
Place of purchase:Laâyoune, Morocco
Date:2006
Mass (g):675
Pieces:1
Class:Martian
Weathering grade:minimal
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):20.2
Type spec location:UWS
Main mass:G. Hupé
Institutions
   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)
Catalogs:
References: Published in Meteoritical Bulletin, no. 91, MAPS 42, 413-466 (2007)
Find references in NASA ADS:
Find references in Google Scholar:
Photos:
CreditPhotos
Photos from the Encyclopedia of Meteorites:
The Hupe Collection      
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Chris Handler   
Denis gourgues   
Francois Pacaud   
MeteoriteCollector.org - FCOM - Russ Finney      
Piotr gural100   
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 4267 approved meteorites from (Northwest Africa) (plus 2445 unapproved names)

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