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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 284 approved meteorites (plus 2 unapproved names) 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 Photo added 19 Apr 2022
Denis gourgues Photo added 19 Apr 2022
Francois Pacaud   
MeteoriteCollector.org - FCOM - Russ Finney      
Piotr gural100 Photo added 19 Apr 2022
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 8636 approved meteorites from (Northwest Africa) (plus 1884 unapproved names)

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