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Northwest Africa 5298
Basic information Name: Northwest Africa 5298
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 5298
Observed fall: No
Year found: 2008
Country: Morocco
Mass:help 445 g
Classification
  history:
Meteoritical Bulletin:  MB 94  (2008)  Martian (shergottite)
Recommended:  Martian (shergottite)    [explanation]

This is 1 of 174 approved meteorites (plus 1 unapproved name) classified as Martian (shergottite).   [show all]
Search for other: Martian meteorites
Comments: Approved 15 May 2008
Writeuphelp
Writeup from MB 94:

Northwest Africa 5298

Northwest Africa

Find: March 2008

Achondrite (Martian, basaltic shergottite)

History: Found near Bir Gandouz, northwest Africa, in March 2008 and purchased by an anonymous dealer.

Physical characteristics: A single 445 g stone lacking fusion crust with a brown exterior weathered surface (Fig. 3). The fresh interior is composed of yellow green grains with interstitial dark gray patches containing small vesicles.

Petrography: (A. Irving and S. Kuehner, UWS) The rock is composed mainly of intergrown prismatic grains of zoned pyroxene (up to 1.5 mm long) and lath-shaped regions of similar size composed of vesicular material with plagioclase composition. Some of this material is clear isotropic glass, but the majority consists of intersecting domains of subradiating, fibrous, birefringent plagioclase crystallites. Accessory minerals are titanomagnetite, ilmenite, silica polymorph, Na-Fe-merrillite, Cl-apatite, pyrrhotite, fayalite and baddeleyite. Silica is relatively abundant and forms subhedral grains (up to 0.4 mm across) within plagioclase composition material. Pyroxene grains have complex compositional zoning, with highly irregular and curvilinear zone boundaries between augite and pigeonite. Titanomagnetite and ilmenite commonly coexist in adjacent portions of composite grains.

Geochemistry: Pyroxene is zoned from subcalcic augite cores (Fs23.8Wo28.4, FeO/MnO = 26.3) to pigeonite mantles (Fs30.2Wo11.7; FeO/MnO = 30.7) to ferropigeonite rims (Fs68.0Wo15.3, FeO/MnO = 39.4). The average composition of the plagioclase is An51.8Or1.9. Titanomagnetite (TiO2 23.7– 24.5 wt%, FeO 68.7–67.6 wt%, Al2O3 2.1–2.1 wt%); ilmenite (TiO2 48.2–49.0 wt%, FeO 48.4–47.7 wt%).

Classification: Achondrite (Martian, basaltic shergottite).

Type specimens: A total of 20 g and one polished thin section are on deposit at UWS. The main mass holder is anonymous.

Data from:
  MB94
  Table 2
  Line 100:
State/Prov/County:Morocco
Date:Mar-2008
Mass (g):445
Pieces:1
Class:Shergottite
Ferrosilite (mol%):23.8-30.2
Wollastonite (mol%):28.4-11.7
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):20
Type spec location:UWS
Main mass:anonymous
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. 94, MAPS 43, 1551-1588 (2008)
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 1312 approved meteorites from Morocco (plus 14 unapproved names) (plus 1 impact crater)

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