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Northwest Africa 7400
Basic information Name: Northwest Africa 7400
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7400
Observed fall: No
Year found: 2012
Country: (Northwest Africa)
Mass:help 138 g
Classification
  history:
Meteoritical Bulletin:  MB 102  (2013)  Eucrite-mmict
Recommended:  Eucrite-mmict    [explanation]

This is 1 of 238 approved meteorites classified as Eucrite-mmict.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 3 Jun 2013
Writeuphelp
Writeup from MB 102:

Northwest Africa 7400 (NWA 7400)

(Northwest Africa)

Purchased: 2012 May

Classification: HED achondrite (Eucrite, monomict)

History: Purchased by JAaronson in May 2012 from a delaer in Erfoud, Morocco.

Physical characteristics: Gray 138 g stone with stained metal.

Petrography: (A. Irving and S. Kuehner, UWS) Breccia consisting of relatively small clasts of ophitic-textured basaltic eucrite (with variable grain size) in a fairly abundant matrix composed of mostly fine grained, related crystal debris plus larger grains of heavily oxidized metal (which also occur in some lithic clasts). Minerals are exsolved pigeonite, anorthitic plagioclase, silica polymorph, altered Ni-free metal, ilmenite, rare altered troilite and very rare zircon (as inclusion in ilmenite).

Geochemistry: Orthopyroxene (Fs66.9-67.3Wo1.5-1.4, FeO/MnO = 30-31), clinopyroxene exsolution lamellae (Fs39.3-44.6Wo32.8-26.3, FeO/MnO = 31-32).

Classification: Eucrite (monomict breccia)

Specimens: 20 g of sample and two polished thin sections are on deposit at UWB. JAaronson holds the main mass.

Data from:
  MB102
  Table 0
  Line 0:
Place of purchase:Erfoud
Date:P 2012 May
Mass (g):138
Pieces:1
Class:Eucrite-mmict
Shock stage:low
Weathering grade:moderate
Ferrosilite (mol%):66.9-67.3; 39.3-44.6
Wollastonite (mol%):1.5-1.4; 32.8-26.3
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):20
Type spec location:UWB
Main mass:J. Aaronson
Comments:JA12-4; submitted by A. Irving
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)
UWB: University of Washington, Box 353010 Seattle, WA 98195, United States (institutional address; updated 27 Jul 2012)
Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010)
JAaronson: Joe Aaronson, 8124 Blaikie Ct., Sarasota, FL 34240, United States (private address; updated 3 Jun 2013)
Catalogs:
References: Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7385 approved meteorites from (Northwest Africa) (plus 1955 unapproved names)

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