header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 18 Jun 2019
Search for: Search type: Search limits: Display: Publication:
Names
Text help
Places
Classes
Years
Contains
Starts with
Exact
Sounds like
NonAntarctic
Falls  Non-NWAs
What's new
  in the last:
Limit to approved meteorite names
Search text:  
Northwest Africa 7203
Basic information Name: Northwest Africa 7203
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7203
Observed fall: No
Year found: 2011
Country: Morocco
Mass:help 107 g
Classification
  history:
Meteoritical Bulletin:  MB 100  (2012)  Angrite
Recommended:  Angrite    [explanation]

This is 1 of 30 approved meteorites classified as Angrite.   [show all]
Search for other: Achondrites, Angrites
Comments: Approved 8 Mar 2012
Writeuphelp
Writeup from MB 100:

Northwest Africa 7203 (NWA 7203)

(Northwest Africa), Morocco

Purchased: 2011

Classification: Angrite

History: One stone covered by fusion crust was purchased by Luc Labenne in Tucson, Ariz., in 2011.

Petrography: (T. Mikouchi, UTok). The thin section shows a very fine- to medium-grained variolitic texture mainly composed of Ca-rich olivine and anorthitic plagioclase associated with intersitial Al-Ti-rich clinopyroxene. The largest grain size reaches to 1 mm, but it drastically becomes fine-grained showing feather-like intergrowth (<10 μm). Minor phases include ülvospinel and troilite. The presence of thin melt veins (~100 μm wide) suggests moderate shock. The variolitic texture suggests rapid cooling of magma, which is common for "quenched" angrites.

Geochemistry: (T. Mikouchi, UTok). Both olivine and Al-Ti-rich clinopyroxene are extensively zoned up to mg# <0.01. The most magnesian olivine is Fo57, but contains ~1 wt% CaO. Kirschsteinite olivine (up to 20 wt% CaO) coexists with fayalitic olivine, and they show a complex intergrowth texture. The most magnesian Al-Ti-rich pyroxene has mg#=0.5. Al-Ti-rich clinopyroxene has Al2O3=6-10 wt% and TiO2=2-4 wt%. Plagioclase is essentially Na-free and pure anorthite (An>99.5).

Classification: Quenched angrite most similar to NWA 1296, but the texture is different, ruling out the pairing.

Data from:
  MB100
  Table 1
  Line 1673:
State/Prov/County:(Northwest Africa)
Place of purchase:Tucson, Arizona
Date:P 2011
Mass (g):107
Pieces:1
Class:Angrite
Shock stage:moderate
Weathering grade:None
Fayalite (mol%):41-100
Ferrosilite (mol%):23-49
Wollastonite (mol%):51-53
Classifier:T. Mikouchi (UTok) and M. Bizzarro (NHMD)
Type spec mass (g):25
Type spec location:NHMD
Main mass:Martin Bizzarro
Finder:Anonymous
Comments:Submitted by Takashi Mikouchi
Institutions
   and collections
UTok: Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan (institutional address; updated 5 Nov 2011)
NHMD: Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark. , Denmark; Website (institutional address; updated 17 Aug 2012)
Labenne: 23, rue de Esperance, 75013 Paris, France; Website (private address; updated 29 Aug 2012)
Catalogs:
References: Published in Meteoritical Bulletin, no. 100, MAPS 49, E1-E101 (2014)
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 2 approved meteorites from (Northwest Africa), Morocco
     This is 1 of 1370 approved meteorites from Morocco (plus 16 unapproved names) (plus 1 impact crater)

Direct link to this page