header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 18 Nov 2023
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:
Include past classifications in search
Limit to approved meteorite names
Search text:  
Northwest Africa 7331
Basic information Name: Northwest Africa 7331
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7331
Observed fall: No
Year found: 2012
Country: Morocco
Mass:help 63.2 g
Classification
  history:
Meteoritical Bulletin:  MB 101  (2012)  Howardite
Recommended:  Howardite    [explanation]

This is 1 of 453 approved meteorites classified as Howardite.   [show all]
Search for other: Achondrites, HED achondrites, and Howardites
Comments: Approved 23 Jul 2012
Writeuphelp
Writeup from MB 101:

Northwest Africa 7331 (NWA 7331)

Morocco

Purchased: 2012 Mar

Classification: HED achondrite (Howardite)

History: Purchased by Sean Tutorow from Morocco, March 2012.

Physical characteristics: Single stone, dark brown, lightly weathered, fusion crusted exterior. Saw cut reveals fresh, brecciated texture, numerous white clasts up to 3 mm set in a medium-gray groundmass.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows a brecciated to cataclastic texture, with three distinct pyroxene populations 42% diogenitic, 32% main-group eucritic, and 25% cumulate eucritic n=65. Some diogenite pyroxenes are larger than 1 mm and zoned, other domains show fine-grained ophitic pyroxene and plagioclase typical of main group or intergranular pyroxene and plagioclase typical of cumulate eucrites. Accessory silica, olivine, chromite, and troilite. Many plagioclase appear maskelynitized.

Geochemistry: (C. Agee and L. Burkemper, UNM) Diogenite low Ca-pyroxene Fs26.4±3.1Wo3.1±1.4, Fe/Mn=30±2, n=27; cumulate eucrite pyroxene Fs38.5±3.5Wo5.7±4.1, Fe/Mn=31±3, n=16; main-group pyroxene Fs54.7±8.2Wo11.3±9.4, Fe/Mn=32±2, n=22 trend from Fs65.1Wo1.4 to Fs29.1Wo42.9; olivine Fa34.3 n=1, plagioclase Or1.1±0.2 Ab16.0±0.7 An82.8±0.9 n=2.

Classification: Achondrite (howardite). Highly shocked (S5) based on the presence of maskelynite, slightly weathered.

Specimens: 14.0 g including a probe mount on deposit at UNM, Sean Tutorow holds the main mass.

Data from:
  MB101
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2012 Mar
Mass (g):63.21
Pieces:1
Class:Howardite
Shock stage:high
Fayalite (mol%):34.3
Ferrosilite (mol%):26.4±3.1, 38.5±3.5, 54.7±8.2
Wollastonite (mol%):3.1±1.4, 5.7±4.1, 11.3±9.4
Classifier:C. Agee, UNM
Type spec mass (g):14.0
Type spec location:UNM
Main mass:Sean Tuturow
Comments:Submitted by C. Agee
Institutions
   and collections		 UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015)
Catalogs:
References: Published in Meteoritical Bulletin, no. 101, MAPS 50, 1661, September 2015
Find references in NASA ADS:
Find references in Google Scholar:
Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
JGarciaMCM   
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 2012 approved meteorites from Morocco (plus 35 unapproved names) (plus 1 impact crater)

Direct link to this page