header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 11 Oct 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:
Include past classifications in search
Limit to approved meteorite names
Search text:  
Northwest Africa 6990
Basic information Name: Northwest Africa 6990
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 6990
Observed fall: No
Year found: 2011
Country: Morocco
Mass:help 395 g
Classification
  history:
Meteoritical Bulletin:  MB 100  (2012)  LL7
Recommended:  LL7    [explanation]

This is 1 of 60 approved meteorites classified as LL7.   [show all]
Search for other: LL chondrites, LL chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 28 Nov 2011
Writeuphelp
Writeup from MB 100:

Northwest Africa 6990 (NWA 6990)

Morocco

Found: 2011

Classification: Ordinary chondrite (LL7)

History: Purchased by A. Habibi in 2011.

Physical characteristics: Complete black stone of 380 g and a smaller stone of 15 g.

Petrography: (C. Agee, UNM) Microprobe examination of a polished section shows 65% olivine, 30% low-Ca pyroxene, 3% plagioclase, ubiquitous troilite and chromite, trace augite, pigeonite, and Fe-Ni metal. Polygonal crystalline aggregate, numerous triple junctions.

Geochemistry: (C. Agee and N. Wilson, UNM) EMPA. Olivine Fa28.9±0.3, Fe/Mn=60±3, n=14, low-Ca pyroxene Fs23.8±0.2Wo3.6±0.6, Fe/Mn=36±1, n=10, augite Fs14.6Wo40.7, Fe/Mn=36, n=1, pigeonite Fs21.7Wo9.9, Fe/Mn=33, n=1, plagioclase Or3.7Ab80.5An15.8.

Classification: Ordinary chondrite (LL7), moderate weathering. This is a LL-chondrite, but chondrules are absent, completely recrystallized with an equigranular graniblastic texture, opx with high Wo-content, thus type 7.

Specimens: AHabibi holds the main mass, 22 g including a probe mount on deposit at UNM.

Data from:
  MB100
  Table 1
  Line 1560:
Place of purchase:Morocco
Date:2011
Mass (g):395
Pieces:2
Class:LL7
Fayalite (mol%):28.9±0.3
Ferrosilite (mol%):23.8±0.2
Wollastonite (mol%):3.6±0.6
Classifier:C. Agee, UNM
Type spec mass (g):22
Type spec location:UNM
Main mass:AHabibi
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)
AHabibi: Palms Hotel Club, Erfoud 52200, Morocco (private address; updated 3 Jan 2010)
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 1402 approved meteorites from Morocco (plus 16 unapproved names) (plus 1 impact crater)

Direct link to this page