header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 21 Feb 2021
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 12911
Basic information Name: Northwest Africa 12911
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12911
Observed fall: No
Year found: 2003
Country: (Northwest Africa)
Mass:help 540 g
Classification
  history:
Meteoritical Bulletin:  MB 108  (2020)  L6
Recommended:  L6    [explanation]

This is 1 of 11485 approved meteorites (plus 6 unapproved names) classified as L6.   [show all]
Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 26 Sep 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12911 (NWA 12911)

(Northwest Africa)

Purchased: 2003

Classification: Ordinary chondrite (L6)

History: Baird purchased at a meteorite auction in Tucson in 2003, and donated an end piece to Cascadia in 2013.

Physical characteristics: The exterior of the end piece is covered by a dark brown/black fusion crust and is faceted. The cut face is polished; most of the face is dark brown, lacks readily defined chondrules, and contains almost no visible metal/sulfide grains. One side of the cut face is light gray and contains moderately abundant metal/sulfide grains.

Petrography: (M. Hutson, A. Ruzicka, W. Fish, Cascadia): The texture of the silicates in thin section are relatively well-integrated; indistinct chondrules are visible. Plagioclase feldspar grains up to 70 microns across are present. Approximately 60-70% of metal and sulfide grains have been replaced.

Geochemistry: Mineral compositions and geochemistry: Olivine and pyroxene grains are equilibrated: Fa25.7±0.5, N=14; Fs21.4±0.1Wo1.6±0.2, N=13.

Classification: Ordinary chondrite (L6) based on chemistry and texture.

Specimens: Cascadia holds 22.2 g in two pieces, in addition to two polished thin sections and a mounted butt. The main mass is held by Baird: Jerry Baird, Lake Havasu City, AZ.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Tucson
Date:P 2003
Mass (g):540.0
Pieces:1
Class:L6
Weathering grade:W3
Fayalite (mol%):25.7±0.5 (N=14)
Ferrosilite (mol%):21.4±0.1 (N=13)
Wollastonite (mol%):1.6±0.2 (N=13)
Classifier:M. Hutson and W. Fish, Cascadia
Type spec mass (g):22.2
Type spec location:Cascadia
Main mass:Baird
Comments:Lab number CML 0710; submitted by Melinda Hutson
Institutions
   and collections
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7579 approved meteorites from (Northwest Africa) (plus 1969 unapproved names)

Direct link to this page