header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 6 Aug 2022
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 14640
Basic information Name: Northwest Africa 14640
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 14640
Observed fall: No
Year found: 2021
Country: (Northwest Africa)
Mass:help 72 g
Classification
  history:
Recommended:  Howardite    [explanation]

This is 1 of 421 approved meteorites classified as Howardite.   [show all]
Search for other: Achondrites, HED achondrites, and Howardites
Comments: Approved 19 Mar 2022
Writeuphelp
Writeup from MB 111:

Northwest Africa 14640 (NWA 14640)

Howardite, (Northwest Africa)

Purchased: 2021 Nov

Classification: HED achondrite (Howardite)

History: The meteorite was purchased from a group of meteorites hunters in Nouadhibou, Mauritania in November, 2021.

Physical characteristics: Brownish rock without fusion crust.

Petrography: Polymict breccia composed of up to 5 mm basaltic and black impact clasts and a variety of up to 500 µm sized mineral fragments set in a more fine-grained clastic mineral matrix. Predominant minerals are Fe-rich low-Ca pyroxenes with augite exsolution lamellae, diogenetic low-Ca pyroxene (about 20 vol%), pigeonite, zoned low-Ca pyroxene, and calcic plagioclase. Minor phases include silica, Ti-poor chromite, ilmenite, and FeS. Metallic iron was not detected. Contains secondary calcite and barite.

Geochemistry: low-Ca pyroxene host to augite exsolution lamellae: Fs58.3±0.3Wo2.4±0.3 (Fs57.9-58.7Wo2.0-3.0, FeO/MnO=27-29, n=7); augite exsolution lamellae: Fs28.1±0.7Wo39.9±0.9 (Fs27.2-29.2Wo38.9-41.9, FeO/MnO=28-32, n=7); diogenetic low-Ca pyroxene: Fs27.3±0.8Wo3.8±1.5 (Fs25.8-28.2Wo1.8-6.2, FeO/MnO=23-26, n=7); pigeonite: Fs42.5±0.3Wo15.6±0.3 (Fs42.1-42.9Wo15.2-15.9, FeO/MnO=26-27, n=7); zoned low-Ca-pyroxene: Fs42.7±10.4Wo5.4±1.9 (Fs29.5-59.5Wo2.2-7.2, FeO/MnO=26-33, n=6); calcic plagioclase: An90.0±1.9 (An87.7-92.7, n=8)

Data from:
  MB111
  Table 0
  Line 0:
State/Prov/County:Howardite
Place of purchase:Nouadhibou, Mauritania
Date:P 2021 Nov
Mass (g):72
Pieces:1
Class:Howardite
Shock stage:moderate
Weathering grade:moderate
Ferrosilite (mol%):58.3; 28.1; 27.3; 42.5; 42.7
Wollastonite (mol%):2.4; 39.9; 3.8; 15.6; 5.4
Classifier:A. Greshake, MNB
Type spec mass (g):16.3
Type spec location:MNB
Main mass:Salamu Ali
Comments:Submitted by Ansgar Greshake
Institutions
   and collections
MNB: Museum für Naturkunde, Invalidenstraße 43, D-10115 Berlin, Germany (institutional address; updated 24 Dec 2011)
Catalogs:
References: Published in Meteoritical Bulletin, no. 111, in preparation (2022)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 8559 approved meteorites from (Northwest Africa) (plus 1896 unapproved names)

Direct link to this page