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Northwest Africa 8724
Basic information Name: Northwest Africa 8724
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 8724
Observed fall: No
Year found: 2014
Country: (Northwest Africa)
Mass:help 491 g
Classification
  history:
Meteoritical Bulletin:  MB 104  (2015)  CO3.2
Recommended:  CO3.2    [explanation]

This is 1 of 13 approved meteorites classified as CO3.2.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CM-CO clan chondrites, and CO chondrites
Comments: Approved 28 Jan 2015
Writeuphelp
Writeup from MB 104:

Northwest Africa 8724 (NWA 8724)

(Northwest Africa)

Found: 2014

Classification: Carbonaceous chondrite (CO3.2)

History: Recovered in April 2014 near the borders of Mauritania, Western Sahara and Algeria. Purchased in Mauritania in June 2014.

Physical characteristics: Single stone. Shiny dark brown weathered exterior. Saw cut reveals small chondrules set in a dark brown matrix.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows numerous chondrules, some fragmental or irregular, most in the size range 50-200 μm, a few up to 400 μm. Scattered metal/sulfide blebs, fine-grained matrix makes up about 40% of this meteorite.

Geochemistry: (C. Agee and N. Muttik, UNM) Ferroan chondrule olivine Fa31.9±9.8, Fe/Mn=116±26, Cr2O3=0.09±0.09, n=33; Type I chondrule low-Ca pyroxene Fs1.9±0.7Wo1.6±1.1, n=5; Type II chondrule low-Ca pyroxene Fs13.2±13.2Wo1.9±1.3, Fe/Mn=60±34, n=12; aluminous diopside Fs3.5±1.3Wo40.9±1.4, n=2; pigeonite Fs52.7Wo15.9, Fe/Mn=74, n=1.

Classification: Carbonaceous chondrite (CO3.2) based on mean value and sigma of Cr2O3 in ferroan olivine, similar values to Kainsaz and Rainbow (both CO3.2) as reported in Grossman and Brearley (2005). Moderately weathered, low shock stage.

Specimens: 20.7 g including a probe mount on deposit at UNM, DPitt holds the main mass.

Bibliography:
  • Grossman J.N. and Brearley A.J. (2005) The onset of metamorphism in ordinary and carbonaceous chondrites. Meteorit. Planet. Sci. 40, 87-122. (link)
Data from:
  MB104
  Table 0
  Line 0:
Place of purchase:Mauritania
Date:2014
Mass (g):490.8
Pieces:1
Class:CO3.2
Shock stage:low
Weathering grade:moderate
Fayalite (mol%):31.9±9.8
Ferrosilite (mol%):13.2±13.2, 1.9±0.7
Wollastonite (mol%):1.9±1.3, 1.6±1.1
Classifier:C. Agee, UNM
Type spec mass (g):20.7
Type spec location:UNM
Main mass:Darryl Pitt
Comments:Field name MAC 61; submitted by C. Agee, UNM
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)
DPitt: Darryl Pitt, 225 West 83rd Street, New York, NY 10024, United States; Website (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 104, MAPS 52, 2284, Octover 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12930/full
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7385 approved meteorites from (Northwest Africa) (plus 1955 unapproved names)

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