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Northwest Africa 11576
Basic information Name: Northwest Africa 11576
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 11576
Observed fall: No
Year found: 2017
Country: (Northwest Africa)
Mass:help 18 kg
Classification
  history:
Recommended:  Eucrite-melt breccia    [explanation]

This is 1 of 25 approved meteorites classified as Eucrite-melt breccia.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 22 Jan 2018
Writeuphelp
Writeup from MB 107:

Northwest Africa 11576 (NWA 11576)

(Northwest Africa)

Purchased: 2017

Classification: HED achondrite (Eucrite, melt breccia)

History: Reportedly found in Mali, September 2017, purchased in Morocco.

Physical characteristics: Single stone, no fusion crust, exterior shows numerous light colored clasts set in a dark matrix of shock melt.

Petrography: (C. Agee, UNM) Microprobe examination shows basaltic clasts with approximately 60% pyroxene and 35% plagioclase grains most in the range 100-200 μm. Many pyroxene grains have exsolution lamellae.

Geochemistry: (C. Agee, UNM) Low-Ca pyroxene Fs62.1±1.1Wo2.7±0.8, Fe/Mn=32±1, n=7; high-Ca pyroxene Fs28.3±1.6Wo42.2±1.8, Fe/Mn=31±1, n=6; plagioclase An88.9±0.4, n=3.

Classification: Eucrite-melt breccia, eucrite clasts are consistent with type 6 (Takeda and Graham, 1991) showing clear compositional separation of low and high calcium pyroxenes.

Specimens: 24.5 g on deposit at UNM, Mohamed Aid holds the main mass.

Bibliography:
  • H. Takeda and A.L. Graham (1991) Degree of equilibration of eucritic pyroxenes and thermal metamorphism of the earliest planetary crust. Meteoritics 26 129-134. (link)
Data from:
  MB107
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2017
Mass (g):18000
Pieces:1
Class:Eucrite-melt breccia
Shock stage:high
Weathering grade:moderate
Ferrosilite (mol%):62.1±1.1, 28.3±1.6
Wollastonite (mol%):2.7±0.8, 42.2±1.8
Classifier:C. Agee, UNM
Type spec mass (g):24.5
Type spec location:UNM
Main mass:Mohamed Aid
Comments:Field name AID 125; 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)
Catalogs:
References: Published in Meteoritical Bulletin, no. 107, in preparation (2018)
Find references in NASA ADS:
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Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Lucian Cojocaru         
Woreczko Jan & Wadi      
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7005 approved meteorites from (Northwest Africa) (plus 2002 unapproved names)

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