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Northwest Africa 7418
Basic information Name: Northwest Africa 7418
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7418
Observed fall: No
Year found: 2012
Country: Mauritania
Mass:help 216 g
Classification
  history:
Meteoritical Bulletin:  MB 102  (2013)  LL6-melt breccia
Recommended:  LL6-melt breccia    [explanation]

This is 1 of 8 approved meteorites classified as LL6-melt breccia.   [show all]
Search for other: LL chondrites, LL chondrites (type 4-7), Melted chondrites, Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 29 Sep 2013
Writeuphelp
Writeup from MB 102:

Northwest Africa 7418 (NWA 7418)

Mauritania

Found: 2011

Classification: Ordinary chondrite (LL6, melt breccia)

History: Discovered by local people in Mauritania in 2011, purchased in Nouadhibou in 2012 July.

Physical characteristics: Three light-brown stones, partly covered by fusion crust, 215.7 g in total. Saw-cut surface shows breccia of fine-grained light brown matrix with darker angular clasts. Broken face shows waxy lustre. Magnetic susceptibility log χ = 3.09.

Petrography: Microprobe examination of a thin section shows fine (mean, 40 μm) granophyric matrix of olivine, pyroxene and feldspar, bearing dominantly pyroxene (<0.8 mm), often with poikilitic olivine and feldspar, globular metal and troilite, and olivine (<0.3 mm). Rare relict chondrules are present.

Geochemistry: (R. Bartoschewitz, Bart, P. Appel and B. Mader, Kiel) Olivine: Fa31.6-35.7, mean Fa32.4±1.0 (n=16), Fe/Mn=61±6 (n=14) and Fe/Mn=82±2 (n=2); low Ca pyroxene: Fs25.9-26.7Wo2.6-3.8, mean Fs26.2±0.3Wo3.3±0.5 (n=6); Ca-rich pyroxene: Fs11.2-13.9En46-47Wo39-42; feldspar: An11-14Or4-6; chromite: Cr/(Cr+Al) = 87, Fe/(Fe+Mg) = 88-91.

Classification: Ordinary chondrite (LL6-melt breccia) with anomalous characteristics. Strong recrystallized texture of moderately equilibrated olivine composition, dominantly with LL-chondritic Fe/Mn, plus some grains above the LL ratio.

Specimens: 20 g on deposit at Kiel, main mass Gren (100 g), 72 g with Bart, and 18 g with SBuhl.

Data from:
  MB102
  Table 0
  Line 0:
Place of purchase:Nouadhibou
Date:2011
Mass (g):215.7
Pieces:3
Class:LL6-melt breccia
Shock stage:S3
Weathering grade:W1
Fayalite (mol%):32.4 (31.6-35.7, n=16)
Ferrosilite (mol%):26.2 (25.9-26.7, n=6)
Wollastonite (mol%):3.3 (2.6-3.8)
Magnetic suscept.:3.09
Classifier:Bart
Type spec mass (g):20.0
Type spec location:Kiel
Main mass:Bart
Finder:anonymous
Comments:Submitted by R. Bartoschewitz
Institutions
   and collections
Kiel: Geologisches und Mineralogisches Museum, Institut für Geowissenschaften, Christian-Albrechts-Universität Kiel, Ludewig-Mayn-Str. 10, D-24118 Kiel, Germany, Germany (institutional address; updated 13 Sep 2013)
Bart: Bartoschewitz Meteorite Laboratory, Weiland 37, D-38518 Gifhorn, Germany; Website (private address; updated 30 Nov 2019)
Gren: Andreas Gren, Hamburg, Germany (private address)
SBuhl: Meteorite Recon (Mr. S Buhl), Muehlendamm 86, 22087 Hamburg, Germany (private address; updated 14 May 2010)
Catalogs:
References: Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Mauritania
Coordinates:Unknown.

Statistics:
     This is 1 of 103 approved meteorites from Mauritania (plus 1 unapproved name) (plus 2 impact craters)

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