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Northwest Africa 11024
Basic information Name: Northwest Africa 11024
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 11024
Observed fall: No
Year found: 2014
Country: (Northwest Africa)
Mass:help 4.7 g
Classification
  history:
Meteoritical Bulletin:  MB 106  (2018)  CM-an
Recommended:  CM-an    [explanation]

This is 1 of 9 approved meteorites classified as CM-an.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), CM chondrites, and CM-CO clan chondrites
Comments: Approved 9 Jan 2017
Writeuphelp
Writeup from MB 106:

Northwest Africa 11024 (NWA 11024)

(Northwest Africa)

Purchased: June 2014

Classification: Carbonaceous chondrite (CM, anomalous)

History: One stone of 4.69 g was purchased in Ensisheim from a Moroccan dealer in June 2014 by Sergey Vassiliev.

Petrography: S. Ebert, A. Bischoff (IfP), D. Harries (UJena): The chondrite consists of 32% chondrules and chondrule fragments (mainly PO and POP), about 54% fine-grained opaque matrix, 9.5% fine-grained dust rims, and 1.2% refractory inclusions (CAIs). Most chondrules have a size of about 150-300 µm and many are surrounded by fine-grained dust rims. Most CAIs are fine-grained, fluffy, spinel-rich inclusions. Many are rimmed by fine-grained dust. Sulfide and some metal present. Most of the metal grains have been destroyed by terrestrial alteration. Carbonate grains are absent. TEM investigations (D. Harries, UJena) of several areas and lithologies (fine-grained dust rims, matrix portions) do not show any phyllosilicates. Instead, the fine-grained inter-chondrule materials mainly consist of nano-crystalline Fe-rich olivine and troilite and small Ni-rich Fe,Ni-metals, which are unaffected by aqueous alteration.

Geochemistry: Mineral composition and geochemistry: S. Ebert, A. Bischoff (IfP) A. Pack (UGött): Most chondrule olivines have Fa<4, but also chondrules and chondrule fragments with olivine of higher Fa-content (up to Fa63) exist. Similarly, most low-Ca pyroxenes are enstatites (Fs<2), but also some low Ca-pyroxenes with somewhat higher Fs-contents exist (e.g., Fs5-13), and  a compound chondrule with abundant low-Ca pyroxene of ~Fs45 was observed. The remaining unweathered large metal grains are Ni-poor (~6 wt% Ni). Two bulk measurements of oxygen isotopes plot with δ18O = 6.85 ‰ and δ17O = -1.6‰ and δ18O = 6.07 ‰ and δ17O = -1.44 ‰, respectively, at the 16O- and 18O-rich edge of the CM-field, clearly distinct from the O-isotope field of the CO3 chondrites.

Classification: The textural observations suggest a CM classification of this rock. This is supported by the O-isotope composition. The lack of hydrous minerals and carbonates suggests a type 3 petrologic type. The olivines do not show undulatory extinction. Thus, the rock is unshocked (S1). Since most of the Ni-poor metal has been destroyed, the sample is strongly weathered (W3).

Specimens: IfP holds the main mass (2.5 g remaining of the 4.7 g) and 2 thin sections.

Data from:
  MB106
  Table 0
  Line 0:
Origin or pseudonym:Desert
Place of purchase:Ensisheim
Date:P June 2014
Mass (g):4.7
Pieces:1
Class:CM-an
Shock stage:low
Weathering grade:high
Fayalite (mol%):13.8±19.7 (0.4-63.4; N=74)
Ferrosilite (mol%):4.1±9.6 (0.7-45.2; N=40)
Wollastonite (mol%):1.9±9.6 (0.4-4.9; N=40)
Classifier:S. Ebert, A. Bischoff, A. Pack, D. Harries, Ifp
Type spec mass (g):4.7
Type spec location:IfP
Main mass:IfP
Comments:Comment: Sample SV-2015-03, submitted by Addi Bischoff; submitted by Addi Bischoff
Plots: O isotopes:  
Institutions
   and collections
IfP: Institut für Planetologie, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany (institutional address; updated 23 Jan 2012)
UJena: Friedrich Schiller University of Jena, Institute of Geosciences, Burgweg 11, 07749 Jena, Germany (institutional address; updated 19 Jul 2011)
Catalogs:
References: Published in Gattacceca J., Bouvier A., Grossman J., Metzler K., and Uehara M. (2019) Meteoritical Bulletin, no. 106. Meteorit. Planet. Sci. 54 in press.
Find references in NASA ADS:
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Photos:
CreditPhotos
Photos from the Encyclopedia of Meteorites:
Sergey Vasiliev   
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6916 approved meteorites from (Northwest Africa) (plus 2027 unapproved names)

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