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Northwest Africa 8614
Basic information Name: Northwest Africa 8614
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 8614
Observed fall: No
Year found: 2002
Country: (Northwest Africa)
Mass:help 24 g
Classification
  history:
Meteoritical Bulletin:  MB 103  (2014)  Winonaite
Recommended:  Winonaite    [explanation]

This is 1 of 35 approved meteorites classified as Winonaite.   [show all]
Search for other: Primitive achondrites, Winonaites
Comments: Approved 15 Nov 2014
Writeuphelp
Writeup from MB 103:

Northwest Africa 8614 (NWA 8614)

(Northwest Africa)

Purchased: 2002 Feb

Classification: Primitive achondrite (Winonaite)

History: Purchased February 2002 at the Gem and Mineral show in Tucson by Edwin Thompson from a Moroccan trader. Donated to Cascadia on May 24, 2002.

Physical characteristics: Small rounded specimen, has fusion coat on two flat faces. Elsewhere a dark colored exterior with abundant metal and a few chondrules visible.

Petrography: (K. Farley, A. Ruzicka, K. Armstrong, Cascadia) Dominantly granoblastic texture with over a dozen indistinct chondrules visible in two small thin sections. Apparent chondrule diameter is 0.48±0.27 mm (N=13). Mineralogy determined by EDS mapping suggests the following mode (area%): 44.3 low-Ca pyroxene, 12.3 olivine, 10.1 feldspar, 4.6 high-Ca pyroxene, 6.9 troilite, 10.6 kamacite, 1.4 taenite, 0.2 schreibersite, 0.4 chromite, 0.7 phosphate, 0.2 daubreelite, 8.4 weathering product. Roughly 40% of the metal has been weathered.

Geochemistry: (K. Farley and A. Ruzicka, Cascadia) Olivine (Fa 6.5±0.5, Fe/Mn = 13±2 at., N=18), low-Ca pyroxene (Fs 7.8±0.3Wo 1.4±0.2En 90.9±0.5, Fe/Mn = 8.8±0.8 at., N=28), high-Ca pyroxene (Fs3.5±0.5Wo45.5±0.3En 50.9±0.5, N=19), feldspar (Ab79.9±2.0Or6.4±1.2An13.6±1.2, N=23). Oxygen isotope compositions (acid-treated samples to remove weathering product, K. Ziegler, UNM) of six subsamples spread along a mass fractionation line with average δ17O = 1.416±0.166, δ18O = 3.543±0.297, Δ17O = -0.455±0.046 (linearized values).

Classification: Winonaite. Oxygen Δ17O values lie on an extension of the Clayton and Mayeda (1996) winonaite line and are distinct from acapulcoites and lodranites. Mineralogy and phase compositions are consistent with winonaites. The sample is unusual among winonaites in containing many identifiable chondrules.

Specimens: Cascadia holds the entire sample which includes 21.6 g, 3 polished thin sections, and 2 butts.

Bibliography:
  • Clayton R. N. and Mayeda T. K. (1996) Oxygen isotope studies of achondrites. Geochim. Cosmochim. Acta 60 1999–2017. (link)
Data from:
  MB103
  Table 0
  Line 0:
Place of purchase:Tucson, Arizona
Date:P 2002 Feb
Mass (g):24
Pieces:1
Class:Winonaite
Shock stage:S2
Weathering grade:W2
Fayalite (mol%):6.5 ± 0.5
Ferrosilite (mol%):7.8 ± 0.3
Wollastonite (mol%):1.4 ± 0.2
Classifier:K. Farley and A. Ruzicka, Cascadia
Type spec mass (g):21.6
Type spec location:Cascadia
Main mass:Cascadia
Comments:Lab number CML 0005; submitted by A. Ruzicka
Plots: O isotopes:  
Institutions
   and collections
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011)
UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015)
Thompson: Edwin Thompson, 5150 Dawn St., Lake Oswego, OR 97035, United States (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 103, MAPS 52, 1014, May 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12888/full
Find references in NASA ADS:
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Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6752 approved meteorites from (Northwest Africa) (plus 2052 unapproved names)

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