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Northwest Africa 14498
Basic information Name: Northwest Africa 14498
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 14498
Observed fall: No
Year found: 2012
Country: Morocco
Mass:help 246 g
Classification
  history:
Recommended:  LL4-6    [explanation]

This is 1 of 78 approved meteorites classified as LL4-6.   [show all]
Search for other: LL chondrites, LL chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 15 Jan 2022
Writeuphelp
Writeup from MB 111:

Northwest Africa 14498 (NWA 14498)

Morocco

Purchased: 2012

Classification: Ordinary chondrite (LL4-6)

History: Sample was purchased in 2012 from Adam Aaronson at the Tucson mineral show who acquired it from Morocco. Sample is catalogued at ROM as M58214.

Physical characteristics: Single individual, mostly fusion crust covered with well-developed desert polish and minor rusting.

Petrography: Cut surfaces and a petrographic thin section reveal a fragmental breccia, consisting of a green-gray clastic groundmass containing chondrule fragments and angular clasts at all scales ranging up to 2 cm. Clasts are dominantly of petrographic grade 5 and 6 and typically have brown, fine-grained rims of groundmass material. Olivine and pyroxene in chondrule fragments and clasts commonly show undulatory to mosaic extinction. Some clasts in thin section contain shock veins bearing minute sulfide grains. Weathering is limited to Fe-oxide staining near sulfide-rich zones. BSE images show evidence for extensive annealing of all silicate, metal and sulfide grain boundaries in the LL6 clasts. Strings of sub-micron metal inclusions are observed in olivine and Ca-poor pyroxene grains in the LL6 clasts as well as in many smaller monomineralic fragments in the groundmass.

Geochemistry: Olivine is equilibrated throughout meteorite. Ca-poor and Ca-rich pyroxene has varied compositions, but appear equilibrated in the petrographically observed LL6 clasts.EPMA: Olivine Fa30.89±0.48 (n=30); Ca-poor pyroxene Fs23.87±2.20 (n=22); Ca-rich pyroxene Wo33.47±11.36 (n=10); LL6 clasts only: Ca-poor pyroxene Fs24.87±0.56 (n=7); Ca-rich pyroxene Wo40.71±1.89 (n=6); BO chondrule fragment: Ca-poor pyroxene Fs15.55-20.41 (n=2); Ca-rich pyroxene Wo17.33±3.36 (n=3).

Classification: LL4-6 breccia (S4) W1. Breccia contains abundant highly-shocked clasts and appears to be a mechanical mixture of fragments and groundmass.

Specimens: Type specimen mass as slices, a billet and thin section at ROM. Main mass: D. Gregory.

Data from:
  MB111
  Table 0
  Line 0:
Place of purchase:Tucson, AZ, USA
Date:P 2012
Mass (g):246
Pieces:1
Class:LL4-6
Shock stage:S4
Weathering grade:W1
Fayalite (mol%):30.89±0.48
Ferrosilite (mol%):23.87±2.20
Classifier:P. McCausland, ROM, UWO
Type spec mass (g):24.30
Type spec location:ROM
Main mass:GREGORY
Comments:M58214; submitted by V. Di Cecco, ROM
Institutions
   and collections
ROM: Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada (institutional address; updated 18 Oct 2011)
UWO: University of Western Ontario, Department of Earth Sciences, BGS 1026, 1151 Richmond St. N, London, Ontario, Canada N6A 5B7, Canada (institutional address; updated 18 Jul 2015)
Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010)
Catalogs:
References: Published in Meteoritical Bulletin, no. 111, in preparation (2022)
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 1903 approved meteorites from Morocco (plus 27 unapproved names) (plus 1 impact crater)

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