header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 22 Sep 2022
Search for: Search type: Search limits: Display: Publication:
Names
Text help
Places
Classes
Years
Contains
Starts with
Exact
Sounds like
NonAntarctic
Falls  Non-NWAs
What's new
  in the last:
Include past classifications in search
Limit to approved meteorite names
Search text:  
Northwest Africa 14791
Basic information Name: Northwest Africa 14791
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 14791
Observed fall: No
Year found: 2015
Country: Morocco
Mass:help 278 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 26 Mar 2022
Writeuphelp
Writeup from MB 111:

Northwest Africa 14791 (NWA 14791)

Morocco

Purchased: 2015

Classification: Ordinary chondrite (LL4-6)

History: Sample was purchased in 2015 from A. Aaronson at the Tucson mineral show who acquired it from Morocco. Sample is catalogued at ROM as M58213.

Physical characteristics: Individual with 60% fusion crust, showing dun colored weathering of broken surfaces as well as dun brown weathering fusion crust indicating that stone was 70% buried at find location. Desert polish well developed on non-weathered fusion crust, along with through-going cracks. Physical properties: Magnetic susceptibility measured for a 22.97 g specimen is log χ (× 10-9 m3/kg) = 3.68.

Petrography: Cut face (14 cm2) reveals a green-brown interior, featuring angular cm clasts in a fragmental breccia. Sub mm-size metal grains are sparsely disseminated in stone. Interpreted buried part of stone shows pervasive development of cracks filled with fine grained dun brown material. A polished thin section shows a breccia, including some light colored chondritic clasts set in a chondrule-bearing groundmass. Chondrules are well delineated, showing microcrystalline mesostases and bearing fine-grained dark rims, set in a slightly recystallized matrix bearing individual euhedral olivine grains and chondrule fragments. Olivine and pyroxene grains typically show undulatory extinction and rarely, mosaicism. Clasts of apparently higher petrographic grade occupy 25% of the section, containing poorly defined chondrules in a recrystallized matrix, with metal and silicates showing simplified grain boundaries. In reflected light, metal typically occurs as isolated grains and as kamacite-taenite-sulfide composite clusters, with Fe oxide rims. Sulfide is abundant, occurring as grains and aggregates up to 1 mm size, commonly partly or nearly completely replaced by Fe oxides.

Geochemistry: EPMA: Olivine Fa28.48±0.60 (n=30); Ca-poor pyroxene Fs20.00±5.51Wo1.54±0.92 (n=24); Ca-rich pyroxene Wo42.06±4.22Fs9.05±0.45 (n=5).

Classification: Ordinary chondrite: LL 4-6 (S3) W3. EPMA average compositions for olivine and pyroxene grains and the variation in pyroxene compositions are consistent with LL4 overall classification. Clasts are of higher petrographic grade up to LL6.

Specimens: Type specimen location: ROM. Main mass: D. Gregory.

Data from:
  MB111
  Table 0
  Line 0:
Place of purchase:Tucson, AZ, USA
Date:P 2015
Mass (g):278.18
Pieces:1
Class:LL4-6
Shock stage:S3
Weathering grade:W3
Fayalite (mol%):28.48±0.60
Ferrosilite (mol%):20.00±5.51
Wollastonite (mol%):1.54±0.92
Magnetic suscept.:3.68
Classifier:P. McCausland, ROM, UWO
Type spec mass (g):28.44
Type spec location:ROM
Main mass:DGregory
Comments: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)
DGregory: David Gregory, 230 First Avenue, Suite 108, St. Thomas, Ontario N5R 4P5, Canada (private address)
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 1887 approved meteorites from Morocco (plus 26 unapproved names) (plus 1 impact crater)

Direct link to this page