header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 27 Nov 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:
Limit to approved meteorite names
Search text:  
Northwest Africa 14807
Basic information Name: Northwest Africa 14807
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 14807
Observed fall: No
Year found: 2019
Country: Morocco
Mass:help 36.5 g
Classification
  history:
Recommended:  Mesosiderite-A3    [explanation]

This is 1 of 10 approved meteorites classified as Mesosiderite-A3.   [show all]
Search for other: Class A mesosiderites, Mesosiderites, and Metal-rich meteorites
Comments: Approved 16 May 2022
Writeuphelp
Writeup from MB 111:

Northwest Africa 14807 (NWA 14807)

Morocco

Purchased: 2019

Classification: Mesosiderite (group A3)

History: The meteorite was purchased from Blaine Reed in 2019, who previously purchased it from a Moroccan meteorite dealer. Meteorite catalogued at UWO as UWO 0247.

Physical characteristics: An irregular individual with dark brown fusion crust and lighter brown broken surfaces where weathered away. The main mass longest dimension is 3 cm. Subsampled fragments are those of a somewhat weathered breccia containing metallic grains.

Petrography: Cut faces (4 cm2) reveal an interior containing many irregular elongate metallic grains, with embayed contacts on a silicate matrix. Polished thin section shows a silicate matrix of pitted pyroxene grains typically larger than 100 µm, along with clear olivine grains as irregular clasts with fine grained rims. Low-Ca pyroxene exhibits exsolution of clinopyroxene in two orientations. Pyroxene and olivine grains show sharp to undulatory extinction. Matrix is strongly recrystallized. Poilkiloblastic textures and intergrowth of plagioclase are present throughout the thin section. The total estimated mineral abundances (vol% with XRF mapping) are: 30% metal (kamacite-taenite), 40% low-Ca pyroxene, 15% plagioclase feldspar (anorthite), 5% Cr-rich olivine as clasts, 5% troilite, 5% other accessory minerals as Fe oxide weathering products, silica polymorph, clinopyroxene exsolution, schreibersite, chromite, ilmenite. BSE images show sulfide grains typically in close association with metal, but also as large (mm), spongy aggregates. Fe oxides typically surround and replace metal and pervasively fill cracks. A 50 µm melt vein composed chiefly of of Mg, Si, Ca, O glass contains spheroidal nodules of metallic Fe-Ni ranging in diameter from less than 1 µm to 10 µm.

Geochemistry: EPMA: Low-Ca pyroxene Fs36.6±2.1Wo3.1±0.5; FeO/MnO=25.8 (n=8); High-Ca pyroxene Fs17.4±0.4Wo40.8±0.5 (n=3), anorthite An90±1 (n=6). The low-Ca pyroxene average chemical composition is Fe0.36Mg0.59Mn0.01Ca0.03Si0.98Al0.01O3. A silicate melt vein identified in BSE imaging contains spheroidal nodules of metallic Fe-Ni that also contain P and S of average composition 79.07 wt% Fe, 14.76 wt% Ni, 2.09 wt% S, 1.75 wt% P, 0.72 wt% Co (n=5).

Classification: Mesosiderite-AA. Specimen is highly recrystallized, contains abundant low-Ca pyroxene, with minor clinopyroxene exsolution. Notable abundance of plagioclase and silica polymorph consistent with group A. The presence of a silicate melt vein with metallic spherules implies textural class A3.

Specimens: One polished thin section, one polished section in epoxy, and an assortment of smaller masses (7 fragments totaling 6.13 g, and a bag of smaller pieces totaling 0.22 g) constitute 7.3 g type specimen at UWO. The 27.6 g main mass location is with Simon deBoer.

Data from:
  MB111
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2019
Mass (g):36.5
Pieces:1
Class:Mesosiderite-A3
Shock stage:low
Weathering grade:moderate
Ferrosilite (mol%):36.6±2.1
Wollastonite (mol%):3.1±0.5
Classifier:A.G. McNeil, B.G. Currie, P. McCausland, UWO
Type spec mass (g):7.3
Type spec location:UWO
Main mass:Simon deBoer
Comments:Submitted by P. McCausland (UWO)
Institutions
   and collections
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)
Reed: Blaine Reed, P.O. Box 1141, Delta, CO 81416, United States; Website (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 1903 approved meteorites from Morocco (plus 27 unapproved names) (plus 1 impact crater)

Direct link to this page