header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 14 Sep 2019
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 8234
Basic information Name: Northwest Africa 8234
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 8234
Observed fall: No
Year found: 2013
Country: (Northwest Africa)
Mass:help 905 g
Classification
  history:
Meteoritical Bulletin:  MB 103  (2014)  Mesosiderite-C2
Recommended:  Mesosiderite-C2    [explanation]

This is 1 of 5 approved meteorites classified as Mesosiderite-C2.   [show all]
Search for other: Class C mesosiderites, Mesosiderites, and Metal-rich meteorites
Comments: Approved 7 May 2014
Writeuphelp
Writeup from MB 103:

Northwest Africa 8234 (NWA 8234)

(Northwest Africa)

Purchased: Nov 2013

Classification: Mesosiderite (group C2)

History: A 906 g stone was purchased by Michael Farmer in Rissani, Morocco, November 2013.

Physical characteristics: (L. Garvie, ASU) Sawn surface shows even distribution of irregular kamacite (200 to 1500 μm, some to 1 cm), with pyroxene to 4 cm. Center of one slice contains a 0.5 cm vug with ropey, melted interior. Interior of the stone fresh with minor weathering at the surface of the stone.

Petrography: (K. Domanik, UAz) Polished mount shows approximately 50% silicates, 35% metal, 10% troilite, and 5% chromite + phosphate. Silicates are predominantly low-Ca pyroxene (~85% of all silicates). Anorthitic plagioclase occurs as clasts (100-1000 μm) and as small (1-10 μm) patchy inclusions along sutured, low-Ca pyroxene grain boundaries. Olivine is rare (approx. 1-2% of the silicates). Boundaries between pyroxene clasts are well annealed. Distinguishable differences in groupings of mineral clasts are observed on a scale of 4-6 mm and consist of 1) low-Ca pyroxene + coarse-grained (200-2000 μm) metal + coarse-grained (100-1000 μm) troilite; 2) low-Ca pyroxene + coarse-grained metal + large plagioclase clasts + fine grained (<100 μm) troilite; and 3) low-Ca pyroxene + fine grained (<100 μm) olivine + chromite + merrilite + troilite. A 1-mm wide band of more highly shocked material occurs along the outer edge of the sample and is characterized by more finely comminuted breccia fragments cross-cut by Ni-bearing troilite veins running parallel to the edge of the sample. There is recrystallization at pyroxene grain margins and the matrix is also recrystallized.

Geochemistry: (K. Domanik U.A.) EPMA. Low-Ca pyroxene Fs25.5±1.0Wo2.2±0.4, Fe/Mn=26±1, n=22; plagioclase Ab6.6±2.0An93.1±2.1Or0.3± 0.2, n=16; olivine Fa28.4±2.2, Fe/Mn=44±2, n=5; kamacite Fe=92.87±0.46, Ni=5.99±0.30, Co=0.53±0.03 wt%, n=16; taenite Fe=63.66±3.45, Ni=35.79±3.38, Co=0.14±.03 wt%, n=7; Chromite Cr/Cr+Al=67.2±0.5, n=3.

Classification: Stony-iron (mesosiderite). Textures and mineralogy suggest a group C mesosiderite of textural type 2.

Specimens: 20.6 g slice at ASU.

Data from:
  MB103
  Table 0
  Line 0:
Place of purchase:Rissani, Morocco
Date:P Nov 2013
Mass (g):905
Pieces:1
Class:Mesosiderite-C2
Weathering grade:W1
Fayalite (mol%):28.4±2.2
Ferrosilite (mol%):25.5±1.3
Wollastonite (mol%):2.2±0.4
Classifier:K. Domanik, UAz; L. Garvie, ASU
Type spec mass (g):20.3
Type spec location:ASU
Main mass:MFarmer
Comments:Submitted by L. Garvie
Institutions
   and collections
ASU: Center for Meteorite Studies, Arizona State University, Tempe, Arizona 85287-1404, United States; Website (institutional address; updated 14 Jan 2012)
UAz: Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721, United States (institutional address; updated 14 Jan 2012)
MFarmer: Michael Farmer, P.O. Box 86059, Tucson, AZ 85754-6059, United States; Website (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:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6900 approved meteorites from (Northwest Africa) (plus 2035 unapproved names)

Direct link to this page