NWA 11397 ( 6,110 g )

Northwest Africa 11397 (NWA 11397)
Western Sahara
Find: Aug 2015
Classification: HED achondrite (Eucrite, polymict)
History: In July 2015, Hamid Maatallaa, collaborator of MCM, recovered five pieces of the meteorite, which were sent to MCM for study. After the first observations, a sample for analysis was sent to Dr. Llorca, who carried out the classification.
Physical characteristics: Fragile rocks, gray in color, partly covered by a darker crust.
Petrography: Breccia composed of disaggregated eucritic debris and some lithic eucrite clasts in a light matrix. Minerals include anorthite, pigeonite, augite, fayalite, silica polymorph, ilmenite, troilite and chromite. Minor Fe metal.
Geochemistry: Low-Ca pyroxene (Fs54.5±3.0Wo5.3±1.2, FeO/MnO=32-38, n=12), high-Ca pyroxene (Fs25.2±2.6Wo40.8±1.1, FeO/MnO=27-32, n=14); orthopyroxene host (Fs34.5±3.2Wo3.2±0.8, FeO/MnO=24-27, n=18), clinopyroxene exsolution lamella (Fs15.8±1.1Wo42.3±0.9, FeO/MnO=28-31, n=15), plagioclase (An90.3±3.3, n=22), fayalite (Fa92.2±2.0, FeO/MnO=41-42, n=11).
Classification: Eucrite, polymict.
Specimens: 20.4 g at UPC, and 15g in MCM. Javier Franco holds the main mass.
 
Origin or pseudonym:
Tirass, Dakhla
Date:
Aug 2015
Mass (g):
1027
Pieces:
5
Class:
Eucrite-pmict
Shock stage:
low
Weathering grade:
moderate
Fayalite (mol%):
92.2
Ferrosilite (mol%):
54.5
Wollastonite (mol%):
5.3
Classifier:
J. Llorca, UPC
Type spec mass (g):
20.4
Type spec location:
UPC
Main mass:
Javier Franco Meteorites collection (private)
Comments:
Submitted by José García