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Northwest Africa 13790
Basic information Name: Northwest Africa 13790
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 13790
Observed fall: No
Year found: 2020
Country: (Northwest Africa)
Mass:help 838 g
Classification
  history:
Recommended:  Winonaite    [explanation]

This is 1 of 63 approved meteorites classified as Winonaite.   [show all]
Search for other: Primitive achondrites, Winonaites
Comments: Approved 28 Mar 2021
Writeuphelp
Writeup from MB 110:

Northwest Africa 13790 (NWA 13790)

(Northwest Africa)

Purchased: 2020 Nov

Classification: Primitive achondrite (Winonaite)

Physical characteristics: Some fragments have fusion crust. The main mass is 131.4 g.

Petrography: (K. Metzler, IfP) Coarse-grained mafic rock, consisting of olivine (~45 vol%), low-Ca pyroxene (~10 vol%), Ca-rich pyroxene (~20 vol%), plagioclase (~10 vol%), Fe-Ni metal (~15 vol%), and small amounts of troilite. Olivine grains with reverse chemical zoning (Mg-rich reduction rims) occur. Metal occurs as isolated grains and as veins up to several cm in length. The rock shows a metamorphic texture with frequent 120° triple junctions at crystal boundaries and partly poikilitic intergrowths. Typical grain sizes vary between 100 and 500 µm. However, cm-sized areas of olivine and pyroxene, respectively, show identical optical orientation.

Geochemistry: Mineral compositions and geochemistry: The mean olivine composition is Fa3.4±0.6 (Fa2.0-4.1; n=15); Fe/Mn (at.): 15.8. The mean low-Ca pyroxene composition is Fs4.4±0.3Wo1.9±0.2 (Fs3.9-5.0Wo1.6-2.2; n=15); Fe/Mn (at.): 12.6. The mean composition of Ca-rich pyroxene is Fs1.3±0.3Wo43.8±0.6 (Fs0.9-2.2Wo42.9-45.1; n=15); Fe/Mn (at.): 10.7. The mean feldspar composition is An20.9±0.7Or3.0±0.5 (An19.9-22.1Or2.1-3.8; n=10).

Classification: Winonaite, based on the mineral chemistry and the high abundance and shape of Fe-Ni metal.

Data from:
  MB110
  Table 0
  Line 0:
Place of purchase:Nouadhibou, Mauritania
Date:P 2020 Nov
Mass (g):838
Pieces:27
Class:Winonaite
Shock stage:M-S1
Weathering grade:Low
Fayalite (mol%):3.4±0.6
Ferrosilite (mol%):4.4±0.3; 1.3±0.3
Wollastonite (mol%):1.9±0.2; 43.8±0.6
Classifier:K. Metzler, IfP
Type spec mass (g):20
Type spec location:IfP
Main mass:Ben Hoefnagels
Comments:Submitted by K. Metzler, IfP
Institutions
   and collections
IfP: Institut für Planetologie, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany (institutional address; updated 23 Jan 2012)
Catalogs:
References: Published in Meteoritical Bulletin, no. 110, in preparation (2021)
Find references in NASA ADS:
Find references in Google Scholar:
Photos:
CreditPhotos
Public domain photographs:
Knut Metzler      
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 8025 approved meteorites from (Northwest Africa) (plus 1951 unapproved names)

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