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Northwest Africa 13991 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 13991 This is an OFFICIAL meteorite name. Abbreviation: NWA 13991 Observed fall: No Year found: 2009 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 393 approved meteorites classified as Eucrite-pmict. [show all] Search for other: Achondrites, Eucrites, and HED achondrites | ||||||||||||||||||||||||||||||
Comments: | Approved 29 May 2021 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 110:
Northwest Africa 13991 (NWA 13991) (Northwest Africa) Purchased: 2009 Jun Classification: HED achondrite (Eucrite, polymict) History: Purchased from a Moroccan mineral dealer at the mineral show in Sainte-Marie-aux-Mines, France Petrography: (K. Metzler, IfP) Polymict achondritic breccia, consisting of eucritic lithic clasts (subophitic, gabbroic, granulitic) and mineral fragments (pyroxene, plagioclase) set in a fine-grained clastic matrix of related debris. Most pyroxenes exhibit augite exsolution lamellae. Several olivine fragments were found. Accessories are silica polymorph, chromite, troilite, and Ni-bearing metal. Geochemistry: Mineral compositions and geochemistry: Granulitic eucrite clast: low-Ca pyroxene (host) Fs60.8±0.7Wo2.6±0.3 (Fs60.2-61.9Wo2.2-3.1); mean Fe/Mn (at.): 29.3; n=6. Ca-rich pyroxene (exsolution lamellae) Fs29.1±1.3Wo40.2±1.0 (Fs28.0-30.9Wo38.9-41.3); n=6. Plagioclase An87.8±1.0Or0.1±0.2 (An86.6-89.0Or0.0-0.5); n=8. Gabbroic eucrite clast: low-Ca pyroxene (host) Fs33.9±0.3Wo2.1±0.3 (Fs33.5-34.4Wo1.8-2.4); mean Fe/Mn (at.): 27.7; n=6. Ca-rich pyroxene (exsolution lamellae) Fs12.3±0.3Wo44.4±0.3 (Fs11.9-12.6Wo44.0-44.7); n=6. Plagioclase An92.3±0.6Or0.0±0.1 (An91.5-93.1Or0.0-0.1); n=8. Olivine fragments: Fa9.1±1.4 (Fa7.5-10.8); Fe/Mn (at.): 43.8; n=5. Classification: Polymict eucrite | ||||||||||||||||||||||||||||||
Data from: MB110 Table 0 Line 0: |
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Institutions and collections |
IfP: Institut für Planetologie, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany (institutional address; updated 23 Jan 2012) |
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Catalogs: |
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References: | Published in Gattacceca J., McCubbin F.M., Grossman J., Bouvier A., Chabot N.L., D'Orazio M., Goodrich C., Greshake A., Gross J., Komatsu M., Miao B., and Schrader D. (2022) The Meteoritical Bulletin, No. 110. Meteorit. Planet. Sci. 1-4
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Geography: |
Statistics: This is 1 of 9013 approved meteorites from (Northwest Africa) (plus 1869 unapproved names) |