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| Northwest Africa 13269 | |||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 13269 This is an OFFICIAL meteorite name. Abbreviation: NWA 13269 Observed fall: No Year found: 2019 Country: Mauritania Mass:  740 g | ||||||||||||||||||||||||||
| Classification history: |
This is 1 of 131 approved meteorites classified as Eucrite-unbr. [show all] Search for other: Achondrites, Eucrites, and HED achondrites | ||||||||||||||||||||||||||
| Comments: | Approved 5 Apr 2020 | ||||||||||||||||||||||||||
| Writeup |
Writeup from MB 109:
Northwest Africa 13269 (NWA 13269) Mauritania Purchased: 2019 Classification: HED achondrite (Eucrite, unbrecciated) History: Purchased in December 2019 by Didi Baidari from a Mauritanian meteorite dealer. Physical characteristics: Two matching stones. Fusion crust typical of eucrites, black and shiny with swirls. Broken surface showing scattered phenocrysts of pyroxene up to 4mm in size all embedded in a grey matrix. The stone is unbrecciated. Petrography: (T. Shisseh, FSAC) Fusion crust is 30-100 μm thick and penetrates the interior up to 1.5mm in some areas. Porphyritic texture with pyroxene phenocrysts up to 2-4 mm embedded in a matrix dominated by equilibrated pyroxene showing exsolution lamella with remnant-Ca zoning in rims plus variolitic and blocky plagioclase. Minor phases are silica, chromite, ilmenite and troilite. Pyroxene phenocrysts show rare tiny (~1um) chromite and high-Ca exsolution lamella with often plagioclase veinlets associated with chromite. Clouding is frequently observed in pyroxene and plagioclase located in the matrix. Pyroxenes have minute inclusions of plagioclase, troilite and chromite. Plagioclase clouding is mostly dominated by pyroxene inclusions. Mesostasis is present commonly located between plagioclase laths. Geochemistry: (T. Shisseh, FSAC and C. Agee, UNM) Pyroxene phenocrysts Fs51±1.6 Wo2.4±0.7, Fe/Mn=31±1, Mg#=47±1.7 (n=15); high-Ca pyroxene in matrix: Fs25±7.5 Wo38±9.3 Fe/Mn=28±1.5, Mg#=58±5 (n=8); low-Ca pyroxene in matrix: Fs48±5.2 Wo11.5±6. Fe/Mn=30±0.8, #Mg=45±2 (n=3); plagioclase in matrix An82±3.2Ab15±2.8Or2±2.5 (n=15); plagioclase veinlets in pyroxene phenocrysts An97±0.2Ab2.7±0.18Or0.07±0.07 (n=3). Chromite associated with plagioclase veinlets Chr67.8±1.7 Uvp7±1.5 Spl23±2.7 (n=3). Classification: Unbrecciated eucrite Specimens: 58.4 g including a probe mount on deposit at UNM, Didi Baidari and Habib Naji hold the main mass. | ||||||||||||||||||||||||||
| Data from: MB109 Table 0 Line 0: |
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| Institutions and collections |
FSAC: Universite Hassan II Casablanca, Faculte des Sciences Ain Chock, Departement de Géologie, BP 5366 Maârif, Casablanca, Morocco (institutional address; updated 9 Jan 2013) UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015) |
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| References: | Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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Geography:
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Statistics: This is 1 of 212 approved meteorites from Mauritania (plus 2 unapproved names) (plus 2 impact craters) | ||||||||||||||||||||||||||