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| Northwest Africa 14700 | |||||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 14700 This is an OFFICIAL meteorite name. Abbreviation: NWA 14700 Observed fall: No Year found: 2021 Country: Mauritania Mass:  127 g | ||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 186 approved meteorites classified as CR2. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), and CR chondrites | ||||||||||||||||||||||||||||||||
| Comments: | Approved 26 May 2022 | ||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 111:
Northwest Africa 14700 (NWA 14700) Mauritania Purchased: 2021 Classification: Carbonaceous chondrite (CR2) History: Found in Mauritania and later bought by Jean Redelsperger from Mohamed Elguirah in 2021. Physical characteristics: A single crusted and oriented stone. Cut face reveals a dark brown interior with large brown chondrules and metal, including a few large millimeter-sized grains. Petrography: (Trygve Prestgard, IPAG) This chondrite contains large chondrules (average apparent diameter of 1022±655 µm, n= 22), which often have mantles of Fe,Ni metal blebs. In addition, metal can be found in the matrix, chondrules or as large millimetre-sized individual grains. Metal grains and their weathering products make up ~5% of the section. The matrix is fine-grained, with an abundance of 29 vol% from point counting (n= 527). Terrestrial weathering is moderate, as indicated by many partially altered metal grains, as well as oxyhydroxide veins crosscutting some chondrules. Sulfides are present, often tens of microns in diameter (mainly, if not exclusively, present in the matrix). Magnetite can be found in the matrix, and rarely inside some chondrules. Combined sulfides and magnetite make up ~1 vol% of the rock. IR spectra of the matrix (T. Prestgard, IPAG) show widespread Fe and Mg-rich phyllosilicates, as well as carbonates. Modest olivine signatures are also present in some of the spectra. The extent of aqueous alteration is likely somewhat comparable to that of Renazzo, based on IR spectra (IPAG) of bulk and matrix material. Geochemistry: Olivine Fa1.5±0.5 (n=6). Low-Ca pyroxene Fs2.4±0.8Wo2.5±1.3 (n=5). Defocused analyses of the matrix FeO 29.9±3.2, analytical total 76.6±1.4 (n=4). The low analytical totals indicate the presence of hydrous phases in the matrix. Classification: Carbonaceous chondrite (CR2). The CR classification is based on petrography and mineral chemistry, the type 2 designation is based on the presence of hydrated silicates and carbonates. Specimens: Type specimen at CEREGE. Main mass with Jean Redelsperger. | ||||||||||||||||||||||||||||||||
| Data from: MB111 Table 0 Line 0: |
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| Institutions and collections |
CEREGE: CEREGE
BP 80
Avenue Philibert, Technopole de l'Arbois
13545 Aix-en-Provence Cedex 4
France, France (institutional address; updated 29 Oct 2018) IPAG: Institut de Planétologie et d’Astrophysique de Grenoble 414, Rue de la Piscine Domaine Universitaire 38400 St-Martin d’Hères , France (institutional address; updated 1 Aug 2013) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 111, in preparation (2022)
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| Photos: |
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Geography:
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Statistics: This is 1 of 192 approved meteorites from Mauritania (plus 1 unapproved name) (plus 2 impact craters) | ||||||||||||||||||||||||||||||||