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Northwest Africa 13188 | |||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 13188 This is an OFFICIAL meteorite name. Abbreviation: NWA 13188 Observed fall: No Year found: 2018 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||
Classification history: |
This is 1 of 131 approved meteorites classified as Achondrite-ung. [show all] Search for other: Achondrites, Ungrouped achondrites | ||||||||||||||||||||||||||
Comments: | Approved 21 Mar 2020 | ||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 109:
Northwest Africa 13188 (NWA 13188) (Northwest Africa) Purchased: 2018 Jun Classification: Ungrouped achondrite Physical characteristics: Partially crusted stone Petrography: (J. Gattacceca, CEREGE) Igneous rock with overall subopthitic texture. Main minerals are pyroxene (300 μm) and plagioclase (to 400 μm). Abundant vesicles 250 μm in diameter. FeTi oxides (~0.5 vol%) as blebs adjacent to vesicles, or acicular and dendritic within the fine-grained intergrowths of plagioclase and pyroxene that are found around plagioclase crystals. No metal was found. Modal abundances from point counting (vol%): plagioclase 49%, pyroxene 26%, vesicles 8%, fine-grained intergrowth of plagioclase and pyroxene 18%. Geochemistry: Low-Ca pyroxene Fs25.4±6.6Wo8.3±0.7, FeO/MnO=42.2±4.3 (n=5). Ca pyroxene Fs18.4±4.2Wo38.1±0.8, FeO/MnO=60.3±11.7 (n=3). Plagioclase An70.1±4.7Ab29.0±4.4Or0.9±0.3 (n=5). The bulk sample has a basaltic composition with 52.3%wt SiO2; 8.0%wt MgO; 10.1 %wt FeO; 10.5%wt CaO; 14.1 %wt Al2O3 (ICP-OES, V. Debaille, ULB), and is enriched in incompatible trace elements: (La/Sm)N=2, (La/Lu)N=3.5 (ICP-MS, V. Debaille, ULB). Oxygen isotopic composition (J. Gattacceca, C. Sonzogni, CEREGE) from two analyses of acid-washed 1.5 mg aliquots of a powdered 128 mg bulk sample is δ17O=3.885, 4.428, δ18O=7.552, 8.516, Δ17O=-0.042, -0.000‰ (slope 0.52, analytical uncertainties 0.08‰, 0.12‰, 0.03‰ respectively). Classification: Achondrite-ung. The oxygen isotopic composition and mineral chemistry (basaltic composition enriched in incompatible elements) set this rock apart from other achondrites. Specimens: Type specimen at CEREGE. Main mass with A. Jambon. | ||||||||||||||||||||||||||
Data from: MB109 Table 0 Line 0: |
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Plots: | O isotopes: | ||||||||||||||||||||||||||
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) ULB: Université libre de Bruxelles Avenue Franklin Roosevelt 50 - 1050 Bruxelles, Belgium (institutional address; updated 27 Sep 2018) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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Geography: |
Statistics: This is 1 of 9111 approved meteorites from (Northwest Africa) (plus 1873 unapproved names) |