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| Northwest Africa 12282 | |||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 12282 This is an OFFICIAL meteorite name. Abbreviation: NWA 12282 Observed fall: No Year found: 2016 Country: (Northwest Africa) Mass:  141.5 g | ||||||||||||||||||||||||||
| Classification history: |
This is 1 of 409 approved meteorites classified as Eucrite-pmict. [show all] Search for other: Achondrites, Eucrites, and HED achondrites | ||||||||||||||||||||||||||
| Comments: | Approved 2 Dec 2018 | ||||||||||||||||||||||||||
| Writeup |
Writeup from MB 107:
Northwest Africa 12282 (NWA 12282) (Northwest Africa) Find: 2016 Classification: HED achondrite (Eucrite, polymict) History: Purchased by Michael Farmer from a Moroccan meteorite dealer at the 2016 Tucson Gem and Mineral show. Physical characteristics: Sand-blasted, angular, orange-stained 141.5 g meteorite with patches of fusion crust. Light-colored clasts to 8 mm readily visible at the surface of the stone and supported by a gray matrix. Fresh stone with low weathering. Petrography: (Dillon, S., Dunham, E., Fitch, R., Karageozian, M., Sedler, M., Teichert, Z., ASU): The meteorite is a breccia dominated by angular to sub-rounded grains and clasts to 8 mm. The petrography is based on two slices (4 × 3 cm and 4 × 4 cm), and a polished mount. The 4 × 3 cm slice is light colored with angular to sub-angular clasts to 4 mm in a poorly sorted clastic matrix dominated by pyroxene and plagioclase. The 4 × 4 cm slice is petrographically more varied with a range of clast textures (subophitic, diabasic, granulitic) supported by the eucritic debris. This slice has a prominent 6 × 5 mm subangular fine-grained dark clast containing a 3-mm spherical fine-grained clast with similar mineralogy as the bulk eucrite. Accessory minerals include silica, troilite, chromite, and ilmenite. The majority of the pyroxene grains exhibit exsolution lamellae. Plagioclase shows extensive twinning. Pyroxene grains are primarily Ca-poor pyroxene with Ca-rich pyroxene present in exsolution lamellae. Plagioclase grains are primarily anorthite rich end members. The sample has a low shock grade; one melt clast within a pyroxene clast is present and is potentially representative of a previous higher-stage shock event. Geochemistry: Pyroxene without exsolution lamellae is pigeonite Fs52.6±4.4Wo10.4±5.6, range Fs43.7-55.8Wo6.5-22.0, FeO/MnO=33.2±2.2, n=8. Pyroxene with exsolution lamellae is predominantly clinopyroxene Fs57.2±0.7Wo4.4±0.9, range Fs55.8-58.2Wo2.7-5.4, FeO/MnO=33.0±2.1, n=12, the lamellae are orthopyroxene Fs27.3±0.9Wo41.9±0.7, range Fs26.3-28.8Wo40.7-42.8, FeO/MnO=34.1±1.7, n=8. Plagioclase has composition An88.5±6.0, n = 18. Specimens: An original mass of 141.5 g was acquired by MFarmer; 21.99 g and one thin section is held by ASU. The main mass is held by Michael Farmer. | ||||||||||||||||||||||||||
| Data from: MB107 Table 0 Line 0: |
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| Institutions and collections |
ASU: Center for Meteorite Studies, Arizona State University, Tempe, Arizona 85287-1404, United States; Website (institutional address; updated 14 Jan 2012) MFarmer: Michael Farmer, P.O. Box 86059, Tucson, AZ 85754-6059, United States; Website (private address) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
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| Geography: |
Statistics: This is 1 of 9710 approved meteorites from (Northwest Africa) (plus 1853 unapproved names) | ||||||||||||||||||||||||||
| Also see: |
This lists the most popular meteorites among people who looked up this meteorite.
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| Revision history: |
This lists important revisions made to data for this record.
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