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| Northwest Africa 13288 | |||||||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 13288 This is an OFFICIAL meteorite name. Abbreviation: NWA 13288 Observed fall: No Year found: 2019 Country: (Northwest Africa) Mass:  633 g | ||||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 589 approved meteorites (plus 1 unapproved name) classified as Eucrite. [show all] Search for other: Achondrites, Eucrites, and HED achondrites | ||||||||||||||||||||||||||||||||||
| Comments: | Approved 2 May 2020 | ||||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 109:
Northwest Africa 13288 (NWA 13288) (Northwest Africa) Purchased: 2019 Classification: HED achondrite (Eucrite) History: Marc Jost (SJS) purchased the 633 g sample in June 2019 from Aziz Mouadine at the St. Marie aux Mines show, France. Physical characteristics: Approximately 40% of this irregular-shaped stone is coated by a dark-brown, weathered fusion crust. The cut face shows the sample is a breccia composed of light- to dark-gray, cm-sized igneous-textured clasts. Petrography: Description and classification (A. Love, App) Sample is a breccia composed of irregularly shaped, up to 3 cm, porphyritic (32 vol%) to basaltic (13 vol%) textured eucrite clasts, diogenite clasts (5 vol%) and vitrophyric shock-melted clasts (10 vol%) surrounded by a comminuted matrix of similar materials. Porphyritic eucrites display quenched textures composed of subequal amounts of up to 1 mm to 1 cm long, prismatic, hollow weakly-zoned, low-Ca pyroxene ("soda straw" texture) phenocrysts set within variolitic textured groundmass of 0.5 mm euhedral plagioclase laths. Basaltic clasts display intersertal texture composed of similar pyroxene morphologies and larger (1 mm avg. long dimension) skeletal - lath-shaped plagioclase that occur in a radial arrangement around pyroxenes. Diogenite occurs as unbrecciated, mosaicized crystalline fragments and a brecciated olivine and plagioclase-bearing lithology. Accessory minerals are a silica polymorph, ilmenite, chromite, troilite and phosphates. Geochemistry: (A. Love, App): Diogenite: low Ca-pyroxene (Fs34.2±4.1Wo3.4±0.6, Mg#64.5±4.4, Fe/Mn=31.3±0.8, n=6); olivine (Fa43.0, Fe/Mn=45.9, n=1). Basaltic clast: pigeonite (Fs40.1±3.1Wo16.3±5.0, Mg#52.5±1.7, Fe/Mn=28.1±0.1, n=3); plagioclase (An93.4±1.4Or0.1±0.1, n=2). Quenched clasts: pigeonite (Fs43.8±2.4Wo8.2±2.2, Mg#52.2±3.0, Fe/Mn=27.8±0.8, n=6); augite (Fs24.1Wo40.2, Fe/Mn=25.7, n=1); plagioclase (An81.4±2.8Or1.2±0.4, n=8). Classification: HED achondrite (polymict eucrite breccia). Based on textures and Fe/Mn ratios within pyroxenes, this sample is an HED breccia. Clast lithologies suggest this is a polymict eucrite breccia, low weathering level, MS-2 (Stöffler et al., 2018). Specimens: Marc Jost (SJS) holds the main mass. A single slice weighing 21.88 g and a polished thin section and mount are on deposit at App. | ||||||||||||||||||||||||||||||||||
| Bibliography: |
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| Data from: MB109 Table 0 Line 0: |
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| Institutions and collections |
App: Department of Geology, 572 Rivers St., Appalachian State University, Boone, NC 28608, United States (institutional address; updated 7 Mar 2013) SJS: Space Jewels Switzerland, 2555 Brügg, Switzerland (private address; updated 3 Jan 2010) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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| Photos: |
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| Geography: |
Statistics: This is 1 of 9370 approved meteorites from (Northwest Africa) (plus 1875 unapproved names) | ||||||||||||||||||||||||||||||||||