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Northwest Africa 11861 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 11861 This is an OFFICIAL meteorite name. Abbreviation: NWA 11861 Observed fall: No Year found: 2018 Country: (Northwest Africa) Mass: 538 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 17 Jul 2018 | ||||||||||||||||||||||||||||||
Writeup |
Writeup from MB 107:
Northwest Africa 11861 (NWA 11861) (Northwest Africa) Purchased: 2018 Classification: HED achondrite (Eucrite, polymict) History: A single 538 g stone was found in Morocco prior to 2018. Steve Arnold purchased the stone from a meteorite dealer during the 2018 Tucson Gem and Mineral Show. Physical characteristics: Stone is irregularly shaped and ~20% is covered by a weathered fusion crust. The weathered exterior is light orangish-gray in color and light gray on the cut face. Numerous mineral and rock clasts can be seen on the cut face. Petrography: Description and classification (A. Love, App): Sample is a breccia composed of up to 5 mm angular basaltic and cumulate textured eucritic (~13 vol%) and diogenitic (~8 vol%) lithic clasts and related mineral fragments hosted within a fine-grained comminuted matrix. Eucrite clasts have ophitic to subophitic textures and exsolved pyroxenes. Minerals: Chromite, Ilmenite, FeS, Si Polymorph, phosphate. Geochemistry: (A. Love, App) Eucrite: Low-Ca pyroxene host Fs49.7±7.6 Wo2.5±0.7 (Fs40.7-65.8Wo1.7-4.5, FeO/MnO=27.5-32.3, N=16); pigeonite (Fs42.0±4.4 Wo12.2±6.7 (Fs35.9-48.4Wo8.5-25.7, FeO/MnO=29.0-31.2, N=5); high-Ca pyroxene exsolution lamellae Fs23.73±6.1Wo42.5±1.8 (Fs16.1-33.5Wo39.5-44.2, N=9); plagioclase An85.8±7.4 Or0.6±0.7 (An71.5-94.7, Or0.0-1.6 N=10). Diogenite: Low-Ca pyroxene Fs26.4±3.8 Wo2.4±0.5 (Fs21.1-31.8Wo1.7-3.4, FeO/MnO=27.8-34.7, N=10) Classification: HED (polymict eucrite breccia). FeO/MnO and Fs compositions of pyroxenes indicate this sample is a HED meteorite composed of a mixture of eucrite and diogenite components. Specimens: Steve Arnold holds the main mass. Three slices and an endcut totaling 20g and a polished thin section are on deposit at App. | ||||||||||||||||||||||||||||||
Data from: MB107 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) |
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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) | ||||||||||||||||||||||||||||||
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Revision history: |
This lists important revisions made to data for this record.
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