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| Northwest Africa 12860 | |||||||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 12860 This is an OFFICIAL meteorite name. Abbreviation: NWA 12860 Observed fall: No Year found: 2019 Country: (Northwest Africa) Mass:  321 g | ||||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 273 approved meteorites classified as Mesosiderite. [show all] Search for other: Mesosiderites, Metal-rich meteorites | ||||||||||||||||||||||||||||||||||
| Comments: | Approved 21 Sep 2019 | ||||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 108:
Northwest Africa 12860 (NWA 12860) (Northwest Africa) Purchased: 2019 Classification: Mesosiderite History: Eleven stones weighing 321 g were found in Western Sahara prior to 2019. John Sinclair and J. Donald Cline purchased the samples from a meteorite dealer while at the 2019 Tucson Gem and Mineral Show. Physical characteristics: Eleven fragments, some of which fit together, comprise a single flight-oriented stone. The largest fragment has a black fusion crust coating 70% of its surface area, shows rollover lipping, and has an irregular pyramidal shape. The interior shows an obvious brecciated texture with coarse clasts up to 1 cm. Petrography: Description and classification (A. Love, App): Sample is a breccia composed of 26 vol% FeNi metal, ~58 vol% Opx (up to 1 cm), 4 vol% plagioclase and 1 vol% olivine. Opx and plag comprise 93 vol% and 6 vol% of the silicates respectively. Pyroxenes poikolitically enclose olivine. Recrystallization is present in fine-grained regions and within some of the clasts. Average grainsize in fine-grained regions is 51µm. Additional minerals are apatite, troilite, kamacite, taenite and chromite. Geochemistry: (A. Love, App) Olivine (Fa23.8±1.0 (Fa23.0-25.7), Fe/Mn=41.7±1.9, N=5), low Ca pyroxene Fs23.4±0.8Wo2.0±0.3 (Fs22.0-24.4Wo1.7-2.8), Fe/Mn=27.0±0.5, N=14), plagioclase An93.4±1.5Or0.2±0.1 (An90.9-95.6Or0.1-0.4, N=10). Classification: Mesosiderite (estimated class C3). Mesosiderite based on texture, modal abundance of metal and magnetic susceptibility. Class C based on modal abundance of plagioclase (6 vol%) and orthopyroxene (93 vol%) of one thin section. Metamorphic grade 3 based on recrystallized nature of fine-grained regions. Specimens: PARI holds the main masses. A polished thin section and a 20.98 g fragment are on deposit at App. | ||||||||||||||||||||||||||||||||||
| Data from: MB108 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) PARI: Pisgah Astronomical Research Institute 1 Pari Dr Rosman, NC 28772, United States (institutional address; updated 13 Sep 2016) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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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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