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| Northwest Africa 14599 | |||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 14599 This is an OFFICIAL meteorite name. Abbreviation: NWA 14599 Observed fall: No Year found: 2021 Country: (Northwest Africa) Mass:  500 g | ||||||||||||||||||||||||||||||
| Classification history: |
This is the only approved meteorite classified as Mesosiderite-A2/3. Search for other: Class A mesosiderites, Mesosiderites, and Metal-rich meteorites | ||||||||||||||||||||||||||||||
| Comments: | Approved 29 Jan 2022 | ||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 111:
Northwest Africa 14599 (NWA 14599) (Northwest Africa) Purchased: January 2021 Classification: Mesosiderite-A2/3 History: Purchased in January 2021 by Yang Shun-Chung and Juan Chen from Ali Mtah in Tindouf, Algeria. Physical characteristics: Single stone with slightly weathered fusion crust. A slice from the interior reveals a metal-rich surface. Petrography: (D. Sheikh, Cascadia) Specimen represents a breccia primarily composed of angular to sub-rounded silicate lithic and mineral clasts (Av. 1 mm, up to 4 mm) and sub-rounded to rounded segregated domains of Fe-Ni metal (Av. 2 mm, up to 5 mm, ~25 % in studied thin section) set within a fine-grained fragmental matrix (~ 0.1 mm) composed of sub-angular to sub-rounded silicate grains and rounded blebs of Fe-Ni metal. The silicate portion (~75 % in studied thin section) consists of ~70 % pyroxene (some are poikiloblastic), ~24 % plagioclase, ~4 % silica, ~2 % olivine, and ~<1 % accessory troilite and chromite. Metal is relatively fresh with only a few weathering veins dispersed throughout the sample. Geochemistry: Olivine (Fa31.4±2.3, range Fa29.3-34.3, FeO/MnO=49±5, n=4), Low-Ca Pyroxene (Fs27.1±4.2Wo3.2±1.2, range Fs23.1-33.2Wo2.0-4.8, FeO/MnO=35±4, n=7), Pigeonite (Fs31.1±1.6Wo7.7±0.7, range Fs28.9-33.2Wo6.9-8.8, FeO/MnO=34±5, n=5), Calcic Plagioclase (An95.2±2.9Or0.2±0.2, range An89.2-97.4Or0.1-0.8, n=11). Classification: Mesosiderite-A2/3. Estimated modal abundance of plagioclase consistent with petrologic class A. Grade 2/3 is estimated due to this sample displaying textural characteristics consistent with both grade 2 (recognizable brecciation in thin section, presence of extremely fine-grained silicate grains (<10 μm) within the matrix, partial replacement of olivine by pyroxene, partial inversion of pigeonite to orthopyroxene) and grade 3 (Average matrix grain size of 0.1 mm, presence of poikiloblastic pyroxene grains, presence of segregated domains of Fe-Ni metal). Specimens: 22.1 g at NHMLAC; main mass with Yang Shun-Chung and Juan Chen. | ||||||||||||||||||||||||||||||
| Data from: MB111 Table 0 Line 0: |
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| Institutions and collections |
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011) NHMLAC: Natural History Museum of Los Angeles County 900 Exposition Blvd., Los Angeles, CA 90007 , United States; Website (institutional address; updated 17 Jul 2021) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 111, in preparation (2022)
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| Geography: |
Statistics: This is 1 of 9013 approved meteorites from (Northwest Africa) (plus 1869 unapproved names) | ||||||||||||||||||||||||||||||