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Northwest Africa 16689 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 16689 This is an OFFICIAL meteorite name. Abbreviation: NWA 16689 Observed fall: No Year found: 2023 Country: (Northwest Africa) Mass: 724 g | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 7130 approved meteorites (plus 6 unapproved names) classified as H6. [show all] Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||||||||||||
Comments: | Approved 5 May 2024 | ||||||||||||||||||||||||||||||
Writeup |
Writeup from MB 113:
Northwest Africa 16689 (NWA 16689) (Northwest Africa) Purchased: 2023 Oct 14 Classification: Ordinary chondrite (H6) History: Sample was purchased from ET Meteorites by A. Ruzicka as part of a group of unclassified northwest African stones, which were donated to Cascadia. Physical characteristics: Physical Characteristics: The meteorite was entirely covered by a medium-brown weathered fusion crust displaying a smooth rounded surface on one side and regmaglypts on the other side. Cut faces showed abundant metal and sulfide with no evidence of terrestrial weathering. Petrography: (M. Hutson, D. Pierce, and A. Ruzicka, Cascadia): Much of the thin section is composed of equigranular grains of silicate, metal, troilite, and chromite. Amidst this background, barely discernible chondrules are visible. Numerous plagioclase feldspar grains >50 µm across are present. Both merrillite and chlor-apatite were observed in thin section. Metal and troilite appear fresh with ~ 2% replacement by terrestrial weathering products. Geochemistry: Olivine: Fa19.8±0.3, N=12; low-Ca pyroxene: Fs17.3±0.2Wo1.3±0.2, N=10, plagioclase feldspar: Ab82.1±0.8Or5.4±0.5An12.5±0.3, N=5. Classification: Ordinary chondrite (H6) based on mineral chemistry, texture, and plagioclase feldspar grain size. Specimens: Cascadia holds 712.9 g in three pieces, as well as a polished thin section and material in an epoxy butt. | ||||||||||||||||||||||||||||||
Data from: MB113 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) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 113, in preparation (2024)
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Geography: |
Statistics: This is 1 of 9933 approved meteorites from (Northwest Africa) (plus 1837 unapproved names) |