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Northwest Africa 4485 | |||||||||||||||||||
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Basic information | Name: Northwest Africa 4485 This is an OFFICIAL meteorite name. Abbreviation: NWA 4485 Observed fall: No Year found: 2006 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||
Classification history: |
This is 1 of 101 approved meteorites classified as Lunar. [show all] Search for other: Lunar meteorites | ||||||||||||||||||
Comments: | Approved 28 Mar 2007 | ||||||||||||||||||
Writeup![]() |
Writeup from MB 91:
Northwest Africa 4485 Algeria Find: September 2006 Achondrite (lunar, KREEP-rich breccia) History: Stefan Ralew purchased the whole stone in September 2006 from a dealer in Ouarzazate, Morocco. Petrography: (A. Irving and S. Kuehner, UWS) Lithic clasts (up to 0.5 cm) are predominantly various types of ophitic to quench-textured basalts (composed of pyroxene(s), plagioclase, olivine, ilmenite, and rare baddeleyite). Granophyre clasts (consisting of subparallel to symplectitic intergrowths of silica and K-feldspar with accessory baddeleyite) are present as a minor component, as well as very fine-grained, quench-textured clasts composed of glass and fine plagioclase microlites. Mineral clasts include pyroxenes, olivine, plagioclase, silica, zircon, baddeleyite, merrillite, Ti-chromite, fayalite, ilmenite, metal (both kamacite and taenite), and troilite (Kuehner et al. 2007). Mineral compositions and geochemistry: Olivine (Fa26.3–63.6; FeO/MnO = 99–121), plagioclase (An88.9–89.7Or0.3–0.6), orthopyroxene (Fs18.9–19.7Wo4.6–3.7; FeO/MnO = 87–89), pigeonite (Fs37.0Wo10.1; FeO/MnO = 62), subcalcic augite (Fs48.9–49.2Wo26.7–39, FeO/MnO = 59–67), fayalite (Fa90.1, FeO/MnO = 80). Bulk composition: (R. Korotev, WUSL) INAA on eight ~30 mg subsamples gave a mean composition of: Na = 0.441, Fe = 7.27 (both wt%), Sc = 21.7, La = 31.6, Sm = 14.12, Eu = 1.46, Yb = 11.0, Zr = 443, Hf = 11.4, Ba = 375, Th = 6.37 (all ppm). Although it is possible that there is a minor mare basalt component, this specimen is dominated by materials with KREEP-like compositions, and is essentially identical in bulk composition and petrologic characteristics to Northwest Africa 4472. Classification: Achondrite (lunar, KREEP-rich breccia). Type specimen: A total of 20 g and one polished mount are on deposit at UWS. Ralew holds the main mass. | ||||||||||||||||||
Data from: MB91 Table 2 Line 344: |
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Institutions and collections |
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012) WUSL: Washington Univ., One Brookings Drive, St. Louis, MO 63130, United States (institutional address; updated 17 Oct 2011) Ralew: Stefan Ralew, Kunibertstraße 29, 12524 Berlin, Germany; Website (private address) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 91, MAPS 42, 413-466 (2007)
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Photos: |
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Geography: |
Statistics: This is 1 of 8890 approved meteorites from (Northwest Africa) (plus 1871 unapproved names) |