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Northwest Africa 4819 | |||||||||
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Basic information | Name: Northwest Africa 4819 This is an OFFICIAL meteorite name. Abbreviation: NWA 4819 Observed fall: No Year found: 2007 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 14 Jan 2008 Revised 4 Aug 2008: final writeup | ||||||||
Writeup![]() |
Writeup from MB 93:
Northwest Africa 4819 Northwest Africa Find: 2007 Achondrite (lunar, feldspathic breccia) History and Physical characteristics: A single 234 g crusted stone was purchased in Rissani, Morocco in 2007. The crust is fresh with dark gray to black crusted areas and vermillion to light brown in abraded to weathered areas; some areas show melt bubbles and flow. A network of thin fractures is filled with weathering products. Petrography: (T. Bunch and J. Wittke, NAU; A. Irving, UWS) This stone is very dark, well indurated, and is fine-grained with few clasts that exceed one mm in diameter. No evidence of flow orientation was observed. NWA 4819 is a regolith breccia and has two unusual characteristics for a lunar sample: (1) a relatively large amount of homogeneously distributed fine-grained metallic nickel-iron (2 wt%) and troilite (1.5 wt%) and (2) a large population of pyroxene fragments. Most lithic clasts follow the ferroan anorthositic trend and include anorthosites, fine-grained anorthositic norites, gabbros, and troctolites, in addition to shock melt clast, K-rich glass, and spherules. No intact basaltic clasts were observed and all clasts are crushed to some extent. Mineral compositions and Geochemistry: Host orthopyroxene (Fs48.9-67.5Wo2.2-4.3; FeO/MnO = 56), exsolution lamellae (Fs24.4-41.4Wo12.3-32.9; FeO/MnO = 60). Anorthositic norite: orthopyroxene (Fs35.4Wo4.3) and plagioclase (An96.5). Anorthositic troctolite olivine (Fa28.1; FeO/MnO = 105), pigeonite (Fs26.9Wo5.9; FeO/MnO = 54), plagioclase (An97) and chromite (cr# = 80). Kamacite (mean Ni = 6.2, Co = 0.77 (both wt%) and taenite (Ni = 8.2- 23.6 wt%). Bulk composition: (R. Korotev, WUSL): FeO = 7.0% wt%, Ni = 290 ppm, Sm = 3.4 ppm, Th = 1.5 ppm, Ir = 12 ppb. Classification: Achondrite (lunar, feldspathic breccia). Type specimens: A total of 20.3 g is on deposit at NAU. The main mass holder is anonymous. Submitted by: T. Bunch, NAU. | ||||||||
Data from: MB93 Table 2 Line 122: |
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Institutions and collections |
NAU: Geology, Bldg 12
Knoles Dr
Northern Arizona University, Flagstaff, AZ 86011, United States; Website (institutional address; updated 12 Apr 2012) 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) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008)
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Geography: |
Statistics: This is 1 of 8890 approved meteorites from (Northwest Africa) (plus 1871 unapproved names) |