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Northwest Africa 4869 | |||||||||||||||||||||
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Basic information | Name: Northwest Africa 4869 This is an OFFICIAL meteorite name. Abbreviation: NWA 4869 Observed fall: No Year found: 2006 Country: Algeria Mass: 191 g | ||||||||||||||||||||
Classification history: |
This is 1 of 451 approved meteorites classified as Howardite. [show all] Search for other: Achondrites, HED achondrites, and Howardites | ||||||||||||||||||||
Comments: | Approved 17 Apr 2008 | ||||||||||||||||||||
Writeup |
Writeup from MB 94:
Northwest Africa 4869 Algeria Find: 2006 Achondrite (howardite) History and physical characteristics: A 191 g dark brown stone with little fusion crust was purchased in Morocco in July 2007 by A. Aaronson. Petrography: (J. Wittke and T. Bunch, NAU) A complex breccia rich in silica minerals and basaltic eucrites, microbasalts, FeO-rich ferrosilite/hedenbergite/fayalite lithologies, shock melt clasts, and diogenitic pyroxene fragments that comprise 14 vol% of the stone. A silica polymorph is enriched in many of the eucrite lithologies and may account for up to 15 vol% of the gabbroic basalts and as much as 21 vol% of medium to fine-grained basalts. The shock level is high with most plagioclase present as maskelynite. Weathering grade is moderate. Mineral compositions: Subophitic orthopyroxene host, Fs53Wo4.5 (FeO/MnO = 26); exsolved augite, Fs26.3Wo44; plagioclase (maskelynite), An92. Cumulate unexsolved pigeonite, Fs45.5Wo12.6 and maskelynite, An84. Silica-rich basalt host pyroxene, Fs61.1Wo3.1; lamellae, Fs32.7Wo42; olivine, Fa60.6 (FeO/MnO = 44); maskelynite, An69 Diogenitic pyroxenes, Fs28–34.4Wo1.1–1.4 (FeO/MnO = 29). Minor minerals include chromite, cr# = 78–88, merrillite, Ni-poor metal, ilmenite and FeS. Classification: Achondrite (howardite). Type specimen: A total of 20.1 g is on deposit at NAU. Aaronson holds the main mass. | ||||||||||||||||||||
Data from: MB94 Table 2 Line 77: |
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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) Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 94, MAPS 43, 1551-1588 (2008)
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Geography: |
Statistics: This is 1 of 1356 approved meteorites from Algeria (plus 30 unapproved names) (plus 4 impact craters) | ||||||||||||||||||||
Also see: |
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Revision history: |
This lists important revisions made to data for this record.
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