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Northwest Africa 4872 | |||||||||||||
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Basic information | Name: Northwest Africa 4872 This is an OFFICIAL meteorite name. Abbreviation: NWA 4872 Observed fall: No Year found: 2007 Country: Algeria Mass: 3 kg | ||||||||||||
Classification history: |
This is 1 of 62 approved meteorites classified as Brachinite. [show all] Search for other: Brachinites, Primitive achondrites | ||||||||||||
Comments: |
Approved 14 Jan 2008 Revised 17 Dec 2008: added erratum from mb94; 2008-08-04 final writeup | ||||||||||||
Writeup |
Writeup from MB 93:
Northwest Africa 4872 Algeria Find: 2007 Achondrite (brachinite) History and Physical characteristics: A 3000 g partially crusted complete stone was purchased in Rissani, Morocco, in 2007. This stone is very dark on both crusted and wind eroded surfaces and has a low weathering grade. Petrography: (T. Bunch and J. Wittke, NAU) Protogranular texture with a strong bimodal olivine grain size: medium-sized grains range from 0.3 to 1.1 mm (mean = 0.6 mm) and the smaller grains range from 0.02 to 0.3 mm (mean = 0.18 mm). Small metal grains are oxidized. Mineral modes (in vol%): olivine = 85; Ca pyroxene = 3; chromite = 5; Cl apatite = 3; metal = 2; sulfides = 2. Mineral compositions: Olivine (Fa35.1; FeO/MnO = 81), Ca-pyroxene (Fs10.3Wo47), chromite (Cr/(Cr + Al) = 0.74), metal (Ni = 3.5 wt%), with pentlandite and troilite. Oxygen isotopes: (D. Rumble, CIW) Replicate analyses of acid-washed material by laser fluorination gave, respectively: δ17O, -0.229 and -0.254; δ18O, 2.061 and 2.012; and Δ17O, 4.354 and 4.308 (all ‰). Classification: Achondrite (brachinite); moderate shock and minimal to moderate weathering. Type specimens: A total of 20.4 g is on deposit at NAU*. Aaronson is the main mass holder. Submitted by: T. Bunch, NAU. Writeup from MB 94: Correction: δ17O = 2.061, 2.012; δ18O = 4.354, 4.308; Δ17O = -0.229,-0.254 (all ‰). | ||||||||||||
Data from: MB113 Table 0 Line 0: |
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Data from: MB93 Table 2 Line 139: |
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Plots: | O isotopes: | ||||||||||||
Institutions and collections |
NAU*: Collection discontinued. Specimens redistributed as shown in individual meteorite records, United States (institutional address; updated 24 Jun 2024) UWB: University of Washington, Burke Museum of Natural History and Culture, Box 353010 Seattle, WA 98195, United States (institutional address; updated 9 Oct 2023) Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010) CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address) NAU: Geology, Bldg 12 Knoles Dr Northern Arizona University, Flagstaff, AZ 86011, United States (institutional address; updated 12 Apr 2012) UCN: Universidad Católica del Norte, Chile (institutional address; updated 7 Aug 2024) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008) Published in Meteoritical Bulletin, no. 94, MAPS 43, 1551-1588 (2008) Published in Meteoritical Bulletin, no. 113, in preparation (2024)
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Geography: |
Statistics: This is 1 of 1402 approved meteorites from Algeria (plus 33 unapproved names) (plus 4 impact craters) |