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Northwest Africa 12437 | |||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 12437 This is an OFFICIAL meteorite name. Abbreviation: NWA 12437 Observed fall: No Year found: 2013 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 11 approved meteorites classified as Acapulcoite/Lodranite. [show all] Search for other: Acapulcoite-lodranite family, Primitive achondrites | ||||||||||||||||||||||||||||||
Comments: | Approved 11 Jun 2019 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 108:
Northwest Africa 12437 (NWA 12437) (Northwest Africa) Purchased: 2013 Classification: Primitive achondrite (Acapulcoite/Lodranite) History: Catalogued at the ROM under M58202. Physical characteristics: Single stone with a weathered exterior and dark-brown fusion crust. Petrography: (T.V. Kizovski, ROM) This specimen exhibits a poikilitic to granulitic texture of pyroxene and olivine grains. Rounded olivine grains varying in size from 18-100 µm (n = 20) are commonly observed poikilitically enclosed by pyroxene oikocrysts (approximately 600 to 900 µm in size). Accessory phases include Fe-sulfides, Fe-Ni metal, iron oxide veinlets, spinels, apatite, and merrillite. Evidence of desert weathering includes the minor oxidation of metals and sulfides. The sample appears to be relatively unshocked. Minor irregular fracturing is observed in pyroxene and sharp extinction is observed in all silicate phases. Feldspar was not observed. Geochemistry: Mineral compositions and geochemistry: (Y.Liu, UTorG; T.V. Kizovski, ROM) Olivine (Fa11.7±0.2; Fe/Mn = 20.1±1.7; n=17), high-Ca pyroxene (Fs4.6±0.4Wo43.2±2.1; Fe/Mn = 8.1±0.7; n=13), low-Ca pyroxene(Fs10.8±0.2Wo2.1±0.7; Fe/Mn = 12.3±1.9; n=13). Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed subsamples by laser fluorination gave δ17O = 0.846, 0.921, 0.892; δ18O = 3.618, 3.769, 3.690; Δ17O = -1.065, -1.069, -1.057 per mil. Classification: (T.V. Kizovski, ROM) Primitive achondrite (Acapulcoite/Lodranite) Specimens: 6.14 g specimen including a thin section and grain mount at the ROM. D. DGregory holds the 23.08 g main mass. | ||||||||||||||||||||||||||||||
Data from: MB108 Table 0 Line 0: |
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Plots: | O isotopes: | ||||||||||||||||||||||||||||||
Institutions and collections |
ROM: Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada (institutional address; updated 18 Oct 2011) UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015) DGregory: David Gregory, 230 First Avenue, Suite 108, St. Thomas, Ontario N5R 4P5, Canada (private address) UTorG: University of Toronto, Dept. Geology, Earth Sciences Centre, 22 Russell Street Toronto, Ontario, M5S 3B1, Canada (institutional address; updated 31 Jan 2011) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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Geography: |
Statistics: This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names) |