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Northwest Africa 15118 | |||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 15118 This is an OFFICIAL meteorite name. Abbreviation: NWA 15118 Observed fall: No Year found: 2021 Country: Algeria Mass: ![]() | ||||||||||||||||||||||||||
Classification history: |
This is 1 of 140 approved meteorites classified as Achondrite-ung. [show all] Search for other: Achondrites, Ungrouped achondrites | ||||||||||||||||||||||||||
Comments: | Approved 4 Mar 2023 | ||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 112:
Northwest Africa 15118 (NWA 15118) Algeria Find: 2021 Classification: Ungrouped achondrite History: Purchased by Xu dengqin in 2022, reportedly found in Algeria 2021. Physical characteristics: The meteorite is a single stone, weighing 230 grams, with one broken surface. The rest of the surface is covered with a white to light green translucent fusion crust with shrinkage cracks. The surface of the stone is covered with terrestrial clay. Petrography: The meteorite is a fragmental breccia composed of mineral clasts of anorthite (up to 6 mm of grain size), orthopyroxene (up to about 100 µm), rare clinopyroxene, chromite, olivine and troilite. Anorthite is the dominant mineral, composed of over 94 vol% of the meteorite. Orthopyroxene is the second most abundant (~6 vol%) mineral in the meteorite. There are no exsolution lamellae of clinopyroxene in orthopyroxene. Minor clinopyroxene only occurs as veins (several to 10 µm in width) in large anorthite grains. Olivine is fairly rare, and only three grains with sizes range in 50-200 µm were observed in two observed sections. Chromite is present with less than 1 vol% in the meteorite and one to a few tens of µm in size. Geochemistry: Plagioclase An95.7±0.6Ab4.1±0.6, n=52; orthopyroxene En72.8±0.9Fs24.8±0.9Wo2.4±0.1, Fe/Mn=28.9±1.5, Mg#=74.6±0.9, n=46; clinopyroxene En44.2±1.6Fs10.0±0.7Wo45.8±1.4, Fe/Mn=21.7±3.3, Mg#=81.5±1.4, n=10; olivine Fa31.2±0.9, Fe/Mn=46.1±1.1, Mg#=68.5±0.7, n=10; chromite Chr69.2±2.9Spl27.0±2.9Usp3.8±1.4, Mg#=17.1±1.6, n=18. Oxygen isotopes Cao Xiaobin, Nanjing University): 3 acid-washed fragments analyzed by laser fluorination gave average δ18O= 3.770±0.111, δ17O=1.717±0.070, Δ17O=-0.243±0.014 (all per mil). Classification: Achondrite, ungrouped | ||||||||||||||||||||||||||
Data from: MB112 Table 0 Line 0: |
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Plots: | O isotopes: | ||||||||||||||||||||||||||
Institutions and collections |
USP: Museu de Geociências - USP
Rua do Lago, 562
CEP: 05508-080
Butantã - SP
Brazil, Brazil; Website (institutional address; updated 22 Oct 2022) IGCAS: Institute of Geochemistry Chinese Academy of Sciences, Guiyang, China (institutional address; updated 27 Mar 2018) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 112, in preparation (2023)
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Photos: |
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Geography:![]() |
Statistics: This is 1 of 1315 approved meteorites from Algeria (plus 30 unapproved names) (plus 4 impact craters) |