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| Northwest Africa 5350 | |||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 5350 This is an OFFICIAL meteorite name. Abbreviation: NWA 5350 Observed fall: No Year found: 2008 Country: (Northwest Africa) Mass:  468 g | ||||||||||||||||||||||||
| Classification history: |
This is 1 of 436 approved meteorites classified as Howardite. [show all] Search for other: Achondrites, HED achondrites, and Howardites | ||||||||||||||||||||||||
| Comments: | Approved 1 Oct 2010 | ||||||||||||||||||||||||
| Writeup |
Writeup from MB 99:
Northwest Africa 5350 (NWA 5350) (Northwest Africa) Purchased: Jan 2008 Classification: HED achondrite (Howardite) History: The main mass holder purchased the sample in Zagora, Morocco. Physical characteristics: This meteorite consists of a single 468 g stone mostly covered with dark fusion crust. Petrography: (Melinda Hutson and Alex Ruzicka, Cascadia). In thin section, this meteorite shows lithic and mineral clasts set in a granular matrix. The clasts are dominantly basaltic, with the two largest clasts consisting of coarse granular basalt containing recrystallized plagioclase and twinned pyroxenes. Both low-Ca pyroxene and plagioclase vary from undeformed to recrystallized with triple junctions. No maskelynite was observed. The section also contains abundant glassy material, including pockets that contain dispersed opaques, devitrified glass shards, and shards of brown-colored bona fide glass. The largest piece of brown glass is ~1 mm. Diogenitic pyroxene mineral clasts make up >10% of the clasts. The largest of these pyroxene clasts (~1.5 mm) is an intermediate composition grain with wormy exsolution. A single cryptocrystalline spherule with microvesicles was observed in thin section. Metal grains vary from unweathered to almost entirely replaced. Geochemistry: (Melinda Hutson and Alex Ruzicka, Cascadia; Ilya Bindeman, UOr). EMPA analyses: Mg-rich low-Ca pyroxene (Wo0.6-4.2 En60.6-79.3 Fs19.5-37.7) Fe/Mn = 27.2 ± 1.8; intermediate low-Ca pyroxene (Wo1.2-5.3 En55.4-59.4 Fs38.0-41.8) Fe/Mn = 30.0±2.2; Fe-rich low-Ca pyroxene (Wo2.0-4.0 En33.7-45.3 Fs50.7-64.2) Fe/Mn = 30.8±1.8; pigeonite (Wo5.5-26.2 En26.2-57.7 Fs33.5-59.7) Fe/Mn = 30.4±1.4; augite (Wo40.8-40.9 En28.5-29.3 Fs 29.8-30.7) Fe/Mn = 33.6±1.1; plagioclase (An90.3±2.5, Ab9.5±2.4, n=22). Oxygen isotopes (whole rock): δ18O = 3.79±0.10 ‰, δ17O = 1.80±0.07 ‰, and Δ17O = -0.191±0.018 ‰ Classification: Achondrite (howardite). Minimal but variable weathering and moderate but variable shock. Specimens: 28 g and one thin section are on deposit at Cascadia. Thompson holds the main mass. | ||||||||||||||||||||||||
| Data from: MB99 Table 0 Line 0: |
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| Plots: | O isotopes: | ||||||||||||||||||||||||
| Institutions and collections |
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011) Thompson: Edwin Thompson, 5150 Dawn St., Lake Oswego, OR 97035, United States (private address) UOr: Department of Geological Sciences, 1272 University of Oregon, Eugene, OR 97403, United States (institutional address; updated 1 Oct 2010) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, No. 99, April 2012, MAPS 47, E1-E52 (2012) [published online only]
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| Geography: |
Statistics: This is 1 of 9013 approved meteorites from (Northwest Africa) (plus 1869 unapproved names) | ||||||||||||||||||||||||