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| Northwest Africa 13580 | |||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 13580 This is an OFFICIAL meteorite name. Abbreviation: NWA 13580 Observed fall: No Year found: 2020 Country: Algeria Mass:  700 g | ||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 449 approved meteorites classified as Diogenite. [show all] Search for other: Achondrites, Diogenites, and HED achondrites | ||||||||||||||||||||||||||||||
| Comments: | Approved 17 Dec 2020 | ||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 109:
Northwest Africa 13580 (NWA 13580) Algeria Purchased: 2020 Classification: HED achondrite (Diogenite) History: A single 700 g sample was found near Tindouf, Algeria, in 2019. Didi Baidari purchased the sample from a meteorite dealer in Tindouf. Physical characteristics: The exterior of the ellipsoidal sample is wind-ablated and is an orangish-cream-colored and has brownish grains protruding through the surface. The interior shows a crystalline brecciated texture composed of cream colored and dark green crystals. Petrography: Description and Classification (A. Love, App) Sample is a breccia composed of cumulate-textured clasts composed of (vol%): 2-5 mm grains of low-Ca pyroxene (66) and plagioclase (34) set within a recrystallized host of finer-grained (avg. grain-size 55µm) plagioclase and low-Ca pyroxene. Some pyroxenes show lamellar and blebby exsolution. Mineral phases within the recrystallized portion share 120º grain boundaries between adjacent minerals. Additional minerals are high-Ca pyroxene, chromite and troilite. Geochemistry: Low-Ca Pyroxene (Fs31.5±0.7Wo3.7±0.4, Fe/Mn=27.4±0.9, Mg#=67.2±0.7, n=16); high-Ca pyroxene (Fs16.0±0.1Wo39.5±0.6, Fe/Mn=21.6±1.3, Mg#73.5±0.2, n=3); plagioclase (An96.8±0.2Or0.0, n=10); chromite (Cr#=75.7±3.7, TiO2=1.5±0.1wt%, Mg#21.7±1.24, n=9). Classification: Achondrite (diogenite, noritic). Based on mineralogy, texture and Fe/Mn ratios within pyroxenes, sample is an HED achondrite. Composition of plagioclase, Fe/Mn ratios and Mg# of pyroxenes are intermediate between diogenites and cumulate eucrites. Ti Vs. Al of low Ca-pyroxenes plot within the field of diogenites. Ti, Al, Cr-content and Mg# of chromite fall in the range observed for diogenites. Abundance of plagioclase (34 vol%) within sample is anomalous for diogenites. Specimens: Didi Baidari holds the main mass. 10 fragments weighing 23.89 g and a polished thin section and mount are on deposit at App. | ||||||||||||||||||||||||||||||
| Data from: MB109 Table 0 Line 0: |
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| Institutions and collections |
App: Department of Geology, 572 Rivers St., Appalachian State University, Boone, NC 28608, United States (institutional address; updated 7 Mar 2013) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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| Photos: |
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Geography:
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Statistics: This is 1 of 1073 approved meteorites from Algeria (plus 26 unapproved names) (plus 4 impact craters) | ||||||||||||||||||||||||||||||