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Northwest Africa 8711 | |||||||||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 8711 This is an OFFICIAL meteorite name. Abbreviation: NWA 8711 Observed fall: No Year found: 2014 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 70 approved meteorites classified as L6-melt breccia. [show all] Search for other: L chondrites, L chondrites (type 4-7), Melted chondrites, Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||||||||||||||||
Comments: | Approved 2 Jan 2015 | ||||||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 104:
Northwest Africa 8711 (NWA 8711) Morocco, (Northwest Africa) Purchased: May 2014 Classification: Ordinary chondrite (L6, melt breccia) History: Purchased by Nicola Castellano at the Genova Mineral Fair in May 2014 from a Moroccan dealer. Physical characteristics: Single stone, dark brown crust. A cut surface shows two different areas: angular fragments up to 2 cm of light gray, coarse grained chondritic material and dark-gray, very fine-grained, shock-melted veins up to 2 mm wide intersecting the matrix. Petrography: (V. Moggi Cecchi) Microprobe examination of a thin polished section displays two distinct domains: the shock-melted domain shows a crystalline portion consisting of ringwoodite, deep blue in plane polars and 20-200 μm wide, plus rare majorite crystals, and a microcrystalline to glassy portion, green in plane polars, made of quenched silicates (mainly augite) with scattered rounded metal and troilite blebs, up to 30 μm wide; the L6 host domain shows an equilibrated chondritic texture with few chondrules not clearly detectable set in a crystalline matrix of olivine, orthopyroxene, minor plagioclase and diopside, Fe-Ni metal, troilite. Geochemistry: (V. Moggi Cecchi, G. Pratesi, S. Caporali, M. Zoppi, UniFi) Chondritic portion: olivine, Fa25.1±0.1 (Fe/Mn=48±2, n=8); low-Ca pyroxene, Fs22.2±0.1Wo1.4±0.1 (0.18 TiO2, 0.18 Al2O3, 0.13 Cr2O3, all wt. %, Fe/Mn=28±2, n=9); diopside, En8.9±0.0Fs47.0±0.3Wo44.3±0.3 (0.40 TiO2, 0.50 Al2O3, 0.88 Cr2O3, 0.29 MnO, 0.54 Na2O, all wt. %); ringwoodite, Fa27.8±0.7 (Fe/Mn=182±3, n=10); majorite, Fs21.3±0.3Wo1.2±0.1 (Fe/Mn=27±2, n=11). Shock melt (broad beam electron microprobe): 47.59 SiO2, 27.17 MgO, 16.64 FeO, 2.60 CaO, 3.19 Al2O3, 0.38 MnO, 0.10 TiO2, 0.33 Cr2O3, 1.20 Na2O, 0.13 K2O, 0.17 NiO, all wt. %, n=7. Classification: L6-melt breccia, W2, S5 Specimens: 21.2 g and one PTS are on deposit at MSP, Nicola Castellano holds the main mass. | ||||||||||||||||||||||||||||||||||
Data from: MB104 Table 0 Line 0: |
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Institutions and collections |
MSP: Museo di Scienze Planetarie, Via Galcianese 20/H, 59100 Prato, Italy, Italy; Website (institutional address; updated 22 Oct 2022) UniFi: Università degli Studi di Firenze, P.zza S. Marco, 4 - 50121 Firenze, Italy (institutional address; updated 14 Sep 2013) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 104, MAPS 52, 2284, Octover 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12930/full
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Geography: |
Statistics: This is 1 of 23 approved meteorites from Morocco, (Northwest Africa) This is 1 of 8904 approved meteorites from (Northwest Africa) (plus 1871 unapproved names) |