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| Northwest Africa 13251 | |||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 13251 This is an OFFICIAL meteorite name. Abbreviation: NWA 13251 Observed fall: No Year found: 2008 Country: Western Sahara Mass:  101 g | ||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 46 approved meteorites classified as L-melt rock. [show all] Search for other: L chondrites, L chondrites (type 4-7), Melted chondrites, Ordinary chondrites, and Ordinary chondrites (type 4-7) | ||||||||||||||||||||||||||||||
| Comments: | Approved 21 Mar 2020 | ||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 109:
Northwest Africa 13251 (NWA 13251) Western Sahara Purchased: 2008 Classification: Ordinary chondrite (L, melt rock) History: Purchased in 2008 from a Moroccan meteorite and mineral dealer in Erfoud for JTESM, then sold to an anonymous owner. Meteorite is reportedly from Western Sahara. Physical characteristics: The exterior has a dark brown to black appearance with lighter-colored red-tan areas. Interior slices reveal mm-scale blebs of metal and sulfide in a very fine-grained, dark-gray matrix. Petrography: (C. Herd, UAb) Optical and microprobe examination of a polished thin section shows Fe-Ni metal and sulfide blebs as well as irregular to subrounded olivine or olivine+low-Ca pyroxene intergrowths up to 600 μm across containing μm-scale inclusions of troilite. These reside in a groundmass consisting of 10-50 μm scale crystallites of olivine and low-Ca pyroxene with interstitial glass of plagioclase composition. Shock effects include weak mosaicism and planar fractures in olivine. Geochemistry: (C. Herd, UAb) Data obtained by EMP examination of carbon-coated thin section: Olivine Fa24.4±0.9 (n=63); Low-Ca Pyroxene Fs19.2±1.3Wo2.7±1.0 (n=42). No difference in composition between olivine and low-Ca pyroxene in intergrowths and olivine and low-Ca pyroxene in the groundmass was observed. Classification: L, melt rock Specimens: Type specimen of 20.8 g, including one thin section, is at UAb. Main mass with an anonymous owner. Writeup from MB 109: Northwest Africa 13251 (NWA 13251) Western Sahara Purchased: 2008 Classification: Ordinary chondrite (L, melt rock) History: Purchased in 2008 from a Moroccan meteorite and mineral dealer in Erfoud for JTESM, then sold to an anonymous owner. Meteorite is reportedly from Western Sahara. Physical characteristics: The exterior has a dark brown to black appearance with lighter-colored red-tan areas. Interior slices reveal mm-scale blebs of metal and sulfide in a very fine-grained, dark-gray matrix. Petrography: (C. Herd, UAb) Optical and microprobe examination of a polished thin section shows Fe-Ni metal and sulfide blebs as well as irregular to subrounded olivine or olivine+low-Ca pyroxene intergrowths up to 600 μm across containing μm-scale inclusions of troilite. These reside in a groundmass consisting of 10-50 μm scale crystallites of olivine and low-Ca pyroxene with interstitial glass of plagioclase composition. Shock effects include weak mosaicism and planar fractures in olivine. Geochemistry: (C. Herd, UAb) Data obtained by EMP examination of carbon-coated thin section: Olivine Fa24.4±0.9 (n=63); Low-Ca Pyroxene Fs19.2±1.3Wo2.7±1.0 (n=42). No difference in composition between olivine and low-Ca pyroxene in intergrowths and olivine and low-Ca pyroxene in the groundmass was observed. Classification: L, melt rock Specimens: Type specimen of 20.8 g, including one thin section, is at UAb. Main mass with an anonymous owner. | ||||||||||||||||||||||||||||||
| Data from: MB109 Table 0 Line 0: |
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| Institutions and collections |
UAb: 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB, T6G 2E3, Canada, Canada; Website (institutional address; updated 17 Oct 2011) JTESM: Joshua Tree Earth And Space Museum PO BOX 101, Lakeville, IN 46536, United States (institutional address; updated 17 Dec 2016) |
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| References: | Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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Geography:
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Statistics: This is 1 of 263 approved meteorites from Western Sahara (plus 19 unapproved names) | ||||||||||||||||||||||||||||||