13C-depleted moissanites in subduction-related rocks: tracers of slab fluids in the Earth’s mantle and a new diamond exploration tool
A magnesian low-Ti shoshonite dike intruding Archean Norwegian Terrane includes numerous grains of black, blue and gray moissanite (SiC). Moissanite contains inclusions of native Si, Fe and Al, Fe-Cr carbides, Fe-Cr-Mn alloys and diamond. The range of observed δ13C values (-24.8 to -29.6‰) is simila...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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EDP Sciences
2019-01-01
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| Series: | E3S Web of Conferences |
| Online Access: | https://www.e3s-conferences.org/articles/e3sconf/pdf/2019/24/e3sconf_wri-162018_08009.pdf |
| Summary: | A magnesian low-Ti shoshonite dike intruding Archean Norwegian Terrane includes numerous grains of black, blue and gray moissanite (SiC). Moissanite contains inclusions of native Si, Fe and Al, Fe-Cr carbides, Fe-Cr-Mn alloys and diamond. The range of observed δ13C values (-24.8 to -29.6‰) is similar to ophiolite-hosted SiC, lower mantle diamonds and slab-derived biogenic carbon. Norwegian moissanites may have been formed during interaction of Earth’s mantle with carbonaceous slab fluids under extremely reducing conditions as suggested by native metal and carbide inclusions. 13C-depleted moissanite can be used as a new exploration tool for sub-lithospheric diamonds in Archean to Phanerozoic accreted terranes and mobile belts. |
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| ISSN: | 2267-1242 |