Крупномасштабное фракционирование редкоземельных элементов в мантии кратонов
Vernadsky National Library of Ukraine
Переглянути архів Інформація| Поле | Співвідношення | |
| Title |
Крупномасштабное фракционирование редкоземельных элементов в мантии кратонов
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| Creator |
Арясова, О.В.
Хазан, Я.М. |
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| Subject |
Науки про Землю
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| Description |
Rare earth element (REE) abundances in clinopyroxene and garnet from xenoliths entrained by kimberlites of the Kaapvaal craton, South Africa, and the Somerset Island, Canada, show a strong and species-dependent variation vs. pressure in a depth range of 70 to 200 km. As a result, the interelement ratios of the REE vary across the upper mantle. This effect can be referred to as a REE large-scale space fractionation. Based upon a strong correlation between the activation energies of the REE diffusion in clinopyroxene, and the logarithmic slopes Γ of the abundance vs. pressure dependence, Γ = –d log C(P)/dP, we speculate that the space fractionation had accompanied mantle melting events and was due to a nonequilibrium REE partition between the melt and the solid residue. A simplified model of the mantle partial melting, which takes into account a PT dependent diffusive exchange between the melt and the multimineral solid residue and a non-modal character of peridotite melting indicates that the observed strong fractionation is resulted from a high degree (10–20%) partial melting of a depleted peridotite (a few wt% of clinopyroxene).
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| Date |
2008-10-10T11:53:18Z
2008-10-10T11:53:18Z 2007 |
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| Type |
Article
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| Identifier |
Крупномасштабное фракционирование редкоземельных элементов в мантии кратонов / О.В. Арясова, Я.М. Хазан // Доп. НАН України. — 2007. — N 8. — С. 110-115. — Бібліогр.: 15 назв. — рос.
1025-6415 http://dspace.nbuv.gov.ua/handle/123456789/2442 552.323 |
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| Language |
ru
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| Publisher |
Видавничий дім "Академперіодика" НАН України
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