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Magmatic evolution of the material of the Earth’s lower mantle: Stishovite paradox and origin of superdeep diamonds (Experiments at 24–26 GPa)статья Исследовательская статья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 6 февраля 2018 г.
- Авторы: Litvin Yu A., Spivak A.V., Dubrovinsky L.S.
- Журнал: Geochemistry International
- Том: 54
- Номер: 11
- Год издания: 2016
- Издательство: Maik Nauka/Interperiodica Publishing
- Местоположение издательства: Russian Federation
- Первая страница: 936
- Последняя страница: 947
- DOI: 10.1134/s0016702916090032
- Аннотация: The ultrabasic-basic magmatic evolution of the lower mantle material includes important physicochemical phenomena, such as the stishovite paradox and the genesis of superdeep diamonds. Stishovite SiO2 and periclase-wustite solid solutions, (MgO center dot FeO)(ss), associate paradoxically in primary inclusions of superdeep lower mantle diamonds. Under the conditions of the Earth's crust and upper mantle, such oxide assemblages are chemically impossible (forbidden), because the oxides MgO and FeO and SiO2 react to produce intermediate silicate compounds, enstatite and ferrosilite. Experimental and physicochemical investigations of melting phase relations in the MgO-FeO-SiO2-CaSiO3 system at 24 GPa revealed a peritectic mechanism of the stishovite paradox, (Mg, Fe)SiO3 (bridgmanite) + L = SiO2 + (Mg, Fe)O during the ultrabasic-basic magmatic evolution of the primitive oxide-silicate lower mantle material. Experiments at 26 GPa with oxide-silicate-carbonate-carbon melts, parental for diamonds and primary inclusions in them, demonstrated the equilibrium formation of superdeep diamonds in association with ultrabasic, (Mg, Fe)SiO3 (bridgmanite) + (MgO center dot FeO)(ss) (ferropericlase), and basic minerals, (FeO center dot MgO)(ss) (magnesiowustite) + SiO2 (stishovite). This leads to the conclusion that a peritectic mechanism, similar to that responsible for the stishovite paradox in the pristine lower mantle material, operates also in the parental media of superdeep diamonds. Thus, this mechanism promotes both the ultrabasic-basic evolution of primitive oxide-silicate magmas in the lower mantle and oxide-silicate-carbonate melts parental for superdeep diamonds and their paradoxical primary inclusions.
- Добавил в систему: Спивак Анна Валерьевна