| Инд. авторы: | Smirnov S.Z., Rybin A.V., Kruk N.N., Timina T.Y., Sokolova E.N., Kuzmin D.V., Maksimovich I.A., Kotov A.A., Shevko A.Y., Nizametdinov I.R., Abersteiner A. |
| Заглавие: | Parental Melts and Magma Storage of a Large-volume Dacite Eruption at Vetrovoy Isthmus (Iturup Island, Southern Kuril Islands): Insights into the Genesis of Subduction-zone Dacites |
| Библ. ссылка: | Smirnov S.Z., Rybin A.V., Kruk N.N., Timina T.Y., Sokolova E.N., Kuzmin D.V., Maksimovich I.A., Kotov A.A., Shevko A.Y., Nizametdinov I.R., Abersteiner A. Parental Melts and Magma Storage of a Large-volume Dacite Eruption at Vetrovoy Isthmus (Iturup Island, Southern Kuril Islands): Insights into the Genesis of Subduction-zone Dacites // Journal of Petrology. - 2019. - Vol.60. - Iss. 7. - P.1349-1370. - ISSN 0022-3530. - EISSN 1460-2415. |
| Внешние системы: | DOI: 10.1093/petrology/egz032; РИНЦ: 41695054; WoS: 000493114100002; |
| Реферат: | eng: Detailed mineralogical and melt and fluid inclusion constraints on magma storage, and the evolution of melts, are presented for the large-volume caldera eruption on the Vetrovoy Isthmus on Itutrup Island (Kuril Islands, Russia). The shallow magma reservoir beneath the Vetrovoy Isthmus is composed of a mush of plagio-rhyolitic melt, phenocrysts and the products of peritectic reaction(s). The melt appears to have formed as a result of partial melting of previously erupted rocks, which probably had andesitic to basaltic compositions and were metamorphosed into amphibole-bearing assemblages. The breakdown of amphibole in the partially melted precursor rocks led to the formation of early Mg-rich clino- and orthopyroxene, along with plagioclase and Fe-Ti oxides, and the release of aqueous fluids. Variations in fluid pressure are recorded by a strong increase of An contents in plagioclase. Crystallization took place at around 850 degrees C with pressure ranging from 0.9 to 3 kbar. This study demonstrates that dacitic magmas erupted during the course of a 20 kyr voluminous eruption were the result of mixing between plagio-rhyolitic partial melts and the breakdown reaction minerals (i.e. pyroxenes, plagioclase and Fe-Ti oxides). Plagioclase and quartz were the last minerals to crystallize from these melts prior to eruption.
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| Ключевые слова: | PLAGIOCLASE; DEHYDRATION; WATER-CONTENT; TRACE-ELEMENT; VOLCANIC-ROCKS; PHASE-RELATIONS; SILICATE-GLASSES; CRYSTALLIZATION; melt inclusions; fluid inclusions; explosive eruption; caldera; Iturup Island; Kuril Islands; CALC-ALKALINE DIFFERENTIATION; ORIGIN; |
| Издано: | 2019 |
| Физ. характеристика: | с.1349-1370 |