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Evidence for Granitoid Magmatism and the Composition of the Silicic Melt in the Gabbroid Assemblage of the Mid-Atlantic Ridge at 13° N: New Data on Melt Inclusionsстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Дата последнего поиска статьи во внешних источниках: 15 декабря 2021 г.
- Авторы: Sholukhov K.N., Prokofiev V.Yu, Solovova I.P., Pertsev A.N., Aranovich L.Ya, Borisovsky S.E., Bortnikov N.S.
- Журнал: Doklady of the Academy of Sciences of the USSR. Earth Science Sections
- Том: 500
- Номер: 2
- Год издания: 2021
- Первая страница: 838
- Последняя страница: 841
- DOI: 10.1134/s1028334x21100159
- Аннотация: Despite the local occurrence of silicic magmatism during the formation of the oceanic crust, the nature of felsic granitoid veins (“oceanic plagiogranite”) remains an important debatable problem of chemical differentiation in the global system of mid-oceanic ridges. To date, the actual compositions of granitoid melts in the modern oceanic crust are still poorly constrained, and this complicates petrogenetic interpretations. The structural patterns and compositional variations of minerals from the oceanic core complex at 13° N on the Mid-Atlantic Ridge show the sequence of magmatic differentiation: coarse-grained gabbronorite → vein microgabbro enriched in Fe–Ti oxides and apatite → biotite–plagiogranite veins. The transition to silicic magmatism corresponds to the local crystallization of quartz and zircon in the vein microgabbro with the further Zr/Hf fractionation by zircon. Experimental study of melt inclusions in zircon demonstrated homogenization at 850–910°C and the granitoid composition of the melt with K2O >1.8 wt % and SiO2 of 75–76 wt %. Such a K/Si ratio of the silicic melt, along with the genetic relation to highly differentiated gabbroids, allows us to prefer the model of a high degree differentiation of MORB-type magma in the oceanic core complex for the studied plagiogranite–gabbro association.
- Добавил в систему: Прокофьев Всеволод Юрьевич