Initial H2O content and conditions of parent magma origin for Gorely volcano (Southern Kamchatka) estimated by trace element thermobarometry

• Published in: Doklady Earth Sciences
• Main Authors: Nazarova, D. P., Portnyagin, Maxim V., Krasheninnikov, S. P., Mironov, N. L., Sobolev, A. V.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2017
• Subjects: Kamchatka
• Online Access: https://oceanrep.geomar.de/id/eprint/37760/; https://oceanrep.geomar.de/id/eprint/37760/1/2017_Nazarova%20et%20al.pdf; https://doi.org/10.1134/S1028334X1701024X

The formation conditions of the parental magmas of Gorely volcano, which is located behind a volcanic front in Southern Kamchatka, have been evaluated using the modern methods of micro-element thermobarometry. These magmas contained 1.7 ± 0.8 (2σ) wt % of H2O, the majority (82%) of which has been lost from inclusions. They crystallized at 1121 ± 17°C and an oxygen fugacity of ΔQFM 1.2 ± 0.2, and could have been produced by about 11% melting of an enriched MORB source (E–DMM) at a temperature of about 1270°C, and a pressure of about 1.5 GPa. A distinctive feature of Gorely volcano, compared with frontal volcanoes of Kamchatka, is the unusually high temperature (925 ± 20°C) of formation of the subduction component corresponding to the region of existence of water-bearing melts.