Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences
2008 Annual Meeting of Japan Association of Mineralogical Sciences
Session ID : S3-02
Conference information

S3: Large silicic magma systems
Origin of felsic magmas of some large-caldera related stratovolcanoes in central part of NE Japan
*Masao BanShiho HirotaniAyaka wakoTakuro SugaYutaka IaiShin-ichi KagashimaKenji ShutoHiroo Kagami
Author information
CONFERENCE PROCEEDINGS FREE ACCESS

Details
Abstract
We examined the genesis of felsic magmas of three post large-caldera volcanoes; Aoso, Takamatsu, and Gassan from front to rear arc side, NE Japan. These volcanoes are mainly composed of andesites which were formed by mixing between mafic and felsic end-members. The following data suggest the two end-member magmas are cogenetic. (1) Increasing potassium contents in felsic end-members from front to back arc side can be observed, as well as in mafic ones. (2) Sr isotopic data of each volcano are rather constant in all range of silica contents. Fractional crystallization process of phenocrystic minerals from the mafic end-member can not explain the whole rock compositions of the felsic one. An alternative process to produce the felsic end-members is partial remelting of solidified mafic ones. The trace element composition shows that the felsic end-member can be formed by remelting, leaving hornblende gabbroic residues.
Content from these authors
© 2008 Japan Association of Mineralogical Sciences
Previous article Next article
feedback
Top