R6: Plutonic rocks, volcanic rocks and subduction factory

2:30 PM - 2:45 PM JST(5:30 AM - 5:45 AM UTC)

[R6-03] Magmatic processes and geographical features of Abu and Aonoyama volcano groups, Yamaguchi Prefecture

*Masaaki Owada¹, Haruka Imachi, Mariko Nagashima¹ (1. Yamagucni Univ. Sci.)

Keywords:

Abu/Aonoyama volcano groups,alkali-basalt,adakite,magmatic process,volcanic landform

Quaternary andesite to dacite of the Abu and Aonoyama volcano groups, Yamaguchi Prefecture, shows distinct geographical features. The andesite to dacite of the Abu group occurs as a plateau, whereas that of the Aonoyama group shows a domal structure. Consequently, the andesite to dacite magmas of Abu volcano group were solidified as lava plateaus because the magmas would be of low-viscosity conditions due to enrichment of alkali contents and high-temperature.