[S-CG56] アジア地域の地震・火山・テクトニクス

[SCG56-01] Tomo-topo-geologic aspect of an erosive margin: NE Japan case

*磯崎 行雄¹、趙 大鵬² (1.東京大学大学院総合文化研究科広域科学専攻広域システム科学系、2.東北大学大学院理学研究科附属地震・噴火予知研究観測センター)

キーワード：くさび状マントル、水和、前弧

Across-arc tomographic image clearly illustrated the development of a hydrous column through the wedge mantle in the fore-arc domain of NE Japan. On the surface, this domain is topographically represented by an elevated region called the Kitakami Mountains. The origin of the uplift is likley of non-volcanic origin, because The Kitakami Mtn. is clearly separated by a prominent lowland from the west-neighboring Ou Mountains with the volcanic front. In this presentation, the unique geological aspect of modern NE Japan with double-arc system is discussed particularly from the viewpoints of mantle tomography and seismic profiles. The non-volcanic buoyant uplift of the fore-arc domain and the combination with tectonic erosion along active trench likely have shaped the unique double-arc system.