著者

高木 圭介 青池 寛 小山 真人

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.102, no.3, pp.252-263, 1993-06-25 (Released:2010-10-13)

参考文献数

42

被引用文献数

2 3

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A synthesis of geological, geomorphological, and petrological data was made to reconstruct the tectonic evolution of the collision zone between the Honshu and Izu-Bonin Arcs during the middle to late Miocene time. The collision zone is composed of four allochthonous terranes, which are overlaid by syn-collisional trough-filling deposits. The four terranes, Izu, Tanzawa, Misaka, and Koma Terranes, were originated in the Izu-Bonin volcanic arc and have in turn collided with and accreted into the Honshu Arc at about 1, 5-3, 11, and 15 Ma, respectively. The geomorphology of the northern part of the Izu-Bonin Arc is characterized by two N-S trending ridges, Shichito-Iwojima and Nishi-Shichito Ridges, and Nishinoshima Trough between the two ridges. We interpret the Nishi-Shichito Ridge as a remnant volcanic arc of early Miocene age. The Nishi-Shichito Ridge was left by backarc rifting, which occurred between the Nishi-Shichito and Shichito-Iwojima Ridges during 15-10 Ma. The backarc rifting resulted in the increase of downdip angle of the Pacific plate slab and the eastward migration of the Izu-Bonin volcanic front. The rifting also generated along-arc compressional strain, which caused the intraarc deformation of the Shichito-Iwojima Ridge at about 10 Ma. This interpretation well explains the geologic history of each allochthonous terrane in the collision zone between the Honshu and Izu-Bonin Arcs as well as the present distribution of the allochthonous terranes.

著者

平田 大二 山下 浩之 谷口 英嗣 菅 香世子 西川 正 青池 寛 有馬 眞 鈴井 正和

出版者

特定非営利活動法人日本火山学会

雑誌

日本火山学会講演予稿集

巻号頁・発行日

vol.1996, no.2, 1996-11-05