京都盆地周縁部における第4紀の断層活動および盆地形成過程

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The Kyoto Basin, which is situated in the central part of the Kinki district, is delineated by several active faults along its eastern and western rims. This paper describes the faulted terrace surfaces and the distribution of the Quaternary deposits in order to estimate the activity of the faults and the tectonic development around the Kyoto Basin. The basin formation model that explains the topographic features around the basin is also discussed. The findings are summarized as follows.The active faults along the eastern rim of the Kyoto Basin are characterized by right lateral movements, and those along the western rim by left lateral movements. These faults show younger activity in the northern part of the basin, and older activity in the southern part.The Osaka Group, Pliocene to Pleistocene in age, is distributed in and around the Kyoto Basin. Its accumulating area migrated northward during the Pleistocene. This migration is considered to be the result of a northword shift of the fault activity.The mechanism of basin formation during the Quaternary is explained by a model in which the compression between the Shigaraki Plateau block, situated east of the Kyoto Basin, and the Hokusetsu Mountains block, situated west of the basin, caused northward movement of the Tamba Mountains block and subsidence of the Kyoto Basin.
日本第四紀学会の論文