房総半島中部における三浦層群天津層の堆積と褶曲の形成過程  [in Japanese] 0n the stratigraphic subdivision of the Amatsu Formation and process of folding in the central part of the Boso Peninsula  [in Japanese]

Several brachy-folds of Matsubushi syncline, Sakagi anticline, Toyo-oka syncline and Shikumi anticline composed of the late Miocene Amatsu Formation run in parallel in E-W direction in the central part of the Boso Peniusula. The authors succeeded in correlating many pyroclastic keybeds and showing the variation of thickness of its members. The result shows the northward polarity of sedimentation, and the progress of folds accompanying with the deposition of the formation. One wing of an anticline is formed as a flexure while a member is deposited, and the other wing is formed at the later stage with or without the deposition. Such crustal movement might be due to the vertical movement of the basement blocks, judging from the computer simulation of virtual basement method.