いなみの台地の地形におけるサイクリック現象とその意味するもの(予察)

Abstract

Inamino Upland in Hyougo Prefecture lies between the river Kakogawa and the river Akashigawa that flow into the Seto Inland Sea, Western Japan. Marine terraces are formed along the coast at the southwestern area of the Upland. The auther previously pointed out that those surfaces were formed with 9 steps of marine surface and postulated that the formation of these 9 steps resulted from 9 marine transgressions corresponding to the 9 maximum extrema of the Milankovitch's time variation curve of insolation over the northern hemisphere in caloric summer during the past 60, 000 to 240, 000 years. Recently, he pointed out that 12-13 steps of fluviatile terrace are formed along the east slope of Upland, that is the right bank of the river Akashigawa, and 7 steps of surface are on the tops over the Upland surface. So, he postulated too, that the formation of these steps resulting from older transgressions corresponding to the Milankovitch theory during the past 60, 000 to 340, 000 and 260, 000 to 420, 000 years, respectively.