Geomorphic development of barriers in the coastal lowlands during the Holocene - a case study of the lowlands along the Suruga Bay, central Japan

Abstract

Considers environmental changes of the bays or drowned valleys on the basis of analysis of the fossil foraminiferal assemblages in the bore hole cores. Examines whether a "primary barrier' existed or not in the course of geomorphic development and how the primary barrier enclosed a bay or a drowned valley. The development of the coastal lowlands has been influenced by the relative change in sea-level. When the rate of sea-level rise decreases, a barrier begins to enclose a bay. And when the sea-level is stable or falls slightly, the barrier completes enclosure of a bay or swampy area. It is difficult to detect the influence of tectonic crustal movements on development in the coastal lowlands along the Suruga Bay before the period ca.7000 to 6000 yr BP. After this period, the tectonic influence is clearly recognized. -from English summary