2011 Volume 50 Issue 2 Pages 113-128
Buried landforms covered by the latest Pleistocene-Holocene deposits were investigated in the middle and upper part of the Arakawa Lowland and the Menuma Lowland based on analysis of over 3,000 columnar sections of borehole data and boring core sediments. The buried surfaces were subdivided into I-V surfaces in descending order. The I-IV surfaces are buried fluvial terrace levels formed during the latter half of the Last Glacial Age. The V surface consists of basal gravel deposited at the bottom of the latest Pleistocene-Holocene incised valley fill, which was formed around LGM. These buried surfaces were formed by fluvial incisions associated with the relative fall of the sea level during the latest Pleistocene.
The Fukaya fault, an active reverse fault, lies concealed around the boundary between the Arakawa Lowland and the Menuma Lowland. It is suggested that buried surfaces were deformed by the Fukaya fault.
