Analyses of 24 shallow cores obtained from the present flood plain and the delta plain area of the Nobi plain, on the footwall side of the Yoro fault, suggest river channel change to west and temporal sea-level rise. The cores are represented by delta system and overlying fluvial system. Stacking patterns of the sedimentary units in the cross sections from the northern flood plain and 14C ages indicate the possibility that river channel change to the west occurred at ca. 2300 cal BE High EC, and brackish-marine diatom species identified in back swamp deposits in the cross section from the southern delta plain suggest temporal relative sea-level rise occurred at 1600 to 2700 cal BR There is synchronism of the above-mentioned channel change and temporal sea-level rise events. It is probably that the cause of these events is tectonic tilting and coseismic subsidence by faulting at Yoro fault.
|ジャーナル||Chikei/Transactions, Japanese Geomorphological Union|
|出版ステータス||Published - 2011 4 25|
ASJC Scopus subject areas
- Earth-Surface Processes