충남 천안시 차암동 일대 구릉지 소유역의 제4기 후기 사면물질이동

Abstract

The purpose of this study is to investigate the Late Quaternary mass-movement of slope material originated from small hilly watershed around Chaam-dong moving to valley bottom. To do this, for the object of valley bottom sediment in the Chaamgol watershed, facies analysis, radiocarbon dating and grain size analysis were conducted. The study watershed belongs to upper region of Yuljicheon which is the tributary of Maegokcheon which flows around Chaam-dong Cheonan-si, Choongnam. The result of analysis is like the following. In study watershed, mass-movement of slope material which occurred in instable period of slope was confirmed to be minimum 12 times and it was discovered that wetland environment formed in stable period of slope was in 3 times. To look at concretely, around until 25,300yrBP 4 times (M1 period~M5 period) of mass-movement of slope material and 2 times (W1 period~W2 period) of wetland environment was confirmed. And around 25,300yrBP~recent period 1 time (W3 period) of wetland environment was continued. In addition in the process where wetland environment of W3 period was changing to land environment, though they were weak a few times of movement of slope material were confirmed. Namely, over around 25,300~18,600yrBP which is converged as the Last glacial, total 3 times (M6 period~M8 period), around 15,300yrBP 1 time (M9 period) and around 11,200yrBP 1 time (M10 period) of mass-movement of slope material event occurred. And in the period converged to the Upper Holocene, 2 times of mass-movement of slope material were confirmed. Namely, around 600yrBP mass-movement of slope material in M11 period and after that, mass-movement of slope material in M12 period occurred.