Fluvial Terrace and Incision Rate in the Middle Sobaek Mountain Range

소백산맥 중부 지역의 하안단구와 하각률

This study tried to reveal distribution of incision rate and the factors from fluvial terrace deposits on the western and eastern slopes in the Middle Sobaek Mountain Range, using OSL age dating and topographical analysis. An average incision rate of 0.220 m/ka was estimated in the western slope streams, while the streams on the eastern slope showed a lower average incision rate of 0.121 m/ka. These results seem to indicate that the study area experienced an asymmetric uplift. Patterns of incision rate in the study area were different from those in the Northern Sobaek Mountain Range, probably suggesting that the Sobaek Mountain Range experienced spatially different uplift patterns. Among the factors, which were considered to influence on distribution of incision rate in the study area (e.g., altitude of sampling point, distance from divide, distance from axis, channel width, and bedrock type), distance from axis showed the strongest relationship with incision rate. Therefore, uplift is thought to be the most significant factor in distribution of incision rate in the Middle Sobaek Mountain Range.