추가령 구조곡의 하안 단구 노두 분석: 철원 율리리 독서당천을 중심으로 = Geomorphotogy and Stratigraphy of Dokseodang River Terrace in the Churgaryeong Rift Valley, Central Korea

다국어 초록 (Multilingual Abstract)

Some river terraces are distributed along the Chugaryeong rift valley, esecially between Cheolwon and Jeongok. 4 different leveled terraces are identified in Dokseodang tributary river valley, as a case study area, which flows into upper Chatan main river. T1, highest terrace surface, has relative height 30.5m from present river bed, weathering degree of 2-4 stage, and 5m depth layer of deposition with subangular to subroundedgravel layers of pebble and cobble classes, interbedded with sand layers. The composition of matrix grain size has gravel 86％ sand 43.93％, and mud 25.21％. T2,second higher terrace, shows characteristics of 24m relative height, 2m depositional depth with subangular gravels of pebble class and clay layer of 0.4m under gravel one, weathering degree of 2-4 stages of volcanic rocks and 5-6 stages of schists, and matrixcomposition of gravel 22.09％, sand 55.79％, and mud 22.13％. T3, lower middle terrae, shows 13m height, 3m depth gravel layer subangular to subrounded cobble class, 1-2stages weathering degree, and matrix composition with grabel 32.19％, sand 32.90％, and mud 34.90％. Generally, the volume of the clay composition in terrace T1 has higher than those of terraces T2 and T3. The latest age of the lava damming in upper and lower channels in Chatan river was 0.27ma calculated according to previous studies. The incision rate of valley from T1 surface to present riverbed can be approximately0.15m/ka from event, using the values of age 0.27ma and relative height 30.5m fromriverbed.