地層構造および堆積物分析による天竜川河口周辺の海浜形成過程の考察

抄録

Stratigraphy of the coastal section about 4km west of the Tenryu River mouth was studied by using a Ground Penetrating Radar (GPR) and sediment cores. GPR profile reveals that the stratum is divided into two parts at horizontal boundary. The lower part was formed by the seaward progradation of foreshore and the upper part was formed by alongshore movement of aeolian dunes. Two types of reflecting surfaces were recognized in the lower part. One is an erosional surface which truncates underlying reflecting surfaces. The other is a depositional surface which concordantly covers underlying surfaces. Erosional surfaces with sharp contacts were also found in cores. These erosion surfaces in cores well correspond with the erosion surfaces in GPR profile. These are thought to be annual records of storm erosion.