ON WAVE-CUT BENCHES ALONG THE SOUTH COAST OF THE MIURA PENINSULA, KANAGA PREFECTURE

Abstract

There are two groups of wave-cut benchs, beveling the Tertiary sedimen-tary rocks, along the coast of Aburatsubo Bay, Zyogashima Island and cape Kengasaki in the southern part of the Miura Peninsula. The higher, eleva-ted benches which were uplifted at the time of the Great Kanto Earthqua-ke in 1923 largely develop at the tip of the capes where the wave action is most vigorous. The lower benches lie below the high tide level and pre-vail along the coast of the calm inlets (Fig. 1). The surface of the elevated benches of which features are controled by the geologic structure and the hardness of rocks slightly incline landward, while the, lower benche have a smooth surface with a gentle seaward inclination and no relation to the rock formation (Fig. 2). Moreover the higher and the lower benches differ in many respects. Accordingly the auther has concluded that the elevated benches have characters of the storm bench, and the lower benches are almost similar to what was called the “Old Hat type bench” by Bartrum (1926).