Abstract
The coastal geomorphology is discussed at Okino-erabu Island, one of the coral islands in the Southwest Archipelagos, Japan.
The author classified the shoreline of this island based on the combination of some elements of coastal geomorphology, i. e. vertical coastal cliff (15-70m a. s. l.), sea cliff, intertidal bench, submarine bench and grooves. The relation between the classification and the distribution of several types of notches is clarified (Fig. 1).
Higher postglacial sea levels are deduced from the altitudes of notches, beach rocks and negroheads, namely:
1) the 2.4m level a. s. l, is suggested by emerged negroheads and emerged beach rocks,
2) the 1.8m level is deduced from average altitude of retreat points of all measured notches without structural ones, average altitude of retreat points of V-shaped notches and emerged beach rocks,
3) the 1.1m level is shown with emerged beach rocks (Fig. 7).
