宮古島北部，大浦田原海岸のビーチロックの形成年代と形成速度

Abstract

Ohuratabaru coast lies in the northern part of Miyako Island, where beachrock develops continu- ously about 400 m in length and 70 m in width. Eight calibrated 14C ages reported previously were used to estimate formative age and rate of beach rock. They suggest that beachrock was formed from inland toward the present strand line between ca. 1,500 cal BP and present time. The average formative rate of beachrock evacuated from age and distance indicated 3～7 cm/y.