Abstract
A total of 87 beach rock samples were collected from 37 sites of Amami Islands in order to determine formative ages of beach rocks on Amami Islands, and to clarify the sea-level change during the late Holocene period. Beach rocks began to form 5,720 yrs cal BP on Yoron Island at first, and formed continuously between 4,050 yrs cal BP and 380 yrs cal BP on the sandy coasts of Amami Islands. Relative sea-levels during the late Holocene period on Yoron Island and Okinoerabu Island were slightly higher than those of the present sea-level. Geomorphic evidences indicate that the islands have probably uplifted by earthquakes occurred along the subduction zone of Eurasian Plate. However the sea-level has remained similar to the present since at least the past 4,000 years at Amami-Oshima Island.
