Corrections of Radiocarbon Ages for Beachrock Samples Based on δ¹³C Values (A Preliminary Report)

Abstract

87 beachrock samples were collected from four islands described in the subtitle, and their radiocarbon ages and δ ¹³C values were measured by the author. Their results are summarized as follows. (1) The δ ¹³C values of beachrock samples were between +4.77 ‰ and −3.28 ‰, and the mean value was +1.96 ‰. (2) The δ ¹³C value decreases gradually from Yoron-jima to Amami-Oshima. (3) The correction value for radiocarbon age of beachrocks were between 357y and 493y (mean=445y). (4) After radiocarbon age correction almost of the radiocarbon ages have coincided within ± 3 σ of statistical error.