The Distribution of 230Th/234U Ages in Corals and the Number of Last Interglacial High-sea Stands

Abstract

The 104 available [230Th/234U] analyses of unrecrystallized corals from stable emerged terraces indicate that the last interglacial period occurred approximately 125,000 yr ago. An estimate is made of the exact duration of this period by accounting for the surprisingly small distribution width observed among the 80 most reliable analyses. This distribution width is compared with those obtained for model populations generated by assuming various characteristic analytical errors and various lengths of the last interglacial period. The results show that (1) if there was only a single rise in sea level, it probably lasted no more than 12,000 yr, in agreement with previous estimates; and (2) if there were two separate rises of sea level, the gap between them must have been less than 7500 yr and not 12,200 as proposed by some authors.