Notes on late quaternary sea levels, Fiji and Rarotonga

Abstract

Abstract Surveyed Holocene beach ridges near Taunova and Ndeumba, Fiji, have no accurate dates. Those at Ndeumba, where wind‐blown sand may be absent, could represent high‐spring‐tide berms and they show that sea level has possibly fluctuated up to 3 ft above and 2 ft below the present within at least the later part of the Holocene. Radiocarbon dates for the 3 ft and 10 ft coral reefs at Rarotonga are 2,030 and 28,200 yr B.P. respectively, but because of recrystallisation these dates are most likely too young. A 6 ft terrace, probably younger than the 10 ft reef, is cut into older reef rock dated as greater than 48,900 yr B.P. A prograded strip of sand that almost completely encircles Rarotonga consists of storm ridges that are unsuitable for determining past sea levels. The oldest storm ridge has a radiocarbon date of 3,510 yr B.P. and is correlated with the oldest Holocene beach ridge in the Firth of Thames which has a radiocarbon date of 3,900 yr.