(Table 1) Uranium-Thorium datings from corals of Hainan Island, South China Sea@en

All isotopic ratios are activity ratios. Errors are quoted as 2 sigma. Half lives used in the calculation are as follows: 230Th, 77381 ± 590 (2s); 234U, 244600 ± 490 (2s); Ludwig et al. [1992]. Corrected 230Th ages assume an 232Th/238U atomic ratio of 3.83 ± 1.9 for the detrital materials, which is at secular equilibrium. Delta 234U initial is calculated on the basis of 230Th age.