Last glacial sea-level change deduced from uplifted coral terraces of HuonPeninsula, Papua New Guinea

We have dated corals sampled from the uplifted terraces of Huon Peninsula, Papua New Guinea. that grew during the Marine Isotope Stage 3, to reconstru ct sea-levels of the last glacial period from 30 to 55 ka (kiloannum). Mass spectrometric U-series dating methods resulted in high precision dates and could also be used to recognize diagenetically altered samples. The only q uantitative test of open-system behaviour of both uranium and thorium isoto pes involves the comparison of U-234/U-238 ratios. at the time of coral gro wth. with present sea-water values. Additional tests included checks for sy stematic variations in stable isotopes. X-ray diffraction to detect calcifi cation and petrographic examination. Sea-levels were corrected for glacio-h ydro-isostatic variations and also for the depth range of coral growth habi tat. Sea-levels from 30 to 55 ka were approximately 80 m lower than present . Superimposed on this general trend. four periodic sea-level high-stands w ere found, at 6-8 ka intervals., approximately at 30. 38, 44 and 52 ka, tha t appear to be synchronous With rapid climate variations previously observe d in ice cores and in deep sea sediments. (C) 2001 Elsevier Science Ltd and INQUA. All rights reserved.