LA-ICPMS U-Pb Dating of Zircon in Paleotsunami Deposits from Miyazaki Plain, Southwest Japan

UPb dating of detrital zircons was performed to characterize the paleotsunami deposits of the 1662 CE Kanbun-Hyuganada sea earthquake in the SY05 core from the Miyazaki plain on the Pacific coast of southwest Japan. Twenty-five large-sized zircon grains (>similar to 50 mu m) were separated from the paleotsunami deposits by chemical abrasion. In the present work,(UPb)-U- 238-Pb-206 ages were measured by a laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-ICPMS) system at Tono Geoscience Center, Japan Atomic Energy Agency. (UPb)-U-238-Pb-206 ages of the detrital zircons ranged from similar to 14 Ma to similar to 2405 Ma, and the age spectrum revealed high relative probability values around similar to 100 Ma and similar to 2000 Ma. Detrital zircons with the age of similar to 100 Ma in the 1662 CE paleotsunami deposits could be partly originated from the Shimanto Super group (CretaceousPaleogene) in Kyusyu Island, southwest Japan. Moreover, the UPb age spectrum of detrital zircons with Precambrian grains from the paleotsunami deposits was similar with those of fore-arc sandstones from central Kyushu Island.