6:15 PM - 7:30 PM
[MIS25-P14] Effectiveness of luminescence dating of tsunami deposits examined from the March 2011 Tohoku-oki Tsunami deposits
Keywords:OSL dating, transport and depositional processes, tsunami deposits, the 2011 off the Pacific coast of Tohoku Earthquake, feldspar
Single grain OSL dating was able to extract the grains indicating true depositional age of the 2011 Tohoku-oki tsunami deposits at 11 locations (26 samples), which shows nearly zero OSL intensities. It is interpreted from the results that single grain OSL dating is a feasible method to estimate appreciate depositional age of tsunami deposits. Meanwhile, some grains were overestimated depositional age remarkably. Therefore general OSL dating, which measures a number of grains on one aliquot, is probably difficult to estimate accurate depositional age of tsunami deposits. The results of OSL dating indicated most of sand grains in tsunami deposits had not been exposed to daylight during tsunami transport processes. This means that sand grains in tsunami deposits preserving bleaching achievements of sediment sources. OSL dating is able to calculate bleaching achievements of minerals, therefore, it might be able to estimate sediment sources of tsunami deposits.