Reducing the age range of tsunami deposits by 14C dating of rip-up clasts

摘要: Abstract Erosion by tsunami waves represents an important issue when determining the age of a deposit, because is usually estimated using dating sediments above and below deposit. Dating material within if suitable obtainable, can be used to further constrain its age. Eroded are sometimes incorporated deposits as rip-up clasts, which might therefore minimum material. However, single calibrated 14 C often shows wide range fluctuations in calibration curve. Therefore, it remains uncertain whether clast measurements useful depositional deposits, or not. In this study, we carried out high-resolution including clasts peat, Rikuzentakata, northeastern Japan, where numerous were observed Sediments deposit 5 cm large dated sequentially. Comparison these results with curve revealed that was inverted. Its better constrained based on stratigraphic order, infer corresponds approximately 100 years sedimentation. The oldest consistent peat immediately suggesting surface probably formed at time tsunami. Thus, narrowed 100 years. Results show ignoring tsunami-related erosion lead overestimation For reason, appropriate site, less affected minor regards paleo-topography, should explored. We propose more effective sampling strategy for estimation deposits.