Applicability of OSL Dating to Fine-Grained Fluvial Deposits in the Mekong River Floodplain, Cambodia

Abstract Optically stimulated luminescence (OSL) dating of fine-grained (4–11 μm) fluvial sediments is rarely attempted but crucial for constraining the evolution mud-dominated floodplains. This study investigated applicability OSL to deposits in Mekong River, Cambodia based on a very young (<600 yr) point-bar riverbank succession and modern flood deposits. In succession, quartz provided youngest ages, whereas age estimates by multi-grain sand-sized OSL, feldspar polymineral infrared-stimulated are >200 years older than estimates. Ages concordant with minimum ages obtained from single-grain OSL. These results supported generally small residual doses (<0.1 Gy) measured flood-plain indicates that River (Cambodia) sufficiently bleached at deposition can yield reliable establishing chronology floodplain. The sufficient bleaching partly long transport distance may also occur other large river systems.