Residual OSL signals in modern fluvial sediments from the Yellow River (HuangHe) and the implications for dating young sediments

The Yellow River is characterized by its tremendous sediment load. In this study we investigated the residual OSL signals in modern fluvial sand and suspended-sediment samples from the middle reach of the river. The residual equivalent dose (De) is found to vary with grain size, mineralogy and the techniques used for the De determination. The results indicate that the OSL signals in some grains from these samples were not completely bleached prior to burial, the maximum individual De value obtained is up to 56 Gy. The results also show that coarse grains are generally better bleached at deposition than fine grains; the fine-grained quartz from suspended sediments are better bleached than the fine-grained quartz from the fluvial sand deposits. The Des obtained using quartz TT-OSL signals are up to ∼380 Gy for these modern samples.