To investigate the feasibility of OSL dating of lakeshore sediments

equivalent dose (De) values of quartz fractions in different grain-size were measured using the "Double-SAR" protocol of optical dating in four lakeshore sediments. There are two obvious different relations between De values and grain sizes. The first situation is that the De values are accordant with eath other for fractions between 63 μm and 400 μm with a slightly decreasing tread of De values as increasing of grain-size. The second situation is that the De values are accordant to each other for fractions between 125 μm and 300 μm

while the De values of the 63–90 μm and even the 90–125 μm fraction are obviously smaller than others. The first is consistent with those reported elsewhere

while the second can’t be understood by the previous theory.