Optically stimulated luminescence dating of fluvial deposits

Two short-lived phases of incision during the first half of the XIX century were probably caused by a decrease of sediment supply due to a decline in the frequency of heavy precipitation events.The channel incised during this period was later partly filled with sediment.disturbing the land surface by ploughing) or settlements (i.e. When a drainage system changes from stable conditions to either an erosional or depositional mode, this is often of major importance for local communities (e.g., due to the loss of fertile soil).It is therefore necessary to understand why systems change their behaviour and one approach is to investigate its response to changes in the past.From this data a complex deposition and incision history is constructed for the last 500 years.It is concluded that sediment deposition was mainly forced by sediment supply from ploughing areas.Different statistical approaches to extract the mean equivalent dose from dose distributions are compared to estimate the effect of differential bleaching of the OSL signal prior to deposition.

the occurrence of extreme events such as heavy thunderstorms), and (iii) whether humans are using land for either agriculture (i.e.

Correction for this phenomenon improves the IR-OSL ages slightly, but does not provide a complete solution to the discrepancy.

We suggest that, in the light of the problems encountered in the IR-OSL dating of feldspar, quartz is the mineral of choice for OSL dating of these deposits.

Le déclin des labours à partir des années 1915 diminua la fourniture sédimentaire alors que le développement de l’urbanisation après 1950 augmenta l’énergie des crues (rejets d’eaux pluviales et de déversoirs d’orages), causant l’incision actuelle qui débuta vers 1975.

., 2004; Leopold & Völkel, 2007; Fuchs & Buerkert, 2008).

Optically stimulated luminescence dating of fluvial deposits