Simulating internal and external controls on fluvial terrace stratigraphy : a qualitative comparison with the Maas record

Palaeohydrological studies indicate that the use of sedimentary palaeoclimatic indicators in fluvial sediments still requires rigorous calibration of the climatic controls on the formation of those indicators. An explorative attempt is made using a simulation experiment with the FLUVER2 model. The simulation illustrates that climate control on the erosion/sedimentation behaviour of a large fluvial system differs along the fluvial system. While in the uplifting hinterland only glacial extremes are recorded as sediments with a relatively limited preservation chance as terraces due to the uplift. The more downstream reach towards the hinge zone displays a sensitive fluvial record registering even stadial/interstadial dynamics well preserved in an extensive glacial/interglacial terrace staircase. Downstream in a subsiding basin the most complete sedimentary record is preserved, which still contains temporal gaps of approximately 20%, related to the spatial delay effects of the external control of climate and related base-level change. A systematic comparison of simulated climate changes and resulting fluvial dynamics illustrates that due to the internal control of fluvial systems a one to one correlation between recorded fluvial dynamics and climate change becomes less the further one moves downstream along the longitudinal profile. A qualitative comparison of the simulation results with the Maas record reveals an interesting match, suggesting that the simulated system dynamics may well apply the Maas system.