Fig. 4
From: Subglacial tunnel valleys in the Alpine foreland: an example from Bern, Switzerland
a The stratigraphy of wells that are based on cuttings and longitudinal section of the central valley (see Fig. 1b for location). The glacio-lacustrine environment in the cuttings does not fit to a glacio-fluvial regime beneath a glacier. The sedimentary deposits can therefore not be used to identify the processes controlling the incisions into the bedrock. b Schematic geomorphic model of subglacial tunnel valley and ascent of melt water underneath the glacier. The black arrows represent the proglacial meltwater pathways, the grey arrows indicate the melt water flow underneath the glacier towards the ice margin, and the light-coloured area represents the glaciations during LGM (after Bini et al. 2009)