THE LATE-GLACIAL DEVELOPMENT OF THE UPPER KLARALVEN VALLEY, SWEDEN

During the retreat of the Late Weichselian ice margin, a narrow ice to ngue filled the upper Klaralven valley in central Sweden. An inlet of the sea, about 150 km long and only 2 km wide, replaced the ice tongue . The sedimentation in this inlet can serve as an example of the devel opment of a river valley in a formerly glaciated area. Against its eas tern side, meltwater from the tributary valleys built up glaciofluvial deltas. Their distal, silty sediments filled the valley only partly d ownstream from the deltas. During the course of the isostatic rebound, braided streams developed and eroded the sediment surfaces rising abo ve the sea-level. The sediments were redeposited as secondary deltas, which eventually filled the valley up to the corresponding sea-level. When the entire valley had been filled with silty sediments, a meander pattern developed, controlled by a bedrock threshold at the lower end of the upper Klaralven valley. The resulting stratigraphy in the bott om of the valley is a thick silt deposit overlain by fluvial meander s ediments.