A re-investigation of hummocky moraine formed from ice sheet decay using geomorphological and sedimentological evidence in the Vomb area, southern Sweden

Abstract: Glacial sediment-landform assemblages have long been used to reconstruct the dynamics of ice sheets throughout the Quaternary time period, particularly so for the period of the last glaciation in northern Europe and southern Scandinavia. One such sediment-landform assemblage is hummocky moraine, which has previously been used as an all-encompassing descriptive terminology strongly associated with dead ice meltout and passive deglaciation. The broad use of this terminology can often result in an incorrect classification of the landscape, which with its strong association to dead ice meltout results in a strong bias toward related deglaciation models. A detailed remote- and field study was conducted over a region in Scania, southern Sweden, that has previously been classified as hummocky moraine. By remotely mapping individual hummocks and landforms on a large scale through the use of LiDAR data, the spatial components related to the hummocks were analysed and showed spatial order and clear orientations in the landscape. Two hummocks were examined and found to contain sedimentological evidence linked to an active ice-margin. With the addition of several ice-walled lake plains, it was concluded that the ‘hummocky moraine’ in the study area were formed from processes linked to both active and stagnant ice.