Sedimentology and internal structure of murtoos - V-shaped landforms indicative of a dynamic subglacial hydrological system

Knowledge about processes beneath ice sheets, and in particular the connected to subglacial hydrology, is crucial for an understanding of sheets how they react a warming climate. Recently, v-shaped landforms (murtoos) have been found those parts former Fennoscandian Ice Sheet where rapid ice-margin retreat occurred. Based on their geomorphology distribution, murtoos suggested form bed experienced high influxes meltwater. Here, we investigate sedimentology internal structure at four localities southern Sweden better understand murtoo genesis. The excavated consist heterogenous diamict showing reasonably strong fabrics interbedded with sorted sediments. Sediments show signs ductile deformation lquefaction. We interpret these as created by till deposition sedimentation from meltwater subsequent deformation. Cross-cutting relationships inter-bedding sediments suggest stepwise formation including periodic events. propose model that based dynamic system. environment within distributed system receives repeated supraglacially derived this are strikingly similar character glaciological hydrological dynamics observed Greenland sheet today.