Postglacial evolution of paleodepressions in glaciokarst areas of the Alps and Dinarides

Abstract

The karstification of the paleodolines of glaciokarst is studied. Our methods included topographical mapping, geomorphological mapping and analysis, vertical electrical sounding (VES) measurements, areal imaging, investigation of the material of the superficial deposit. On glaciokarst, the paleodolines without cover are the bare karst patches, while paleodolines with cover belong to allogenic karst (if the cover is impermeable) or covered karst (if the cover is permeable). The covered karst also occur in patches, their pattern depends on the distribution of paleodolines, the size of glacier valleys and on the type of the former glaciers. The paleodolines can be exhuming or infilling. A paleodoline is infilling if more sediment is transported into the doline than from the doline into the karst. In case of exhuming paleodolines, more sediment is removed into the endokarst. Allogenic karst depressions become exhumed since their sediments are transported into the endokarst through ponors. Covered karst depressions remain unaffected in case of non-soluble debris in permeable cover. No subsidence dolines can be observed in the cover and the endokarst is not able to receive sediment. Covered karst depressions can be exhuming a.) to small extent if the cover comprises soluble limestone debris and the subsidence dolines have little ability to receive and transport sediment, b.) to a medium extent in case of large shafts beneath subsidence dolines, and c.) to large extent if the cover is partly impermeable, but gullies and creeks lead to the dolines. In case of a recent sediment input of large extent, the paleodolines (mainly those with covered floor) are filled up.