Cave development under the influence of Pleistocene glaciation in the Dinarides - an example from Štirovača Ice Cave (Velebit Mt., Croatia)

Abstract

This paper analyses for the first time the influence of glaciation on underground karst landforms in the Croatian part of the Dinarides, as well as the interrelation between underground and surface relief developments under glacial conditions. The karst environment, as a good recorder of palaeo-environments, provides some new information on Quaternary glaciation in the Velebit Mountain in Croatia, and reveals, generally, the morphogenetic evolution of Stirovaca Ice Cave (in Croatian, Ledenica u Stirovaci) and of the surrounding area. During cold periods, glacial exaration produced a particularly significant quantity of sediments. Consequently, underground karst conduits situated below the snow line during the Pleistocene were filled with high-energy sedimentary structures, glacial and fluvioglacial sediments. This reduced or even stopped their conduit function, and led to difficulties in the drainage of meteoric water, to lake formation within morphological depressions and to a rise in the local water-table level. With the denudation of these deposits, conduit reactivation and a drop in the underground water level occurred. Stabilisation during milder climatic conditions led to aggradation of the cave and to the deposition of flowstones from 8230 ± 150 years BP.