Particularly Interesting and Rare Occurrences in Caves of the Dinaric Karst in Croatia

Abstract

Some phenomena that occur frequently in the Dinaric Karst of Croatia are rarely seen in other parts of the World, so they are mentioned here. For instance, vruljas (underwater freshwater springs under the surface of the Adriatic Sea) are sometimes impressive with the amount of water discharge and the length of submerged channels. They are always present under the large mountain massifs of Učka, Velebit, Mosor, Biokovo, etc. Estavelas—caves located on the edges of karst fields have a dual hydrogeological function: spring and ponor. The largest karst fields in the world, which are located in the Dinaric Karst, are also mentioned here. Large vertical shafts are a special feature of this karst area. Rare occurrences of caves in clay, marl and tufa, special and rare types of speleothems, caves in ice, underground bifurcations and measurements of radon gas concentration in the caves of the Dinaric Karst in Croatia are also mentioned.