Caves

Abstract

Cavernosity of the Classical Karst, karstification of the karst in the area between Divača and Črni Kal based on the cores of boreholes which were dug into depths reaching as deep as 150–350 m, karstological research made during the construction of motorways across Slovenian Karst, anticipated cavernosity along the planned railway line, and biology of subterranean habitats, ecological parameters and the state-of-the-art subterranean invertebrates in selected habitats are topics of the chapter. There are 777 caves in the Classical Karst known already, of which 177 are located in the broader area of the future railway line. All most important data on the caves are from the Cave Registry, edited by the Karst Research Institute ZRC SAZU and the Speleological Association of Slovenia. They can be divided into those through which streams of water are or were passing at various speed and shafts formed by percolating water. On the base of the karstological research made during the motorway construction across the karst area in SW Slovenia and on the base of the found cores of 13 boreholes dug into the earth on the route of two longest future railway tunnels we estimate the expecting cavernosity in individual sections in the area of the planned railway. The Dinaric karst, and especially its Slovenian part, is a global hotspot for subterranean biodiversity. The Section about biology of the subterranean habitats presents various underground habitats, sampling methods of fauna in the study area and results of this research which show that the most abundant organisms, having been brought to the caves by percolating water, are copepod crustaceans. There are more and more useful data for evaluating karst cavernosity in the area of the planned railway route. For assessing the cavernosity of this part of the Classical Karst (Kranjc 1997; Gams 2004) we used the Cave Registry, which we are compiling together with the Speleological Association of Slovenia, the results of the karstological supervision of the construction of motorways in the Classical Karst, and precise measurements in the profiles of the quarries. All the listed data testify to karst cavernosity, particularly in the epikarst zone and the zone beneath it, to a depth of a few tens of metres. An assessment of cavernosity at greater depths, i.e. at the depths where the tunnels’ line will run, can be given on the basis of the current knowledge of the development of the karst aquifer and the results of the karstological-geological, geomorphological, speleological and geomechanical research of this area. The experience gained in the construction of motorways and road tunnels in the Classical Karst is also of great help (Knez and Slabe 2007).