Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Questions of origin of sinkholes, caves and large springs in Hrubá Skála sandstone and implications for hydrogeological conceptual model of quader sandstone
AbstractDolines are common landforms in Bohemian Paradise area. About 530 dolines occur here with length up to ~50 m and depth up to 13 m. Dolines are developed in Hrubá Skála sandstone, a quartz sandstone bond by kaolinite, which at studied places does not contain any carbonate or other dissoluble material. According to most of authors the dolines were created by erosion of surface water entering the tectonic fractures in weakly cemented sandstone, but relatively recently one author claims that slope movements are dominantly responsible for origin of dolines. Position of dolines and direction of doline groups with respect to the escarpments supports idea that most of dolines are erosional in origin. Presence of dolines, semi-blind valley, up to 190 m long caves and relatively large springs shows that Hrubá Skála sandstone is (or in recent geological history was) easily erodible at many different areas in Bohemian Paradise. Hydrogeologists should consider the likely existence of highly permeable conduits with high flow velocities (10-40 cm/s) which may be self-organized in similar way as those described from Střelec quarry.