Sandstone Crags and Blockfields in the Świętokrzyskie (Holy Cross) Mountains

The majority of ca. 90 sites of sandstoneSandstone cragCrag groups and individual cragsCrag in the Świętokrzyskie (Holy Cross) Mts. region are built of the following crag-forming lithostratigraphic units: Cambrian Wiśniówka Fm, Devonian Barcza Fm and Zagórze Fm, Triassic Zagnańsk Fm and Krynki Beds as well as Jurassic Skłoby Fm and Ostrowiec Fm. Specific features of these rocks are the occurrence of sandstone series up to 20 m thick above plastic, clayey or heterolithic series, high-energy depositional environments, and siliceous composition. The cragCrag-forming sandstones differ in the amount of siliceous cement, from strongly cemented Palaeozoic quartzitic sandstones to porous Mesozoic sandstones with poor cement, which determines diverse mechanical properties. Strongly cemented Palaeozoic rocks display high strength and abrasionAbrasion resistance, while porous Mesozoic sandstones are characterised by high grain packing due to compaction. Gravitational disintegration of rock massifs under the periglacialPeriglacial conditions in the Pleistocene has played the principal role in cragCrag origin. Other factors influencing cragCrag formation and shaping are the spatial (tectonic) orientation of strata and joints, adequate joint spacing, and bed thickness. The interrelations between specific lithological and structural features as well as tectonics of sandstones that conditioned weathering and gravity-induced processes, resulted in the formation of the cragsCrag.