Geografie 1971, 76, 13-24
Evorsional Phenomena in River Bed of the Kamenice
On an 8 km long section of the lower course of the river bed of the Kamenice 13 occurrences of giant pots with 480 measured forms have been discovered. Evorsional phenomena were predominantly formed in metamorphosed rocks of the paleozoic volcanic mass (green slates, metadiabases, etc.), less in graphitic and sericitic phyllites of the Železný Brod crystalline system. Giant pots may predominantly be found in a 3600 m long section, between the flow of Zlatý potok and the village called Úzké Údolí where the mean river gradient makes 14,0. Most significant forms arose close to the mouth of the Zlatý potok in the section of the greatest gradient, i. e. 20,9 within the distance of 500 m. Statistical data show that giant pots are predominantly small-size or middle-size phenomena (in 85 % the longer axis is shorter than 50 cm). Giant pots in their majority (60 %) are bowl-shaped, in 19 % are of cylindrical shape, in 11 % cone-shaped. Almost all evorsional phenomena occur within the reach of the yearly inundation water, only a few giant pots were discovered at a height of 350 cm above the low surface reached by the river water only at maximum water level (inundations occurring in 30-50 years' intervals). The prevailing majority of giant pots (90 %) occur in the rocky substratum, few of them being found in the rock debris filling the river bed in some places. Approximately every other giant pot is partly filled with sandy gravel. The unusually rich occurrence of evorsional phenomena in the lower section of the river bed of the Kamenice is the best proof of the present intense erosion activity performed by the river in the area of the Železný Brod Hills. The section of the Kamenice valley under study is of an expressly antecedent character.
