Český ráj sever II.
Rock mushroom
Rock mushrooms are in top shape mezoreliéfu parts of the mountain towns. They are spherical, bochníkovité, ovate or pyramidal. Mushroom rocks typically occur in sandstones disaggregated set of vertical cracks on individual rock towers or even smaller rocks. These are formations created on the edge of the platform, on ridges or in rocky scenery. The emergence Boletaceae shapes in temperate climates important horizontal division sandstone massif. The emergence of hats here usually is caused by the presence of horizontal positions ferric sandstones and conglomerates or positions imbued with siliceous cement. That is, this sandstone is stronger and more resistant to erosion caused by water and rain. Narrowed parts rocks (leg) are in turn linked to the level of erosion surfaces, which consist of less resistant sandstone, mostly with clay and kaolinitickým sealant. Greater susceptibility to erosion is not caused only by the chemical composition of the sandstone, but also the intense bioturbací or presence valounového material in the rock. At narrowing legs can also participate in a higher frequency of horizontal or slightly inclined cracks.
