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Rocks and "rock city"

Prachov rocks

Rock outcrops were created at 130 m mighty body of mostly medium-grained quartz sandstone Teplice Formation (Upper Turonian to coniak) Czech Cretaceous Basin. Bottom are called hruboskalske sandstone block. Along fissures in sandstone penetrated in the Miocene basaltic magma and utuhlo as he lived. Around these volcanics meet up with portions of the ferric form of vertical slabs of sandstone (Babince area and Svinčice) or tubes (stump).

Prachov rocks are articulated in detail the rest sandstone plateau, sloping slightly to the south. They are broken down ravines, boulder gorges, rocky gorges and valleys wider shapes, mostly in the direction of the principal crushed zones.

Rock towers with a height of 40 meters are limited to two systems of mutually perpendicular cracks. Can distinguish several groups of rocks, which can be considered as a separate rock city. The largest is the central rock around the Cisarska chodba (Imperial hall).

Expansion cracks formed vertical joints, chimneys and fissures in them then angled ledge. At the top of the mountain in places beginning separating rocks are common sufózní sinkholes. Rock around the perimeter of cities leads to rock avalanches to form false rock gates and small fissure caves. Vaulting collapsed block area was 30 m long cave Fraternal prayer.

GPS position

N 50° 28.102', E 15° 17.106'



Geopark UNESCO Český ráj
Jiří Vlasák