Geografie 1967, 72, 202-213
Geomorphology of the NE Part of the České Středohoří Mts. in the Environs of Úštěk, Northern Bohemia
For this country has been made a geomorphological map in the field scale of 1 : 25 000. The geological structure is formed by Upper Cretaceous sediments and partly by overlying Tertiary volcanic rocks and pyroclastic material. Orographically belongs the NW part of this country to a volcanic mountain range České středohoří Mts. The SW part belongs to the Bohemian Cretaceous plateau. All this country lies on the N side of the Středohorský zlom fault dating from Oligocene - Miocene Ages (Saxonian tectonic movements - Savian phase). Along this fault may be seen a subsiding zone Úštěcká kotlina basin. These faults dating from Attic phase of Saxonian movements caused a small extent of the Post - Basalt level in the České středohoří Mts. which had been formed during Miocene age in a large area in North Bohemia and adjacent Saxonia as a peneplain. This plateau was disturbed and only in places preserved. It is limited nowadays to 2 small areas over 575 m a. s. but nevertheless it is the most characteristic feature of the NE part of the České středohoří Mts. Systematical geomorphology contains here plain and peneplain phenomena consisting of the post-basalt level mentioned above, denudation plains on the volcanits (trapp - plains) being very common in the plateau of Verneřice, denudation plains on the Cretaceous sediments being of the Pliocene age and forming large plateaus often in the uniform altitudes of 450 and about 270 m a. s. Both of the latter plains may be called structural plains, too, because they are influenced by the geological structure of the rocks. Two plains af piedmont proluvial sediments may be seen on the SE slopes of the České středohoří Mts. forming transitions into the river terraces which do not really occur in this country. There are only remnants of pebbles or erosional river terraces. The slopes may be called owing to their polygenic character the erosional - denudational ones and are divided into the steep, smooth and those on the loess sheets. Of the group of structural volcanic relief features exist in this country the conic summits, heaplike summits and dikes. The group of valley relief features contains outwash valleys (erosianal, V - shaped valleys), erosianal-accumulational valleys including flood plains, waterfalls with rapids and dellen. Other relief features include forms as follows: flood fans, landslides being very common owing to marly and tuffitic rocks, talus piles and block fields (seas of rock). Quarzit blocks and silicic conglomerates being the products of fossil weathering may be found in some places pointing to a former existence of the Oligocene peneplain.
