On the Geomorphology of the Doupov Hills

Abstract

The Doupov Hills belong to the Ore Mountains System. They cover approximately a circular area of a diameter of 25-30 km on the right bank of the river Ohře between the Sokolov and Most basins. They originated in the first phase of the neo volcanic activity in the Lower Miocene. Their structure is typical of a stratovolcano with prevailing pyroclastics (80 %). The alternating of pyroclastics and flat, periclinal effusions causes the occurrence of tablelands and expressive changes in the inclination of slopes. Typical phenomena are table mountains with stepped slopes. The surface rises towards the center of the mountain range. The highest peaks (about 800 m, the highest is Hradiště 934 m) occur around an approximately 200 m deep depression in which the main feeding channel filled with essexite has been incised by erosion. Since their origin in Lower Miocene up to the present time, the surface of the Doupov Hills has been affected by gradual lowering. The main modelling factors are numerous slope streams strongly affecting the margins of the mountain range, meanwhile in the central part plateaus and flat ridges have been preserved as remains of the original surface lowered by denudation. Only one of the streams (the brook Liboc) has penetrated as far as the center of the mountain range and helped in the widening of the original crater in caldera. The erosion basis for the majority of slope streams is the surface of the Ohře flowing in a deep canyon across the northern margin of the range. The origin of the Ohře valley was explained for the first time by the antecedent behaviour and this opinion has survived in spite of some discrepancies. Its acknowledgement or modification becomes the aim, of future investigations. Their results will throw light upon one of the most interesting problems in the geomorphological development of northwest Bohemia.