Using geomorphological and geophysical survey to research relations between landforms and joint tectonics in the Broumovská vrchovina (Czech Republic)

Abstract

We analyze relationships between fault and joint tectonics and landforms in the south-western part of the Broumovská vrchovina (Bohemian Massif ), where the surface topography is strongly influenced by the tectonics and lithology of the Upper Cretaceous and Permo- Carboniferous sedimentary series. We examine joint orientation using field measurements and 3D seismic tomography. The orientation of linear topographic features (morpholineaments) shows a clear dependency on two perpendicular joint systems, which exhibit either a NE -SW or a N W-SE orientation. Morpholineaments oriented in a N W-SE direction are more apparent in the surface topography and their frequency is higher. This can be attributed to the mechanical properties of NW-SE striking joints, which tend to be more open and penetrate to greater depths, making them more favourable for erosion processes.