Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

462 PATA Days 2024 (3 km north of Bor) Neogene fluvio-lacustrine sediments are cut by the fault. The main strand of the MLF here shows offset valleys seen on the digital elevation model (Fig. 6 - inset). As the fault scarp here looked young we choose the site Nová Hospoda for further geophysical survey and trenching. We excavated two trenches; the trench A revealed several W-dipping fault strands cutting the geliflucted layers during at least 6 events during late Pleistocene but being sealed by Holocene colluvium. The results of OSL dating are still not available, however since the gelifluction could have been Late Glacial (Štěpančíková et al. 2010, 2022), last motion must have been late Pleistocene. From Bor to Staré Sedlo the fault scarp is bending twice from N-S direction to WNW-ESE and reaches the height 15-35 m. C O N C L U S I O N The MLF was segmented based on varying fault strike and geology, which in strong correlation with the results of morphometric methods applied by Flašar, Štěpančíková (2022), such mountain-front sinuosity, basin asymmetry and analysis of longitudinal river profiles. Different grades of facets evolution, water stream erosion and river network changes in different parts of the MLF suggest a complicated tectonic history and possibly the difference in age and rate of the tectonic movements along the particular segments of the MLF (Flašar, Štěpančíková 2022). We proved this variable tectonic activity along the MLF also by paleoseismic trenching survey, which confirmed the northern segment within the Cheb basin being the youngest one - Holocene (Štěpančíková et al., 2019) and the potentially young activity of the southern segment around Planá to Bor was proven to be Late Pleistocene. A C K N O W L E D G E M E N T S The research was supported by the Grant Agency of the Czech Republic no. No. 16-10116J and 21-29826S, and by the Johannes Amos Comenius Programme (P JAC), project No. CZ.02.01.01/00/22_008/0004605, Natural and anthropogenic georisks.