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

second trench was excavated next to Libocký Brook to compare the deposits within the valley floor. The trench exposed late Pleistocene fluvial terrace deposits of Weichselian glacial period, which fill most of valleys in Bohemian massif and were later covered by Holocene floodplain deposits. The Pleistocene fluvial deposits at Horka site appeared to be folded, which is displayed by warped dark brown manganese layer indicating the ancient groundwater level. These Pleistocene gravels are covered by fine grained Holocene floodplain deposits, dated in the trench as ca 4 ka and which are displaced by minor fault branches within the MLF zone. So, it was the second site in the Cheb basin, where as young as late Holocene surface-rupturing earthquakes within the MLF were documented and proved. Central portion of the MLF In the central portion of the MLF, the fault strike is bent and controls the most elevated area, the Slavkovský les Mts by up to 300 m high fault scarp. The scarp is expressed by pronounced trapezoidal to triangular facets (Fig. 2, and Fig. 5). FromMariánské Lázně the strike is again NW to NNW and it steps to the right near Planá, and later after 5 km it steps left where the Mže river flows along the stepover antecedently into about 50 m high fault scarp. Southern portion of the MLF More to the south, the fault steps over or is bent to the left several times and is traceable in morphology by fault scarp up to Horšovský Týn (Fig. 2). The southern portion is almost N-S striking, and between Mže river to Bor is expressed by two parallel gentle fault scarps, 10-15 m high (Fig. 6). Near Nová Hospoda Fig. 5: Trapezoidal to triangular facets along the central portion of the MLF where it controls the highest elevated area, Slavkovský les Hill country, by up to 350 m high fault scarp.