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

458 PATA Days 2024 (Fig. 1). The Saxothuringian unit, composed of heavily metamorphosed rocks, lies to the northwest, the Moldanubian unit (metamorphosed rocks like paragneisses, orthogneisses, and migmatites, with granitic intrusions) to the west and south, and the Teplá- Barrandian unit (less metamorphosed phyllites, schists, and paragneisses) to the east. The Mariánské Lázně complex is situated between a Saxothuringian unit and Teplá-Barradian unit – the two former microcontinents amalgamated during the Variscan orogeny (Cháb et al., 2008, Mlčoch and Konopásek, 2010). According to Špičáková et al. (2000) the MLF was reactivated as a sinistral strike slip in late Pliocene resulting in present-day structure of Cheb basin and Cheb-Domažlice graben and in formation of a horse- tail splay of oblique-extensional faults at the northern termination of the MLF within the Cheb basin (Fig. 2). This northern part of the MLF controls the eastern limit of the Cheb Basin and western mountain front of the Krušné hory Mts. The Cheb basin is a half-graben formed at the crossing of the Cheb-Domažlice Graben and ENE trending Eger (Ohře) Rift. The Eger Rift is an element of European Cenozoic Rift Systems in the Alpine forelands and consists of a system of sedimentary basins, high heat flow and voluminous alkaline intraplate volcanism (e.g. Malkovský 1987, Dezés et al. 2004, Ulrych et al. 2016). The Cheb basin is filled with Oligocene to Plio-Pleistocene fluvio-lacustrine sediments and volcanoclastics. The thickest sedimentary infill of the basin, up to 400 m, is located in its eastern part, which is controlled by the MLF (Špičáková et al., 2000). The youngest Plio-Pleistocene Vildštejn formation is not present only in the Cheb basin, but also in several relicts in the Cheb-Domažlice Graben along the MLF (Pešek, 1972; Teodoridis et al., 2017). The Cheb basin is also famous for Quaternary volcanism, mantle-derived CO2 emanations and present-day earthquake swarm seismicity (max. ML=4.6). The MLF is morphologically expressed at the length of 120 km from Plauen in Germany to Horšovský Týn despite the lack of any fault outcrops (Fig. 2). The well-expressed escarpment is from 50 to 350 m high while being the highest in the central part of the fault, Fig. 2: Digital elevation model showing the striking morphology along the Mariánské Lázně fault - pointed by red arrows. Digital elevation model showing the striking morphology along the Ma iánské Lázně fault - pointed by red arrows.