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

of major crustal-scale strike-slip faults, such as the Salzach-Ennstal- Mariazeller- Puchberger fault, theMur-Mürz fault, the Periadriatic Line and the Pöls-Lavanttal fault, evidence of this activity in the geological record remains scarce. Notably, caves have provided significant evidence of fault activity (e.g., Plan et al., 2010; Baron et al., 2019; Szczygieł et al., 2022). However, less attention has been given to the central part of the NCA, specifically the Königssee– Lammertal–Traunsee (KLT) fault system, despite its significance in bounding escaping wedges during lateral extrusion in the Oligocene- Miocene period. The KLT fault system, extending 110 km, exhibits a complex segmented pattern due to the reactivation of Triassic salt structures (Fernandez et al., 2024; Fig. 1), featuring contractional strike-slip duplexes, positive flower structures, and high-angle Riedel shears (Decker et al., 1994). The sinistral offset along the fault system is estimated at 7–10 km (Linzer et al., 2002). The KLT central sector – the Torrener fault duplex (TFD) - displays micro and macroseismic activity with earthquakes reaching up to Mw 5.0 (Reiter et al., 2018; Hofman et al., 2023). Research in caves within the Hoher Göll and Hagengebirge massifs has revealed a close relationship between speleogenesis and reverse faults of the TFD and evidence of fault reactivation postdating cave formation. Additionally, faults offsetting cave passages have been identified in the Tennengebirge massif, bounded north by the Lammertal fault. This research aims to unravel the Quaternary evolution of the KLT fault system through the integration of kinematic, geomorphological, and geochronological data obtained from deep caves adjacent to faults. Fig. 1: a) SRTM DEM of the Alps with marked Northern Calcareous Alps (semitransparent) with major fault zone (after Linzer et al., (2002); B) zoom in to the Königssee– Lammertal– Traunsee fault; explanations: TFD – Torrener fault duplex, H – Hagengebirge, G - Hoher Göll; T – Tenenngebirge.