Data used in the paper entitled: "Hidden faults: the Late Pleistocene transpression of the Königssee–Lammertal–Traunsee Fault inferred from caves deformation (Eastern Alps)"

Manuscript Abstract: The Eastern Alps have undergone lateral extrusion since the late Oligocene, with major crustal-scale strike-slip faults still active, as evidenced by earthquakes up to M6, despite scant geological record. Research has focused more on the Salzach-Ennstal-Mariazell-Puchberg (SEMP) and Mur-Mürz faults, leaving the central part of the Northern Calcareous Alps cut by the 110 km long Königssee–Lammertal–Traunsee (KLT) fault system under-studied. We took advantage of a cave environment isolated from erosion, providing unparalleled structural indicators exposure to fill the Pleistocene deformation history gap of the KLT. We reconstruct paleostress for 26 reverse, strike-slip, and oblique reactivated faults that offset passages in seven caves close to sinistral KLT and dextral Lammertal faults. 230Th/U dating of faulted and broken speleothems revealed two reactivation events since the Middle Pleistocene. The older event dates can be constrained to 331 (+89/-54) to 287 ± 6 ka, or 297-281 ka if the KLT and Lammertal faults were reactivated simultaneously. The younger event occurred between 130 and 90 ka, aligning with fault reactivations in the eastern Alps. Cave observations allowed us to analyze reverse faults in the positive flower structure of the KLT and mode I fracture with minor antithetic dextral slip, suggesting a sinistral component of regional rejuvenation. Our findings indicate that the KLT was reactivated due to simple shear with NNE compression. Along the Lammertal fault, we recorded a strike-slip regime driven by NNW compression. The KLT and Lammertal faults form a system of conjugated shears that efficiently accommodate N-S shortening compared to the SEMP fault, which is perpendicular to the compression. Combining our neotectonic data with current seismicity shows that the KLT plays a key role in the Quaternary extrusion process in the studied Alpine sector, surpassing the more prominent SEMP fault. In this dataset, we make available: iPhone13Pro LiDAR scan of the two cave passage offsets: one in the Dependance cave and Gamssteig cave PDF file with dated sample location and description Published in: Szczygieł, J., Plan, L., Hellstrom, J., & Grasemann, B. (2024). Hidden Faults : The Late Pleistocene Transpression of the Königs- see – Lammertal – Traunsee Fault Inferred from Caves Deformation ( Eastern Alps ). Lithosphere, (Number Special 15), lithosphere_2024_177, 14. https://doi.org/10.2113/2024/lithosphere This research was founded by the NCN Polish National Science Center [grant No 2020/39/D/ST10/00615]