We are analyzing a suite of limestone samples for 36Cl to determine the age of the Almtal landslide (Totes Gebirge, Salzburg province, Austria). Morphological relationships point to an early Lateglacial age. To provide initial temporal constraints we are dating an ice-marginal position located topographically above and outside of the landslide deposit. This deposit formed as a small landslide spread out on ice that filled the valley during the waning stages of the Last Glacial Maximum. The Almtal landslide itself originated from a niche, about 1 km wide and 1 km deep, located just below the top of Hochplatterkogel on the eastern flank of the Totes Gebirge plateau. The landslide hit the valley wall opposite the niche and careened into the narrow (< 1 km wide) Stranegg valley where it was confined for nearly 10 km. At the junction with Alm valley it encountered a lake and fluidization processes became dominant as the slide mass continued northward. The slide deposit (about 1 km3) is characterized by tens of meter high transverse ridges and isolated toma hills made up of angular Dachstein limestone clasts, ranging up to 10-20 m in diameter. Samples for 36Cl surface exposure dating of the huge limestone blocks were taken from several locations in the landslide deposit. In contrast to most of the other large landslides in the Alps that have proven to be Holocene in age (e.g. Tschirgant, Flims), preliminary results for the Almtal slide appear to bear out the Lateglacial age assignment.
See more of Poster Session II
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)