MSc Dario Asam (2016)

The research at the Aach cave system has recently begun, therefore not all of its evolution, properties and characteristics have been understood completely yet. This paper was targeted to investigate the paleo environmental history of the Blätterteighöhle by the help of cave sediments.
Cave sediments can be seen as a recorder, which save valuable information regarding the hydrological characteristics during their deposition. These informations can be “read” by analyzing the sediment outcrops in caves in order to draw conclusions regarding the whole cave system.
Therefore the question was, which informations can be derived from the present sediments in the Blätterteighöhle. The performed investigations focused on the one hand on the age and the origin of sediments, and on the other hand on sedimentary structures, which reflect the depositional characteristics in former periods. Furthermore, the investigations aimed on diciphering, why and when increased sedimentation in the Blätterteighöhle took place and when it was finally separated from the active Aach cave system.
Therefore, several dating methods were applied (OSL-, U-Th- and 14C- dating) in regard to the age of the sediments. To obtain further information on the origin of the sediments, heavy mineral analysis was performed. Additionally, detailed sedimentological profiles were recorded and evaluated to derive former hydrological conditions during deposition.
The results of the investigations indicate that periods of intense sedimentary input led to the clogging of main cave passages. The sedimentological analysis revealed diamicton deposits, which were likely the dominant cause for the clogging of narrow cave sections. Diamicton deposits are transported as suspended load, therefore high energy phreatic conditions are necessary for the deposition. High energy phreatic conditions are caused by a high abundance of water in a cave system. Therefore, a possible relationship in regard to meltwaters due to the retreat of glaciers can be assumed, which seems consistent to the obtained estimated OSL age values of the sediments analyzed within the Blätterteighöhle.