Meteoric diagenesis of Quaternary carbonate-rocky talus slope successions (Northern Calcareous Alps, Austria)

In the Northern Calcareous Alps (NCA), meteoric cementation of Quaternary talus slopes was mainly sourced by dissolution of matrix and lithoclasts, by leaching of glacial till, and by groundwaters entered from underneath. Cement precipitation can take place within a few hundreds to a few thousands of years after talus deposition, but later diagenetic changes locally are indicated. Downslope along well-preserved talus successions, a change in prevalent diagenetic pathways is related to prolonged availability of pore waters from the apex to the toe of the slope. Talus slopes contain a significant proportion of carbonate mud probably produced by a combination of physical, chemical, and biological processes. (234)U/(230)Th cementation ages of talus successions are scattered over a total range of 5-480 ka. The talus relicts of the NCA thus became cemented at highly different times during the late Quaternary. With the available data, we could not identify a specific palaeoclimatic significance of talus cementation.