Correlations of cave levels, stream terraces and planation surfaces along the River Mur—Timing of landscape evolution along the eastern margin of the Alps

Abstract

The transition zone of the Eastern Alps to the Pannonian Basin provides one of the best sources of information on landscape evolution of the Eastern Alpine mountain range. The region was non-glaciated during the entire Pleistocene. Thus, direct influence of glacial carving as a landscape forming process can be excluded and relics of landforms are preserved that date back to at least the Late Neogene. In this study, we provide a correlation between various planation surfaces across the orogen-basin transition. In particular, we use stream terraces, planation surfaces and cave levels that cover a vertical spread of some 700 m. Our correlation is used to show that both sides of the transition zone uplifted together starting at least about 5 Ma ago. For our correlation we use recently published terrestrial cosmogenic nuclide (TCN) burial ages from cave sediments, new optically stimulated luminescence (OSL) ages of a stream terrace and U–Th ages from speleothems. Minimum age constraints of cave levels from burial ages of cave sediments covering the last ~ 4 Ma are used to place age constraints on surface features by parallelizing cave levels with planation surfaces. The OSL results for the top section of the type locality of the Helfbrunn terrace suggest an Early Würm development (80.5 ± 3.7 to 68.7 ± 4.0 ka). The terrace origin as a penultimate gravel deposit (in classical Alpine terminology Riss) is therefore questioned. U-series speleothem ages from caves nearby indicate formation during Marine Isotope Stages (MIS) 5c and 5a which are both interstadial warm periods. As OSL ages from the terrace also show a time of deposition during MIS 5a ending at the MIS 5/4 transition, this supports the idea of temperate climatic conditions at the time of deposition. In general, tectonic activity is interpreted to be the main driving force for the formation and evolution of these landforms, whilst climate change is suggested to be of minor importance. Obvious hiatuses in Miocene to Pleistocene sediments are related to ongoing erosion and re-excavation of an uplifting and rejuvenating landscape.

Characterizing the spatiotemporal variability of groundwater levels of alluvial aquifers in different settings using drought indices

“…At the town of Mixnitz, roughly in the upper third of the subregion, this changes to the shales and mostly limestones of the Paleozoic of Graz, which forms the central Styrian Karst and the Graz Highlands (Wagner et al, 2011). This change in geology is also reflected in the structure of the aquifer, where considerable aquifer bodies are only found downstream of Mixnitz (Anderle, 1969).…”

Cave levels as proxies for measuring post-orogenic uplift: Evidence from cosmogenic dating of alluvium-filled caves in the French Pyrenees

“…Thus far, fewer than 10 sites have been studied globally using this approach (Granger et al, 1997Stock et al, 2004Stock et al, , 2005aStock et al, , 2005bHäuselmann and Granger, 2005;Häuselmann, 2007;Häuselmann et al, 2007, in press;Hobléa et al, 2011;Wagner et al, 2010Wagner et al, , 2011Liu et al, 2013;Tassy et al, 2013). No such study exists in the Pyrenees, even though the karst-related features of several deep karst systems have been well studied by speleologists and geomorphologists in the Arbas Massif (Bakalowicz, 1988), the Pierre Saint-Martin system (Maire, 1990;Quinif and Maire, 1998), and the Arbailles Massif (Vanara, 2000).…”

Threshold behavior of karst aquifers: the example of the Lurbach karst system (Austria)

“…Multiple, distinct, cave levels can be distinguished in the Lurbach karst system (Wagner et al 2010(Wagner et al , 2011a. Thus, the overflow is probably activated when conduits at a distinct elevation are flooded, which suggests that a threshold value of hydraulic heads can be defined.…”