Abstract In situ 10 Be concentrations in granites on Corsica (Mediterranean), exposed to subalpine climate, yield weathering rates of between 9 and 20 mm ka −1 , when averaged over the last 30–100 ka. Weathering rates rise with increasing precipitation and brittle deformation. Thermal history modelling of apatite fission-track (AFT) data confirms that average denudation rates of 5–20 mm ka −1 were typical during the Neogene. Short- and long-term denudation rates are in the same range and indicate that a late Neogene global increase in denudation rates has probably not affected geomorphically stable uplifted palaeosurfaces of hilly to low mountainous local relief. A Southwards decrease in short- and long-term denudation rates indicate a linear relationship with decreasing precipitation. Post-glacial downwearing of moraine matrix, as constrained by soil-derived humic etching of dated glacial boulders, yields 40–140 mm ka −1 , which indicates a poor preservation potential of moraines older than the last glaciation. This weathering rate is of the order of 3 times faster than that found for long-term regolith formation from granites based on of geomorphic evidence.

In this study, we discuss potential problems connected with using geochronological data from foreland basins to unravel exhumation histories of the hinterland. In particular, we compare the results of a provenance analysis solely based on zircon fission-track ages from the foreland basin with a multi-method approach based on (i) the aforementioned zircon fission-track data, (ii) Nd isotope ratios of detrital epidote, and (iii) sediment accumulation rates in the foreland basins. For the example of the Central European Alps, we demonstrate that the multi-method approach can lead to highly different interpretations in terms of hinterland exhumation and geodynamic evolution. This is due to the fact that fission-track dating on detrital zircons alone only monitors the exhumation and erosion of zircon-containing lithologies and therefore only of restricted areas of the hinterland while the combination with Nd isotope ratios on detrital epidote also includes the erosion of zircon-free or -poor units such as basic magmatic rocks. A comparison of zircon fission-track and epidote Nd data with the sediment accumulation curve shows whether hinterland exhumation was predominantly caused by tectonic or by erosional denudation. Furthermore, we discuss some problems that may arise from using geochronological data from foreland basins to assess the maturity of a mountain belt in the hinterland. Applied to the Central Alps, our combined approach shows that the metamorphic core became exposed simultaneously over large areas by one sudden pulse of exhumation between 21 and 20 Ma. The main trigger for that exhumation event was tectonic denudation which is consistent with a geodynamic setting of large-scale extension. The Central Alps did not achieve exhumational steady-state conditions before 14 Ma.

Abstract A succession of deep burial carbonate cements with two types of saddle dolomite and three types of blocky calcite was investigated in Permian to Tertiary sedimentary rocks in different nappes of the Eastern Alps. The first generation of saddle dolomite occurs only in rocks of Permian to Late Triassic/Early Jurassic age. All otlier carbonate cements occur within rocks of Permian to Early Tertiary age. Carbon and oxygen isotopic compositions of the carbonate cements and of the Triassic to Tertiary host rocks exhibit regional trends as well as trends to more negative δ 18 O with increasing burial. Fluid inclusion data show homogenization temperatures between 90° and 250°C for the carbonate cements. Temperatures decrease from the bottom to the top of the stratigraphic column, and regional trends are also exhibited. Calculated oxygen isotopic compositions of fluids precipitating the carbonate cements suggest strong positive 8’“0 values, which are characteristic of saline formation waters or metamorphic waters. The first generation of saddle dolomite is inferred to have formed in the same paleo-fluid system as Late Triassic/Early Jurassic Pb-Zn ores by fluid flow directed from the hinterland in the north (Vindelician high, Bohemian massif) to the East Alpine area. The fluids ascended and precipitated saddle dolomite and, under certain conditions, Pb-Zn ores. All other carbonate cements formed post-Oligocene time after the peak of metamorphism in the Central Eastern Alps and during uplift of this area. Results suggest that meteoric fluids descended and equilibrated with metamorphic rocks subsequently mixed with metamorphic waters in this uplifted area and flowed northwards and southwards, ascending through the rock pile. Fluid mixing with a second, near surface, meteoric groundwater system could explain a renewed decrease in carbonate cement δ 18 O values at the top of the sedimentary succession and in northern parts of the Alpine realm.