| Summary: | The Neogene sedimentary record provides strong indications for a sharp increase in global sediment fluxes during the Pliocene. In Europe, sediment flux from the Alps has been inferred to have at least doubled since ˜5 Ma, and numerous studies have hinted at accelerating denudation rates in other orogens (e.g., Betics, Apennines, southern Carpathians, Caucasus) around this time. Although tectonic mechanisms have been invoked to explain such increases in each individual setting, the roughly synchronous nature of a continent-wide and even global increase in denudation rates suggests that it may be climatically driven. Possible climatic mechanisms for increasing Pliocene denudation rates include a global increase in climatic variability, onset of Northern Hemisphere glaciations and, for Europe, increasing precipitation due to the onset of North Atlantic Gulf Stream circulation. We review the evidence for, and possible controlling mechanisms on, increased Pliocene denudation rates in the European Alps.We have recently exploited the unique density of fission-track thermochronology data in the Western European Alps to estimate exhumation rates on the orogen scale between 13.5 and 2.5 Ma. This analysis corroborates both the timing and magnitude of the increase in denudation rates inferred from the sedimentary record, but also suggests some spatial variability in the signal. An independent analysis of the exhumation of the Molasse foreland basin indicates relatively uniform, km-scale denudation of the basin since early-mid Pliocene times, which can be explained at least in part as recording flexural isostatic rebound of the orogen-basin system in response to erosional unloading of the orogen core. Such flexural rebound is also recorded by tilting of late Pliocene foreland basin remnants in south-eastern France. The timing of increased denudation post-dates orogenic wedge growth in the Alps and cannot be readily linked to a particular tectonic event. It is consistent with regional climatic change driven by the onset of ...
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