『Abstract
　A sharp increase in deposited sediment volume since Pliocene times has been observed worldwide and in particular around the European Alps. This phenomenon has been linked to a rise in denudation rates controlled by an increase of either climatic or tectonic forcing. Observation of in-situ cooling histories for orogens is critical to assess the reality of the inferred increase in denudation rates, and to determine whether this phenomenon is widespread or localized at active tectonic structures. We exploit the unique density of fission-track ages in the Western European Alps to reconstruct cooling isoage surfaces and to estimate exhumation rates on the orogen scale between 13.5 and 25 Ma. Our novel technique is based on the association of isoage contours with age-elevation relationships. It uses map-view interpolation, enabling a spatio-temporal analysis of exhumation rates over the entire Western Alps. The resulting exhumation histories reconstructed for eight areas of the Western Alps display strong similarities in timing and rates with orogen-wide average denudation rates inferred from sediment volumes. This consistency validates the use of both techniques for the study of an orogen characterized by strong relief and high recent exhumation rates. We conclude that exhumation rates in the Western Alps have increased more than twofold since Late Miocene times. This increase may have been locally modulated by the distinct response of different tectonic units.

Keywords: Neogene exhumation; fission-track; isoage surface; Western Alps』

1. Introduction
2. Geological setting of the Alps
3. Data
　3.1. Apatite and zircon fission-track databases
　3.2. Quality and homogeneity of the data
4. Methods
　4.1. Maps of interpolated ages/track lengths
　4.2. Exhumation rates calculated from paired ZFT and AFT ages
　4.3. Reconstruction of isoage surfaces
　　4.3.1. Production of arrays of isoage points
　　4.3.2. Interpolation of isoage point arrays
　4.4. Estimation of exhumation rates
5. Results
　5.1. Main features of the fission-track age patterns
　5.2. Variation in exhumation rate from paired AFT and ZFT ages
　5.3. Description of isoage surfaces
　5.4. Spatial and temporal evolution of exhumation rates
6. Discussion
　6.1. Conditions of use of isoage surfaces
　6.2. Errors affecting exhumation rate calculations
　6.3. Comparison between exhumation rates and the volume of sediment deposited through time
　6.4. Possible causes for increased recent exhumation
7. Conclusions
Acknowledgements
References