Reconstructing orogen dynamics from detrital geo-thermochronological signals in pro- and retro-foreland basins: A case sudy of the Pyrenees, France

A bivergent orogenic belt and its foreland basins form an intimately coupled system for which cause-effect relationships have generated much debate. This is the case in the Pyrenees, where the contemporaneity of crustal thermal events (cooling) with foreland tectonic events (subsidence) during convergence has, until recent years, remained unclear due to little quantification of processes during early orogenesis. Over the last 5 years, the development of new tools for generating, manipulating and modelling data and processes in geo-thermochronology has been stimulating new research that challenged established paradigms in both Pyrenean pro- and retro-foreland systems. Results obtained for these systems must now be compared and integrated into a reconstruction of the Pyrenean orogen history.

In this study we first review published detrital geo-thermochronology data in the eastern to central Pyrenees, harmonizing the way by which they are inverted for the inference of sediment provenance with use of current statistical modelling methods. Second, we re-interpret these detrital data in terms of provenance for both Pyrenean pro- and retro-foreland systems. Last, we compare the geo-thermochronological signals in both foreland basins to reconstruct orogen dynamics in the Pyrenees. We critically assess the implications of this newly proposed reconstruction for the validity of conceptual models for orogenic evolution and of plate kinematic models in the northwestern Mediterranean region.