U-Pb on syn-kinematic calcite, Pyrenees, France

The Mediterranean region provides a natural laboratory for studying complex deformations resulting from interactions between the convergence of the Africa and Eurasia plates since the Cretaceous and body forces. These interactions led to the formation of a mosaic of basins and orogenic domains, whose intrinsically complex evolution over time is still subject to debate.
Investigating the timing of deformation recorded on both sides of an orogen, and within the intraplate domain, allows linking local-scale processes to regional geodynamic events. This study combines microstructural analysis and U-Pb dating of syn-kinematic calcite to precisely constrain the timing of contractional stress propagation in the Pyrenean orogen and the whole western Europe. The eastern Pyrenean retro-foreland is a strategic study area, as, while many U-Pb dating studies on syn-kinematic calcite have been conducted in the western intraplate domain, the northern part of the Pyrenees remains to be investigated. This study highlights (1) a continuous deformation over Eocene time, from ca. 48 Ma to 30 Ma, marking the phase of continental collision between Iberia and Eurasia, and (2) a newly evidenced miocene deformation episode, that spanned from ca. 16 to 11 Ma, thus occurring during the post-orogenic stage. (3) Through a comparison of U-Pb dating data from syn-kinematic calcite in the pro-foreland basin and the intraplate domain, this study shows that deformation occurred simultaneously at the plate boundaries and within a large part of the intraplate domain of the overriding plate. These results provide new insights into the geodynamic evolution of the Pyrenean orogen and its implications for Mediterranean geodynamics.
All data used to calculate U-Pb dates are listed in a table, and the isotopic ratio for each spot are provided, raw and corrected from the primary reference material WC1.