Timing of Contractional Stress Propagation, From the Pyrenean Orogen to the Intraplate Domain, Evidenced by U-Pb Dating of Syn-Kinematic Calcite

Abstract

The Mediterranean region provides a natural laboratory for studying complex deformation resulting from body forces and interactions between the convergence of the Africa and Eurasia plates since the Cretaceous. 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, links local-scale processes to regional geodynamic events. This study combines microstructural analysis and U-Pb dating of syn-kinematic calcite with implications for the timing of contractional stress propagation in the Pyrenean orogen and the whole of western Europe. 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, and, therefore, a strategic study area. This study highlights (a) continuous deformation from ca. 48 Ma to 30 Ma, marking the phase of continental collision between Iberia and Eurasia and (b) a newly evidenced post-orogenic Miocene deformation episode, spanning from ca. 16 to 11 Ma. (c) Through a comparison of U-Pb geochronological 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 insights into the geodynamic evolution of the Pyrenean orogen and its implications for Mediterranean geodynamics.