Deciphering the Cenozoic exhumation history of the Eastern Pyrenees along a crustal-scale normal fault using low-temperature thermochronology

Abstract

In orogenic belts, crustal-scale faults are key deformation markers that accommodate various regimes of plate tectonics during rock burial, exhumation or strike slip activity (

Fault Gouge Dating in the Spanish Pyrenees: Fault Ages, Thrust Propagation Sequence, Wall‐Rock Provenance, and Thermal Constraints

“…Contemporaneously, normal faulting in the eastern end of the Axial Zone began at 35 Ma, further suggesting a latest Eocene shift in the dynamics of the range (Milesi et al., 2022). The eastern end of the range records localized extension within the Axial Zone, related to the opening of the Gulf of Lyon, evidenced by modeling of 43–18 Ma apatite (U‐Th)/He cooling ages sampled across the Têt normal nault (Milesi et al., 2022). No similar late Eocene extension has been documented in the central or western portions of the range.…”

“…The coeval ages of thrusting on many faults in multiple regions of the Pyrenees during the Middle and Late Eocene demonstrate that the range effectively behaved as a doubly tapered critical wedge, analogous to the no‐backstop critical wedge model (sensu Dahlen et al., 1984). Contemporaneously, normal faulting in the eastern end of the Axial Zone began at 35 Ma, further suggesting a latest Eocene shift in the dynamics of the range (Milesi et al., 2022). The eastern end of the range records localized extension within the Axial Zone, related to the opening of the Gulf of Lyon, evidenced by modeling of 43–18 Ma apatite (U‐Th)/He cooling ages sampled across the Têt normal nault (Milesi et al., 2022).…”

40 Ar/ 39 Ar geochronology of crustal deformation

“…Low-temperature thermochronometric studies often emphasize one or more tectonic phases as the cause of accelerated exhumation and highlight the role of major faults. The combined use of thermochronometric tools and fault gouge dating allows the age of fault activity to be better constrained [Duvall et al, 2011, Münch et al, 2021, Milesi et al, 2022, Parry et al, 2001, Tagami, 2012.…”

Tectono-geomorphological evolution of the Eastern Pyrenees: Insights from thermo-kinematic modeling

“…Moreover, these previous studies have been particularly focused on the Paleogene Pyrenean contractional phase. The Eastern Pyrenees have a specific evolution, reflected by a complex tectonic history with an Eocene contractional phase (Laumonier, 2015;Ternois et al, 2019;Calvet et al, 2021;Ford et al, 2022) followed by 2 significant post-orogenic periods: i) a transtensionnal phase associated with the opening of the West European Rift (Angrand and Mouthereau, 2021;Milesi et al, 2022), and ii) an Oligocene-Miocene extensional phase associated to the Gulf of Lion opening (Calvet et al, 2021;2020Romagny et al, 2020;Séranne et al, 2021;Taillefer et al, 2021;Milesi et al, 2022). The Têt normal fault is the most prominent tectonic structure in the Eastern Pyrenees, and localizes high-relief massifs in such as the Mont-Louis (hanging wall), and the Canigou and Carança (footwall) massifs.…”

“…The development of these high topographic reliefs has been related to normal faulting during the Oligocene-Miocene period (Maurel et al, 2008, Milesi et al, 2022. However, the topographic evolution of the area is still highly debated (e.g.…”