Skip to Main content Skip to Navigation
Journal articles

Post-orogenic exhumation in the western Pyrenees: evidence for extension driven by pre-orogenic inheritance

Abstract : We discuss the drivers of the Pyrenean post-orogenic exhumation, including drainage migration, flexural rebound and tectonic reactivation.We provide new low-temperature thermochronological data and inverse thermal modeling from both the hinterland and foreland of the western Pyrenees. Our new thermochronological ages range from 6.6 to 61.4 Ma and reveal a Late Miocene exhumation phase in several massifs. The contrasting thermal histories define a domain of focused exhumation in the western Pyrenees that coincides with the present-day extensional tectonics in a region to the north of the Axial Zone. Based on the inferred cooling rates and paleogradient estimates, we highlight an exhumation phase of c. 1 mm yr –1 between 11 and 9 Ma in the Axial Zone, well above rates expected for a post-orogenic evolution. The thermal evolution inferred from three boreholes of the Aquitaine foreland basin reveals that sediments eroded from the hinterland did not accumulate in the Piedmont region but were transported offshore in the Bay of Biscay. We infer that the significant c. 10 Ma post-orogenic exhumation event must be related to the modern normal faulting regime of the western Pyrenees, associated with contrasting crustal thickness and densities, inherited from the Mesozoic rift evolution of the northern Pyrenees. Supplementary material: Laboratory analytical procedures, radial plot visualization of AFT detrital data and Age/eU relationship of AHe and ZHe samples are available at https://doi.org/10.6084/m9.figshare.c.5212581
Document type :
Journal articles
Complete list of metadata

https://hal.inrae.fr/hal-03257239
Contributor : Christopher Lallemant <>
Submitted on : Thursday, June 10, 2021 - 5:59:41 PM
Last modification on : Tuesday, September 7, 2021 - 3:44:09 PM

Identifiers

Citation

Charlotte Fillon, Frédéric Mouthereau, Sylvain Calassou, Raphaël Pik, Nicolas Bellahsen, et al.. Post-orogenic exhumation in the western Pyrenees: evidence for extension driven by pre-orogenic inheritance. Journal of the Geological Society, Geological Society of London, 2021, 178 (2), pp.jgs2020-079. ⟨10.1144/jgs2020-079⟩. ⟨hal-03257239⟩

Share

Metrics

Record views

41