When did the Pyrenean shortening end? Insight from U–Pb geochronology of syn‐faulting calcite (Corbières area, France)

Abstract

Absolute dating helps to define the age and duration of orogen building. Here we present new U-Pb ages of syn-faulting calcites collected in the northern foreland basin of the Pyrenees. The studied area underwent deformation during the Eocene growth of the belt. This orogenic growth is considered to have persisted until the Late Oligocene, after which post-orogenic processes prevailed. Microstructural analysis coupled with U-Pb dating of syn-faulting calcite confirms the well-known NW-SE to N-S main shortening stage of the Pyrenean orogen during the Eocene (from 48.7 ± 2.2 to 43.2 ± 5.3 Ma). But our data further reveal NE-SW shortening during the Miocene, ca. 16 Ma ago, that has never been seen in the northern Pyrenean foreland. We propose that this tectonic phase, now identified on both sides of the Pyrenean Belt, is a consequence of a stronger coupling between Africa, Iberia and Europe at this time.

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

“…This is consistent with the timing for late contractional episode on the North Pyrenean Thrust Front (Grool et al, 2018) and the last main peak of Pyrenean activity (Bartonian-Priabonian) recorded in Provence (Lacombe & Jolivet, 2005). On another side, new U-Pb on calcite studies suggest that shortening in the external units of the Pyrenees proceeded until the middle Miocene (Cruset et al, 2020;Hoareau et al, 2021;Parizot et al, 2021), which could be a consequence of the far-field stress imposed by Africa-Europe convergence (Jolivet, Baudin, et al, 2021;Mouthereau et al, 2021). Based on the sedimentary record, a recent study in the Gulf of Lion margin revealed that the shift between the Pyrenean contractional and extensional tectonics occurred during the late Rupelian (∼30 Ma, Séranne et al, 2021), with evidence for a rapid change in the tectonic regime.…”

Geodynamic evolution of a wide plate boundary in the Western Mediterranean, near-fieldversusfar-field interactions

“…During this long evolution from the Early Cretaceous to the Present, deformation in the Western Mediterranean region has been mainly controlled by the Africa-Eurasia convergence and the flow of mantle due to large-scale convection, except between 35 and 8 Ma when slab retreat and associated mantle flow were dominant drivers and partly prevented the compressional stresses due to convergence to be transmitted from Africa to Eurasia. The observation of a compressional structures in the Central and Western Pyrénées, as well as in the Corbières until the Early Miocene (Bosch et al, 2016;Labaume et al, 2016;Teixell et al, 2018;Parizot et al, 2021), shows that some stress transmission was locally possible within the lithosphere.…”

Deciphering the Cenozoic Exhumation History of the Eastern Pyrenees Along a Crustal‐Scale Normal Fault Using Low‐Temperature Thermochronology

“…This is consistent with the timing for late contractional episode on the North Pyrenean Thrust Front (Grool et al., 2018) and the last main peak of Pyrenean activity (Bartonian‐Priabonian) recorded in Provence (Lacombe & Jolivet, 2005). On another side, new U‐Pb on calcite studies suggest that shortening in the external units of the Pyrenees proceeded until the middle Miocene (Cruset et al., 2020; Hoareau et al., 2021; Parizot et al., 2021), which could be a consequence of the far‐field stress imposed by Africa‐Europe convergence (Jolivet, Baudin, et al., 2021; Mouthereau et al., 2021). Based on the sedimentary record, a recent study in the Gulf of Lion margin revealed that the shift between the Pyrenean contractional and extensional tectonics occurred during the late Rupelian (∼30 Ma, Séranne et al., 2021), with evidence for a rapid change in the tectonic regime.…”