Basement‐Cover Decoupling During the Inversion of a Hyperextended Basin: Insights From the Eastern Pyrenees

Abstract

It is commonly accepted that the major part of collisional orogens often results from the inversion and contraction of former continental rifted margins. However, the early stages of orogenic processes, corresponding to the inversion of the rifted system, usually affected by hyperextension, remains poorly constrained. The lack of knowledge on the early orogenic processes stems from the obliteration of the hyperextended part of former rift systems, during collision, by a strong metamorphic and tectonic overprint or because this domain is now buried in the crustal root of belts. Therefore, the inherited rift-related geometries and thermal-mechanical structure of the pre-orogenic crust and lithosphere play important roles in the structural style of collisional orogens (e.g.,

Decoding low-temperature thermochronology signals in mountain belts: modelling the role of rift thermal imprint into continental collision

“…In contrast, the short delay (5-15 Myrs) between the end of rifting with associated high-temperature metamorphism and the onset of convergence makes it difficult to recognise the thermal signature of early orogenesis and to constrain early orogenic deformation (Vacherat et al, 2016;Ternois et al, 2019aTernois et al, , 2019b. Maximum temperatures recorded by numerical particles taken in the hyperextended and exhumed mantle domains are in line with those recorded in pre-orogenic Aptian-Cenomanian strata deposited over the inverted distal European margin (estimations of 350-500 °C, possibly 600 °C, obtained by Raman spectroscopy on carbonaceous material in the Metamorphic Internal Zone (Figure 6); Vauchez et al, 2013;Clerc et al, 2015;Chelalou et al, 2016;Ducoux et al, 2019Ducoux et al, , 2021. Our integrated modelling approach can therefore provide a way to predict and help reconstructing the pre-orogenic rifted margin architecture and evolution in the Pyrenees based on low-temperature thermochronology signatures.…”

Evidence of decoupled deformation during Jurassic rifting and Cenozoic inversion phases in the salt-rich Corbières-Languedoc Transfer Zone (Pyreneo-Provençal orogen, France)

“…In the SW part of the Corbières Virgation, the DNCO is detached above the basement of the Mouthoumet massif. From Vingrau area, it passes to the SW in continuity to the basins constituting the eastern NPZ (Ford & Vergès, 2021;Ducoux et al, 2021), describing a structural virgation of approximately 55°, passing towards the west from a strike of N045 to N100 (Figs. 2a, b).…”

“…In this case the Corbières-Languedoc area never was a rift transfer zone during the Mesozoic, but was an orthogonal segment to the kinematics of the NW-SE oriented Mesozoic extension (2) The extensional trend could be N-S oriented (e.g. Tavani et al, 2020;Ducoux et al, 2021), in which case the Corbières-Languedoc area became at that time a rift transfer zone (dextral slightly transtensional) between the Pyrenean and Provençal domains. In both cases, the deformation in the Corbières Virgation seems to be localised on some basement transfer faults (e.g.…”

Native H2 Exploration in the Western Pyrenean Foothills

“…However, the seismic data reveal fault structures to the north that are well correlated with the location of most of these CO 2 anomalies (Figure 4). Thus, they could be related to fluids migration (Figure ; Ducoux et al., 2021). We note that one anomaly located in the Arzacq basin cannot be explained by tectonic reason, but may be due to biological activities as suggested by their peculiar O 2 versus CO 2 correlation (sample #8 “Héres” in Figure 5; Tables and ).…”