Pre-Pliocene tectonostratigraphic framework of the Provence continental shelf (eastern Gulf of Lion, SE France)

Abstract

Abstract. -The seaward extension of onshore formations and structures were previously almost unknown in Provence. The interpretation of 2D high-resolution marine seismic profiles together with the integration of sea-bottom rock samples provides new insights into the stratigraphic, structural and paleogeographic framework of pre-Messinian Salinity Crisis (MSC) deposits of the Provence continental shelf. Seven post-Jurassic seismic units have been identified on seismic profiles, mapped throughout the offshore Provence area and correlated with the onshore series. The studied marine surface and sub-surface database provided new insights into the mid and late Cretaceous paleogeography and structural framework as well as into the syn-and post-rift deformation in Provence. Thick (up to 2000 m) Aptian-Albian series whose deposition is controlled by E-W-trending faults are evidenced offshore. The occurrence and location of the Upper Cretaceous South-Provence basin is confirmed by the thick (up to 1500 m) basinal series downlaping the Aptian-Albian unit. This basin was fed in terrigenous sediments by a southern massif ("Massif Méridional") whose present-day relict is the Paleozoic basement and its sedimentary cover from the Sicié imbricate. In the bay of Marseille, thick syn-rift (Rupelian to Aquitanian) deposition occurred (>1000 m). During the rifting phase, syn-sedimentary deformations consist of dominant N040 to N060 sub-vertical faults with a normal component and N050 drag-synclines and anticlines. The syn-rift and early post-rift units (Rupelian to early Burdigalian) are deformed and form a set of E-W-trending en echelon folds that may result from sinistral strike-slip reactivation of N040 to N060 normal faults during a N-S compressive phase of early-to-mid Burdigalian age (18-20 Ma). Finally, minor fault reactivation and local folding affect post-rift deposits within a N160-trending corridor localized south of La Couronne, and could result from a later, post-Burdigalian and pre-Pliocene compressive phase.

Formation of the Iberian‐European Convergent Plate Boundary Fault and Its Effect on Intraplate Deformation in Central Europe

“…This fold and thrust belt records Triassic to Cretaceous extension, followed by Late Cretaceous to Eocene N-S directed shortening (Bestani et al, 2016;Leleu et al, 2009;Mauffret & Gorini, 1996). Recently, up to 2,000 m of Apto-Albian strata have been reported offshore Marseille by Fournier et al (2016), suggesting that Apto-Albian major rift system continued east from the Pyrenees (see also Tavani et al, 2018). Whether the rifting resulted in the exhumation of mantle rocks and limited crustal break up as in the Pyrenees is not clear.…”

LA‐ICP‐MS dating of detrital zircon grains from the Cretaceous allochthonous bauxites of Languedoc (south of France): Provenance and geodynamic consequences

“…(Fig. 13C), subsidence increased eastward (Fournier, F. et al, 2016)and southward (Chelalou, R. et al, 2016) of the study area, and uplift of the hinterland enhanced denudation (Barbarand, J. et al, 2001;Peyaud, J. B. et al, 2005;Olivetti, V. et al, 2020).…”

“…Further south, notably in the study area, block faulting preserved part of the Valanginian formation in the hanging-wall while in the footwall, Malm limestones were uplifted, denuded and karstified (Husson, E., 2013). Further south, South Provence and the future Pyrenees underwent rifting, subsidence and sediment deposition (Fournier, F. et al, 2016). (Fig.…”

“…This episode was characterized by erosion and karstification of platform carbonates related to the northern Tethyan margin, as well as intense weathering leading to the formation of bauxite deposits (Combes, P.-J., 1990) Such a hiatus obliterates the understanding of a key period of the geodynamic evolution of southern Europe, when important events occurred such as : 1) rifting between Iberia and Europe, involving hyperextension, and mantle exhumation (Lagabrielle, Y. & Bodinier, J.-L., 2008) (Lagabrielle, Y. et al, 2010) (Tugend, J. et al, 2014); (Clerc, C. et al, 2015;Cochelin, B. et al, 2018;Oldum, M. L. & Stockli, D. F., 2019) (Lagabrielle, Y. et al, 2019); 2) basin subsidence and deposition of thick sequences of deep marine sediments from the present-day eastern Pyrenees (Souquet, P. et al, 1985) (Debroas, E.-J., 1990) (Chelalou, R. et al, 2016) to offshore Provence (Fournier, F. et al, 2016) and 3) the uplift of the Variscan basement of southern France (Barbarand, J. et al, 2001;Séranne, M. et al, 2002;Peyaud, J. B. et al, 2005); (Olivetti, V. et al, 2020).…”

Tectonic and climate control on allochthonous bauxite deposition. Example from the mid-Cretaceous Villeveyrac basin, southern France

“…This marine sedimentary succession was interrupted during the Neocomian, when the opening of the North Atlantic Ocean induced differential movement between the SW margin of the Eurasian plate with Iberia and associated small continental blocks. This period was characterized by the development of a highly subsident E-W trending elongated Pyrenean rift (e.g., Lagabrielle et al, 2010), extending eastwards to southern Provence (Fournier et al, 2016). This area is now filled with deep marine sediments (e.g., Debroas, 1990) bordered by uplifted margins (Wyns et al, 2003).…”