Western Alps geological constraints on western Tethyan reconstructions

Structural and sedimentary records of the Oligocene revolution in the Western Alpine arc

“…This is consistent with a palaeogeographic location of the Briançonnais domain to the east of the Iberia-Sardinia-Corsica microplate (e.g. Stampfli et al, 1998Stampfli et al, , 2002. A complete renewal of the tectonic setting ocurred close to the Eocene-Oligocene boundary, initiating a mature stage of collision with westward escape of the Internal Nappes stack.…”

“…A complete renewal of the tectonic setting ocurred close to the Eocene-Oligocene boundary, initiating a mature stage of collision with westward escape of the Internal Nappes stack. According to many authors (Ziegler, 1989;Stampfli et al, 2002;Collombet et al, 2002;Rosenbaum & Lister, 2005;Ford et al, 2006;Molli, 2008), the formation of the western Alpine arc occurred mainly after Eocene times, that is during this mature stage of collision with lateral extrusion. The deep part of the paleo-accretionnary wedge, having migrated northwards during the previous, continental subduction stage, was then cross-cut and thrust westwards over the emerged proximal part of the flexural basin, allowing a metamorphic rocks provenance for the synorogenic sediments during the Early Oligocene, a scenario which is summarized in fig.…”

“…However this estimation is poorly constrained and it assumes that Adria was not moving independantly from Africa during Eocene times, which is still debated because of the possible occurrence of spreading of the Ionian sea between Africa and Adria before 35 Ma (Michard et al, 2002;Handy et al, 2010). Anyway, as pointed by Handy et al (2010), the northward displacement of Adria during Eocene fits the palinspastic width of distal European margin (about 120 to 150 km of Briançonnais domain; Lemoine et al, 1986 ;Stampfli et al, 1998Stampfli et al, , 2002 predicted to have been consumed in the subduction zone. Considering the Adria plate motion direction, the tectonic transport criteria in the Internal nappes and the evidence of N-NW propagation of the foreland flexural basin during Eocene, an important northward amount of displacement of the Briançonnais units, presently spreading around the arc, is needed during the early stages of Alpine continental subduction.…”

A Geological Itinerary Through the Southern Apennine Thrust Belt (Basilicata—Southern Italy)

“…During the TriassicJurassic time, the Africa-Europe continental separation led to the opening of the so-called Ligurian-Piedmont Ocean that is considered the western branch of the Alpine Tethys Ocean (Stampfli et al 2002). In the same time interval, the northern margin of the African plate was characterized by a series of fault-bounded structural highs and lows, which favoured the formation of a series of platforms and basins.…”

Tunisian Transtensive Basins in Tethyan Geodynamic Context and Their Post-Tortonian Inversion

“…In addition, as noticed by these authors Maurin, 1991, 1992), we conclude also that the opening was done on a mobile zone of the crust in Tunisia, more precisely on a submeridian fault, inherited from the African craton. Finally, the SW-NE detected extension originates from the rifting and oceanic activity in Northern basin (tethyan western branch) and the Eastern basin (Tethyan southernmost branch: Mesogea) (Dercourt et al, 1985;Martinez and Truillet, 1987;Ricou, 1994;Stampfli et al, 2002;Schettino and Scotese, 2002). In this context, the northern margin behaves like a strike-slip margin (Gibraltar-Messine transform fault) from the upper Liassic onwards, while the Eastern margin represents a www.intechopen.com…”