Map view restoration of Aegean–West Anatolian accretion and extension since the Eocene

Abstract

[1] The Aegean region (Greece, western Turkey) is one of the best studied continental extensional provinces. Here, we provide the first detailed kinematic restoration of the Aegean region since 35 Ma. The region consists of stacked upper crustal slices (nappes) that reflect a complex paleogeography. These were decoupled from the subducting African-Adriatic lithospheric slab. Especially since $25 Ma, extensional detachments cut the nappe stack and exhumed its metamorphosed portions in metamorphic core complexes. We reconstruct up to 400 km of trench-perpendicular (NE-SW) extension in two stages. From 25 to 15 Ma, the Aegean forearc rotated clockwise relative to the Moesian platform around Euler poles in northern Greece, accommodated by extensional detachments in the north and an inferred transfer fault SE of the Menderes massif. The majority of extension occurred after 15 Ma (up to 290 km) by opposite rotations of the western and eastern parts of the region. Simultaneously, the Aegean region underwent up to 650 km of post-25 Ma trench-parallel extension leading to dramatic crustal thinning on Crete. We restore a detachment configuration with the Mid-Cycladic Lineament representing a detachment that accommodated trench-parallel extension in the central Aegean region. Finally, we demonstrate that the Sakarya zone and Cretaceous ophiolites of Turkey cannot be traced far into the Aegean region and are likely bounded by a pre-35 Ma N-S fault zone. This fault became reactivated since 25 Ma as an extensional detachment located west of Lesbos Island. The paleogeographic units south of the İzmir-Ankara-Sava suture, however, can be correlated from Greece to Turkey.

Kinematic reconstructions and magmatic evolution illuminating crustal and mantle dynamics of the eastern Mediterranean region since the late Cretaceous

“…the kinematics of such a fault is enigmatic, presented either as a dislocation zone [Walcott and White, 1998], as a detachment fault [van Hinsbergen and Schmid, 2012] or as a dextral strike-slip fault [Philippon et al, 2012[Philippon et al, , 2014. In our reconstructions, considering fully deforming domains, it appears that these opposite rotations could be accommodated by a gradient of finite extension, without the need of a localized fault .…”

“…The small component of trench-parallel extension [Reilinger et al, 2006;van Hinsbergen and Schmid, 2012] resulting from the progressive curvature of the arc since the middle Miocene is also considered within this framework.…”

“…W-E and N-S trending detachments have thus been successively proposed to accommodate the Oligocene-Miocene back-arc extension in the Aegean domain Brun, 2010, Grasemann et al, 2012;van Hinsbergen and Schmid, 2012]. To tackle this problem, robust data provided by the large number of field studies performed in this region have to be considered.…”

“…All these reconstructions show that the geodynamics of this region has been governed by the convergence between Africa and Eurasia and by the interactions between several oceanic domains belonging to the Neo-Tethys Ocean and continental blocks previously rifted from the African margin and belonging to the Apulian (or Adria) plate. However, apart from van Hinsbergen and Schmid [2012], these reconstructions generally consider the entire western…”

“…Several sets of kinematic and paleogeographic reconstructions have thus been proposed to constrain the geological evolution of the eastern Mediterranean region (figure 1) [Dercourt et al, , 1993Ricou, 1994;Jolivet et al, 2003;Barrier and Vrielynck, 2008;Stampfli and Hochard, 2009;van Hinsbergen and Schmid, 2012]. All these reconstructions show that the geodynamics of this region has been governed by the convergence between Africa and Eurasia and by the interactions between several oceanic domains belonging to the Neo-Tethys Ocean and continental blocks previously rifted from the African margin and belonging to the Apulian (or Adria) plate.…”