Mantle dynamics in the Mediterranean

Abstract

The Mediterranean offers a unique opportunity to study the driving forces of tectonic deformation within a complex mobile belt. Lithospheric dynamics are affected by slab rollback and collision of two large, slowly moving plates, forcing fragments of continental and oceanic lithosphere to interact. This paper reviews the rich and growing set of constraints from geological reconstructions, geodetic data, and crustal and upper mantle heterogeneity imaged by structural seismology. We proceed to discuss a conceptual and quantitative framework for the causes of surface deformation. Exploring existing and newly developed tectonic and numerical geodynamic models, we illustrate the role of mantle convection on surface geology. A coherent picture emerges which can be outlined by two, almost symmetric, upper mantle convection cells. The downwellings are found in the center of the Mediterranean and are associated with the descent of the Tyrrhenian and the Hellenic slabs. During plate convergence, these slabs migrated backward with respect to the Eurasian upper plate, inducing a return flow of the asthenosphere from the back-arc regions toward the subduction zones. This flow can be found at large distance from the subduction zones and is at present expressed in two upwellings beneath Anatolia and eastern Iberia. This convection system provides an explanation for the general pattern of seismic anisotropy in the Mediterranean, first-order Anatolia, and Adria microplate kinematics and may contribute to the high elevation of scarcely deformed areas such as Anatolia and eastern Iberia. More generally, the Mediterranean is an illustration of how upper mantle, small-scale convection leads to intraplate deformation and complex plate boundary reconfiguration at the westernmost terminus of the Tethyan collision.

A Miocene onset of the modern extensional regime in the Isparta Angle: constraints from the Yalvaç Basin (southwest Turkey)

“…Glover and Robertson 1998;Deynoux et al 2005;Hall et al 2014). This scenario may be inspired by the broadly similar age inferred for this collision (~10-13 Ma) based on stratigraphic and volcanological-geochemical data, and uplift and exhumation ages in the collision zone (Şengör et al 2003;Keskin 2003;Faccenna et al 2006Faccenna et al , 2014Hüs-ing et al 2009;Okay et al 2010).…”

The Tell-Rif orogenic system (Morocco, Algeria, Tunisia) and the structural heritage of the southern Tethys margin

“…The location and the vergence of this (these) subduction(s) remain(s) currently the matter of debates. Some authors (Faccenna et al, 2014;Jolivet and Faccenna, 2000;Lacombe and Jolivet, 2005;Stampfli and Marchant, 1997) place a single and permanent west/northwest-verging subduction east and south of AlKaPeca. This hypothesis minimizes or ignores the existence of a western Ligurian Tethys.…”

Holocene Relative Sea-Level Changes from Near-, Intermediate-, and Far-Field Locations

“…Regional compilations of RSL data have been produced for both the eastern [126][127][128] and western [129][130][131] Mediterranean coast. Due to its complex tectonic setting [132], RSL histories in the eastern Mediterranean were influenced by the Holocene activity of major faults [126,133,134]. In this region, RSL rise slowed significantly in the last 7.5 ka, with consequent initiation of deltaic progradations of the largest Mediterranean rivers [135] such as the Nile delta [136,137].…”