Post-collisional mantle delamination in the Dinarides implied from staircases of Oligo-Miocene uplifted marine terraces

Abstract

The Dinarides fold-thrust belt on the Balkan Peninsula resulted from convergence between the Adriatic and Eurasian plates since Mid-Jurassic times. Under the Dinarides, S-wave receiver functions, P-wave tomographic models, and shear-wave splitting data show anomalously thin lithosphere overlying a short down-flexed slab geometry. This geometry suggests a delamination of Adriatic lithosphere. Here, we link the evolution of this continental convergence system to hitherto unreported sets of extensively uplifted Oligocene–Miocene (28–17 Ma) marine terraces preserved at elevations of up to 600 m along the Dinaric coastal range. River incision on either side of the Mediterranean-Black Sea drainage divide is comparable to the amounts of terrace uplift. The preservation of the uplifted terraces implies that the most External Dinarides did not experience substantial deformation other than surface uplift in the Neogene. These observations and the contemporaneous emplacement of igneous rocks (33–22 Ma) in the internal Dinarides suggest that the Oligo-Miocene orogen-wide uplift was driven by post-break-off delamination of the Adriatic lithospheric mantle, this was followed by isostatic readjustment of the remaining crust. Our study details how lithospheric delamination exerts an important control on crustal deformation and that its crustal signature and geomorphic imprint can be preserved for millions of years.

Adria in Mediterranean paleogeography, the origin of the Ionian Sea, and Permo-Triassic configurations of Pangea

“…Continental lithospheric delamination has also become central to tectonic models for the Neogene evolution of the Alboran Sea (Platt and Vissers, 1989;Docherty and Banda, 1995;Seber et al, 1996;Molnar and Houseman, 2004;Duggen et al, 2005;Pérouse et al, 2010;De Lis Mancilla et al, 2013;Timoulali et al, 2014;Baratin et al, 2016;Heit et al, 2017;Spakman et al, 2018), although for counter arguments see Doglioni et al (1997). Continental lithospheric delamination has also entered the debate over the formation of the Pannonian Basin (Knapp et al, 2005;Houseman and Gemmer, 2007;Bennett et al, 2008;Lorinczi and Houseman, 2009;Matenco and Radivojević, 2012;Balling et al, 2021) and the Aegean Sea (Mantovani et al, 1997;van Hinsbergen et al, 2005;Roure et al, 2012). In the context of the Tyrrhenian Sea, Channell and Mareschal (1989) applied finite element analysis to demonstrate that continental mantle lithospheric delamination, triggered by localized lithospheric thickening, can rapidly change a region of compression into a region of extension, and that the extension can drive further shortening in a surrounding thrust belt.…”

Tomographic Image Interpretation and Central-Western Mediterranean-Like Upper Mantle Dynamics From Coupled Seismological and Geodynamic Modeling Approach

“…Similarly, the extent of the Dinaric slab at ~30 Ma is largely debated. Post-collisional uplift and contemporaneous emplacement of igneous rocks (33-22 Ma) in the internal Dinarides may suggest either 1) "that the Oligocene-Miocene orogen-wide uplift was driven by post-break-off delamination of the Adriatic lithospheric mantle" Balling et al (2021), or 2) verticalization of the Adria slab driven by slab pull and consequent upper plate extension, which is exactly what is modeled in our Model CWM. In conclusion, the available geophysical and geological data do not allow to discriminate between a model of post-collisional slab break-off and one of post-collisional slab verticalization (as modelled for the Alps and Dinarides in our Model CWM), as both would imply upper plate extension, uplift and magma emplacement (Faccenda et al, 2008(Faccenda et al, , 2009.…”

Torn Between Two Plates: Exhumation of the Cer Massif (Internal Dinarides) as a Far‐Field Effect of Carpathian Slab Rollback Inferred From 40Ar/39Ar Dating and Cross Section Balancing

“…Evidence in favor of this model was provided by Casale et al (2013), who showed that the Mid-Bosnian Schist Mountains, located further externally with respect to Cer, also represent a MCC that was exhumed between 43 and 27.5 Ma, with rapid cooling occurring between 35 and 27 Ma-coincident with the timing of slab-breakoff and subsequent mantle delamination proposed by Pamić et al (2002) and Schefer et al (2011). This hypothesis is further supported by evidence for regional uplift during Oligocene times (Balling et al, 2021).…”