Abstract
We integrate structural, geophysical, and geodetic studies showing that the Dinarides-Hellenides orogen along the Adria-Europe plate boundary in the Western Balkan peninsula has experienced clockwise oroclinal bending since Eocene-Oligocene time. Rotation of the Hellenic segment of this orogen has accelerated since the middle Miocene and is associated with a north-to-south increase in shortening along the orogenic front. Within the Paleogene nappe pile, bending was accommodated by orogen-parallel extension, clockwise block rotation, and thrusting in the hanging wall of the Skhoder-Peja Normal Fault (SPNF). The SPNF and related faults cut the older Skhoder-Peja Transfer Zone with its pre-Neogene dextral offset of the West Vardar ophiolite nappe. Rotation of the SPNF hanging wall involved Miocene-to-recent, out-of-sequence thrusting that was transferred to the Hellenic orogenic front via lateral ramps on dextral transfer zones. Along strike of the Dinarides-Hellenides and coincident with the southward increase in Neogene shortening, the depth of the Adriatic slab increases from ~160 km north of the SPNF to ~200 km just to the south thereof, to several hundreds of kilometers to the south of the Kefalonia Transfer Zone. The geodynamic driver of tectonics since the early Miocene has been enhanced rollback of the Hellenic segment of the Adriatic slab in the aftermath of Eocene-Oligocene slab tearing and breakoff beneath the Dinarides, which focused slab pull in the south. The SW-retreating Hellenic slab segment induced clockwise bending of the southern Dinarides and northern Hellenides, including their Adriatic foreland, about a rotation pole in the vicinity of the Mid-Adriatic Ridge.
Original language | English |
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Pages (from-to) | 2803-2828 |
Number of pages | 26 |
Journal | Tectonics |
Volume | 38 |
Issue number | 8 |
DOIs | |
Publication status | Published - Aug 2019 |
Funding
We thank Daniel Bernoulli, Bernhard Fügenschuh, Eline Le Breton, Douwe van Hinsbergen, Bruno Tomljenović, Liviu Matenco, and Marko Vrabec for discussions, as well as PhD and MSc students at the FU Berlin (S. Cionoiu, P. Groß, D. Goris, M. Grund, and S. Zertani) for mapping along the SPNF. Martina Grundmann and Marc Grund (FU‐Berlin) helped draw figures for an earlier version of the manuscript. Jean‐Pierre Brun provided a very constructive review, and Liviu Matenco and Gideon Rosenbaum made helpful suggestions on how to render the text more understandable. Grants of the German Science Foundation (DFG Projects Ha 2403/21‐1, Gi 825/4‐1, PI‐534/3‐1, and Us 100/5‐1) and the Research Council of Norway, Centres of Excellence (project 223272) supported our research, and stipends of the German Academic Exchange Service (DAAD Promos fund, 2011–2017) partly funded student mapping and cooperation with colleagues in Albania. The data supporting this paper are available in the supporting information and references or by contacting the first author.
Keywords
- Dinarides-Hellenides
- oroclinal bending
- orogen-parallel and orogen-normal faulting
- rollback subduction
- Shkoder-Peja