Lithosphärendelamination oder rückschreitende Subduktion als Auslöser für Extension im Dinariden-Helleniden Übergang?
Physik des Erdkörpers
Zusammenfassung der Projektergebnisse
The junction of the Dinarides and Hellenides mountain belts in southern Montenegro, northern Albanian, and Kosovo has proven to be an intriguing place to study an along-strike transition in convergence regime, from highly oblique collision (Dinarides) to roll-back subduction (Hellenides). Our studies reveal that the orogenic crust accommodates this transition differently than the mantle on either side of the junction. In the mantle, the Adriatic slab lengthens from only ~160 km north of the junction to ~200 km just to the south thereof, to several hundreds of kilometers even further to the south in the vicinity of the Kefalonia Transfer Zone. There, the long slab segment is bent clockwise with respect to the detached slab segment beneath the Dinarides and is retreating to the SW towards the southern Adriatic Seas. The Adriatic slab has therefore rotated about a pole in the vicinity of the Mid-Adriatic Ridge. This pole marks the fragmentation of the Adriatic Plate into two counter-rotating subplates. In contrast, the overlying orogenic crust comprises the bent Dinaric-Hellenic nappe stack that has fragmented into thin flakes rooted in the nappe stack. They have undergone clockwise rotation about a crustal pole at the SW end of a large normal fault (the Shkoder-Peja Normal Fault, SPNF) that transects the orogen and accommodated orogen-parallel extension. This crustal rotation does not coincide with the plate rotation pole above. Rotation of the hanging wall of the SPNF effected Miocene-to-recent, out-of-sequence thrusting that was transferred to the orogenic front via lateral ramps on dextral transfer zones. The geodynamic driver of this tectonics since the early Miocene has been 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 along the Hellenic segment. A big surprise was the discovery of metamorphic domes that deform Dinaric thrusts and folds in the footwall of the SPNF. The peak temperature in these domes partly records metasomatism in the vicinity of Triassic granitoids (350-450°C) and partly registers heating due to nappe stacking in Paleogene time. These temperatures were certainly attained before orogen-parallel extensional faulting that began in Eocene time and continued in Miocene time. We propose that the SPNF formed during two phases of extension and clockwise rotation: an initial ductile-to-brittle phase (Eocene), and a later brittle phase (Miocene) associated with the formation of the Neogene Dukagjini Basin in Kosovo that is sealed by Plio-Pleistocene strata. This later phase was associated with clockwise oroclinal bending driven by aforementioned bending of the retreating Adriatic slab beneath the Hellenides. The age of the first phase of normal faulting is still unclear, even in light of the existing thermochronological data – late Paleogene and/or early Neogene activity are possible. Normal faulting at the Dinaric-Hellenic Junction provided a structural and erosional template upon which climate-induced erosion in Holocene time effected reorganisation of the regional drainage pattern. This included the formation and partial demise of lakes and basins. The long-lasting tectonic effect on morphology is manifested by arcuation of the main drainage divide between the Adriatic and Aegean Seas around the SPNF. Our analyses of structures in the Periadriatic Foredeep in NW Albania lead to the a posteriori prediction that the M 6.4 Durres event of Nov. 26, 2019 was triggered by slip on the basal thrust at the NW-most end of the Hellenic chain. Potentially, these results can be used by government agencies and re-insurance companies to improve models of stress distribution in the Periadriatic Basin (Durres and Tirana region) that contains most of Albania’s sensitive infrastructure (hydro-electric dams, cities).
Projektbezogene Publikationen (Auswahl)
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One microplate-three orogens: Alps, Dinarides, Apennines and the role of the Adriatic plate. Geophysical Research Abstracts, Vol. 19, EGU 2017-16444, 2017 EGU General Assembly 2017
Ustaszewski, K., Le Breton, E., Balling, P., Handy, M.R., Molli, G. & Tomljenovic, B.
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Slab rollback and Neogene deformation at the Dinarides-Hellenides transition. pp. 42 in Abstract Vol., EGU Series – Emile Argand Conferences, 13th Workshop on Alpine Geological Studies, September 7th- 18th, 2017, Zlatibor Mts. (Serbia)
Handy, M.R., Giese, J. & Schmid, S.M.
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Evolution of the Tropoja basin in NE Albania and possible links to the Shkodër-Peja Normal Fault. 17th TSK (Tektonik- Struktur-Kristallin) Meeting, Abstract Vol., p. 115, 19-25 March, 2018 in Jena, Germany
Simon, D., Giese, J., Handy, M.R., Grund, M. & Onuzi, K.
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Footwall exhumation along the Shkoder-Peja Normal Fault vs. regional uplift and erosional denudation (Dinarides-Hellenides junction). 17th TSK (Tektonik- Struktur-Kristallin) Meeting, Abstract Vol., p. 45, 19-25 March, 2018 in Jena, Germany
Giese, J., Grund, M., Zertani, S., Handy, M.R., Schmid, S.M., Pleuger, J. & Onuzi, K.
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Geological map (1 :10 000) of the Shkoder-Peja Normal Fault in its central segment near Bajram Curri (northern Albania) – evidence for distributed normal faulting and extension. 17th TSK (Tektonik- Struktur-Kristallin) Meeting, Abstract Vol., p. 50, 19-25 March, 2018 in Jena, Germany
Grund, M., Giese, J., Handy, M.R. & Onuzi, K.
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Regional uplift and erosional denudation vs. footwall exhumation along the Shkoder-Peja Normal Fault at the Dinarides-Hellenides transition. Geophysical Research Abstracts, Vol. 20, EGU2018- 8470, EGU General Assembly 2018
Giese, J., Grund, M., Zertani, S., Handy, M.R., Schmid, S.M., Pleuger, J. & Onuzi, K.
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The Shkoder- Peja Normal Fault system and its relation to the Kosovo basin. 17th TSK (Tektonik- Struktur-Kristallin) Meeting, Abstract Vol., p. 46, 19-25 March, 2018 in Jena, Germany
Goris, D., Grund, M., Giese, J., Handy, M.R. & Onuzi, K.
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Transfer and rotational normal faulting at the Dinarides- Hellenides junction - their relation to tearing and retreat of the Adriatic slab. 17th TSK (Tektonik- Struktur-Kristallin) Meeting, Abstract Vol., p. 55, 19-25 March, 2018 in Jena, Germany
Handy, M.R., Giese, J., Onuzi, K., Pleuger, J., Schmid, S.M., Spakman, W. & Ustaszewski, K.
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Along-strike change from oblique collision to rollback subduction at the junction of the Dinarides and Hellenides. Abstract Vol., Leibnitz Society Berlin-Helmholtz Centre Potsdam, Workshop on The Geology of Eurasia, June 27-28th, 2019, Potsdam, Germany
Handy, M.R., Giese, J., Pleuger, J., Le Breton, E. & altri
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Change from rollback subduction to oblique collision at the junction of the Dinarides and Hellenides. pp. 28 in Abstract Vol., EGU Series – Emile Argand Conferences, 14th Workshop on Alpine Geological Studies, September 4-6th, 2019, Sion, Switzerland
Handy, M.R., Giese, J., Pleuger, J., Schmid, S.M., Spakman, W., Onuzi, K. & Ustaszewski, K.
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Coupled Crust‐Mantle Response to Slab Tearing, Bending, and Rollback Along the Dinaride‐Hellenide Orogen. Tectonics, 38(8), 2803-2828.
Handy, Mark R.; Giese, Joerg; Schmid, Stefan M.; Pleuger, Jan; Spakman, Wim; Onuzi, Kujtim & Ustaszewski, Kamil
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Faulting, cooling and exhumation in the footwall of the Shkoder-Peja Normal Fault (Dinaric-Hellenic junction) and its relation to the western Kosovo basin. Geophysical Research Abstracts, Vol. 21, EGU2019-8549, EGU General Assembly 2019
Grund, M.U., Giese, J., Zertani, S., Handy, M.R., Pleuger, J., Le Breton, E. & Onuzi, K.
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Tectonic, erosional and climatic controls on sedimentary basin evolution a case study from the Tropoja Basin (Albania). Copernicus GmbH.
Gemignani, Lorenzo; Simon, Daniel; Mittelbach, Benedict; Hippe, Kristina & Handy, Mark, R.
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The 2019Durrës, Albania earthquake sequence – preliminary results from a post-seismic campaign. Copernicus GmbH.
Dushi, Edmond; Schurr, Bernd; Kosari, Ehsan; Soto, Hugo; Gjuzi, Olgert; Rohnacher, Alicia; Haberland, Christian; Rietbrock, Andreas; Tilmann, Frederik; Handy, Mark; Koci, Rexhep; Ustaszewski, Kamil; Dahm, Torsten; Meier, Thomas & Duni, Llambro
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The M 6.4 Albanian earthquake of Nov. 26, 2019 and its relation to structures at the Dinarides-Hellenides junctions. Copernicus GmbH.
Handy, Mark R.; Schmid, Stefan M. & Briole, Pierre
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Response of Drainage Pattern and Basin Evolution to Tectonic and Climatic Changes Along the Dinarides-Hellenides Orogen. Frontiers in Earth Science, 10.
Gemignani, L.; Mittelbach, B. V.; Simon, D.; Rohrmann, A.; Grund, M. U.; Bernhardt, A.; Hippe, K.; Giese, J. & Handy, M. R.
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Faulting, basin formation and orogenic arcuation at the Dinaric–Hellenic junction (northern Albania and Kosovo). International Journal of Earth Sciences, 112(6), 1613-1634.
Grund, Marc U.; Handy, Mark R.; Giese, Jörg; Gemignani, Lorenzo; Pleuger, Jan & Onuzi, Kujtim
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The Shkoder Peja Normal Fault system at the Dinaric-Hellenic Junction: a structural and thermochronological study. Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften im Fachbereich Geowissenschaften, Freie Universität Berlin, 157 S.
Grund, M.U.
