Synconvergence extension and midcrustal exhumation in the Internal Dinarides

Author(s):  
Gabriele Casale ◽  
Richard Bennett ◽  
Darrel Cowan ◽  
Marijana Surkovic
Keyword(s):  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Philipp Balling ◽  
Christoph Grützner ◽  
Bruno Tomljenović ◽  
Wim Spakman ◽  
Kamil Ustaszewski

AbstractThe 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.


2010 ◽  
Vol 61 (2) ◽  
pp. 89-109 ◽  
Author(s):  
Senecio Schefer ◽  
Daniel Egli ◽  
Sigrid Missoni ◽  
Daniel Bernoulli ◽  
Bernhard Fügenschuh ◽  
...  

Triassic metasediments in the internal Dinarides (Kopaonik area, southern Serbia): stratigraphy, paleogeographic and tectonic significanceStrongly deformed and metamorphosed sediments in the Studenica Valley and Kopaonik area in southern Serbia expose the easternmost occurrences of Triassic sediments in the Dinarides. In these areas, Upper Paleozoic terrigenous sediments are overlain by Lower Triassic siliciclastics and limestones and by Anisian shallow-water carbonates. A pronounced facies change to hemipelagic and distal turbiditic, cherty metalimestones (Kopaonik Formation) testifies a Late Anisian drowning of the former shallow-water carbonate shelf. Sedimentation of the Kopaonik Formation was contemporaneous with shallow-water carbonate production on nearby carbonate platforms that were the source areas of diluted turbidity currents reaching the depositional area of this formation. The Kopaonik Formation was dated by conodont faunas as Late Anisian to Norian and possibly extends into the Early Jurassic. It is therefore considered an equivalent of the grey Hallstatt facies of the Eastern Alps, the Western Carpathians, and the Albanides-Hellenides. The coeval carbonate platforms were generally situated in more proximal areas of the Adriatic margin, whereas the distal margin was dominated by hemipelagic/pelagic and distal turbiditic sedimentation, facing the evolving Neotethys Ocean to the east. A similar arrangement of Triassic facies belts can be recognized all along the evolving Meliata-Maliac-Vardar branch of Neotethys, which is in line with a ‘one-ocean-hypothesis’ for the Dinarides: all the ophiolites presently located southwest of the Drina-Ivanjica and Kopaonik thrust sheets are derived from an area to the east, and the Drina-Ivanjica and Kopaonik units emerge in tectonic windows from below this ophiolite nappe. On the base of the Triassic facies distribution we see neither argument for an independent Dinaridic Ocean nor evidence for isolated terranes or blocks.


2010 ◽  
Vol 61 (4) ◽  
pp. 273-292 ◽  
Author(s):  
Damir Slovenec ◽  
Boško Lugović ◽  
Irena Vlahović

Geochemistry, petrology and tectonomagmatic significance of basaltic rocks from the ophiolite mélange at the NW External-Internal Dinarides junction (Croatia)At the NW inflexion of the Sava-Vardar Suture Zone ophiolite mélanges, known as the Kalnik Unit, form the surface of the slopes of several Pannonian inselbergs in the SW Zagorje-Mid-Transdanubian Zone. The Mt Samoborska Gora ophiolite mélange, thought to be a part of the Kalnik Unit, forms a separate sector obducted directly onto Dinaric Triassic carbonate sediments. Basaltic rocks, the only magmatic rocks incorporated in the mélange, include Middle-Triassic (Illyrian-Fassanian) alkali within-plate basalts and Middle Jurassic (uppermost Bathonian-Lower Callovian) tholeiitic basalts. The latter sporadically constitute composite olistoliths, and are geochemically divided into N-MORB-like (high-Ti basalts) and transitional MORB/IAT (medium-Ti basalts). These geochemically different rocks suggest crystallization at various tectonomagmatic settings, which is also indicated by the rock paragenesis and host clinopyroxene compositions. Alkali basalts reflect melts derived from an OIB-type enriched mantle source [Ti/V= 62.2-82.4; (La/Lu)cn= 6.4-12.8] with Nd-Sr isotope signatures close resembling the Bulk Earth [εNd(T=235 Ma)= + 1.6 to + 2.5]. They are recognized as preophiolite continental rift basin volcanic rocks that closely predate the opening of the Repno oceanic domain (ROD) of the Meliata-Maliac ocean system. The high-Ti and medium-Ti basalts from composite blocks derived from a similar depleted mantle source (εNd(T=165 Ma) = + 6.01 vs. + 6.35) succesively metasomatized by expulsion of fluids from a subducting slab leading to a more pronounced subduction signature in the latter [Ti/V=31.6-44.8 and (Nb/La)n=0.67-0.90 vs. Ti/V=21.5-33.9 and (Nb/La)n=0.32-0.49]. These composite blocks indicate crust formation in an extensional basin spreading over the still active subducting ridge. The majority of high-Ti basalts may represent the fragments of older crust formed at a spreading ridge and incorporated in the mélange of the accretionary wedge formed in the proto-arc-fore-arc region. The Mt Samoborska Gora ophiolite mélange represents the trailing edge of the Kalnik Unit as a discrete sector that records the shortest stage of tectonomagmatic evolution related to intraoceanic subduction in the ROD.


Lithos ◽  
2009 ◽  
Vol 108 (1-4) ◽  
pp. 106-125 ◽  
Author(s):  
Kamil Ustaszewski ◽  
Stefan M. Schmid ◽  
Boško Lugović ◽  
Ralf Schuster ◽  
Urs Schaltegger ◽  
...  

2018 ◽  
Vol 112 (1) ◽  
pp. 217-234 ◽  
Author(s):  
Kristóf Porkoláb ◽  
Szilvia Kövér ◽  
Zsolt Benkó ◽  
Gábor H. Héja ◽  
Melinda Fialowski ◽  
...  

2003 ◽  
Vol 140 (3) ◽  
pp. 335-342 ◽  
Author(s):  
DAVIDE LENAZ ◽  
VADIM S. KAMENETSKY ◽  
FRANCESCO PRINCIVALLE

In Late Cretaceous times, subduction of oceanic crust occurred to the north of the Adria plate and was followed by the formation of ophiolitic complexes. Continental collision in Alpine orogenic belts lasted from Late Cretaceous to Early Tertiary times. The progressive contraction of oceanic crust caused the uplift of previously rifted continental margin and platforms and the formation of foredeep flysch basins. Detrital Cr-spinels are widespread in Eocene sandstones of the Brkini, Istrian and Krk Island foredeep flysch basins. On the basis of their TiO2 content and FeO/Fe2O3 ratio, spinels derived from peridotites and mantle-derived magmatic rocks were distinguished. The first are statistically more abundant and are considered to have been derived from type I and II peridotites. The second appear to be mainly related to backarc basin products. These results suggest that Cr-spinels were derived from the erosion of the Internal Dinarides, where type II and III peridotites are present, and also from the Outer Dinarides, where type I peridotites crop out.


2016 ◽  
pp. 13-21 ◽  
Author(s):  
Natasa Gerzina ◽  
Nevenka Djeric

Cherts are quite frequently occurring rocks in the Internal Dinarides, an extremely complex area composed of several tectonostratigraphic units in which oceanic sediments, ophiolites and partly metamorphosed parts of the distal continental margin of Adria are preserved. Therefore, these cherts differ in age and the original depositional environment in which they were formed. Results of investigations carried out in the chert blocks found in the melange in the vicinity of Jasenovo village on SE slopes of Zlatibor Mt. are presented here. Radiolarian cherts from the studied localities represent blocks in melange of the East-Bosnian-Durmitor Unit, exposed in a large tectonic window below the Triassic carbonates of Drina-Ivanjica Unit. Biostratigraphic data revealed Callovian-early Kimmeridgian ages of the studied chert blocks, thus implying a Kimmeridgian or younger age of obduction of the West Vardar ophiolites.


Geologija ◽  
2005 ◽  
Vol 48 (1) ◽  
pp. 53-72
Author(s):  
Marijan Poljak ◽  
Andrej Lapanje ◽  
Ivan Gušić ◽  
Bernarda Bole ◽  
Bojan Ogorelec
Keyword(s):  

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