Late and post-collisional tectonic evolution of the Adria-Europe suture in the Vardar Zone

The Vardar Zone is a product of the Triassic-Jurassic opening of the Neotethys, Jurassic obduction, Late Cretaceous/Paleogene consumption of the oceanic crust and continental collision. During the last process, the Eastern Vardar Zone was thrust over the Central and eventually both onto the Western Vardar Zone. The present paleomagnetic and structural study provided new results from the first two zones in the Belgrade area. The younger set of data, together with published ones from the third zone, provide firm evidence for about 30° clockwise vertical axial rotation of the Vardar Zone between 23-18 Ma, connected to extension driven by the roll-back of the Carpathians lithosphere. Earlier, the Vardar Zone was affected by intensive compression generating a nappe pile, comprising the Eastern, Central and Western Vardar Zones. This assembly was eventually thrusted over CCW rotating Adriatic elements in the Paleogene. The rotation triggered a system of right lateral strike slip faults between different tectonic slices in the Vardar Zone. This tectonic model offers a plausible explanation for the paleomagnetic directions of post-folding age of the Upper Cretaceous flysch of the Central Vardar Zone. Nevertheless, the possibility of remagnetization of the magnetite bearing flysch during Late Neogene uplift can not be excluded

Vardar Zone : New insights into the tectono-depositional subdivision

Vardar mega-unit represents complex tectonic unit, which was structured during Mesozoic tectono-depositional evolution of Neotethys and the adjoining continental margins. Vardar mega-unit can be subdivided into the three tectonic entities characterized by contrasting lithostratigraphic and structural features. Going from west towards east these are: Western Vardar Zone, Central Vardar Zone, and Eastern Vardar Zone. Lithostratigraphic contents of these zones were, again, deposited in three different domains. From west to east, these domains are: basin of the Adriatic passive margin, subduction trench, and forearc basin of the European active margin

Vardar Zone : New insights into the tectono-depositional subdivision

Vardar mega-unit represents complex tectonic unit, which was structured during Mesozoic tectono-depositional evolution of Neotethys and the adjoining continental margins. Vardar mega-unit can be subdivided into the three tectonic entities characterized by contrasting lithostratigraphic and structural features. Going from west towards east these are: Western Vardar Zone, Central Vardar Zone, and Eastern Vardar Zone. Lithostratigraphic contents of these zones were, again, deposited in three different domains. From west to east, these domains are: basin of the Adriatic passive margin, subduction trench, and forearc basin of the European active margin

Internal structure of the Supragetic Unit basement in the Serbian Carpathians and its significance for the late Early Cretaceous nappe-stacking

Fault-related folds and hanging-wall structures reflect the geometry of the main thrusts in foldthrust belts. The results of the structural analysis of the Supragetic Unit metamorphic basement in eastern Serbia at map-, outcrop- and thin-section scale, and its importance for the late Early Cretaceous nappe-stacking are presented in this paper. The Supragetic Unit metamorphic basement includes various volcano-sedimentary rocks of Ordovician-Silurian protolith age. They were metamorphosed to the low greenschist facies with temperatures reaching 300-350°C and pressure reaching 0.3-0.5 GPa. The microscale studies show that quartz and albite demonstrate dominantly bulging and locally subgrain rotation recrystallisation, while chlorite, sericite and muscovite define spaced to continuous foliation recognised both at the outcrop- and the thin-section-scale. The statistical analysis based on the available map data shows low- to high-angle west-dipping foliation which is interpreted as an indicator of flat-ramp geometry of the Supragetic thrust, rather than east-vergent tight to isoclinal folding. At the thin-section scale ductile to semi-ductile C’-S structures indicate top to ESE thrusting. Subsequent kinking, recognised both at the outcrop- and the thin-section-scale, deform the older foliation. Those kink bands are the result of WNW-ESE to NW-SE compression and could represent the later stage of a continuous deformation event during which C’-S structures were formed. The youngest, brittle deformation is represented by subvertical joints with no offset recognised in thin-sections. The structural characteristics of the Supragetic Unit low-grade metamorphic basement in the studied areas, combined with tectonothermal events recognised elsewhere in Dacia mega-unit, could imply a possible initiation of the late Early Cretaceous nappe-stacking in the ductile to semi-ductile/semi-brittle domain. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. OI176015 and Grant no. OI176019

Top-view and cross-section photographs from analogue experiments of strain partitioning around a rigid indenter performed in the Tectonic modelling laboratory (TecLab) at Utrecht University

This dataset contains original top-view and cross-section photographs of 12 crustal-scale analogue models. Top-view photographs were taken in regular time intervals from the beginning until the end of each experiment (for details see below). Cross-section photographs were taken at the end of each experiment. Therefore, top-view photographs provide means to track and analyse surface deformation through time and space and cross-sections allow to demonstrate overall vertical deformation of each model. The data are grouped in 12 folders that contain the data for the individual models (model1 to model12). The numbering of the folders corresponds to the model numbers as described in Krstekanić et al. (2020, in prep.). Each folder contains two sub-folders named m#-cross-sections and m#-top-views where m stands for the model and # for the number of the model (i.e., the same number as the parent folder). The m#-cross-sections sub-folder contains one top-view photograph indicating the locations of the cross-sections as well as the pertinent cross-section photographs. A number in each cross-section photograph corresponds to the number next to the cross-section location in the top-view. The m#-top-views sub-folder contains all top-view photographs of that particular model, from its initial, undeformed state to the end of the experiment. All photographs are in .jpg format and their names are original generic names created by the camera software at the moment of acquisition. The data is provided in 12 subfolders for 12 models. Detailed information about the files in these subfolders as well as information on how the data is processed is given in the explanatory file krstekanic-et-al-2020-data-documentation.docx. Contact person is Nemanja Krstekanić - PhD Candidate - [email protected] - https://www.uu.nl/staff/nkrstekani

Top-view and cross-section photographs from analogue experiments of strain partitioning during coeval indentation and back-arc extension performed in the Tectonic modelling laboratory (TecLab) at Utrecht University

This dataset contains original unaltered top-view and cross-section photographs of 4 crustal-scale analogue models. Top-view photographs were taken at a regular time interval from the beginning until the end of each experiment (for details see below). Cross-section photographs were taken at the end of each experiment. Top-view photographs were used to analyse surface deformation through time and space, while in cross-sections vertical deformation was studied. The dataset is arranged in 4 folders, each containing the data for the individual models (model1 to model4). The folder numbering corresponds to the model numbers as described in Krstekanić et al. (in prep.). Each folder contains two sub-folders named m#-cross-sections and m#-top-views where m stands for the model and # for the number of the model (i.e., the same number as the parent folder). The m#-cross-sections sub-folder contains one top-view photograph showing the locations of the cross-sections as well as the corresponding cross-section photographs. A number in each cross-section photograph is the same as the number next to the cross-section location in the top-view. The m#-top-views sub-folder contains all top-view photographs of that particular model, from its initial, undeformed state to the end of the experiment, showing the surface of the model at the moment of the photo acquisition. All photographs in this dataset are in .jpg format and their names are original generic names created by the camera software at the moment of acquisition. Detailed information about the files as well as information on how the data is processed is given in the explanatory file krstekanic-et-al-2021-data-documentation.docx. Contact person is Nemanja Krstekanić - PhD Candidate - [email protected] - https://www.uu.nl/staff/nkrstekani

Paleogene-early miocene deformations of Bukulja-Venčac crystalline (Vardar zone, Serbia)

Low-grade metamorphic rocks of the crystalline of Mts. Bukulja and Venčac, which are integral parts of the Vardar Zone, are of Late Cretaceous age. From the Middle Paleogene to the beginning of the Miocene, they were subjected to three phases of intensive deformations. In the first phase, during the Middle Paleogene, these rocks were subjected to intense shortening (approximately in the E-W direction), regional metamorphism and deformations in the ductile and brittle domains, when first-generation folds with NNE-SSW striking fold hinges were formed. In the second phase, during the Late Oligocene and up to the Early Miocene, extensional unroofing and exhumation of the crystalline occurred, which was followed by intrusion of the granitoid of Bukulja and refolding of the previously formed folds in a simple brachial form of Bukulja and Venčac with an ESE-WNW striking B-axis. The third phase was expressed in the Early lowermost Miocene (before the Ottnanghian), under conditions of NE-SW compression and NW-SE tension. It was characterized by wrench-tectonic activity, particularly by dextral movements along NNW-SSE striking faults

Quaternary tectonic and depositional evolution of eastern Srem (northwest Serbia)

The area of eastern Srem is situated in the southern periphery of the Pannonian basin. Its depositional evolution during the Neogene and the Quaternary has been controlled by tectonic processes. Miocene extensional subsidence was followed by the Pliocene-Quaternary inversion of the basin. The latter was accomplished as the result of replacement of the tensile by the compressive stress field. Since the Late Neogene, the regional tectonic activity has been controlled by compressive stress produced by the northnortheastern propagation of the Adria microplate. In the compressive NE-SW-oriented stress field, the recent structural plan of the Pannonian basin and its wider environment, including its southern periphery, was reactivated. The youngest tectonic deformations are characterized by positive and negative vertical motions of large intrabasinal segments and basinal periphery, resulting in the final inversion of the basin. The effects of the basinal inversion can be recognized in genetic features of Quaternary sediments and geomorphological characteristics of the relief. Sources of data used for the interpretation of the Quaternary tectonic activity in the area of eastern Srem are of geological, geomorphological, thermochronological, and geophysical character. The positions of prominent fault structures have been ascertained by remote sensing, interpretations of available geophysical cross-sections, and using the field data. [Projekat Ministarstva nauke Republike Srbije, br. 176015

Analogue modelling of strain partitioning along a curved strike-slip fault system during backarc-convex orocline formation: Implications for the Cerna-Timok fault system of the Carpatho-Balkanides

Large-scale strike-slip faults are associated with significant strain partitioning in releasing/restraining bends and often display map-view curvatures ending in horse-tail geometries. Such faults are commonly associated with indentation tectonics, where shortening in front of indenters is transferred laterally to transpression, strike-slip and the formation of transtensional/extensional basins. We investigate how these structurally distinct domains are kinematically linked by the means of a crustal-scale analogue modelling approach where a deformable crust is moved against a stable and rigid indenter. The modelling demonstrates that the geometry of the indenter is the major controlling parameter driving strain partitioning and deformation transfer from thrusting and transpression to strike-slip and transtension, whereas the rotation of the mobile plate controls the opening of triangular shaped transtensional basins. Flow of the ductile crust leads to the distribution of deformation over a wider area, facilitating strike-slip splaying into transtension/extension behind the indenter. Our results show a very good correlation with the Moesian indentation in the Carpatho-Balkanides system of South-Eastern Europe, where strain is partitioned around the dextral Cerna and Timok strike-slip faults and transferred to thrusting in the Balkanides part of the Moesian indenter and to transtension/extension in the neighbouring South Carpathians