Rastislav Vojtko

Cretaceous—Quaternary tectonic evolution of the Tatra Mts (Western Carpathians): constraints from structural, sedimentary, geomorphological, and fission track data

Abstract The Tatra Mts area, located in the northernmost part of Central Western Carpathians on the border between Slovakia and Poland, underwent a complex Alpine tectonic evolution. This study integrates structural, sedimentary, and geomorphological data combined with fission track data from the Variscan granite rocks to discuss the Cretaceous to Quaternary tectonic and landscape evolution of the Tatra Mts. The presented data can be correlated with five principal tectonic stages (TS), including neotectonics. TS-1 (~95-80 Ma) is related to mid-Cretaceous nappe stacking when the Tatric Unit was overlain by Mesozoic sequences of the Fatric and Hronic Nappes. After nappe stacking the Tatric crystalline basement was exhumed (and cooled) in response to the Late Cretaceous/Paleogene orogenic collapse followed by orogen-parallel extension. This is supported by 70 to 60 Ma old zircon fission track ages. Extensional tectonics were replaced by transpression to transtension during the Late Paleocene to Eocene (TS-2; ~80-45 Ma). TS-3 (~45-20 Ma) is documented by thick Oligocene-lowermost Miocene sediments of the Central Carpathian Paleogene Basin which kept the underlying Tatric crystalline basement at elevated temperatures (ca. > 120 °C and < 200 °C). The TS-4 (~20-7 Ma) is linked to slow Miocene exhumation rate of the Tatric crystalline basement, as it is indicated by apatite fission track data of 9-12 Ma. The final shaping of the Tatra Mts has been linked to accelerated tectonic activity since the Pliocene (TS-5; ~7-0 Ma).

Neogene and Quaternary development of the Turiec Basin and landscape in its catchment: a tentative mass balance model

Neogene and Quaternary development of the Turiec Basin and landscape in its catchment: a tentative mass balance model The development of the Turiec Basin and landscape evolution in its catchment has been reconstructed by methods of geological research (structural geology, sedimentology, paleoecology, and geochronological data) as well as by geophysics and geomorphology. The basin and its surrounding mountains were a subject of a mass balance study during periods of tectonic activity, accompanied by considerable altitudinal differentiation of relief and also during quiet periods, characterized by a development of planation surfaces in the mountains. The coarse clastic alluvial fans deposited beneath the offshore pelitic sediments document the rapid Middle Miocene uplift of mountains on the margin of the Turiec Basin. The Late Miocene finegrained sedimentation represents the main fill of this basin and its origin was associated with the formation of planation surfaces in the surrounding mountains. The rapid uplift of the western and northern parts of the catchment area during the latest Miocene and Early Pliocene times further generated the deposition of coarse-grained alluvial fans. The Late Pliocene basin inversion, due to uplift of the whole Western Carpathians mountain chain, was associated with the formation of the Early Quaternary pediment and ultimately with the formation of the Turiec river terrace systems.

Late Miocene and Pliocene history of the Danube Basin: inferred from development of depositional systems and timing of sedimentary facies changes

Late Miocene and Pliocene history of the Danube Basin: inferred from development of depositional systems and timing of sedimentary facies changes The development of the northern Danube Basin (nDB) was closely related to the Late Miocene geodynamic evolution of the Pannonian Basin System. It started with a wide rifting which led to subsidence of several basin depocenters which were gradually filled during the Late Miocene and Early Pliocene. In the Late Pliocene the subsidence continued only in the basins central part, while the northern marginal zone suffered inversion and the uplifted sedimentary fill began to be eroded. Individual stages of the basin development are well recorded in its sedimentary succession, where at least three great tectono-sedimentary cycles were documented. Firstly, a lacustrine cycle containing Lower, Middle and lowermost Upper Pannonian sediments (A-F Zones; sensu Papp 1951) deposited in the time span 11.6-8.9 Ma and is represented in the nDB in Slovakia by the Ivanka and Beladice Formations. In the Danube Basin of the southern part in Hungary, where the formations are defined by the appearance of sedimentary facies in time and space, the equivalents are: (1) the deep-water setting marls, clays and sandy turbidites of the Endrod and Szolnok Formations leading to the overlying strata deposits of the basin paleoslope or delta-slope represented by the Algyő Formation, and (2) the final shallow-water setting deposits of marshes, lagoons and a coastal and delta plain composed of clays, sands and coal seams, represented by the Újfalu Formation. The second tectono-sedimentary cycle was deposited in an alluvial environment and it comprises the Upper Pannonian (G and H Zones; sensu Papp 1951) and Lower Pliocene sediments dated 8.9-4.1? Ma. The cycle is represented in the nDB, by the Volkovce Formation and in the southern part by the Zagyva Formation in Hungary. The sedimentary environment is characterized by a wide range of facies from fluvial, deltaic and ephemeral lake to marshes. The third tectono-sedimentary cycle comprises the Upper Pliocene sediments. In Slovakia these are represented by the Kolárovo Formation dated 4.1-2.6 Ma. The formation contains material of weathering crust preserved in fissures of Mesozoic carbonates, diluvial deposits and sediments of the alluvial environment.

Pliocene to Quaternary tectonics in the Horná Nitra Depression (Western Carpathians)

Pliocene to Quaternary tectonics in the Horná Nitra Depression (Western Carpathians) The Horná Nitra Depression is an Upper Miocene-Quaternary intramontane sedimentary basin. This N-S elongated half-graben structure is rimmed from the west by the marginal Malá Magura fault which is the most distinctive fault in the Horná Nitra Depression, traditionally considered as an active fault during the neotectonic phase. This dislocation is attended by contrasting landforms and their parameters. The low S-index of about 1.10, at least two generations of well-preserved faceted slopes along this fault, and longitudinal river valley profiles point to the presence of a low-destructed actual mountain front line, which is typical for the Quaternary active fault systems. Comparison with known normal fault slip rates in the world makes it possible to set an approximate vertical slip rate between 0.3-1.1 m · kyr-1. The present-day fault activity is considered to be normal, steeply dipping towards the east according to structural and geophysical data. The NNW-SSE present-day tectonic maximum horizontal compressional stress SH and perpendicular minimum horizontal compressional stress Sh was estimated in the Horná Nitra region. The Quaternary activity of the Malá Magura fault is characterized by irregular movement. Two stages of important tectonic activity along the fault were distinguished. The first stage was dated to the Early Pleistocene. The second stage of tectonic activity can by dated to the Late Pleistocene and Holocene. The Malá Magura fault is permeable for gases because the soil atmosphere above the ca. 150 meters wide fault zone contains increased contents of methane and radon.

Reconstruction of Cenozoic paleostress fields and revised tectonic history in the northern part of the Central Western Carpathians (the Spišská Magura and Východné Tatry Mountains)

Reconstruction of Cenozoic paleostress fields and revised tectonic history in the northern part of the Central Western Carpathians (the Spišská Magura and Východné Tatry Mountains) This study investigates the chronology of paleostress evolution and faulting in the northern part of the Central Western Carpathians (Spišská Magura and Východné Tatry Mts). Paleostress analysis of brittle and semibrittle structures of the Eocene-Oligocene succession of the Central Carpathian Paleogene Basin (CCPB) supplemented by measurements in the Triassic sequence of the Krížna Nappe, revealed the existence of six tectonic regimes during the Cenozoic. Orientation of the paleostress field before the deposition of the CCPB was characterized by the E-W oriented compression. After this compression, the paleostress field rotated approximately 40-50°, and NW-SE directed compression took place in the Early Miocene. During the latest Early Miocene, the extensional tectonic regime with fluctuation of σ3 orientation between NW-SE to NE-SW dominated. The Late Badenian-Pannonian is characterized by a new compressive to strike-slip tectonic regime during which the principal maximum stress axis σ1 progressively rotated from a NW-SE to a NE-SW position. Uplift and tilting of the Tatra Massif took place during this stage. The neotectonic stage (Pliocene to Holocene) is characterized by extensional tectonic regime with the two directions of tension. The first one is oriented in the E-W direction and could be considered older and the second one, NNW-SSE tension is considered to be Late Pliocene to Quaternary in age. In general, orientation of the stress fields shows an apparent clockwise rotation from the Oligocene to Quaternary times. This general clockwise rotation of the Oligocene to Quaternary paleostress fields could be explained by both the effect of the counter-clockwise rotation of the ALCAPA microplate and by the regional stress field changes.

Late Quaternary fault activity in the Western Carpathians: evidence from the Vikartovce Fault (Slovakia)

Late Quaternary fault activity in the Western Carpathians: evidence from the Vikartovce Fault (Slovakia) The Cenozoic structure of the Western Carpathians is strongly controlled by faults. The E-W striking Vikartovce fault is one of the most distinctive dislocations in the region, evident by its geological structure and terrain morphology. This feature has been assumed to be a Quaternary reactivated fault according to many attributes such as its perfect linearity, faceted slopes, the distribution of travertines along the fault, and also its apparent prominent influence on the drainage network. The neotectonic character of the fault is documented herein by morphotectonic studies, longitudinal and transverse valley profile analyses, terrace system analysis, and mountain front sinuosity. Late Pleistocene activity of the Vikartovce fault is now proven by luminescence dating of fault-cut and uplifted alluvial sediments, presently located on the crest of the tilted block. These sediments must slightly pre-date the age of river redirection. Considering the results of both luminescence dating and palynological analyses, the change of river course probably occurred during the final phase of the Riss Glaciation (135 ± 14 ka). The normal displacement along the fault during the Late Quaternary has been estimated to about 105-135 m, resulting in an average slip rate of at least 0.8-1.0 mm · yr-1. The present results identify the Vikartovce fault as one of the youngest active faults in the Central Western Carpathians.

The Alpine tectonic evolution of the Danube Basin and its northern periphery (southwestern Slovakia)

Abstract The tectonic evolution of the pre-Cenozoic basement, as well as the Cenozoic structures within the Danube Basin (DB) and its northern periphery are presented. The lowermost portion of the pre-Cenozoic basement is formed by the Tatricum Unit which was tectonically affected by the subduction of the Vahicum / Penninicum distal continental crust during the Turonian. Tectonically disintegrated Tatricum overlaid the post-Turonian to Lower Eocene sediments that are considered a part of the Vahicum wedge-top basin. These sediments are overthrust with the Fatricum and Hronicum cover nappes. The Danube Basin Transversal Fault (DBTF) oriented along a NW–SE course divided the pre-Neogene basement of the DB into two parts. The southwestern part of the DB pre-Neogene basement is eroded to the crystalline complexes while the Palaeogene and Mesozoic sediments are overlaid by the Neogene deposits on the northeastern side of the DBTF. The DBTF was activated as a dextral fault during the Late Oligocene – Earliest Miocene. During the Early Miocene (Karpatian – Early Badenian) it was active as a normal fault. In the Middle – Late Miocene the dominant tectonic regime with NW – SE oriented extension led to the disintegration of the elevated pre-Neogene basement under the simple and pure shear mechanisms into several NE – SW oriented horst and graben structures with successive subsidence generally from west to east. The extensional tectonics with the perpendicular NE – SW orientation of the Shmin persists in the Danube Basin from the ?Middle Pleistocene to the present.

The resistivity image of the Muráň fault zone (Central Western Carpathians) obtained by electrical resistivity tomography

The resistivity image of the Muráň fault zone (Central Western Carpathians) obtained by electrical resistivity tomography The paper describes the application of geophysical prospecting techniques for estimation of the faults inclination. The field survey was carried out across the Muráň fault structure in the Slovenské rudohorie Mts (central Slovakia). Three different geophysical methods were used to map the fault zone: Electrical Resistivity Tomography (ERT), induced polarization (IP) and radon emanometry. All these methods have been used to locate the fault zone area, but the principal aims of this research are to test the efficiency of the 2D ERT technique to recognize the geometrical characterization of the fault and to improve our tectonic knowledge of the investigated area. For the synthetic cases, three geometric contexts were modelled at 60, 90 and 120 degrees and computed with the l2 norm inversion method, the l1 norm with standard horizontal and vertical roughness filter and the l1 norm with diagonal roughness filter. In the second phase this geophysical methodology was applied to fieldwork data. Our results confirm that the ERT technique is a valuable tool to image the fault zone and to characterize the general geometry, but also the importance of setting up the right inversion parameters. The main contribution of the geophysical investigations in this case was the determination of the location and confirmation of the inclination of the Muráň fault. The result of this study is the ability to make a visual estimation of the direction and dip of the fault. Pursuant to this work the dipole-dipole electrode configuration produces the best resolution, particularly for the location of vertical and dipping structures. The advantage of this array is that it shows the ability to assess the trend of the dip and therefore it can be strongly recommended. The result is also a case study of a small scale tectonic survey involving geophysical methods.

Geological evolution of the southwestern part of the Veporic Unit (Western Carpathians): Based on fission track and morphotectonic data

Abstract Zircon and apatite fission track (FT) and morphotectonic analyses were applied in order to infer quantitative constraints on the Alpine morphotectonic evolution of the western part of the Southern Veporic Unit which is related to: (1) Eo-Alpine Cretaceous nappe stacking and metamorphism of the crystalline basement in the greenschist facies. (2) Exhumation phase due to underthrusting of the northerly located Tatric-Fatric basement (~ 90–80 Ma), followed by a passive en-block exhumation with cooling through ~ 320–200 °C during the Palaeocene (ZFT ages of ~ 61–55 Ma). (3) Slow Eocene cooling through ~ 245–90 °C, which most likely reflected erosion of the overlying cover nappes and the Gosau Group sediments. Cooling reached up to 60 °C till the Oligocene (AFT ages of ~ 37–22 Ma) in association with erosion of cover nappes. The efficient Eocene erosion led to the formation of the first Cenozoic planation surface with supergene kaolinization in many places. (4) The early Miocene erosion coincided with surface lowering and resulted in the second planation surface favourable for kaolinization. (5) In the middle Miocene, the study area was covered by the Poľana, Javorie, and Vepor stratovolcanoes. (6) The late Miocene stage was related to the erosion and formation of the third Cenozoic planation surface and the final shaping of the mountains was linked to a new accelerated uplift from the Pliocene.

Structural evolution of the Turňa Unit constrained by fold and cleavage analyses and its consequences for the regional tectonic models of the Western Carpathians

Abstract The Turňa Unit (Turnaicum, Tornaicum) is one of the three nappe systems involved in the geological structure of the inner zones of the Western Carpathians. The unit is formed by a system of partial nappes and duplexes, which overlie the Meliata Unit s.l. and are overridden by the Silica Nappe. The Slovenská skala partial nappe in the investigated area includes clastic sediments of the mid-Carboniferous, Permian and Early Triassic age, followed by mostly deep-water Middle-Upper Triassic succession predominantly composed of carbonates. Structural analysis of cleavage planes and folds was carried out predominantly in the Lower Triassic Werfen Formation. The measured deformational structures are polygenetic and were principally formed in three successive deformation stages. The first deformation stage is represented by bedding-parallel, very low-grade metamorphic foliation that was related to nappe stacking and formation of the Mesozoic accretionary wedge during the latest Jurassic and earliest Cretaceous. The second deformation stage is represented by systems of open to closed, partly asymmetric folds with SW-NE oriented, steeply NW- or SE-dipping axial-plane cleavage. Regionally, the folded bedding planes are usually moderately SE-ward dipping, the NW-ward and subvertical dips are less common. The mesoscopic fold structures predominantly occur in the SW-NE trending anticlinal and synclinal hinge zones of large-scale folds. These structures evolved in a compressional tectonic regime with the NW-SE to N-S orientation of the maximum compressional axis. The third observed deformation stage was activated during ENE-WSW oriented shortening. This stage is chiefly represented by open, kink-type folds. Some inferences for regional structures and tectonic evolution of the area are discussed as well.