Witold Zuchiewicz

Quaternary tectonics of the Outer West Carpathians, Poland

Abstract Quaternary tectonic activity in the Polish segment of the Outer West Carpathians has been relatively weak and can be reconstructed on the basis of indirect evidence, provided by geomorphological mapping, the construction of various morphometric maps based on mathematical transformation of the present-day topography, and the use of some mathematical techniques to model the theoretical longitudinal river profiles and the valley network and to process statistically the drainage pattern parameters. Morphological evidences of tectonic movements include deformed strath terraces, differentiated amounts and rates of fluvial incision in individual geomorphic units which occurred despite of regionally consistent Quaternary climatic conditions throughout the West Carpathians and more or less uniform bedrock resistance to erosion, as well as changes in the drainage network. The values of some morphometric indices, like abnormally high river-bed gradients and bifurcation ratios or low valley floor width/valley height ratios differ throughout that part of the Carpathian arc, and cluster into a number of zones that are aligned subparallel to the mountain belt and coincide with geomorphic units showing upwarped strath terraces. These zones become more numerous from the west to the east, and some of them are located at or in front of the present-day Carpathian frontal thrust, cutting it obliquely and passing into the eastern Carpathian Foredeep. The spatial arrangement of such zones showing alternatively uplifting/subsiding tendencies suggests that one of the main driving forces leading to Quaternary tectonic deformations is that resulting from the relaxation of remnant horizontal stresses, built up during the late Neogene thrusting.

Neotectonics and Paleoseismicity within the Stockholm intracratonal region in Sweden

Abstract A number of sites with fresh faults and fractures have been mapped in detail. Their postglacial (and sometimes late glacial) age is confirmed. They form simple and similar patterns consistent with stress release due to a combination of acting forces. They are associated with the peak rate of glacial isostasy and increased strain rates by two orders of magnitude. They often cut straight across bedrock hills between so-called weak zones. The fault throws correspond to approximately magnitude 7 on the Richter scale. Sedimentary and morphological data confirm the seismo-tectonic origin. Newly discovered large-scale network of crossing faults is found to have changed the course of the Stockholm esker in a way that reveals at least two major seismo-tectonic events. This is consistent with paleoseismic events of magnitude 7 or more.

Quaternary exhumation of the Carpathians: a record from the Orava-Nowy Targ Intramontane Basin, Western Carpathians (Poland and Slovakia)

Quaternary exhumation of the Carpathians: a record from the Orava-Nowy Targ Intramontane Basin, Western Carpathians (Poland and Slovakia) The Neogene-Quaternary infill of the Orava-Nowy Targ Intramontane Basin comprises two tiers showing contrasting lithologies. The Neogene tier is largely composed of claystones and siltstones, whereas the Quaternary tier is dominated by gravels. The two sequences are separated by an erosional surface underlain by a regolith. Deposition of the Neogene sequence took place during subsidence of the basin. No prominent relief existed in the area of the present-day mountains actually surrounding the basin at that time. The regolith started to form at the onset of basin inversion. Still, no prominent relief existed in the present-day mountains. The onset of deposition of Quaternary gravels in the basin corresponds to acceleration of uplift of the surrounding mountains, which has been continuing until now. The Pieniny Klippen Belt has been subject to erosion, at least locally, from the deposition of the basal part of the Neogene sequence filling the Orava-Nowy Targ Basin until present times. In contrast, the Paleogene cover of the Tatra Mts was removed only during the Quaternary.

Cenozoic stress field and jointing in the outer West Carpathians, Poland

Abstract The Polish segment of the outer Carpathians fold-and-thrust belt is composed of a number of North-verging nappes. Preliminary studies of joint patterns within different lithostratigraphic units of these nappes, as well as within discordantly overlying younger strata, enable one to constrain the Late Cretaceous through Quaternary stress fields of that region. In the medial segment of the area studied, joints have been analysed in several nappes, most of the data coming from the Magura Nappe. In the latter one, joint pattern suggests diversified orientation of the reconstructed maximum stress axes, depending on the age of strata. The maximum stress axis inferred from the position of the acute bisector between conjugate Coulomb-shear or hybrid-shear fractures is oriented N-S within the Turonian-Campanian, NNE-SSW in the Maastrichtian, ENE-WSW in the Palaeocene, and NNW-SSE within the Eocene through Miocene strata. The maximum stress axes reconstructed for post-Cretaceous strata of other nappes in the eastern part of the area studied are oriented NNE-SSW to NE-SW, being nearly perpendicular to the fold axes. On the other hand, the Pliocene molasses of the Inner Carpathians display joint patterns indicative of the NE-SW oriented maximum stress axis, which coincides with that in the eastern segment of the Polish outer Carpathians, both in the Paleogene strata and in the unconformably overlying Middle Miocene molasses.

Late neogene-quaternary tectonics of the polish Carpathians in the light of neotectonic mapping

Abstract A new neotectonic map of the Polish Carpathians, constructed on the basis of morphometric, geological, geophysical and geomorphological data, is presented. A number of morphostructures, dependent upon faults, deep crustal fractures, the thickness of flysch deposits and geophysical properties of the Carpathian substratum, have been distinguished. Neotectonic movements are regarded as being Badenian-Sarmatian and Plio-Quaternary in age, their amplitudes ranging from 2000 to 500 m. The observed neotectonic differentiation of structural elements is the combined effect of the mobility of the Carpathian substratum and of horizontal movements of the flysch nappes.

Neotectonics versus gravity and crustal thickness: a case study of the polish Flysch Carpathians

Abstract Plio-Quaternary tectonic activity of the Outer Northern Carpathians results from isostatic adjustment to diachronous nappe thrusting in the late Neogene, possible motions of various blocks in the Carpathian substratum and/or relaxation of horizontal remnant stresses along the fronts of thrust sheets. Tectonic activity of this area in the Quaternary has been relatively weak. The amount of excessive stress is only 11–13 MPa, the rate of present-day vertical movements varies from −1 to +2 mm/yr, and the average intensity of earthquakes ranges from IV to VI, Mercalli scale. Neotectonic phenomena seem to reflect isostatic rebound, suggested also by linear relationships between crustal thickness, heat flow and recent crustal movements.

Neotectonic movements in the carpathians

Abstract This article discusses the main results of neotectonic investigations in the Polish Carpathians. Longitudinal elevations and isolated blocks have been uplifted at different rates, ranging from 0.05 to 0.3 mm/yr. Intramontane basins and longitudinal depressions reveal subsidence attaining 0.12 mm/yr. Present-day velocities of vertical movements attain 3 mm annually while the contemporary thrusting of the Carpathians onto their foreland is from 2 to 6 mm/yr. Four Quaternary episodes of increased tectonic activity have been distinguished: at the Pliocene—Pleistocene boundary, in the Early Pleistocene, before the Matuyama—Brunnes boundary and during the Holsteinian Interglacial. The latter is thought to be the most prominent.

Neotectonic movements of the polish west carpathians

Summary The article deals with neotectonic movements which have been affecting the Dunajec drainage basin (Polish West Carpathians) since the Sarmatian. The amount and intensity of these movements varied considerably, attaining in the Quaternary 100 – 160 m. A number of blocks showing different neotectonic adjustment to the Carpathian basement were distinguished. The Plio-Pleistocene tectonics of the West Carpathians reflects tectonic mobility of the flysch substratum, being related to still continuing backward thrusting of the East-european Platform under the Carpathian orogene.