Wyniki wyszukiwania - Biblioteka Nauki

1

Evidence for differential crustal uplift between the neighbouring Kamienica and Ochotnica river valleys in the Polish Outer Western Carpathians

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Olszak J.

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tom Vol. 79, No 2

187-193

EN

Young tectonic movements in the Carpathians, both vertical and horizontal ones, display local varia- tions. The Dunajec River valley is one of the areas where this differentiation has been documented best. New data on differentiated tectonic uplift, based on the study of changing elevations of five levels of fluvial strath terraces, were obtained in the lowermost reaches of two Dunajec’s tributaries: Kamienica and Ochotnica. The results indicate a change in the rate of valley bottom incision during the Pleistocene. Initially, the rate of incision was higher in the Kamienica River valley during ca. 600–350 ka BP. Later, since ca. 130 ka BP until now, the proportion became reversed and the rate of incision was nearly twice as fast in the Ochotnica River valley than in the Kamienica River valley. This is probably related to the mobility of the overthrust of the Krynica slice onto the Bystrica slice, both building the inner portion of the Magura Nappe. Reactivation of this thrust may be a result of neotectonic activity of large-scale faults situated at the depths of 5–20 km and possibly rooted in the Palaeozoic– Mesozoic basement.

2

Cenozoic dynamics of the Dębina Salt Dome, Kleszczów Graben, inferred from structural features of the Tertiary-Quaternary cover

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Hałuszczak A.

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tom Vol. 74, No 3

311--318

EN

The Dębina Salt Dome (DSD) is located in the central part of the Tertiary Kleszczów Graben, between the open-cast brown coal mines: "Bełchatów" and "Szczerców". Complicated geological features of the DSD are related to the polyphase tectonic activity in the Kleszczów Graben, and the salt structure dynamics which is believed to be coupled with that activity. The distinctive anticlinal elevation of the sedimentary cover of the DSD points to Cenozoic uplift of the salt. The timing of these salt pulses can be considered as related to main phases of tectonic activity in the Tertiary and Quaternary, well-documented during field studies in the brown coal open mine "Bełchatów". Due to the Middle/Late Tertiary salt uplift, a vast asymmetric anticline of up to 400 m amplitude was formed in the Early Miocene sandy and coaly sediments, including the so-called main coal seam. Renewed salt movements of the DSD occurred in the Quaternary. Considering the magnitude of the top-Tertiary surface elevation versus preliminary dating of this activity, it is concluded that the rate of the salt uplift was about 0.3 mm/ year, with the strain rate estimated at 4 x 10-14 s-1. Both parameters show relatively fast Quaternary salt movements of the DSD, being representative for the diapir rise active phase (from 10-14 s-1 to 10-16 s-1 ).

3

Neotectonics and planation surfaces in the High Bieszczady Mountains (Outer Carpathians, Poland )

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Kukulak J.

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tom Vol. 74, No 3

339-350

EN

The interfluves and slopes of the High Bieszczady Mts., SE Poland, bear flat surfaces that are both structurally-controlled and represent fragments of planation surfaces. More extensive are planated surfaces that can be associated with the intramontane, foothills, and riverside levels of planation. The oldest planated surfaces are most numerous in the most elevated parts of the Bieszczady Mountains. Older surfaces display traces of relief rejuvenation, including steps and minor ridges developed upon thick-bedded sandstones. These planated levels display relief energy of 50-100 m, increasing within older landforms of that type. Locally occurring rolling topography of structurally-controlled flat surfaces appears to result from tectonic undulations and the presence of fault zones. Strong structural control dominating the topography of the Bieszczady Mts. obliterates any possible young tectonic influcences upon development of flat surfaces on the slopes.

4

Neotectonic activity and present-day sea coast morphodynamic

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Piotrowski A. , Latałowa M. , Relisko-Rybak J. , Musielak S. , Łabuz T. , Wochna-Bartnik S. , Schiewe M. , Krzymińska J. , Dobracki R.

Biuletyn Państwowego Instytutu Geologicznego

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2007

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tom nr 424, guide book

57-83

5

Neotectonics of the Polish Outer Carpathians: some insights from geomorphic studies

100%

Zuchiewicz W.

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tom nr 396

170-170

6

Neotectonics of Poland: an overview of active faulting

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Zuchiewicz W. , Badura J. , Jarosiński M.

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2007

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tom Vol. 24

5-20

EN

Neotectonic studies in Poland concern mainly manifestations of those tectonic movements that have been active in Late Neogene and Quaternary times, as well as geodetically measured recent vertical and horizontal crustal motions. Among problems of particular interest, the following should be listed: periodicity of neotectonic (mostly Quaternary) activity, estimation of the parametres of the neotectonic stress field, amplitudes and rates of Quaternary and recent movements, development of neotectonic troughs and young faults, mutual relationships among photolineaments, geological structures and recent seismicity, as well as the role of tectonic reactivation of fault zones due to human activity. Neotectonic faults in Poland have developed in Neogene and Quaternary times due to reactivation of Laramian or older structures, or in the Quaternary due to reactivation of Neogene faults. The size of throw of Quaternary faults changes from 40-50 m and >100 m in the Sudetes and the Lublin Upland, to several - several tens of metres in the Carpathians. The average rate of faulting during Quaternary times has been 0.02 to 0.05 mm/yr, what enables one to include these structures into the domains of inactive or low-activity faults. A similar conclusion can be drawn from the results of repeated precise levellings and GPS campaigns. Strike-slip displacements have been postulated for some of these faults. Isolated faults in Central Poland have shown middle Quaternary thrusting of the order of 40-50 m, and some of the Outer Carpathian overthrusts tend to reveal young Quaternary activity, as indicated, i.a., by concentrations of fractured pebbles within the thrust zones. Episodes of increased intensity of faulting took place in the early Quaternary, in the Mazovian (Holsteinian) Interglacial, and during or shortly after the Odranian (Drenthe) glacial stage. Some of the faults have also been active in Holocene times. Recent seismic activity is often related to strike-slip faults, which in the Carpathians trend ENE-WSW and NE-SW, whereas outside the Carpathians they are oriented parallel to the margin of the East-European Platform and the Sudetic Marginal Fault. Future investigations should put more emphasis on palaeoseismotectonic phenomena and practical application of neotectonic research.

7

Fractured clasts in neotectonic reconstructions: an example from the Nowy Sącz basin, western outer Carpathians, Poland

100%

Tokarski A. K. , Świerczewska A. , Zuchiewicz W.

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2007

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tom Vol. 24

47-52

EN

This paper presents the results of a detailed analysis of fractured clasts hosted within Miocene and Pleistocene paraconglomerates that are exposed close to a map-scale overthrust. Both these paraconglomerates bear numerous fractured clasts (22-50%). The architecture of fractures (joints and minor faults) is well-organized and independent of both clast orientation and the degree of clast roundness. The fractures were formed in situ, most probably due to neotectonic activity of the map-scale overthrust. The number of fractured clasts is positively correlated with the clast size, and negatively correlated with the grain-size of clasts of detrital rocks. The number of fractured clasts increases in clasts of detrital rocks, compared to those of quartzites and magmatic rocks.

8

Plio-Pleistocene wrench tectonics in the Western Sicily Chain

100%

Nigro F. , Renda P.

Annales Societatis Geologorum Poloniae

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1999

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tom Vol. 69, No. 3-4

99-112

EN

Western Sicily represents a fragment of the Apenninic-Maghrebian Chain, largely built during the Miocene and formed by a set of tectonic units with southern vergence of folds and ramp-flat style of thrust surfaces. The thrust tectonics-related structures are displaced by a high-angle fault system, which bounds the main Mesozoic "carbonatic massifs" and generally interpreted as a neotectonic dip-slip extensional tectonics-related faults. The present paper, with the support of mesostructural analysis, presents an important Plio-Pleistocene strike-slip tectonics, represented by high-angle net- and strike-slip fault system. Different scale flower structures and associated fold systems, which cut the Miocene tectonic units, characterise the areas along the main transcurrent fault zones. Strike-slip neotectonics is mostly represented by right-lateral NW-SE/W-E and left-lateral N-S/NE-SW transcurrent faults, which may represent a W-E trending deep-seated Riedel system connected to the Tyrrhenian spreading. The NW-SE first order synthetic structures appear to control the opening of several rhomboidal tectonic depressions located in north-western Sicily and its offshore, and are counteracted by W-E trending transpressional structures located in the central Sicily mainland. An attempt at semi-quantitative restoration shows the neotectonic evolution of north-western Sicily during the Pliocene and Pleistocene, characterised by the progressive activation towards the east of en-échelon strike-slip fault strand, in an overall horsetail splay geometry, which produced releasing bends in off-shore and restraining bends in the mainland.

9

Tectonics of the Upper Nysa Kłodzka Graben, the Sudetes

100%

Badura J. , Rauch M.

Geologia Sudetica

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2014

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tom Vol. 42

137--148

EN

The Upper Nysa Kłodzka Graben is a geological unit well identifiable on geological, topographical and digital elevation model (DEM) maps. Tectonic activity in the area dates back to the Late Cretaceous, when the frames of the tectonic trough were formed due to the uplift of the Śnieżnik Massif Range in the east, Krowiarki Mts. Range in the north and the Bystrzyca Mts. and Orlicka Mts. ranges in the west. The total vertical displacement between the deepest locations in the graben and the highest peaks in the Śnieżnik Range varies between 1200 and 1700 m. The vertical differences in topographical relief of the graben basement exceed 500 m. Although the Upper Nysa Kłodzka Graben extends NNW–SSW, concordantly with the trend of mountain ridges in the Śnieżnik Range, subordinate tectonic structures within the graben trend N–S in its southern part near Králíky and NW–SE in the middle and northern parts. The trends of the subordinate tectonic structures are, thus, parallel to the main mountain ranges in the Orlica Mts., Bystrzyca Mts. and Krowiarki Mts. The most intensive vertical movements took place in the Late Touronian, Coniacian, at the turn of the Creataceous and Tertiary, in the Paleogene and Early Neogene. Although the Late Neogene and Quaternary activity in this area is not well documented, the vertical displacement along faults is assessed at ~70 m. The presence of volcanic rocks covering river gravels in Lądek Zdrój, thermal and mineral springs as well as the occurrence of minor earthquakes in historical times point to tectonic activity also in the Pleistocene. Recent tectonic activity in the Upper Nysa Kłodzka Graben area is evidenced by geodetic measurements and microseismicity recorded over the adjacent East Sudetes area.

10

The role of neotectonics in the Quaternary evolution of the landscape of the Sowie Mts, Sudetes, southwestern Poland

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Krzyszkowski D. , Olejnik W.

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tom Vol. 31, nr 2

221-239

EN

The Sowie Mts range comprises distinct morphological features that may be related to active tectonics. These are large-scale scarps up to100-200 m high, with triangular facets, at the Sudetic Marginal Fault, which separates the mountain range from its foreland; stepped morphology in the mountain interior with 100-300 m high scarps between flat surfaces; and straight, asymmetric valleys. The last two features are related to differently oriented faults. Meso-scale tectonically induced morphological features are represented by localised steepening of longitudinal valley profiles at fault lines (breaks, knickpoints), distinct downstream divergence of terraces, offset terraces, and the formation of fault scarps, basal scarplets beyond the valleys, frequent occurrence of alluvial fans and their onlap, and stream deflections at the Sudetic Marginal Fault. Apart from incipient Neogene offset, two phases of subsequent Quaternary tectonic uplift are possible. Total neotectonic uplift of the Sowie Mts range is about 100-300 m and, most probably, major tectonic activity took place during the Early Pleistocene. Late Pleistocene uplift was much less (10-40 m), although it is much better documented. The late Pleistocene tectonic activity was related to post-early Saalian glacio-isostatic rebound. Generally, the central part of the Sowie Mts was uplifted at least twice as much as the northern and southern area during each tectonic event. As a result, all geomorphic surfaces, including the flat surfaces, are deflected, and the height of the large-scale scarps, valley fault scarps, basal scarplets and knickpoints in the valley longitudinal profiles changes regionally.

11

Late Quaternary evolution of the Nysa Kłodzka river valley in the Sudetic Foreland, southwestern Poland

100%

Przybylski B.

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tom Vol. 31, nr 2

197-211

EN

The late Quaternary Nysa Kłodzka river terrace system has developed since the retreat of the Early Saalian (Odranian) ice sheet, which entirely covered the Sudetic Foreland and partly the Sudetes Mts. There are four terraces in the river valley, where the oldest one, the Upper Terrace, developed during and immediately after the ice sheet retreat, other terraces were deposited during the subsequent cold and warm stages, Wartanian, Weichselian and the Holocene. At the initial stage, the present river valley formed at the margin of retreating ice sheet. Later, the valley developed due to several erosion and sedimentation phases. The Nysa Kłodzka river flows through a zone of moderate to distinct tectonic activity, which is confirmed by seismic activity and recent crustal movements in the eastern part of the Sudetic Foreland. The neotectonic movements influenced much the evolution of morphology of this zone throughout the Quaternary and led to the shaping of the valley into its current form. During the late Quaternary, neotectonics could have been strenghten due to post-glacial isostatic rebound. These vertical movements disturbed the terrace system of the Nysa Kłodzka river valley, with the strongest terrace tilt in the Upper Terrace level, but less deflections visible even in the Holocene terrace levels.

12

Geomorphic evolution of the mountain front of the Sudetes between Dobromierz and Paszowice and adjacent areas, with particular reference to the fluvial systems

88%

Migoń P. , Krzyszkowski D. , Gogół K.

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tom Vol. 31, nr 2

289-305

EN

The morphology of the marginal part of the Sudetes between Dobromierz and Paszowice reflects above all lithological and structural differences within bedrock. Major landforms include watershed surfaces of low relief, monadnocks and intramontane basins. Drainage pattern changes were associated with the decay of the early Saalian (Odranian) ice-sheet, whilst stages of further development of fluvial systems are well documented by multiple terrace levels. The mountain front of the Sudetes, genetically related to the Sudetic Marginal Fault, is only up to 100 m high and overall strongly degraded. In contrast to southern sectors of the Sudetic mountain front, active Quaternary tectonics played minor part in the landscape development.

13

Late Cainozoic evolution of the Nysa Kłodzka river system between Kłodzko and Kamieniec Ząbkowicki, Sudetes Mts, southwestern Poland

88%

Krzyszkowski D. , Przybylski B. , Badura J.

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tom Vol. 31, nr 2

133-155

EN

The Nysa Kłodzka river drainge basin in the Sudetes Mts, SW Poland, preserves a complex late Cainozoic sequence that includes eight fluvial series/terraces and deposits from two glacial episodes as well as locally volcanic rocks, slope covers and loess. Sedimentation took place during the late Pliocene and since early Middle Pleistocene (Cromerian), with a long erosion phase (hiatus) during the Early Pleistocene. Fluvial series occur in the late Pliocene, Cromerian, Holsteinian, late Saalian/Eemian, Weichselian and the Holocene. Glacial deposits are represented in the early Elsterian and early Saalian stages. The main tectonic uplift and strong erosion was during the Early Pleistocene, with displacement about 60-70 m. Tectonic uplift was documented also for the post-Elsterian and the post-early Saalian time, and these uplift phases are most probably due to glacio-isostatic rebound. The Quaternary terrace sequence has been formed due to base level changes, epigenetic erosion after glaciations and neotectonic movements. The Cromerian fluvial deposits/terraces do not reveal any tectonic influence. However, all other Quaternary terraces indicate clear divergence, and the post-early Saalian terraces also offset by fault scarps. The total Late Pleistocene displacement along the fault scarps is about 25 m. The fluvial pattern is stable, once formed during the Pliocene, it continued in the same place until recently, with only minor changes along the uplifted block surrounding the Bardo gorge which infers the antecedent origin of the Bardo gorge. During the post-glacial times, epigenetic incisions have only slightly modified the valley.

14

Terraces of the Bystrzyca river valley, Middle Sudetes, and their deformation along the Sudetic Marginal Fault

88%

Krzyszkowski D. , Biernat J.

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tom Vol. 31, nr 2

241-258

EN

There are three stages in the evolution of the Bystrzyca river valley, dated to the Pliocene, the Early to late Middle Pleistocene, and the late Middle Pleistocene to recent. The Pliocene landscape was flat to hilly, with a weakly developed margin of the mountains. The valleys were shallow and wide, most probably with sinuous rivers, and are today represented by the 100-120 m high terrace. The scarp of the Sudetic Marginal Fault and the mountain landscape with deeply incised valleys were not formed until the Early Pleistocene tectonic phase, during which the uplift was about 60-70 m. The late Middle to Late Pleistocene stage of the valley development may be subdivided into several sub-stages, during each of which, one of three morphogenetic factors, namely fluvial activity, glacial erosion and sedimentation and tectonic uplift, prevailed. Five fluvial terraces have been found, one formed before glaciation and the other four during the post-glacial times. The valley was glaciated only once, during the early Saalian (Odranian) stage. The total postglacial uplift was about 40-50 m and fluvial activity that time was influenced by varying uplift rates. At first, erosion prevailed due to strong glacio-isostatic uplift. Then, it diminished quickly and was replaced by more localised tectonic uplift, which decreased with time. As a result, fluvial activity in the mountains and in the foreland became different, as is highlighted by the increased thickness of fluvial deposits in the foremoutain zone, the rapid change of terrace height, formation of a distinct, 25-30 m high, fault scarp along the Sudetic Marginal Fault, and the increased erodibility along the fault lines.

15

Geomorphological evidence of neotectonics in the Kaczawa sector of the Sudetic Marginal Fault, southwestern Poland

88%

Migoń P. , Łach J.

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tom Vol. 31, nr 2

307-317

EN

The Kaczawa sector of the marginal escarpment of the Sudetes Mts is 80-120 m high and separates upland denudation surfaces, probably Late Miocene in age, and flat foreland surfaces underlain by Cainozoic sediments. Genetically the scarp is related to the course of the Sudetic Marginal Fault. Scarp dissection by short, deeply incised valleys was the response to the Pliocene-Early Quaternary uplift of the Sudetes Mts relative to their foreland. Evidence for tectonic activity during the Late Quaternary is equivocal. Deformations of terrace levels have not been recorded whilst upper valley slope benches apparently cut off at the mountain front do not bear an alluvial cover.

16

Neofractures versus inherited fractures in structural analysis : A case study from Quaternary fluvial gravels (Outer Carpathians, Poland)

88%

Tokarski A. K. , Świerczewska A.

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tom Vol. 75, No. 1

95--104.

EN

This paper presents the results of a detailed analysis of flysch-derived clasts within Quaternary fluvial gravels exposed close to a map-scale overthrust. These clasts are commonly fractured. For a given population of clasts, the number of fractured clasts is positively correlated with the clast size and negatively correlated with the grain size of clast-forming rocks. The fractures comprise both those inherited from earlier joints cutting source strata, and those formed in situ within the gravels (neofractures). These two groups of fractures show different diagnostic features. The inherited fractures are orientated at random in relation to geographic coordinates, where as the neofractures show a well-organized architecture. The inherited fractures are mostly inclined 80–90° to the a-b planes of the host clasts, whereas the neofractures are usually inclined at 0–80° to these planes. The occurrence of neofractured clasts within the analysed gravels results from tectonic activity post-dating gravel deposition.

PL

W czwartorzędowych żwirach rzecznych odsłoniętych w pobliżu regionalnego nasunięcia w polskich Karpatach Zachodnich powszechnie występują spękane klasty skał fliszowych. W analizowanym materiale klasty skał drobnoziarnistych są częściej spękane, niż klasty skał gruboziarnistych. Obserwuje się też dodatnią korelację pomiędzy liczbą spękanych klastów a ich wielkością. Wśród spękań występują spękania odziedziczone po spękaniach ciosowych tnących skały macierzyste oraz neospękania, które powstały in situ w żwirach. Te dwie grupy spękań cechuje różna orientacja w stosunku do współrzędnych geograficznych oraz do powierzchni a-b klastów, tj. płaszczyzny zawierającej oś o maksymalnym (a) i pośrednim (b) wymiarze. Spękania odziedziczone są zorientowane chaotycznie w stosunku do współrzędnych geograficznych, podczas gdy orientacja neospękań jest uporządkowana. Spękania odziedziczone są zorientowane niemal pionowo (80-90°) względem powierzchni a-b klastów macierzystych, natomiast neospękania są zorientowane pod katami 0-80° do tych powierzchni. Pochodzenie neospękań jest wynikiem aktywności tektonicznej, która miała miejsce po osadzeniu analizowanych żwirów.

17

The role of neo-tectonics in the variation of the relative mean sea level throughout the last 6000 years on the Taman Peninsula (Black Sea, Azov Sea, Russia)

75%

Fouache E. , Porotov A. , Müller C. , Gorlov Y.

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tom Vol. 11

47-57

EN

Sediments, carbon-datings on seashells, allow us to reconstruct the evolution of the average sea level for some 6000 years on the Taman Peninsula. The current sea level, regionally, appears to be the highest level ever reached on the peninsula. It seems that for the Anapa area and Tchouchtchka Spit area it is possible to propose a sea level curve characterised by a slow, continuous rising during the past 6000 years. On the Taman Peninsula itself, the sedimentary record of this slow ascent has been distorted by a heavy tectonic subsidence. We have identified this neo-tectonic subsidence effect on at least two areas on the peninsula. The south of the peninsula, Burgaz Spit and Vityazevos Lagoon, is the most affected area. The Taman Gulf is an intermediate area. The tectonic subsidence is particularly noticeable from 1500 to 500 BC, which we believe to have been misinterpreted until now, and to be at the origin of the notion of "Phanagorian Regression".

18

The pattern of surface deformations in the Dąbrowa Basin (Poland) based on PSInSAR analysis

75%

Leśniak A. , Porzycka-Strzelczyk S.

Geological Quarterly

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2020

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tom Vol. 64, No. 2

304--318

EN

Slow, long-term ground deformations in the Dąbrowa Basin (southern Poland) were identified based on ERS-1, ERS-2 and ENVISAT Synthetic Aperture Radar (SAR) images that were processed by means of Permanent Scatterer SAR Interferometry (PSInSAR). The Dąbrowa Basin is a region where two major factors can affect surface stability: intensive coal exploitation and neotectonic processes. In this study, in order to clarify the origin of surface deformations, the authors propose applying a newly developed algorithm of spatio-temporal PSInSAR data analysis. This analysis revealed that subsidence is a characteristic feature of the Dąbrowa Basin. A significant correlation exists between slow, long-term ground deformations and the location of the main tectonic structure of this region. The proposed spatiotemporal analysis of the PSInSAR data additionally showed some degree of correlation between mining activity and the studied deformations. This interconnection is a significant achievement of this study since the deformation values determined by means of PSInSAR were identified in earlier works solely on the basis of Dąbrowa Basin neotectonics.

19

Geodynamika i neotektonika polskich Karpat zewnętrznych

75%

Zuchiewicz W.

Przegląd Geologiczny

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2001

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tom Vol. 49 nr 8

710-716

PL

Polskie Karpaty zewnętrzne reprezentują pasmo fałdowo-nasuwcze, zbudowane z płaszczowin nasuniętych ostatecznie na siebie w środkowym i późnym miocenie. Neotektoniczna (plioceńsko-czwartorzędowa) aktywność tego obszaru przejawiała się w: deformacjach plioceńskich i wczesnoczwartorzędowych powierzchni częściowego zrównania, spaczeniu i pochyleniu cokołów skalnych czwartorzędowych teras rzecznych, zróżnicowanym tempie rozcinania cokołów skalnych jednowiekowych teras rzecznych w obrębie różnych jednostek fizjograficznych, wzmożonej akumulacji w obniżanych zapadliskach śródgórskich oraz zachodniej części zapadliska przedkarpackiego, powstaniu nielicznych czwartorzędowych uskoków normalnych w osadach stokowych i rzecznych, jak również umiarkowaną sejsmicznością w południowej części badanego obszaru. Strefy wykazujące tendencje wypiętrzające są stosunkowo wąskie, a układają się subrównolegle do czół głównych nasunięć i złuskowanych fałdów. Kulisowy układ tych stref, nieco odmienny w zachodniej i wschodniej części Karpat zewnętrznych zdaje się sugerować obecność młodych ruchów lewoprzesuwczych wzdłuż strefy uskokowej Kraków–Lubliniec w podłożu nasuniętych płaszczowin karpackich.

EN

The Polish Outer Carpathians represent a fold-and-thrust belt, composed of a stack of nappes that were finally emplaced during the middle-late Miocene times. The neotectonic (Pliocene-Quaternary) activity of this area is evidenced by: deformed ero-sional surfaces of Pliocene and early Quaternaiy age, upwarped/downwarped/tilted strath and complex-response Quaternary terraces, drainage pattern changes, diversified rates of fluvial downcutting in different units during the same time-span, increased accumulation in subsiding intramontane basins and in the westernmost part of the Carpathian Foredeep, few examples of Late Quaternary faulting of fluvial and slope sediments, young jointing within Pliocene molasses in intramontane basins and those of early Quaternaiy age in the Carpathian foredeep, as well as by historical records of minor seismicity, usually confined to the Pieniny Klippen Belt and some oblique-slip faults that cut the inner parts of the Outer Carpathians, of magnitudes not exceeding 5.0 on the Richter scale. The zones showing tendencies to Recent uplift tend to be aligned subparallel to frontal thrusts of individual nappes and larger slices, suggesting the presence of Plio-Quaternary horizontal stresses in the flysch nappes. En echelon arrangement of theses zones, however, slightly different in the western and eastern parts of the study area appears to indicate young sinistral motions along the Kraków-Lubliniec fault in the substratum of the overthrust nappes.

20

Topography of the Magura floor thrust and morphotectonics of the Outer West Carpathians in Poland

75%

Zuchiewicz W. , Oszczypko N.

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tom Vol. 78, No 2

135-149

EN

Neotectonic (Pliocene-Quaternary) elevations and depressions detected on maps of subenvelope surfaces of the topography of the Outer West Carpathians of Poland are, to a certain extent, portrayed on the map showing topography of the Magura floor thrust, particularly in the western segment of the study area. The floor thrust of the Magura Nappe is highly uneven, its position changing from 725 m a.s.l. to more than 7,000 m b.s.l. The most prominent depression is located in the medial (S of Dunajec and Poprad confluence) segment of the Polish Outer Carpathians (2-7 km b.s.l.), and its axis trends NW-SE from the eastern margin of the Mszana Dolna tectonic window to the Poprad River valley. Another, much more shallower, Jordanów depression (2 km b.s.l.) is to be found NW of the Mszana Dolna tectonic window, shortly north of the Skawa River valley. Elevated structures, in turn, include the Mszana Dolna tectonic window, Sól-Skomielna (on the west), and Limanowa (on the east) elevations of subparallel orientation. Still farther to the east, a longitudinal elevation extending between the Klęczany-Pisarzowa and Świątkowa tectonic windows is to be seen some 10-15 km south of the Magura frontal thrust. South of this area, the Magura floor thrust slopes steeply down to more than 4 km b.s.l. A comparison between the pattern of elevated and subsided structures of the Magura floor thrust and subenvelope surfaces of different orders shows that in the western part of the Polish Outer Carpathians the highest-elevated neotectonic structures (in the southern portion of that area) coincide with depressions of the Magura thrust, whereas farther north a reverse pattern becomes dominant: neotectonic elevations coincide either with the Magura frontal thrust or with elevations of its surface. This is particularly true for an area comprised between 20° and 20°30’E meridians. The origin of such relationships is difficult to explain. We infer that one of possible factors could be Pliocene-Quaternary reactivation of faults cutting the Magura floor thrust, and particularly that one, which appears to separate the western-medial segment of the Outer Carpathians from their more eastern portion.