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1

Tectonics of the northern Carpathians basement in the light of electromagnetic and gravity data analysis

Stefaniuk Michał, Cygal Adam

Geotourism / Geoturystyka

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2023

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nr 1-2 (72-73)

67--67

EN

The northern part of the Carpathians covers the north-eastern area of the Western and north-western of the Eastern Carpathians. The basement of the Carpathians in this zone is of a transitional nature and is relatively poorly explored, which results from its deep burial, in particular under the so-called Outer Carpathians. The interpretation of the tectonics and geodynamics of the basement depends to a large extent on the analysis of large scale geophysical data. In this area, regional seismic surveys were carried out mainly using the so-called deep refraction and numerous geophysical works using gravity, magnetic, geomagnetic and magnetotelluric methods. The subject of the presented work is a review of the regional image of electromagnetic and gravity studies carried out in this area, with particular emphasis on the territory of Poland, within which the authors carried out numerous research works. Electromagnetic research allows for the construction of a regional model of basement resistivity distributions and the determination of general outlines of its geometry as well as the formulation or testing of the concept of its geodynamical interpretations. An auxiliary role in this aspect is played by gravity data allowing to recognize the density distribution of the basement and constituting a set of additional data for integrated interpretation. The area outside the territory of Poland was presented on the basis of literature data, creating an extensive regional background for the results of research related with the participation of the authors in Poland. Within the Polish Carpathians, there is a structural reconstruction of the Carpathian overthrust and its basement, as well as a clear change in the nature of geophysical fields, e.g. the system of gravity field anomalies. Due to the deep burial of the Carpathian overthrust in this area and the complex structure of the orogen, which hinder effective drilling penetration, its fragmentary and uncertain recognition is based mainly on geophysical surface studies. The complex structure of the orogen reduces the effectiveness of the use of the seismic reflection method, the participation of which is limited in practice to the recognition of the basement in the marginal zone of the Carpathian overthrust. In the remaining area, alternative methods of surface geophysics are used, i.e. the magnetotelluric and gravity method. An important role in recognizing the basement of the Eastern part of the Polish Carpathians was played by magnetotelluric soundings that cover the above mentioned area with a relatively dense network of several generations of measurement points. The results of the interpretation of the MT soundings were used to construct a resistivity model, which was verified by new results of regional processing of seismic data and magnetotelluric and gravity modelling. The visualization of resistivity distributions was presented through maps interpreted at selected depth levels and in the resistivity cross-sections form. Resistivity distributions are the basis for interpreting tectonic zones marked as resistivity contrasts. Forward modelling and inversion of gravity data were used to verify resistivity structural models.

2

Remnant Neo-Tethyan ocean from the Ladakh Himalaya: constraints on their nature, age and tectonic setting

Talat Ahmad, Bhat Irfan, Chauhan Hiredya

Geotourism / Geoturystyka

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2023

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nr 1-2 (72-73)

11

EN

The Indus and Shyok Suture Zones represent the remnants of the Neo-Tethyan ocean in terms of Nidar arc volcanics and Zildat ophiolitic melange in the eastern Ladakh, Dras Arc volcanics and Shergol ophiolitic melange in the western Ladakh along the Indus Suture Zone. The Shyok-Nubra ophiolitic volcanics of the northern Shyok suture zone, north of the Ladakh batholith, represent the remnant northern portion of the Neo-Tethyan. The Nidar-Dras arc volcanics represent intra oceanic arc that developed as the Indian plate was moving northwards around 140 My ago. These units preserve arc tholeiite, representing primitive arc which passed on to calc alkaline series as the arc matured. These rocks are characterised by depleted nature in terms of incompatible trace elements including rare earth elements and Sm-Nd isotopic characteristics. The Zildat-Shergol ophiolitic melanges are represented by N-MORB and Ocean Island Basalt (OIB) characteristics. These units have also preserved exotic blocks of limestone, physically mixed with other units of the ophiolitic melange. The Shyok-Nubra volcanics are represented by enriched trace elements and isotopic characteristics, very different from those of the Indus Suture zone. They don’t preserve ophiolitic melange, as observed in the Indus suture zone. Our tectonic model indicate double subduction of the Neo-Tethyan ocean, in the north it got subducted under the Tibetan plate giving rise to Andean type continental arc along the Shyok suture zone. In the south the Neo-Tethyan ocean got subducted under the same oceanic crust giving rise the intra-oceanic Mariana type subduction. Thus, in the Ladakh Himalaya there is preservation of almost all components of the Neo-Tethyan ocean preserving the N-MORB and OIB type magmatism in the melange zone. The Andean and Mariana type arc components indicating very different tectonic settings. Neo-Tethyan ocean appear to have all the components that we observe presently in the Pacific-Atlantic ocean. These data will be presented and elaborated during my presentation.

3

Factors controlling a depositional architecture in synorogenic Outer Carpathian basins – an example of Oligocene-age successions from the Fore-Magura Unit, Poland

Siwek Piotr, Waśkowska Anna, Wendorff Marek

Geotourism / Geoturystyka

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2023

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nr 1-2 (72-73)

62--63

EN

A Fore-Magura Unit is strongly tectonically-engaged tectonic unit of the Polish Outer Carpathians, sandwiched between Magura and Silesian nappes. Due to poor and sparse exposure of the Fore-Magura Unit, which is covered by the Magura Nappe, there has been no comprehensive interpretation of depositional systems of the Fore-Magura Basin (Eocene–Oligocene), a part of the Paratethys realm. Therefore, in order to broaden our knowledge about depositional conditions in this part of the Outer Carpathian basins, two turbidite sequences (Szczawa and Klęczany) were subjected to detailed lithofacies and sedimentological analysis. The 100 m thick Szczawa section is predominantly composed of thin and medium thick turbidite sandstones associated with co-genetic turbidite mudstones, which thickness greatly exceeds that of underlying sandstone. The latter ones show another peculiar features, like opposite palaeocurrent directions between base and top of a bed, mud-rich banded and heterolithic structures, and combined-flow bedforms, including small-scale hummocky-type structures. All those sedimentary features reflect deposition from mud-rich low-density turbidity currents enclosed within small confined basin, which prevent each flow from further down-current propagation, and eventually resulted in trapping (ponding) of the whole flow within confinement, a process associated with flow reflections and internal Kelvin-Helmholtz waves propagation (Siwek et al., 2023). This mini-basin can be situated on the southern flank of the Fore-Magura Basin, i.e., on the slope of the Fore-Magura Ridge (Siwek et al., 2023). The 170 m thick succession at Klęczany is composed of thick-bedded amalgamated sandstones, grading into sandstone-mudstone turbidite sequences. The former reflect deposition from high-density turbidity currents and hybrid flows, and are stacked into a few to over ten metres thick tabular lobes, and can be interpreted as lobe axis or distributary channel deposits. These lobes are often topped by socalled ‘bypass’ facies indicating the moment a lobe attained a critical thickness which prevented the accommodation of new deposit, thus heralding a feeder channel avulsion. The recurring process of lobe building and feeder channel avulsion resulted in compensational stacking of subsequent lobes (Piazza & Tinterri, 2020). The upper part of the Klęczany section reflects deposition from low-density turbidity currents and aggradation of turbidite beds into upward-thickening sequences resulting from lateral compensation and/ or forward progradation of subsequent lobes. Considered as a whole, the Klęczany succession is fining upward, and shows decrease of sand net-to-gross, accompanied by increase of more distal facies. Therefore, that depositional system can be situated within single submarine base-of-slope fan featured by retrogradational stacking pattern. Ponded turbidite beds, together with their whole inventory of sedimentary structures, are an evidence of the crucial influence of structural confinement on unrestricted flow propagation on the seafloor. The presence of structural confinement on the basin slope may have been associated with regional compression and tectonic activity of the Outer Carpathian basins. In the case of the Klęczany section, shortterm autocyclicity is manifested in compensational lobe stacking pattern and cyclic feeder channel avulsions. A longterm variability, probably covering the whole Fore-Magura realm, can be identified with one sequence stratigraphy cycle – from forced regression resulting from sea-level falling stage to sea-level lowstand, reflected in the transition from amalgamated massive sandstones to sandstone-mudstone turbidite sequences (Catuneanu, 2006). Alternatively, the uplift-denudation cycle due to tectonic activation of source area (Mutti et al., 2003) can be considered as an explanation of retrogradational stacking pattern of the Klęczany Fan, with eustatic sea-level fall involved (Pszonka et al., 2023). To conclude, the regional and local changes of depositional conditions in deep-water basins can be related to tectonics, as well as to eustatic short- or long-term sea-level changes, or combination of both, and can give the readable rock record in sedimentary successions accumulated especially in synorogenic marginal basins (Pszonka et al., 2023). These include foreland-type Outer Carpathians basins during Oligocene times, which were located in the Central Paratethys isolated from the Tethys Ocean during Eocene-Oligocene geotectonic reconstruction of the Circum-Carpathian realm.

4

Coevolution of Paleo-Tethys and Rheic: New tectonic constraints from Iran and Turkey

Chu Yang, Wan Bo, Lin Wei, Allen Mark B., Talebian Morteza, Uysal Ibrahim, Xin Guangyao

Geotourism / Geoturystyka

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2023

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nr 1-2 (72-73)

15--15

EN

In the Paleozoic, one large ocean once separated the Eurasia of the north and the Gondwana of the south, but it has two names, Paleo-Tethys and Rheic, suggesting different tectonic history. The Paleo-Tethys represent the ocean from east Asia to Middle East regions and vanished in Early Mesozoic, while the Rheic existed across the Europe and finally closed in Carboniferous. The two oceans coevolved for a long time, but the interaction and mutual effect at subduction and collision stages are not well understood. Initiation processes of ocean spreading, subduction and collision are crucial in plate tectonics, so resolving the timing for these turning points may greatly enhanced the precision and accuracy of reconstruction of the two oceans, especially for the western Paleo-Tethys. In NE Iran, we find that all the Paleozoic clastic rocks record two major zircon U-Pb age groups peaked at ~800 Ma and ~600 Ma. Consistency in age patterns show a dominant provenance from Neoproterozoic basement of the north Gondwana and a long-lasting passive margin sedimentation after the spreading of the Paleo-Tethys. This environment was interrupted by initial collision between the Turan (Eurasia) and Central Iran (Gondwana) Blocks with massive coarse clastic deposition, i.e. the protolith of the Mashhad Phyllite, in a peripheral foreland basin on the Paleozoic passive margin. The Mashhad Phyllite yields a striking provenance change from passive margin to active margin. The Paleozoic ages reveal a long-lived subduction zone at the south Turan Block initiated since the latest Ordovician. More importantly, the provenance shift better constrains the initial collision timing with the maximum deposition age of the Mashhad Phyllite (~228 Ma) refining the evolution history of Paleo-Tethys. Based on our new results and previous data, we compare the tectonic history of the Paleo-Tethys in its western segment with eastern Rheic, and further discuss the interaction between the Rheic and Paleo-Tethys. We find existence of a lateral subduction zone plays a crucial rule in initiating new subduction zone after an old oceanic plate vanishes and two continents collides, while a lateral collision can also result into shallowing of subducted slab and preservation of coeval compressional structures. These new insights help us to better interpret the emplacement of high-pressure metamorphic rocks during subduction and subduction zone jump when the Rheic and Paleo-Tethys coevolved.

5

The development and origin of the two-stage silicification of Upper Jurassic limestones from the northern part of the Kraków-Częstochowa Upland (Southern Poland)

Kochman Alicja, Matyszkiewicz Jacek

Geology, Geophysics and Environment

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2023

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Vol. 49, no. 3

225--243

EN

The Upper Jurassic carbonates representing the microbial-sponge megafacies in the area of the Kraków-Częstochowa Upland (KCU) were locally silicified. In the reclaimed Lipówki Quarry, in Rudniki near Częstochowa (in the northern part of the Upland), macroscopically different silicification products were observed in blocks of Upper Jurassic limestones, deposited as mining waste. Two varieties were distinguished: (i) chert concretions representing the I silicification stage and (ii) light-brown, silicified limestones infilling the fractures in chert concretions or forming the cortices around the concretions or forming irregular bodies, all representing the II silicification stage. The diagnostic features are the following: (i) macroscopic development, (ii) the presence of moganite exclusively in chert concretions and (iii) significant differences in crystallinity index (CI) values, namely: 0.1–0.7 for chert concretions and 6.0–6.6 for silicified limestones. The formation of chert concretions was initiated as early as in unconsolidated sediment, whereas the II silicification stage followed the chemical compaction of the limestones. The results of geochemical analyses of the products of both silicification stages indicated that the probable source of silica were the low-temperature hydrothermal solutions. Two types of fractures were found in the chert concretions, generated during different tectonic events. The older, open fractures were formed during the extension of the Late Jurassic sedimentary basin, which formerly occupied the territory of the more recent KCU. These fractures were infilled with unconsolidated, fine-detrital carbonate sediment, in which the concretions were embedded and finally silicified in the II silicification stage. The younger, closed fractures, transversal to those filled by the products of II silicification stage, along which small displacements are evident, document the later tectonic deformations presumably related to Cenozoic faulting.

6

Patterns, processes and models – an analytical review of current ambiguous interpretations of the evidence for pre-Pleistocene glaciations

Molén Mats O.

Geologos

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2023

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Vol. 29, No. 3

139--166

EN

Models (paradigms) and former interpretations have often been presupposed when conducting field research. In the 19th century diamictites were for the first time interpreted to have originated from ancient glaciations. These interpretations have to a large part prevailed in the geological community, although there has been much progress in the areas of sedimentology, glaciology and physical geography. The present work is an effort to find criteria which most clearly discriminate between geological features produced by different processes, mainly glaciation and mass flow, the latter predominantly sediment gravity flows. Geological features which have been interpreted to have formed by glaciation throughout pre-Pleistocene Earth history are compared to similar-appearing geological features formed by mass flow and tectonics, so as to uncover variations in the appearance between features resulting from these different processes. The starting point for this comparison is documentation of the appearance of Quaternary products of erosion and deposition, in order to discern the origin of older formations. It is shown that the appearance and origin of pavements, dropstones, valleys, small-scale landforms, surface microtextures and most other geological features may in some cases be equivocal, but in others the details are indicative of the process which generated the feature. Detailed geological field data which have been compiled by geologists from outcrops of pre-Pleistocene strata, more often than is considered in most papers, commonly point to a mass flow origin, mainly a sediment gravity flow origin, rather than a glaciogenic or- igin. A process of multiple working hypotheses or interpretations is therefore advocated, based mainly on a comparison of the appearance of features formed by different geological processes documented from different research disciplines. Instead of starting with current interpretations or models, this multiple working hypothesis or methodology helps to avoid confirmation bias and jumping to conclusions.

7

Stratigraphy and geological structure of the Magura Nappe in the south-western part of the Gorce Mountains, Outer Carpathians, Poland

Szczęch Mateusz, Waśkowska Anna

Annales Societatis Geologorum Poloniae

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2023

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Vol. 93, No. 2

103--136

EN

The south-western part of the Gorce Mts (Outer Carpathians) is composed of flysch deposits of the Krynica and Bystrica subunits of the Magura Nappe. The Krynica Subunit includes the Late Cretaceous–Paleocene Ropianka Fm, the Early Eocene Beloveža Fm, the Early Eocene–Oligocene Magura Fm and the Oligocene–Early Miocene Malcov Fm, while the Bystrica Subunit includes the Middle Eocene–?Oligocene Magura Fm, represented mainly by the thick-bedded Magura Sandstone. Thin- and medium-bedded sandstone-shale turbidites predominate in the other formations. The lithostratigraphic units are dated on the basis of foraminifers. The studied deposits accumulated in the southern part of the Magura Basin. Their detrital material was derived from a ridge, bounding the basin in the south. In the study area, the Krynica Subunit overthrusts the Bystrica Subunit. The studied deposits are folded, thrust and cut by numerous faults. The Turbacz Thrust Sheet and the newly identified Kudłoń Thrust Sheet were distinguished in the Krynica Subunit. Faults of different lengths and throws are transverse or oblique. Some of them form complex dislocation zones with lengths of up to several km. In general, the high-resolution digital elevation model DEM contributed significantly to progress in the geological and geomorphological research.

8

Zastosowanie metody K-Ar do oznaczenia wieku deformacji skał metaosadowych formacji Yargait terranu Zavkhan (Khasagt, Mongolia) : wstępne wyniki badań

Sikora Rafał, Wójcik Antoni, Szczerba Marek, Bazarnik Jakub, Madej Stanisław

Przegląd Geologiczny

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2021

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Vol. 69, nr 7

448--453

EN

The SW margin of the Zavkhan terrane is significant for research on Paleozoic amalgamation of the Central Asian Orogenic Belt (CAOB). The study area is located in the western part of the Khasagt Mountains, western Mongolia. We present a new preliminary K-Ar dating of metasedimentary rocks from the Yargait Formation which were deformed during collision of the Zavkhan terrane with the Lake Zone terrane. Our results include two dating that are similar to earlier data by other authors (Stípskáetal., 2010; Bold et al., 2016b). The first dating equal to 544.1 ±13.7 Ma can be interpreted as the age ofmetamorphism and the subduction of the SW margin ofthe Zavkhan terrane under the Lake Zone terrane during the late Ediacaran-early Cambrian. The second dating of 441.1 ±11.7 Ma indicates the Late Ordovician - Silurian regional extension event.

9

Ancient and modern anastomosing rivers: insights from sedimentological and geomorphological case studies of the Triassic, Neogene and Holocene of Poland

Kędzior Artur, Widera Marek, Zieliński Tomasz

Geological Quarterly

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2021

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Vol. 65, No. 4

art. no. 54

EN

We review the three regional anastomosing fluvial systems, both ancient and modern. The dinosaur-bearing upper Triassic succession in Krasiejów (S Poland) is composed of siltstones and claystones that are divided into three facies associations. One of the fluvial associations is characterized by features typical of a low-energy anastomosing river system in a tropical semiarid climate, interpreted as the result of accumulation in deep, wide and low-sinuosity palaeochannels with pronounced vertical accretion. Deposition from suspension predominated in flows of very low stream power. The upper Neogene muddy succession in a tectonically active area (Kleczew Graben, central Poland) includes a great number of fluvial palaeochannels filled with sand and/or mud. These ribbon-shaped fluvial bodies are deep and wide, and represent channels showing very lim ited lateral migration. They were filled mostly under low-energy condi tions, and their mapped course shows an “anabranching” pattern in plan view. The palaeochannels are transitional from sand- to mud-dominated. The Holocene upper Narew River (NE Poland) represents a modern anastomosing fluvial system. The interconnected channels form an anabranching pattern. The channels are straight to slightly sinuous, relatively deep and wide. Interchannel, low-lying “islands” are covered by peat-forming plants. Despite the low stream power, in-channel deposition is dominated by sand transported as bedload. The channel banks are stabilised by vegetation, which effectively prevents their lateral migration.

10

Differential and source terms locations of the 2015 Teresva (East Carpathians) series and their tectonic implications

Gnyp Andriy, Malytskyy Dmytro

Acta Geophysica

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2021

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Vol. 69, no. 6

2099--2112

EN

Earthquakes of the 2015 Teresva series have been relocated using differential arrivals only of their P-waves at the same set of seismic stations and source-specific station terms. At least six distinct groups had been identified in the series as a result of single linkage clustering analysis of cross-correlations between their waveforms. Differential arrivals were estimated separately in each group, and not directly relative to the master event, but through the chains of events with the largest cross correlations. Time drift at some Ukrainian stations had been detected by comparing intervals between the first P-waves from the same earthquakes at pairs of stations and taken into account, assuming a linear drift rate. The relocated epicenter of the main MSH3.5 earthquake was only~2.3 km to the east of the macroseismic one and almost exactly at the intersection of the two major local faults, perpendicular and parallel to the Carpathians arc. The almost linear alignment of the other earthquakes in azimuth~320° almost coincided with the parallel fault and with the nodal plane of the almost purely strike-slip focal mechanism estimated for the strongest earthquake from its first polarities at 26 stations, and by moment tensor inversion of the ground displacement amplitudes and duration of the first P-wave pulses at 18 stations. A very interesting oscillatory (cyclic) pattern of the epicenter migration along the SE–NW axis, obtained as a result of relocation, was also confirmed by variations in S-relative to P-wave delays: During the cycle, the epicenters gradually shifted to NW and at the beginning of the new cycle returned.

11

Tectonic-climatic interactions during changes of depositional environments in the Carpathian foreland: An example from the Neogene of central Poland

Widera Marek, Zieliński Tomasz, Chomiak Lilianna, Maciaszek Piotr, Wachocki Robert, Bechtel Achim, Słodkowska Barbara, Worobiec Elżbieta, Worobiec Grzegorz

Acta Geologica Polonica

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2021

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Vol. 71, no. 4

519--542

EN

Many geological problems have not been convincingly explained so far and are debatable, for instance the origin and changes of the Neogene depositional environments in central Poland. Therefore, these changes have been reconstructed in terms of global to local tectonic and climatic fluctuations. The examined Neogene deposits are divided into a sub-lignite unit (Koźmin Formation), a lignite-bearing unit (Grey Clays Member), and a supra-lignite unit (Wielkopolska Member). The two lithostratigraphic members constitute the Poznań Formation. The results of facies analysis show that the Koźmin Formation was deposited by relatively high-gradient and well-drained braided rivers. Most likely, they encompassed widespread alluvial plains. In the case of the Grey Clays Member, the type of river in close proximity to which the mid-Miocene low-lying mires existed and then were transformed into the first Mid-Miocene Lignite Seam (MPLS-1), has not been resolved. The obtained results confirm the formation of the Wielkopolska Member by low-gradient, but mostly well-drained anastomosing or anastomosing-to-meandering rivers. The depositional evolution of the examined successions depended on tectonic and climatic changes that may be closely related to the mid-Miocene great tectonic remodelling of the Alpine-Carpathian orogen. This resulted in palaeogeographic changes in its foreland in the form of limiting the flow of wet air and water masses from the south and vertical tectonic movements.

12

Strukturalne, litologiczne oraz tektoniczne uwarunkowania rozwoju i ewolucji świętokrzyskich skałek piaskowcowych

Urban Jan

Przegląd Geologiczny

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2020

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vol. 68, nr 2

112--126

EN

Majority of ca. 90 sites ofsandstone crag groups and individual crags, occurring in the Świętokrzyskie (Holy Cross) Mts. region, represent the following crag-forming lithostratigraphic units: Cambrian Wiśniówka Formation, Devonian Barcza Fm and Zagórze Fm, Triassic Zagnańsk Fm and Krynki Beds, as well as Jurassic Skloby Fm and Ostrowiec Fm. Specific features of these rocks are the occurrence of sandstone series, up to 20 m thick, above more plastic, clayey or heterolithic series, high-energy depositional environments, and siliceous composition. The crag-forming sandstones differ in the amount of siliceous cement: from strongly cemented Paleozoic quartzitic sandstones to porous Mesozoic sandstones with poor cement, which determines diverse mechanical properties. Strongly cemented Paleozoic rocks display high rock strength and abrasion resistance, while porous and theoretically friable Mesozoic sandstones are characterised by high grain packing due to compaction. Regarding the principal role of gravitational disinte¬gration of rock massifs under the periglacial conditions in the Pleistocene, other factors constraining the crag formation and shaping are the tectonic situation of rocks (orientation of strata and joints), adequate joint spacing, and bed thickness. The interrelations between lithological and structural features of crag-forming sandstones and tectonics, conditioning erosion and weathering rates are specific for particular types of these sandstones.

13

Wykorzystanie wyników badań współczesnej aktywności tektonicznej do oceny chwilowego poziomu zagrożenia zdarzeniem sejsmicznym na obszarach wydobywczych południowo-zachodniej Polski

Kaczorowski Marek, Rudnicki Marcin

Cuprum : czasopismo naukowo-techniczne górnictwa rud

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2020

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nr 2

5--15

PL

Zmiany tektonicznego pola naprężeń w jednostce Depresji Świebodzic są powodem skomplikowanej kinematyki bloków skalnych. Pole sił tektonicznych wytwarza efekty rotacji, ruchów poziomych i pionowych skalnych bloków rozdzielonych licznymi uskokami. System pomiarowy Laboratorium Geodynamicznego w Książu, składający się z instrumentów stojących na skalnych blokach, jest naturalnym detektorem aktywności tektonicznej. System ten pozwala na wyznaczanie chwilowych wartości funkcji aktywności tektonicznej z mikrometryczną dokładnością. Porównanie zmian funkcji aktywności tektonicznej i ich pochodnych z czasowym rozkładem zdarzeń sejsmicznych w obszarach Dolnego i Górnego Śląska wskazuje, że trzęsienia ziemi występują zgodnie ze szczególnymi i powtarzającymi się stanami procesu deformacji tektonicznych górotworu Depresji Świebodzic. Ta obserwacja wzmacnia tezę o istnieniu wielkoskalowego, jednorodnego pola naprężeń tektonicznych, którego zasięg w tym samym czasie obejmuje obszary Depresji Świebodzic oraz regiony górnicze Czech, Górnego i Dolnego Śląska. Wiarygodność tej tezy jest niezależnie potwierdzona przez wieloletnie pomiary horyzontalnych składowych ruchów skorupy ziemskiej, wykonanych technikami satelitarnymi przez sieć stacji GNSS, SLR, DORIS i VLBA, rozmieszczonych na płycie europejskiej. W obszarze Europy Centralnej pomiary te pokazują jednorodne pole horyzontalnych prędkości przesuwu Płyty Europejskiej. Jednorodny ruch płyty jest wynikiem działania jednorodnego, wielkoskalowego pola sił tektonicznych, które ten ruch wywołują. Bieżący stan wielkoskalowego jednorodnego pola naprężeń tektonicznych ma duży wpływ na wywołanie wstrząsu sejsmicznego. Przedstawione wyniki badań zjawisk tektonicznych są dedykowane potrzebie wzmocnienia wiedzy o aktualnej możliwości zajścia zdarzenia sejsmicznego. Problem ten ma kluczowe znaczenie dla poprawy warunków bezpieczeństwa robót górniczych w obszarach wydobywczych Górnego i Dolnego Śląska.

EN

Changes of the tectonic stress field in Świebodzice Depression unit are the reason of complex variations of the rock blocks kinematic. Field of tectonic stresses produced effects of rotations and horizontal/vertical displacements of rocky blocks separated by numerous faults. The measurement system of the Geodynamic Laboratory in Ksiaz, equipped with instruments situated on the rocky blocks, is a natural detector of tectonic activity, allowing determination of the temporal functions of tectonic activity with sub-micrometric accuracy. Comparison of the functions of the tectonic activity variations and their derivatives with temporal distribution of the seismic shocks in the Lower and Upper Silesia indicate that earthquakes occurred in accordance with particular and repeatable conditions of the Świebodzice Depression tectonic deformations. This observation strengthens the thesis about large-scale, homogeneous field of tectonic stresses which, at the same time, affect the Świebodzice Depression as well as mining areas of the Czech and Lower and Upper Silesian. The credibility of this thesis is independently confirmed by the results of many years long measurements of the Earth crust motions, performed on hundreds of stations by the space and satellite techniques i.e. GNSS, SLR, DORIS, VLBA. Current state of the large-scale, homogeneous field of tectonic stresses decided about the triggering of the earthquakes. Presented investigations of tectonic phenomena are dedicated to improve the safety conditions of mining works, executed in Upper and Lower Silesian mining areas.

14

Seismically induced soft-sediment deformation in crevasse-splay microdelta deposits (Middle Miocene, central Poland) – reply

Chomiak Lilianna, Maciaszek Piotr, Wachocki Robert, Widera Marek, Zieliński Tomasz

Geological Quarterly

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2019

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Vol. 63, No. 2

429--433

EN

We expected that our paper on the crevasse-splay microdelta (Chomiak et al., 2019) would arouse the interest of other researchers for at least two reasons. First, this is the first such palaeoform discovered and described within the Mid-Miocene lignite seam in Poland. Second, the microdelta siliciclastic deposits are strongly deformed both ductile and brittle. Therefore, we would like to thank Tom van Loon for his effort to comment on our article, including his words of appreciation, and above all, for pointing out some of the terminological and interpretative shortcomings. Our reply will be in line with the issues discussed in his comment.

15

The Jurassic to Palaeogene strata in the northern boundary fault zone in deep borehole PD-9 at Szczawnica, Pieniny Klippen Belt, West Carpathians, Poland : biostratigraphy and tectonic implications

Birkenmajer Krzysztof, Gedl Przemysław

Annales Societatis Geologorum Poloniae

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2019

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Vol. 89, No. 3

233--257

EN

The Jurassic through Palaeogene stratigraphy and tectonic structure of the PD-9 borehole at Szczawnica, Pieniny Klippen Belt, West Carpathians, Poland, is revised. The borehole was drilled in the strongly tectonized northern boundary fault zone of the Pieniny Klippen Belt, of Miocene age. Age revision is given by dinoflagellate cysts. Late Cretaceous taxa are reported from the Hałuszowa Formation. The Bryjarka Member (previously with the rank of formation) yielded rich Early Eocene (Ypresian) assemblages. Similar ones are reported from the Szczawnica Formation. A tectonic thrust sheet of the Jurassic Szlachtowa Formation (Grajcarek Unit) in the Palaeogene of the Magura Nappe is evidenced; it yielded late Toarcian-Aalenian dinoflagellate cyst assemblages. The succession of strata recorded from the PD-9 borehole shows the steep, almost vertical attitude of the Grajcarek Main Dislocation at Szczawnica, separating the structures of the Magura Nappe (to the north) and the Pieniny Klippen Belt to the south.

16

Seismo-geological model of the Baltic Basin (Poland)

Kasperska Monika, Marzec Paweł, Pietsch Kaja, Golonka Jan

Annales Societatis Geologorum Poloniae

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2019

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Vol. 89, No. 2

195--213

EN

The aim of this study is to construct a seismo-geological model of the western part of the Baltic Syneclise. This model enables reconstruction of the tectonic processes taking place in this area, which had a significant impact on the formation of prospective zones for the occurrence of unconventional hydrocarbon accumulations. The two seismic surveys Opalino 3D and Kościerzyna-Gdańsk 2D, together with borehole data available in the vicinity, were used for the research. Well data were used not only for the seismic-to-well tie, but also for the construction of well cross-sections (including balanced ones). The structural interpretation of seismic boundaries enabled the separation of four structural stages: Precambrian; Caledonian, Permian-Mesozoic and Cenozoic. The seismic interpretation of the Opalino 3D survey indicates the presence of block-style tectonics in this area. This system is considered to be a part of a large block system, also extending throughout the area of the 2D survey. The Caledonian interval shows the greatest degree of structural complexity. Most of the large Palaeozoic dislocations already had been formed in the Cambrian. They underwent reactivation and/or inversion in the Silurian, or in the final stages of the Caledonian and/or Variscan Orogeny, at the latest. The current shape and structure of the Baltic Syneclise and the development of the Palaeozoic sedimentary cover were significantly influenced by the processes taking place in the Teisseyre-Tornquist Zone (TTZ). The dislocations of the Lower Palaeozoic stage are characterized by general NW-SE and NE-SW trends, although the first of these seems to be dominant.

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The Pieniny Klippen Belt in Poland

Golonka J., Krobicki M., Waśkowska A.

Geology, Geophysics and Environment

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2018

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Vol. 44, no. 1

111--125

EN

The Pieniny Klippen Belt in Poland marks the Central Carpathian-North European plate suture zone. The strictly tectonic present-day confines of the Pieniny Klippen Belt are characterized as (sub)vertical faults and shear zones. A strong reduction in the space of the original sedimentary basins took place. The strike-slip-bounded tectonic blocks, thrust units, toe-thrusts and olistostromes are mixed together, resulting in the present-day mélange character where individual tectonic units are difficult to distinguish. The sedimentary rocks of the Pieniny Klippen Belt were deposited in the paleogeographic realm known as the Alpine Tethys that was divided into two basins separated by the Czorsztyn Ridge. The accretionary prism formed in front of the advancing Alcapa (Central Carpathians) terrane had overridden the Czorsztyn Ridge during the Late Cretaceous-Paleocene. The destruction of the Czorsztyn Ridge supplied huge amounts of coarse-clastic material, including olistoliths, into the Magura Basin during the Late Cretaceous-Paleocene. The rotation of the Alcapa caused the strike-slip motions which led to the deformation of the previously created nappes and development of the flower structure. Two parallel faults delineate the southern and northern limits of the Pieniny Klippen Belt. The stops in Sromowce (Macelowa and Sobczański Gorge area) allow the observation of the southern marginal zone of the Pieniny Klippen Belt, the overturned position of the rotated counterclockwise deformed rock as well as the diapiric uplift of the Pieniny rocks in a transpressional strike-slip regime. The Zawiasy (Krościenko area) stop is located in the northern marginal zone (Hulina Unit) of the Pieniny Klippen Belt along the major dextral strike-slip Dunajec Fault.

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The North European Platform suture zone in Poland

Golonka J., Pietsch K., Marzec P.

Geology, Geophysics and Environment

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2018

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Vol. 44, no. 1

5--16

EN

The authors interpret the structure of the Central Carpathian-North European plates suture zone in Poland, where three main Carpathian tectonic units: the Central Carpathian, Pieniny Klippen Belt (PKB) and Outer Carpathian are present. In general, the PKB follows this zone. Several deep bore-holes were drilled in this region and the seismic lines were tied to bore-hole data and geological maps. The Polish PKB belongs to the complex geological structure stretching from Vienna in Austria to Romania. The rocks included in the PKB tectonic components were deposited within the paleogeographic realm known as the Alpine Tethys, mainly during the Jurassic-Early Cretaceous times. Both strike-slip and thrust components occur within the Polish section of the PKB. The strongly tectonized, few kilometer wide PKB zone is limited by a flower structure marked by two major faults, linked to the strike-slip zone. These faults reach the North European Platform (part of the North European Plate). The flysch sequences, arranged into a series of north-vergent thrust-sheets, constitute the main component of the PKB in the survey zone. They contain olistoliths, which are mainly Jurassic-Early Cretaceous in age. The PKB tectonic components of different age, strike-slip, thrust as well as toe-thrusts and olistostromes are mixed together, giving the present-day mélange character of this belt, where individual units are hard to distinguish. Two olistostrome belts (mélange units) exist within the PKB structure. The seismic lines show the Central Carpathian Paleogene rocks covering the Paleozoic Central Carpathian Basement south of the PKB. The Subtatric covers the High-Tatric autochthonic and allochthone rocks. The Central Carpathian Plate is thrust over the North European Platform in the Podhale region. The allochthonous Outer Carpathians consist of several nappes (thrust-sheets) verging northward. They are thrust over each other and over the North European Platform which dips gently southward.

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Sedimentary response to tectonic uplift of the Dukla basin margin recorded at Skrzydlna – the Menilite Beds (Oligocene), Outer Carpathians, S Poland

Siemińska A., Starzec K., Godlewski P., Wendorff M.

Geology, Geophysics and Environment

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2018

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Vol. 44, no. 2

231--244

EN

The Menilite Beds (Oligocene of Polish Flysch Carpathians) at Skrzydlna crops out in a structurally complex zone of the Fore-Magura Unit, which is tectonically overridden by Magura Nappe thrust form the S. The exposed sedimentary suite, representing the Dukla Basin, consists of fine-grained, well organised strata deposited in a low-energy, deep marine basin, which are abruptly overlain by poorly organised, coarse sandy conglomerate that forms a Mass Transport Deposit (MTD) complex. The MTD contains large boulders of extrabasinal rocks, massive sandstone beds with intrabasinal mudstone clasts, and slump sheets of sandstones. Above rests a fining- upwards sequence of sandstone beds interlayered with mudstones. The fine-grained facies reappear above to terminate the exposed succession. Erosional contacts and rapid facies changes, both vertical and lateral, are characteristic for the MTD unit. The sandstone-mudstone unit above contains laterally migrating erosional channels filled with massive sandy conglomerate in the lower part. Turbidites of varying density and completeness of internal structures that occur above are accompanied by an association of mixed facies including large-scale dune cross-bedding. Mineralogically, the sandstones are quartz arenites, sub-lithic arenites and wackes. Calcarenite grains – bioclasts, micrite and marl occur in substantial proportions only in the uppermost part of the succession. The point-counting data plotted on Qm-F-Lt diagram are clustered within the recycled fields: quartzose and transitional. Mineralogical maturity of the sandstones has the tendency to decrease from the sub-MTD strata upwards via the MTD unit to the lower part of the sandstone-mudstone complex; then it increases to the youngest sandstone beds with carbonate grains. These tendencies, associated with sedimentary features of the succession, reflect rapid uplift, emergence and progressive erosion of the terrigenous detritus source area, followed by tectonic stabilisation reflected by the appearance of the “carbonate factory”.

20

On the nature of the Teisseyre-Tornquist Zone

Mazur S., Krzywiec P., Malinowski M., Lewandowski M., Aleksandrowski P., Mikołajczak M.

Geology, Geophysics and Environment

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2018

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Vol. 44, no. 1

17--30

EN

The Teisseyre-Tornquist Zone (TTZ) is the longest European tectonic and geophysical lineament extending from the Baltic Sea in the NW to the Black Sea in the SE. This tectonic feature defines a transition zone between the thick crust of the East European Craton (EEC) and the thinner crust of the Palaeozoic Platform to the SW. The TTZ is evident from the seismic data as a perturbation of the Moho depth as well as from magnetic and gravity anomaly maps and heat flow distribution. For over a century, the TTZ has been considered a fossil plate boundary of the EEC corresponding to the limit of early Palaeozoic palaeocontinent Baltica. The results of quantitative interpretation of gravity and magnetic data, integrated with data from the new reflection seismic profiles crossing the TTZ, indicate the continuation of the Precambrian basement of the EEC and its lower Palaeozoic cover toward the SW underneath the Palaeozoic Platform. Potential field modelling also suggests the occurrence of a crustal keel underneath the TTZ. These results imply the location of a Caledonian tectonic suture, marking the site of the collision between Avalonia and Baltica, not along the TTZ, but farther SW, in NE Germany and SW Poland.