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Sejsmiczne obrazowanie złóż karpackich Bóbrka-Rogi i Krościenko

Maćkowski Tomasz, Zając Aurelia

Wiadomości Naftowe i Gazownicze

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2025

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R. 28, Nr 11 (321)

4-12

PL

Zastosowanie migracji PreSDM Reverse Time Migration (RTM) w przetwarzaniu danych sejsmicznych z silnie zaangażowanego tektonicznie obszaru Karpat zewnętrznych pozwala na poprawę jakości i detalizację obrazowania sejsmicznego. Na przykładzie odkrytych jeszcze w XIX w. złóż ropy naftowej, których budowa geologiczna została dobrze rozpoznana na podstawie danych z licznych otworów eksploatacyjnych, wykazano, że migracja RTM umożliwia zobrazowanie elementów strukturalnych, takich jak strome i wąskie fałdy, czy uskoki o niewielkich zrzutach, które nie są lub są słabo obrazowane przez algorytm Kirchhoffa. Istotne znaczenie ma wykorzystanie RTM w wariancie anizotropowym TTI, który daje możliwość poprawnego pozycjonowania poziomego kulminacji potencjalnych struktur złożowych, kluczowego z punktu widzenia projektowania lokalizacji otworów wiertniczych. Głównym wyzwaniem w aplikacji algorytmu RTM pozostaje wciąż opracowanie realistycznego i dokładnego modelu prędkości, co w przypadku skomplikowanej budowy górotworu stanowi poważną trudność. Zaproponowano zastosowanie hybrydowego podejścia łączącego inwersję grawimetryczną oraz inwersję pełnego pola falowego w wariancie wczesnych wstąpień (FWI/EWI), ponieważ standardowe metody, stosowane w basenach platformowych, okazują się w tym rejonie nieskuteczne.

EN

PreSDM Reverse Time Migration (RTM), used in the processing of seismic data from the strongly tectonically disturbed Outer Carpathians, enhances the quality and resolution of seismic imaging. Using the example of oil fields discovered as early as the 19th century, whose geological structure was well characterized based on data from numerous production wells, it was demonstrated that RTM enables imaging of geological features such as steep and tight folds or small-displacement faults, which are either not imaged or poorly imaged by the Kirchhoff algorithm. Of particular importance is the use of TTI RTM, which enables accurate horizontal positioning of the crests of potential reservoir structures, a key factor in the effective planning of drilling sites. The main challenge in applying the RTM algorithm remains the development of a reliable and accurate velocity model, which is particularly difficult in areas of complex geological structure. Since conventional methods used in platform basins prove ineffective in such cases, a hybrid approach was proposed that combines gravity inversion and the Full Waveform Inversion in Early Arrival Waveform Inversion variant (FWI/EWI).

2

Geologia Lubelskiego Zagłębia Węglowego -- fundament Bogdanki

Szpak Krzysztof, Kołomański Dawid, Kulpa Jarosław

Przegląd Górniczy

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2025

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T. 82, nr 3

22--30

PL

Artykuł omawia genezę i budowę geologiczną Lubelskiego Zagłębia Węglowego oraz rozwój kopalni Lubelski Węgiel „Bogdanka” S.A. Przedstawiono historię poszukiwań prowadzonych od okresu międzywojennego, które doprowadziły do udokumentowania złóż węgla kamiennego na Lubelszczyźnie. Scharakteryzowano litostratygrafię i tektonikę basenu sedymentacyjnego, ze szczególnym uwzględnieniem warstw lubelskich, zawierających liczne pokłady węgla energetycznego o korzystnych parametrach jakościowych. Omówiono również florę i faunę karbonu oraz ich znaczenie w procesach sedymentacyjnych węgla kamiennego. W części metodycznej opisano sposoby dokumentowania i rozpoznawania złoża, takie jak kartowanie geologiczne, wiercenia rdzeniowe czy badania litologiczne. Szczególną uwagę poświęcono cyfrowemu modelowaniu złoża jako narzędziu wspierającemu planowanie i optymalizację eksploatacji. Podkreślono jego rolę w standaryzacji danych, integracji procesów decyzyjnych i racjonalnym zarządzaniu zasobami.

EN

This paper examines the origin and geological structure of the Lublin Coal Basin, focusing on the development of the Lubelski Węgiel "Bogdanka" S.A. mine. The study outlines the history of exploration initiated in the interwar period, which ultimately resulted in the documentation of hard coal deposits in the Lublin region. The lithostratigraphy and tectonic evolution of the sedimentary basin are analyzed, with emphasis on the Lublin Beds that host multiple seams of thermal coal characterized by favorable quality parameters. The Carboniferous flora and fauna are discussed in relation to their role in coal-forming sedimentary environments. Methodological considerations address techniques of deposit recognition and documentation, including geological mapping, core drilling, and lithological studies. Digital deposit modeling is presented as a key tool for mine planning and operational optimization. The study highlights its importance for data standardization, decision-making integration, and sustainable resource management.

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Sudety w kenozoiku : od tektonicznej ekshumacji podłoża do współczesnej rzeźby – wnioski z termochronologii niskotemperaturowej

Sobczyk Artur

Przegląd Geologiczny

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2025

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Vol. 73, nr 9

804--812

EN

Low-temperature the rmochronology based on apatite and zircon (40-240°C) provides essential infor¬mation on the evolution of the Sudetes during the Mesozoic and Cenozoic. AFT data from various areas of the Sudetes indicate intense cooling and basement exhumation during the Late Cretaceous-Paleogene (~90-45 Ma). The estimated mean exhumation rate during this period varied between 1.0 and 0.04 km/Ma. In the Cenozoic, there was a significant slowdown in tectonic processes and a decrease in the exhumation rate to <0.01 km/Ma. Results from numerical modelling of AFT data suggest that the folding of Cretaceous sediments in the lntra-Sudetic Synclinorium and the Upper Nysa Kłodzka Graben took place between 75 and 70 Ma. Thermochronology has also provided evidence of deep burial of the Sudetes in the Late Cretaceous, with the observed thermal reset suggesting that the thickness of the sedimentary cover may have reached up to 6 km. The development of the Sudetic landscape into a form similar to the present one did not occur earlier than after the Eocene, when the last phase of basement rock cooling and associated denudation of the Me¬ta-Carpathian Swell was recorded. The final uplift of the Sudetic Block began in the Middle Miocene (15±5 Ma), and the total erosion over the past 90 million years reached 5-6 km.

4

Outline of the geological structure of the western part of the Pieniny Klippen Belt in Poland

Golonka Jan, Chowaniec Józef, Waśkowska Anna

Annales Societatis Geologorum Poloniae

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2025

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Vol. 95, No. 1

1--16

EN

The Pieniny Klippen Belt forms a narrow suture zone between the Central and Outer (Flysch) Carpathians and is composed of deposits, laid down in the Alpine Tethys. The lithostratigraphy and tectonic structure of the central part of Pieniny Klippen Belt west of the Białka River, in the area between Krempachy and Stare Bystre, were analysed. The Pieniny Klippen Belt is made up of a mixture of components of different ages and lithologies, referred to as a mélange, which was formed as a result of complex tectonic and sedimentary processes. In the lithological inventory, it contains rocks from the Jurassic up to the Miocene age, which originated in the syn-rift and synorogenic stages of Alpine Tethys evolution. Sedimentation in the Alpine Tethys took place in conditions from shallow- to deep-water, related to the development of the uplifted structure of the Czorsztyn Ridge in its central part. The carbonates and carbonate-siliceous rocks of the syn-rift stage are fragmented and occur in the form of blocks of different sizes within the flysch deposits of the synorogenic stage of development. The flysch deposits of the synorogenic stage are bounded by the results of activity of the accretionary prism, which started in the Albian in the Złatne Basin on the southern side of the ridge and successively prograded to the north. They began with marly and shale-dominated variegated facies, passing into facies with a significant proportion of sandstones. West of Białka River, the Pieniny Klippen Belt has a nappe structure. The sequence of nappes corresponds to that in the sedimentary area of the Alpine Tethys. The uppermost Złatne Nappe contains deposits that originated in the southern part of the basin, while the other nappes contain rocks, laid down in the more northern areas.

5

Seismicity and Tectonics of the Republic of Kosovo

Retkoceri Blertë, Ahmeti Muhamet, Çadraku Hazir S.

Studia Geotechnica et Mechanica

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2024

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Vol. 46, nr 3

223--229

EN

Kosovo is distinguished by a particularly high degree of seismic activity as a result of its location in the alpine-Mediterranean seismic area. The thickness of the seismic zone in the Earth’s crust is a crucial element in seismotectonics, as it affects the design of fault systems, relative fault activity, earthquake size and distribution within a fault system, and the long-term accumulation of tectonic deformation. Kosovo’s large depressions and high relief make it challenging geomorphologically. The country of Kosovo is divided into numerous chunks along the fault lines because of the inclinations of these prevalent motions. Normal faults, along which differentiations on the order of 2000 m occurred during the neotectonics period, identify the contacts between these blocks. Understanding Kosovo’s seismotectonic characteristics requires an exact analysis of hypocenter parameters when historical earthquakes that have struck the country are reassessed for magnitude. This study deals with the seismicity and tectonics of the territorial space of the Republic of Kosovo.

6

Naturalne wycieki ropy w Karpatach – kłopot czy bogactwo?

Jankowski Leszek, Leśniak Grzegorz, Brzeszcz Joanna, Kapusta Piotr

Nafta-Gaz

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2024

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R. 80, nr 11

663--678

PL

Celem artykułu jest zwrócenie uwagi na problem tzw. rekultywacji naturalnych wycieków ropy naftowej, występujących często w Karpatach. Wieloletnie obserwacje wskazują, że ich szkodliwość i wpływ na środowisko są raczej niewielkie (jakkolwiek zagrożenie istnieje), natomiast stanowią one istotny przedmiot badawczy dla wielu dziedzin nauki i mają znaczenie edukacyjne oraz historyczne, wpisując się w bogatą historię rozwoju przemysłu naftowego w Polsce. Wycieki ukazano w różnorakich kontekstach: geologicznych, przyrodniczych, zwrócono uwagę na ich rolę w badaniu systemu naftowego, a także na walory edukacyjne i geoturystyczne. Badania wycieków są jednym z szeregu elementów składających się na tzw. rozpoznanie systemu naftowego (ang. play elements) – oprócz elementów głównych, jak np. skały macierzyste, skały zbiornikowe. Są wskaźnikiem procesu ciągłej migracji ropy naftowej, najprawdopodobniej z dużych głębokości. Oprócz wycieków zwrócono uwagę na ważność przesyconych ropą naftową stref melanży tektonicznych, które okazały się główną drogą migracji ropy naftowej w orogenie karpackim. Wskazano istotną rolę tzw. postkompresyjnych etapów deformacji tektonicznych w procesie ich formowania. Wycieki ropy naftowej są także obserwowalne w rejonie pozakarpackim, a ich związek z karpackim systemem naftowym powinien zostać przebadany. Zwrócono uwagę na konieczność zachowania, a nawet ochrony wielu stref wycieków, ale także miejsc ekshalacji gazowych czy wycieków wód mineralnych. Ochronie powinny również podlegać stare pola naftowe w rejonie Karpat. Dają one możliwość sprawdzenia wpływu eksploatacji na środowisko. Przypomniano także kilka ważnych postaci, szczególnie zasłużonych dla karpackiego i światowego przemysłu naftowego.

EN

This article addresses the issue of the reclaiming natural oil seeps that frequently occur in the Carpathians. Years of field observations suggest that their environmental impact is rather minimal, though some risks exist. Despite this, these seeps constitute an important subject of study for many fields of research and hold significant educational and historical value, contributing to the rich history of the development of the oil industry in Poland. The article discusses the geological and natural aspects of oil seeps, emphasizing their role in studying the petroleum systems and their educational and geotourism potential. Oil seeps are one of a number of so-called play elements of the Carpathians: e.g. source rocks, reservoir rock, caps rocks. They serve as indicators of oil migration, most likely from great depths. The importance of oil-saturated tectonic mélange zones, which turned out to be the main route of oil migration in the Carpathian orogen, was also highlighted, along with the important role of the so-called post-compression stages of tectonic deformations in the process of their formation. Moreover, oil seeps are also observed in the Carpathian Foredeep region, though their connection to the Carpathian oil system warrants further study. The article underscores the need to preserve and protect many seepage zones, as well as areas with gas exhalations and mineral water leaks. Old oil fields in the Carpathian region should also be preserved, as they offer opportunities to study the environmental impact of oil production. Several key figures in the development of the Carpathian and global oil industry are also recognized.

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Tectono-sedimentologic and lithostratigraphic control in Aures Region: Case study Djebel Metlili, Batna, Algeria

Touahri Abdeldjebar, Sahraoui Salah, Benmansour Sana, Hadjkouider Mohammed

Geomatics, Landmanagement and Landscape

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2024

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no. 2

111--124

EN

This research delves into the geological features of the western section of the Aures Basin, with a primary focus on Djebel Metlili. The geological characteristics span Mesozoic and Tertiary deposits, ranging from the Triassic to the Quaternary epochs. Notably, the higher Cretaceous period stands out for its substantial carbonate-rich sequence. The research relied on geological maps, field observations, core samples, and laboratory analyses, including lithostratigraphic examinations (cross-section) and thin section. Structural features show that is formed by large regular folds of ENE-WSW or E-W direction. Anticlines and synclines are often affected by transverse accidents at the axes of the folds. In its northern part is located immediately south of the Belezma-Batna mountains. Structural analysis highlights significant tectonic disturbances, oriented in a northwest-southeast direction. A detailed lithostratigraphic examination reveals marly formations interspersed with limestone-rich layers containing Inoceramus. The southern part of Dj. Metlili, particularly the Santonian-Campanian series, unveils three distinct meso-transgressive sequences, linked to sea-level fluctuations associated with sedimentary basin subsidence. The studied area exhibits three distinct facies: one characterized by gray phosphate limestone with crisscrossed stratifications and agitated bioclastic sand, another featuring a mollusk-rich bioclastic limestone indicating a turbulent intertidal environment, and a third presenting a clay limestone bank with fine to medium grains and lumachels rich in oysters and gastropods. The associated grainstone texture in the microfacies suggests an internal platform environment marked by dissolution, bioturbation, and ferruginization. This comprehensive exploration provides valuable insights into the geological history of the region, significantly contributing to our understanding of its evolution over time.

8

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.

9

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.

10

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.

11

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.

12

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.

13

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.

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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.

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Stratigraphic Emmental: High-resolution allostratigraphy reveals multiple intra-formational unconformities in shallow ramp mudstone: Upper Cretaceous, Western Canada Foreland Basin

Hooper Elizabeth A., Plint A. Guy

Acta Geologica Polonica

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2023

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Vol. 73, no. 4

773--799

EN

Marine mudstone of Coniacian age (c. 89.51–86.49 Ma) was deposited on a storm-dominated ramp spanning the foredeep of the Cretaceous Western Canada Foreland Basin. Marine flooding surfaces define 18 allomembers that thin over 300 km, from c. 140 m in the proximal foredeep to c. 20 m close to the forebulge crest. The broadly conformable succession of allomembers is partitioned into five ‘tectono-stratigraphic units’ by low-angle unconformities that bevel off c. 10 to 20 m of strata over ‘arches’ that have a length scale of c. 50–100 km and are bounded by relatively linear zones of flexure. Depositional history involved two alternate modes: ‘Background’ deposition of subtly-tapered allomembers took place on a planar sea floor, subject to regional flexural subsidence, with sea-level modulated by Milankovitch-scale (c. 125 kyr) eustatic cycles. ‘Flexural’ events deformed the strata into troughs and arches across narrow zones of flexure. Arch crests were bevelled off, probably by submarine wave erosion. Eroded sediment did not accumulate in troughs but was advected beyond the study area by storm-driven processes. Cycles of deposition, warping and erosion were repeated five times on an average timescale of 600 kyr. Arches and troughs do not coincide with Precambrian basement structures, and their origin remains enigmatic. Changes in in-plane stress may have effected the localized vertical motion.

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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.

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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.

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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.

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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.

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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.