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EN
The Cenozoic tectonic evolution of the Polish Platform reflects repeated changes in loading condi tions at the Al pine–Carpathian and Arctic–North Atlantic margins of the European continent. After the Late Cretaceous–Paleocene main phase of the Mid-Polish Basin inversion, a second phase of limited uplift of the Mid-Polish Swell occurred during the Middle–Late Eocene. End Eocene and Early Oligocene subsidence of narrow grabens on the Fore-Sudetic Monocline was coeval with normal fault ing in the East Alpine foredeep basin and the development of the Central European rift system. At the sametime the Outer Carpathian flysch basins were rearranged, presumably in response to the build-up of compressional stresses at crustal levels, whilst subsidence and erosion patterns changed in the Carpathian Foreland from being dominated by the NW–SE trending Mid-Pol ish Swell to being controlled by the development of the W–E trending Meta-Carpathian Swell. At the end of the Oligocene the Fore-Sudetic graben system propagated into the area of the Trans-European Suture Zone and the Sudetes and remained active during the Early and Middle Miocene. This was paralleled by intensified subduction activity and thrusting of the Carpathians and the development of their flexural foredeep basin. A short early Sarmatian episode of basement in volving transpression along the SW margin of the Mid-Pol ish Swell correlates with the termination of north-directed nappe transport in the Outer Carpathians. This was followed by eastward migration of the subsidence centre of the Carpathian Foredeep Basin and the gradual termination of tectonic activity in the grabens of the Polish Lowlands. After a period ofpost-orogenic relaxation the present-day compressional stress regime built up during the Pliocene and Quaternary. Intensified ridge push forces exerted on the Arctic–North Atlantic passive margins contribute to this compressional stress field that is dominated by collision-related stresses reflecting continued indentation of the Adriatic Block. This sequence of events is interpreted in terms of changing tectonic loads in the Carpathians, Alps and at the NW passive margin of Europe. The complex and diachronous interaction of mechanically coupled and uncoupled plates along collision zones probably underlies the temporally varying response of the Carpathian Foreland that in addition was complicated by the heterogeneous structure of its lithosphere. Progressively increasing ridge push on the passive margin played a secondary role in the stress differentiation of the study area.
PL
Utwory górnej jury i dolnej kredy w środkowej części przedgórza Karpat, wykształcone głównie jako węglany, zostały przebadane w związku z intensywnym poszukiwaniem złóż węglowodorów. Na podstawie interpretacji licznych danych wiertniczych, wyodrębniono 9 nieformalnych jednostek litostratygraficznych, nazywając je seriami. Reprezentują one wiekowo przedział od oksfordu po walanżyn, a możliwe nawet po hoteryw. Korelacje stratygraficzne wskazują, iż płytkowodna platforma węglanowa, z charakterystycznymi, skośnie warstwowanymi oolitami, przesunięta została w najpóźniejszym wczesnym kimerydzie z obszaru świętokrzyskiego na południowy wschód, w rejon Pilzno-Nawsie, gdzie utwory tej facji tworzyły się aż po walanżyn/?hoteryw. Jednocześnie, w rejonie tym powstawały rafy koralowe o barierowym charakterze, obrzeżając blok tektoniczny, podlegający mniejszej subsydencji. Miąższość utworów górnego kimerydu-tytonu gwałtownie wzrasta na SE od strefy Pilzna, tj. w kierunku krawędzi szelfu Tetydy.
EN
Upper Jurassic through Lower Cretaceous, mainly carbonate succession of the middle Polish Carpathian Foreland, has currently been studied due to intensive hydrocarbon exploration. According to interpretation of abundant well data, the succession has been sub divided into 9 lithostratigraphic formations that represent Oxfordian through Valanginian (or possibly even Hauterivian) stages. Stratigraphic correlation indicates that in the latest Early Kimmeridgian shallow water carbonate platform facies, namely oolitic shoals, were shifted southeastwards from the Holy Cross area and persisted in the Pilzno-Nawsie area until the Valanginian/Hauterivian time. Simultaneously, coral reefs of a barrier type developed in the later area, fringing edge of a less subsiding tectonic block. Thickness of the Upper Kimmeridgian-Tithonian deposits abruptly increases southeastwards from the Pilzno zone, i.e. towards edge of the Tethyan shelf.
EN
A series of analogue models are used to demonstrate how multistage development of the Mid Polish Trough (MPT) can be influenced by oblique basement strike-slip faults (Gutowski & Koyi 2006). In the light of the results, Jurassic - Early Cretaceous tectonic evolution of the SE Mid-Polish Trough can be interpreted in terms of relative movement of basement blocks bounded by strike-slip faults which segmented the basin. Based on interpretation of geophysical, well and outcrop data, the following successive stages in the basin history are simulated in the models: 1. Oblique extension of the NW segment of the MPT accompanied by sinistral movement along the Holy Cross Fault Zone (HCF, Early Triassic - latest Early Jurassic). 2. Oblique extension of both the NW and SE segment of the MPT, parallel to the HCF (latest Early and Middle Jurassic). 3. Oblique extension of the SE segment of the MPT and much lesser extension of its NW segment connected with dextral movement along the HCF (Early Oxfordian - latest Early Kimmeridgian) (Fig. 1A). 4. Oblique extension of the SE segment of the MPT and much lesser extension of its NW segment connected with dextral movement along the Zawiercie Fault (ZF, latest Early Kimmeridgian - Valanginian) (Fig. 1B). The different sense of movement of the HCF and ZF resulted in successive extensional en echelon fault systems, which widely penetrated the south-western margin of the MPT (Fig. 1). The en echelon fault systems interfered with the SW bounding fault system of the MPT. The NE margin of the SE segment of the MPT is a typical, steep and distinctly marked graben margin fault zone, dominated by normal and dip-slip/strike slip faults parallel to its axis. A specific pull apart basin developed in the zone between the HCF and SW border fault of the SE segment of the MPT during Oxfordian and Early Kimmeridgian times (Fig. 1A). It resulted from interaction between the en echelon fault system and dip slip fault system bounding the MPT. Extensive south-westward progradation of the shallow water carbonate and continental clastic depositional systems of the Late Oxfordian - Early Kimmeridgian onto the central part of the basin located above the HCF was controlled by development and propagation of en echelon relay ramps along the NE wedge of the MPT (Fig. 1A''). These ramps were faulted during the Late Kimmeridgian-Tithonian - earliest Berriasian due to reorientation of the extension direction from WNW-ESE to W-E (Fig. 1B'-B''). Dextral strike-slip movement of the HCF was replaced by dextral strike slip movement along the ZF. The same mechanism controlled also propagation of the depocenter from the western to the eastern margin of the basin.
4
Content available remote Evolution of the SE segment of Mid-Polish Trough in Jurassic and Early Cretaceous
EN
Facies and palaeo-thickness analysis of the Jurassic and Early Cretaceous sediments (Gutowski et al. 2005, 2006) combined with interpretation of gravity and magnetic images have allowed to construct a regional model for the syndepositional tectonic activity of the sub-Mesozoic basement 7thInternational Congress on the Jurassic System, Abstract Volume, Session 1: Geodynamics and evolution of different areas of the peri-Carpathian (SE) segment of the Mid-Polish Trough (MPT) during Jurassic through Early Cretaceous times (Fig. 1A). Taking into account: (1) location of the Jurassic and Lower Cretaceous palaeo-thickness gradients, (2) location of facies contrasts, (3) location of tectonic lineaments on the gravity and magnetic images, a tectonic map of main basement fault zones was constructed. Results from the analogue models (Gutowski & Koyi 2006a, b) helped to understand activity of the inferred fault zones and its impact onto synsedimentary fault systems developed within the Jurassic and Early Cretaceous sedimentary infill. They also helped to restore extensional tectonic structures that existed in the axial part of the SE segment of the MPT before its Late Cretaceous-Palaeogene inversion and almost total removal of the syn-extensional sedimentary infill. Sedimentary records show that the NW segment of the MPT, located north-westwards from the Holy Cross Fault Zone (HCF), formed since the Permian whereas its SE, peri-Carpathian segment did not open and accumulate sediments until the latest Early to Middle Jurassic (e.g. Kutek 2001). The Holy Cross Fault Zone played a role of a major tectonic boundary that limited south-eastward propagation of the MPT. This was achieved by the sinistral strike-slip movement along the HCF (Fig. 1B). The SE segment of the MPT started to open in the latest Early Jurassic (Fig. 1C). During the Late Jurassic the depocenter of the MPT was shifted to this segment. This was probably connected with reorientation of the strike-slip movement along the HCF from sinistral to dextral (Fig. 1D). The northeastern boundary of the SE segment of the MPT was controlled by the SW margin of the East-European Craton whilst, similarly as in the NW segment of the MPT (Krzywiec 2006), its SW bounding normal fault zones were complicated by an interfering system of en-echelon fault zones oriented obliquely to the main axis of the MPT (Fig. 1A, D, E). These strike-slip basement fault zones are generally W-E oriented and are not parallel to the WNW-ESE running Holy Cross Fault Zone and to the major basement strike-slip fault zones inferred within the northwestern part of the MPT (Krzywiec 2006). It is therefore assumed that direction of extension, evolved from WNW-ESE oriented (as postulated recently for the Permian-Mesozoic basin by Mazur et al. 2005) in Early, Middle Jurassic and probably also in Oxfordian and Early Kimmeridgian times, to W-E (WSW-ENE) oriented in Late Kimmeridgian to Barremian times, respectively (Fig. 1B -E). This process was supposedly driven by opening and rifting of the Silesian Basin which likely joined the SE segment of MPT south-eastwards of Rzeszów (Fig. 1E). The northern margin of this basin most probably coincides with the gravity-induced lineament running E-W about 20-40 km southward from the present-day extent of the Outer Carpathian front, beneath the nappes of the Silesian Unit (Fig. 1E). Consequently, it can be assumed that during the Late Jurassic and Early Cretaceous the SE Mid-Polish Trough was included into the system of marginal Tethys basins.
EN
Well, outcrop, seismic and gravity data were used to construct a series of palaeogeographic maps revealing architecture and evolution of the carbonate platform developed within the northern shelf of Tethys in SE Poland and W Ukraine during Oxfordian through Barremian times. The platform developed in a transition zone between the epicontinental Mid-Polish Trough and the Outer-Carpathian basins. A variety of depositional systems included open shelf spongemicrobial bioherms, coral reefs and oolitic-bioclastic grainstones (see Gutowski et al. 2005, Gliniak et al. 2005) which form hydrocarbon reservoirs in connection with overlying Cenomanian sandstones. Palaeogeographic distribution of the depositional systems evolved in time and was controlled by syn-depositional basement normal/transtensional and strike-slip faulting. A series of analogue models (Gutowski & Koyi 2006a, b) helped to understand a role of strike-slip movements along deep fault zones directed obliquely to the axis of the Mid Polish Through and related to modifications of the extension direction (Gutowski & Wybraniec 2006). These movements controlled fault geometry and the shift of depocenters. Pelagic, black and grey, often bituminous shales (Karolina Formation in Western Ukraine and Cieszyn Shales in Poland), deposited in front of the bioherm-reef belt on the shelf margin, form excellent source rocks. They were deposited since the Late Kimmeridgian due to breaking-up of the peri-Tethyan carbonate platform (Âtramberk type carobonates) and opening of the Silesian Basin (Fig. 1). Consequently, promising traps should mainly be located close to the Late Kimmeridgian - Early Cretaceous shelf margin (Fig. 1), the location of which was inferred using gravity data (Gutowski & Wybraniec 2006). Additional source rocks are of Palaeozoic or Middle Jurassic age. Quality of the reservoirs was often enhanced by diagenesis (e.g. dolomitization), fracturing and pre-Cenomanian karstification. The reservoirs are sealed by Miocene evaporates and/or clays and Upper Cretaceous marls. The Mid-Polish Trough was inverted during the Late Cretaceous and Palaeogene. As a result of Carpathian thrusting, the basin in its southernmost part was covered by the Miocene sediments of the Carpathian foredeep and/or by the Outer Carpathian nappes. Although these tectonic processes modified the evolution of the hydrocarbon system, the Late Jurassic - Early Cretaceous facies development and evolution of the carbonate platform were decisive for the primary distribution of the source rocks and potential reservoirs. Therefore, they should play a key role in hydrocarbon exploration strategy.
EN
The system of huge organic buildups (sponge-microbial bioherms and coral reefs) has recently been mapped in the Carpathian foreland, S Poland, using high-quality petroleum seismic and well data interpreted using original, newly developed techniques. The sponge-microbial bioherms were formed during the Oxfordian time and the flat and mound-shaped coral reefs replaced them during the Late Oxfordian through Tithonian time. Both the bio-herms and reefs reflect the system of synsedimentary active extensional-transtensional blocks of the basement that controlled sea bottom highs which were likely colonized by the buildups constructors. It is possible to identify two systems of such faults: NW-SE oriented one and, less visible, W-E oriented one. The Late Jurassic organic buildups form excellent reservoirs for hydrocarbon accumulations. Effective seal for the traps is provided by the Upper Cretaceous (Senonian) marls. Late Cretaceous inversion resulted in reverse reactivation of main basement fault zones. During the Miocene, Carpathian thrusting-related flexural extension basement fault zones have been again reactivated in transtensional regime, which enhanced hydrocarbon prospectivity of selected areas due to juxtaposition of source and reservoir rocks. Miocene foredeep evaporates provide additional, very effective seal.
EN
The deposits of the Niżniów Formation, exposed around Niżniów, mainly on the banks of Dnister River, accumulated in the most proximal, marginal position of the latest Jurassic-earliest Cretaceous epicontinental basin on the SW margin of the East European Platform. The Niżniów Formation directly onlaps a Palaeozoic substrate and consists of transgressive cliff-derived conglomerates, and sandstones and marls which pass laterally into shallow marine carbonates: mainly biomicrites, oncomicrites, and pelmicrites with an abundant benthic fauna dominated by nerineid gastropods. The thickness of the formation in the area studied ranges from 0 to more than 20 metres and was controlled bymorphology of the pre-transgression substrate (mainly built of Devonian clastic rocks), synsedimentary fault tectonics and pre-mid-Albian erosion. The age of the Niżniów Formation can be determined, on the evidence of benthic foraminifers encountered in thin sections, as most probably late Tithonian-early Berriasian.
EN
The following Late Jurassic depositional systems have been recognized in the WUkrainian and SE Polish margin of the East European Platform: shelf slope/basin, open shelf, carbonate ramp, siliciclastic shelf, fluvial/playa, deltaic/swamp, restricted marine/evaporate lagoon. Three depositional megasequences have been identified. Their upper boundaries have been dated by means of targeted stratigraphic studies, compilation of existing data and reinterpretation of stratigraphic correlation concepts respectively as: lower Kimmeridgian divisum/hypselocyclum zones boundary, uppermost upper Kimmeridgian and lower Berriasian. Analysis of thickness and depositional system architecture within themegasequences in six regional cross-sections indicates that depocentre was located in the SW margin of the Mid-Polish Trough during Oxfordian and early Kimmeridgian times and propagated in Tithonian time to the Lviv region. This can be explained by changes in the palaeostress field. Approximately N–S oriented extension during Oxfordian and earliest Kimmeridgian times was replaced by approximately NE–SW oriented extension in Tithonian time. The thickness pattern of the megasequences as well as proximity trends of the system tracts within the sequences clearly coincide with the depocentre propagation.
EN
In Late Jurassic the area of Central Poland was a part of the northern Tethyan shelf which developed in the margins of the East European Craton. The present day NE margin of the Holy Cross Mountains was situated in a proximal part of thhis shelf. The Oxfordian sedimentationbegan with open shelf, sponge-algal mudstones of the mariae, cordatum, and plicatilis Zones. During the latest transversarium and bifurcatus Chrons, shallow water biogenic and oncolitic facies developed. They were, in turn, replaced during the Late Oxfordian and the Early Kimmeridigian by oolitic-bioclastic grainstones and laminites. During the divisum Chron and the Late Kimmeridgian oyster shellbeds and clays were deposited. Within the studied sequence thirteen lithostratigraphic units are esablished and described. The collected ammonite fauna document the following ammonite zones: mariaem cordatum, plicatilis, transversarium, bifurcatus, planula, hypselocyclum and divisum.
PL
Opracowanie przedstawia syntezę lito- i biostratygrafii utworów górnojurajskich północno-wschodniego obrzeżenia Gór Świętokrzyskich odsłaniających się między Dobrutem i Wierzbicą, w okolicach Iłży, w dolinie Kamiennej od Przepaści, przez Bałtów po Skarbkę oraz nad Wisłą w Zawichoście i Rachowie. Na podstawie 76 profili z odsłonięć i otworów wiertniczych wyróżniono 13 nieformalnych jednostek stratygraficznych. Obejmują one zarówno osady dolnego i niższej części środkowego oksfordu wykształcone w facji gąbkowej i mikrytowej otwartego szelfu, jak i utwory płytkowodnej facji platformy węglanowej, tworzone od przełomu poziomów transversarium i bifurcatus, a wykształcone początkowo jako wapienie biogeniczne z koralami, a następnie wapienie onkolitowe, oolitowe oraz laminaty i wreszcie (od poziomu divisum) - muszlowce ostrygowe i margle. Na podstawie kolekcji amonitów obejmującej 94 okazy udokumentowano następujące poziomy amonitowe: mariae, cordatum, plicatilis, transversarium, bifurcatus, planula, hypsalocyclum oraz divisum. W wyniku neokimeryjskiego ścięcia erozyjnego utwory neokomu lub albu kontaktują z różnymi ogniwami górnej jury. Najgłębiej neokimeryjska erozja sięgnęła w rejonie Ożarowa, gdzie piaskowce albu kontaktują bezpośrednio z muszlowcami ostrygowymi poziomu divisum.
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