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The stratigraphy of Zechstein strata in the East European Craton of Poland : an overview

Peryt Tadeusz Marek, Skowroński Leszek

Geological Quarterly

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2021

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Vol. 65, No. 4

art. no. 48

EN

The sedimentary and stratigraphic patterns established for Zechstein of the western part of the Peribaltic Syneclise (and in particular the eastern Łeba Elevation) were applied to other parts of the East European Craton (EEC) in Poland: the eastern Peribaltic Syneclise and the Podlasie region. A very large number of mostly fully-cored borehole sections in the Puck Bay region certainly predestines the eastern Łeba Elevation area to use it as a model. The most part of the EEC, except of its part adjacent to the Teisseyre-Tornquist Zone, during the Zechstein deposition represents the marginal parts of the basin. The fauna occurring in the Zechstein carbonate deposits of the EEC makes it possible to distinguish between the Zechstein Limestone and the younger carbonate strata, but certainly not between the Main Dolomite and the Platy Dolomite and hence the facies models for the Zechstein that have been previously developed in the western part of the Peribaltic Syneclise augmented by sequence stratigraphic approach seem to be the best tool to apply in other peripheral areas in the EEC area. The Zechstein sequence in the western part of the Peribaltic Syneclise consists, in general terms, of three parts: (1) carbonate platform of the Zechstein Limestone (occurring only in the north-westernmost corner of the study area and passing into basin facies dominant in the most part of the area); (2) the PZ1 evaporite platform system composed of sulphate platforms and adjacent basin system and constituting the major part of the Zechstein sequence; and (3) the Upper Anhydrite-PZ3 cover. There is a consensus, as far as the western part of the Peribaltic Syneclise is concerned, that the Platy Dolomite platform is wider than the Main Dolomite platform. In the easternmost part of the Peribaltic Syneclise, the stratigraphical interpretations are diverse. We have included the anhydrite overlying the Zechstein Limestone into the Upper Anhydrite, and concluded that the overlying interbedded mudstone and anhydrite also belong to the Upper Anhydrite. When above the Upper Anhydrite one carbonate unit occurs, it is assigned either to the Main Dolomite and Platy Dolomite, or to the Platy Dolomite. The same conclusion is proposed for the marginal parts of the Podlasie Bay. The deposition of Zechstein Limestone resulted in the origin of carbonate platforms along the basin margins which changed an inherited topographic setting. The Lower Anhydrite deposits are lowstand systems tracts (LST) deposits, lacking in more marginal parts of the western and eastern Peribaltic Syneclise and in the major part of the Podlasie Bay. The accommodation space existed and/or created during the Lower Anhydrite and the Oldest Halite deposition in the Baltic and Podlasie bays was filled and at the onset of the Upper Anhydrite deposition, a roughly planar surface existed except in the area ad jacent to the main Polish basin. The Upper Anhydrite deposits are transgressive systems tracts deposits and then highstand systems tracts deposits and they encroached the Zechstein Limestone platforms. The Upper Anhydrite deposition was terminated by sea level fall, and the Upper Anhydrite deposits in the marginal areas became subject to karstification. The Main Dolomite transgression took place in several phases but its maximum limit did not reach the Upper Anhydrite limit. The deposition of the PZ2 chlorides (LST deposits) resulted in the filling of the accommodation space that was inherited after the deposition of the Main Dolomite and the Basal Anhydrite. Subsequently, the area became exposed, and marine deposits (Grey Pelite and Platy Dolomite) related to the last major transgression during the life of the Zechstein basin that resulted in a flooding of the exposed surface of older Zechstein deposits, including the area that was emergent during deposition of the PZ2 cycle. Microbial carbonates, being stromatolites and thrombolites, are a common feature of all Zechstein carbonate units but in particular this is the case of the Platy Dolomite. There are no direct premises allowing for convincing settlement doubts regarding the stratigraphical position of the upper carbonate unit in many cases, but several lines of evidence suggest that, as in the entire Zechstein basin, the Main Dolomite considerably shifted basinward, and the Platy Dolomite - landward, although it is difficult to ascertain whether the original Platy Dolomite extent was similar to or greater than the limit of the Zechstein Limestone as elsewhere in the Zechstein Basin.

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The Tajno ultramafic-alkaline-carbonatite massif, NE Poland : a review. Geophysics, petrology, geochronology and isotopic signature

Wiszniewska Janina, Petecki Zdzisław, Krzemińska Ewa, Grabarczyk Anna, Demaiffe Daniel

Geological Quarterly

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2020

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Vol. 64, No. 2

402--421

EN

This paper reviews all available geological data on the Tajno Massif that intruded the Paleoproterozoic crystalline basement of NE Poland (Mazowsze Domain) north of the Teisseyre-Tornquist Zone, on the East European Craton. This massif (and the nearby Ełk and Pisz intrusions) occurs beneath a thick Mesozoic-Cenozoic sedimentary cover. It has first been recognized by geophysical (magnetic and gravity) investigations, then by drilling (12 boreholes down to 1800 m). The main rock types identified (clinopyroxenites, syenites, carbonatites cut by later multiphase volcanic/subvolcanic dykes) allow characterizing this massif as a differentiated ultramafic, alkaline and carbonatite complex, quite comparable to the numerous massifs of the Late Devonian Kola Province of NW Russia. Recent geochronological data (U-Pb on zircon from an albitite and Re-Os on pyrrhotite from a carbonatite) indicate that the massif was emplaced at ~348 Ma (Early Carboniferous). All the rocks, but more specifically the carbonatites, are enriched in Sr, Ba and LREE, like many carbonatites worldwide, but depleted in high field strength elements (Ti, Nb, Ta, Zr). The initial87Sr/86Sr (0.70370 to 0.70380) and ɛNd(t) (+3.3 to +0.7) isotopic compositions of carbonatites plot in the depleted quadrant of the Nd-Sr diagram, close to the “FOcal ZOne” deep mantle domain. The Pb isotopic data (206Pb/204Pb <18.50) do not point to an HIMU (high U/Pb) source. The ranges of C and O stable isotopic compositions of the carbonatites are quite large; some data plot in (or close to) the “Primary Igneous Carbonatite” box, while others extend to much higher, typically crustal ẟ18O and ẟ13C values.

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Prospective zones of unconventional hydrocarbon reservoirs in the Cambrian, Ordovician and Silurian shale formations of the East European Craton marginal zone in Poland

Podhalańska Teresa, Feldman-Olszewska Anna, Roszkowska-Remin Joanna, Janas Marcin, Pachytel Radomir, Głuszyński Andrzej, Roman Michał

Geological Quarterly

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2020

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Vol. 64, No. 2

342--376

EN

The paper presents the latest state of knowledge on the vertical and lateral ranges and characteristics of prospective zones (PZ) within the Lower Paleozoic unconventional hydrocarbon systems in the Baltic-Podlasie-Lublin Basin (Poland). The PZ were identified within the prospective formations based on rigorously determined criteria with the application of stratigraphic, sedimentological, mineralogical, petrographic, geochemical, petrophysical, and geomechanical studies, and interpretations of borehole logs. Archival geological data and information acquired from boreholes drilled recently in concession areas have also been applied in the interpretations. Following these criteria, four prospective zones have been distinguished. The deposits encompass partly or almost completely the Piaśnica, Sasino, and Jantar formations and the lower part of the Pelplin Formation. The characteristic feature of the Lower Paleozoic deposits at the East European Craton (EEC) margin in Poland is the diachronous appearance of the Sasino and Jantar black shale formations from west to east. The Baltic area is most prospective for the occurrence of unconventional hydrocarbon reservoirs in shale formations, specifically the Łeba Elevation, where all 4 prospective zones have been distinguished. The occurrence of liquid and gaseous hydrocarbons is expected in all zones. Due to the very high TOC content and geochemical characteristics, the Piaśnica Formation within PZ1 is the main petroleum source rock in the Polish part of the Baltic Basin. PZ2 (partly corresponding to the Sasino Formation) present in a large part of the Baltic Basin, is the next important prospective unit, despite not being uniform. PZ3 within the Jantar Formation was distinguished only on a limited area of the Łeba Elevation. Due to the low content of organic matter, the Lublin area is characterized by the lowest hydrocarbon potential. However, low values of that parameter are compensated by a greater thickness and lateral range of PZ4, partly corresponding to the Pelplin Formation. Comparison with other areas within the Lower Paleozoic Baltic Basin reveals the occurrence of shale deposits that may constitute a potential source of hydrocarbons, and that demonstrate diachronism. Towards the east and south-east, ever younger deposits possess the potential for hydrocarbon accumulations. In Poland, in the western part of EEC, these are: the Furongian and the Lower Tremadocian Piaśnica Formation, the Sandbian and Katian Sasino Formation and the Lower/Middle Llandovery (Rhuddanian and Aeronian) Jantar Formation. In the central part of the Baltic Basin (Lithuania), these are the Upper Ordovician and Aeronian shale successions. In the southeastern part of the basin (Ukraine), the Ludlow strata are considered to be the most promising in terms of the potential unconventional hydrocarbons accumulations.

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Linia Teisseyre’a-Tornquista : ewolucja poglądów na temat krawędzi kratonu wschodnioeuropejskiego

Grad Marek

Przegląd Geofizyczny

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2019

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Z. 1-2

167--183

PL

Nie ma wątpliwości co do znaczącego wkładu Wawrzyńca Teisseyre’a i Alexandra Tornquista w wyznaczenie przebiegu SW krawędzi kratonu wschodnioeuropejskiego w Europie Centralnej (Teisseyre 1893, 1903; Tornquist 1908, 1910; rys. 1). Teisseyre jako pierwszy udokumentował SW krawędź horstu podolskiego (linia Berdo-Narol), jednak w swoich pracach powoływał się na wcześniejsze prace innych geologów: Wilhelma Blöde (1830, 1845), Aloisego Altha (1874, 1881), Józefa Siemiradzkiego i Emila Dunikowskiego (1891), oraz Eduarda Suessa (1883-1888). Również Tornquist wykorzystywał wyniki swoich poprzedników: Alberta Schücka (1899, 1902), Wilhelma Deecke (1906) i Hansa Preußa (1910). Linia Teisseyre’a-Tornquista (TTL) w jej południowej części biegnie SW skrajem horstu podolskiego wzdłuż linii Berdo-Narol (Teisseyre 1893, 1903), a w części północnej wzdłuż SW krawędzi płyty bałtyckiej, linii Skania-Łysogóry (Tornquist 1908, 1910). Obie linie spotykają się w pobliżu Sandomierza (rys. 3). Nowoczesne badania geofizyczne pokazują, że krawędź kratonu jest ważną strukturą litosfery, dobrze widoczną w tomografii sejsmicznej, na mapie głębokości granicy Moho (rys. 6), w ano¬maliach grawitacyjnych i magnetycznych (rys. 7), jak również w badaniach strumienia ciepła i elektromagnetycznych. Położenie SW krawędzi kratonu określone przez różnych autorów może się różnić nawet o 50 km. Z tego powodu częściej używany jest termin „strefa” niż „linia”. Terminy opisujące SW krawędź kratonu powinny być rozumiane tak jak poniżej. Linia Teisseyre'a-Tornquista (TTL) jest elementem liniowym, ostrą krawędzią cokołu krystalicznego górnej ("granitowej") skorupy ziemskiej kratonu. Strefa Teisseyre'a-Tornquista (TTZ) jest strefą o szerokości do kilkudziesięciu kilo¬metrów związaną z krawędzią kratonu. W pokrywie osadowej może przejawiać się systemem uskoków. Kontynuacją TTZ na północy jest strefa Sorgenfrei-Tornquista (STZ). Strefa szwu transeuropejskiego (TESZ) jest terminem określającym zespół terranów pomiędzy kratonem wschodnioeuropejskim i platformą paleozoiczną; TESZ nie należy mylić z TTL, TTZ i STZ.

EN

There is no doubt in a significant contribution of Wawrzyniec Teisseyre and Alexander Tornquist in the determination of the SW edge of the East European Craton (Teisseyre 1893, 1903; Tornquist 1908, 1910; fig. 1). Wawrzyniec Teisseyre first documented SW edge of the Podolian horst (Berdo-Narol line), however in his papers he mentioned earlier contributions of other geologists: Wilhelm Blöde (1830, 1845), Alois Alth (1874, 1881), Józef Siemiradzki and Emil Dunikowski (1891), and Eduard Suess (1883-1888). Similar in the case of Alexander Tornquist – earlier contributions of Schück (1899, 1902), Deecke (1906) and Preuß (1910), has benefited him by designating the southwest edge of the crystalline East European Craton (EEC). The Teisseyre-Tornquist Line (TTL) follows in its southern part the SW edge of the Podolian horst, along Berdo-Narol line (Teisseyre, 1893, 1903) and in its northern part along the SW edge of the Baltic plate, Scania-Łysogóry line (Tornquist, 1908, 1910). Both lines meet together closely to Sandomierz (fig. 3). Modern geophysical investigations show that the edge of the craton is a major lithospheric structure, well seen in seismic tomography, Moho depth map (fig. 6), gravity and magnetic (fig. 7) data, as well as in terrestrial heat flow and electromagnetic investigations. The location of SW edge of the EEC determined by different authors is different and the variation in location may reach up to 50 km. It could be reason, that instead of “line” a term “zone” is mostly used. However, the understanding of terms describing SW edge of the EEC should be as bellow. Teisseyre-Tornquist Line (TTL) conceived as a linear feature is border of crystalline, “granitic” upper crust of the EEC. Teisseyre-Tornquist Zone (TTZ) is a few tens of kilometers wide zone related to craton edge. In the sedimentary cover it could manifests itself as a system of faults. To the north it continues as Sorgenfrei-Tornquist Zone (STZ). Trans-European Suture Zone (TESZ) is a term for an assemblage of suspect terranes boarded by the EEC and Paleozoic Platform; TESZ should not be mistaken with TTL, TTZ and STZ.

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Relative secular variations of the Earth’s magnetic field in the years1966–2016 along the profile across the main tectonic units of Poland (Zgorzelec-Wiżajny profile)

Wojas Anna, Grabowska Teresa

Geology, Geophysics and Environment

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2019

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Vol. 45, no. 3

183--194

EN

The paper summarizes 50 years of research on relative local secular variations of the total magnetic intensity (TMI) along Zgorzelec-Wiżajny profile (Z-W profile) through the years 1966–2016. The Z-W profile (approximately 650 km length) cuts through Europe’s major tectonic units, including a zone of Variscan folds in the Paleozoic platform (PP), the Trans-European Suture Zone (TESZ) and the Polish part of the East European Craton (EEC). Measurements of TMI were made at 31 sites of the profile and reduced to the base recordings at the Central Geophysical Observatory in Belsk. Based on linear approximations of relative geomagnetic field values changes in time, relative annual changes in time (relative secular variations) expressed in nanoteslas [nT] per year were calculated. The study on relative geomagnetic field values revealed slower secular variations of the geomagnetic field in EEC as compared to those in PP and TESZ. However, they show lower amplitudes of these variations. An interesting phenomenon are rapid changes in the time of the relative values (trends) of TMI starting from the year 2000, also expressed as the relative secular variations per year, particularly visible in PP area. In the qualitative sense, relative secular variations show a correlation with the main geological units in the Polish territory and also important elements in the seismic and geothermal model of the lithosphere.

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Preface : Unconventional hydrocarbon accumulations in the East European Craton in Poland

Golonka Jan, Porębski Szczepan J., Bębenek Sławomir

Annales Societatis Geologorum Poloniae

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2019

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Vol. 89, No. 4

343-- 346

EN

This collection of eight papers is a follow-up to the series of articles that appeared in Issue 2 of ASGP Volume 89 (see also Golonka and Bębenek, 2017). [...]

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Graptolite biostratigraphy and dating of the Ordovician–Silurian shale succession of the SW slope of the East European Cratond

Podhalańska Teresa

Annales Societatis Geologorum Poloniae

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2019

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Vol. 89, No. 4

429--452

EN

This paper deals with the graptolite biostratigraphy and age determination of the Ordovician and Silurian lithological successions of the Baltic, Podlasie and Lublin basins that existed during the early Palaeozoic on the SW slope of the East European Craton. The biostratigraphic research described was conducted on core material coming from old boreholes and cores from several new wells. Graptolite zones were identified and the chronostratigraphic succession was constrained, with the depths to the stratigraphic units, especially those considered prospective for petroleum, being determined in the individual borehole sections. Old local stratigraphic schemes of the Silurian used for many years in the Polish geological literature are correlated with the standard schemes. The most complete succession of graptolite zones, both in the Ordovician and the Silurian, is observed in the Baltic region. The number of stratigraphic gaps increases towards the east and southeast of the regions. The stratigraphic range of the Sasino Shale Formation decreases in this direction; in the Podlasie and Lublin regions, it comprises only the Katian Stage. The stratigraphic range of the Jantar Formation in the western part of the area spans not only the Rhuddanian but also part or the whole of the Aeronian. In the Podlasie and especially the Lublin regions, sedimentation of the Jantar Formation began in the latest Rhuddanian–Aeronian. A large stratigraphic gap, spanning part or the whole of the Llandovery and increasing eastwards, was documented in the Podlasie-Lublin region. The biostratigraphic research allowed a more precise constraint on the temporal and spatial extent of erosion of Pridoli deposits and the beginning of coarse-grained, siliciclastic sedimentation (Kociewie Formation) in the Baltic Basin.

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Burial and thermal history of the Lower Palaeozoic petroleum source rocks at the SW margin of the East European Craton (Poland)

Botor Dariusz, Golonka Jan, Anczkiewicz Anneta A., Dunkl István, Papiernik Bartosz, Zając Justyna, Guzy Piotr

Annales Societatis Geologorum Poloniae

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2019

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Vol. 89, No. 2

121--152

EN

Thermal maturity modelling was carried out in over sixty wells along the SW margin of the East European Craton (EEC). The burial and thermal history modelling of the EEC, using thermochronological data, allowed the construction of burial history maps showing its geological development in the Phanerozoic. These results have proved that the Ordovician and Silurian source rocks occurring at the SW margin of the EEC reached a maximum palaeotemperature in the Palaeozoic, mainly during Devonian-Carboniferous time and at the latest during the Silurian in the most westerly part of this margin, along the Teisseyre-Tornquist Zone. In Mesozoic and Cainozoic time, the Ordovician and Silurian strata generally were subjected to cooling or to very minor heating, certainly below the Variscan level. The maximum burial and maximum temperature of the Ediacaran-Lower Palaeozoic strata were reached during the Early Carboniferous in the Baltic Basin and during the Late Carboniferous in the Lublin area, and even in the Early Permian in the SE corner of the Lublin Basin. Thus, the main period of maturation of organic matter and hydrocarbon generation in the Ordovician and Silurian source rocks was in the Late Palaeozoic (mainly Devonian-Carboniferous) and in the westernmost zone along the Teisseyre-Tornquist line at the end of the Silurian.

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Zachodnie przedpole kratonu wschodnioeuropejskiego : paleozoiczne terrany czy marginalna część kontynentu Bałtyki?

Mizerski W., Olczak-Dusseldorp I.

Przegląd Geologiczny

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2017

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Vol. 65, nr 12

1521--1528

EN

Provenance of the tectonic blocks located in the recent, western foreland of the East European Craton in Poland is subject to debate. These blocks are regarded either as Avalonian blocks adjacent to the East European Craton along the T-Tzone or accretional wedge (or its fragments) formed during the collision of Baltica and Avalonia. This implies that the western edge of the Baltica Continent was active, with a subduction zone developed along which Avalonian blocks and Baltica should be smashing together Baltica. However, no objective geological facts indicate the occurrence of a subduction zone along the present-day SW edge of the East European Craton. On the contrary, there are many evidences indicating the sedimentation taking place in a continental passive margin during the Palaeozoic and there is no proof that the older Palaeozoic rocks are thrust over the Baltic margin. Consequently, tectonic deformation in Palaeozoic rocks, recorded in the present-dayforeland of the East European Craton, are related to the mobility of the craton margin and should be regarded as platform-type deformation.

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O nowych rozwiązaniach tektonicznych w „Atlasie geologicznym Polski”

Aleksandrowski P., Mazur S.

Przegląd Geologiczny

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2017

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Vol. 65, nr 12

1499--1510

EN

Authorial comprehensive comments and explanations are given to some of the interpretations applied in the tectonic part of the newly published Geological Atlas of Poland (Nawrocki, Becker, 2017) that considerably change the hitherto generally accepted concepts. It should be, however, admitted that most of those "new’" solutions were already proposed in the past by other workers as hypotheses that could not have been tested in the then state of knowledge on Poland’s deep geology and scientific tools at hand. This has now changed with abundant new data obtained with modern seismic techniques and advanced methods of potential field modelling. Using those data, we justify the reasons for, among others, a significant eastward shifting the front of the Variscan Orogen in Poland andfor the accompanying change in position of the division line between the Precambrian and Palaeozoic platforms. We also show the rationale for accepting a far-reaching southwestward extent of the East European Craton’s crystalline basement below the Palaeozoic Platform and for reinterpretation of the Teisseyre-Tornquist Zone’s nature, together with the question of early Palaeozoic terranes in the TESZ and the situation of the Caledonian foredeep at the SW margin of the East-European Craton.

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Rozpoznanie stref perspektywicznych występowania niekonwencjonalnych złóż węglowodorów w Polsce : nowe wyniki oraz dalsze kierunki badań

Podhalańska T., Waksmundzka M. I., Becker A., Roszkowska-Remin J.

Przegląd Geologiczny

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2016

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Vol. 64, nr 12

953--962

EN

Studies that have recently been carried out by the Polish Geological Survey aim at, among others, deepening and supplementing the knowledge of unconventional hydrocarbon systems in Poland, including petroleum systems of the lower Palaeozoic in the Polish part of the East European Craton and of the Carboniferous in the South-Western Poland. The article presents the main principles and objectives of the research and the results of the project titled “Identification of prospective zones for unconventional hydrocarbon accumulations in Poland, stageI”,which is the only project that uses a wide range of recently conducted regional geology research and laboratory analyses, integrated with geological information derived from newly drilled boreholes. Geological constraints for the occurrence of unconventional hydrocarbon deposits in the Cambrian, Ordovician Silurian and Carboniferous rocks are presented. What is emphasized is the need to continue the work and to extend it to new research directions aimed at petroleum system modelling (e.g.burial history and analysis of hydrocarbon generation), and the need to refine and clarify some of the results obtained, supplementing them with an analysis of the latest data from newly drilled boreholes.

12

Petrografia i mineralogia łupków niższego paleozoiku kratonu wschodnioeuropejskiego oraz piaskowców karbonu podłoża monokliny przedsudeckiej

Sikorska-Jaworowska M., Kuberska M., Kozłowska A.

Przegląd Geologiczny

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2016

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Vol. 64, nr 12

963--967

EN

The study deals with clay-silt shales occurring in the lower Palaeozoic basin at the western slope of the East European Craton, and sandstones known from the Carboniferous Basin of SW Poland (basement of theFore-SudeticHomocline).The clay groundmass of the shales consistslargely of illite, and the silt fraction is made up of quartz with a variable admixture of feldspars. Quartz and carbonate cements are common, while pyrite, kaolinite and phosphate cements are rare. The clay groundmass reveals microporosity in the form of microchannels paralleling illite plates, and visible with in mica packets. Carboniferous sandstones are represented mostly by sublithic or subarkosic wackes and rarely by lithic, sublithic or subarkosic arenites. The pore space between sand grains is completely filled by clayey matrix. Both porosity and permeability are very low in the sandstones.

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Proterozoiczne podłoże krystaliczne polskiej części Bałtyku w świetle badań strukturalnych

Cymerman Z.

Przegląd Geologiczny

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2015

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Vol. 63, nr 4

228–-238

EN

This paper presents structural data and regional correlations based on drill cores from 8 boreholes (B2-1/80, B3-1/81, B4-1/81, B6-1/82, B6-2/85, B7-1/91, B16-1/85 and B21-1/95) penetrating Precambrian crystalline rocks in the Polish part of the Baltic Sea. The crystalline rocks from the ftom these boreholes were compared to cores from several wells in Eastern Pomerania, and the Kashubian and Warmia regions and above all with the Mesoproterozoic granitoids and metamorphic rocks of Bornholm and Southern Sweden. The pre-existing basement map of the Southern Baltic, showing Palaeoproterozoic or even Archaean granitoid massifs and narrow north-south fold belts is questioned. Instead, in the present interpretation, the studied area of the Polish part of the Southern Baltic Sea is underlain by a fragment of the Mesoproterozoic (ca. 1.47–1.43 Ga) Danopolonian („Hallandian”) orogeny, comprising mainly regional-scale ductile shear zones, which, striking probably in W–E to WNW–ESE directions, are characterized by the predominance of a thrust to transpressional strain regime with tectonic transport top-to-the S or SSW. The structural kinematic and lithological interpretations of these shear zones are based on comparison with the other parts of the East European Craton that are exposed in Bornholm and the Blekinge and Skne regions in Southern Sweden.

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Induction Sounding of the Earth's Mantle at a New Russian Geophysical Observatory

Moilanen J., Pushkarev P.Yu.

Acta Geophysica

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2015

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Vol. 63, no. 2

385--397

EN

Deep magnetotelluric (MT) sounding data were collected and processed in the western part of the East European Craton (EEC). The MT sounding results correspond well with impedances obtained by magnetovariation (MV) sounding on the new geophysical observatory situated not far from the western border of Russia. Inversion based on combined data of both induction soundings let us evaluate geoelectrical structure of the Earth’s crust and upper and mid-mantle at depths up to 2000 km, taking into account the harmonics of 11-year variations. Results obtained by different authors and methods are compared with similar investigations on the EEC such as international projects CEMES in Central Europe and BEAR in Fennoscandia.

15

Mapa geologiczna podłoża krystalicznego polskiej części platformy wschodnioeuropejskiej : podsumowanie projektu badawczego

Krzemiński L., Krzemińska E., Petecki Z.

Przegląd Geologiczny

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2014

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Vol. 62, nr 6

288--289

EN

A new geologic map of the crystalline basement of NE Poland has been constrained on the basis of the magnetic and gravity imaging, data from seismic profiles of POLONAISE'97 and CELEBRATION'2000, and extensive geochemical, isotopic and U-Pb dating studies of drill core samples. This updated reconstruction of the hidden southwestern margin of the East European Craton revealed of several late Svecofennian orogenic domains with ages in the range 2.0–1.74 Ga, belonging to the Fennoscandia. The age of these Paleoproterozoic domains is becoming regionally younger towards NW. Furthermore, there is two Paleoproterozoic domains, which form integral part of the westernmost youngest rim of the Sarmatia block. During the early Mesoproterozoic between 1.54 and 1.45 Ga intracratonic plutons of the AMCG suite intruded a large area of the Mazury-Warmia, Pomorze and SE Baltic region. Several deep-sourced ultramafic-alkaline bodies of Early Carboniferous age (354–338 Ma) are related to the youngest magmatic event.

16

Graptolity : narzędzie stratygraficzne w rozpoznaniu stref perspektywicznych dla występowania niekonwencjonalnych złóż węglowodorów

Podhalańska T.

Przegląd Geologiczny

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2013

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Vol. 61, nr 8

460–-467

EN

In connection with the exploration of zones prospective for the occurrence of unconventional hydrocarbon deposits, numerous studies of source rocks have been conducted in Poland. Stratigraphic examinations are among the basic elements. The main group of fossils occurring in shale successions, being a potential source of hydrocarbons, is graptolites. This paper describes the assemblages of graptolites from Ordovician and Silurian deposits and shows their importance for the stratigraphy of shale complexes. Due to their abundance and rapid evolution, graptolites are an excellent tool for biostratigraphic dating, regional correlations and biozonation of rock successions in terms of the high-resolution sequence stratigraphy. The paper presents the significance of taphonomic research of graptolites to identify zones of increased accumulation of hydrocarbons in rocks. It has been found that graptolites are an equally important instrument, in addition to elevated TOC values or increased gamma ray radiation on well logs, that allows identification of potential source rocks for hydrocarbons, including shale gas.

17

Graptolites – stratigraphic tool in the exploration of zones prospective for the occurrence of unconventional hydrocarbon deposits

Podhalańska T.

Przegląd Geologiczny

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2013

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Vol. 61, nr 11-1

621--629

EN

In connection with the exploration of zones prospective for the occurrence of unconventional hydrocarbon deposits, numerous studies of source rocks have been conducted in Poland. Stratigraphic examinations are among the basic elements. The main group of fossils occurring in shale successions, being a potential source of hydrocarbons, is graptolites. This paper describes the assemblages of graptolites from Ordovician and Silurian deposits and shows their importance for the stratigraphy of shale complexes. Due to their abundance and rapid evolution, graptolites are an excellent tool for biostratigraphic dating, regional correlations and biozonation of rock successions in terms of the high-resolution sequence stratigraphy. The paper presents the significance of taphonomic research of graptolites to identify zones of increased accumulation of hydrocarbons in rocks. It has been found that graptolites are an equally important instrument, in addition to elevated TOC values or increased gamma ray radiation on well logs, that allows identification of potential source rocks for hydrocarbons, including shale gas.

18

Alkaliczna intruzja syenitowa Mławy a perspektywy występowania pierwiastków ziem rzadkich

Krzemińska E., Krzemiński L.

Biuletyn Państwowego Instytutu Geologicznego

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2012

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nr 448 (2)

401--407

PL

Obecność kilku alkalicznych i alkaliczno-ultramaficznych ciał w obrębie zakrytego podłoża kratonu wschodnioeuropejskiego na obszarze północno-wschodniej Polski była znana od dawna, na podstawie badań geofizycznych, jako wyraźne anomalie Ełku, Pisza, Tajna i Mławy. Jedynie cztery głębokie otwory wiertnicze na peryferiach anomalii Mławy (Płońsk IG 2A/2, Ciechanów 1, Konopki Wielkie 1 i Gradzanowo 2) odsłoniły syenity i kwarcowe syenity. Metaluminowe, bogate w pierwiastki ziem rzadkich (REE) i Zr syenity Mławy są względnie późnym produktem procesów frakcjonowania magmy. Analizy chemiczne w mikroobszarze potwierdziły obecność pierwotnych fluorowęglanów REE (bastnäsyt, parisyt) i obfitość cyrkonu jako faz bogatych w REE i Zr w syenitach. Istotna koncentracja minerałów nośników REE ma genetyczne i przestrzenne związki ze skałami alkalicznymi, dlatego intruzja Mławy powinna być obiektem dalszych badań.

EN

A number of alkaline and alkaline-ultramafic bodies have been known within the hidden basement of the East European Craton (EEC) in north-western Poland for a long time. These are the strong anomalies of Ełk, Pisz, Tajno and Mława identified based on a geophysical survey. Syenite and quartz syenites, were drilled by only four deep boreholes on the periphery of the Mława anomaly (Płońsk IG 2A/2, Ciechanów 1, Konopki Wielkie and Gradzanowo 2). The REE- and Zr-rich Mława metaluminous syenites are relatively late-stage products of fractionation processes. Electron microprobe analyses confirm primary-appearing REE-fluorocarbonate (bastnäsite–parisite) and zircon abundance as major host phases to REE and Zr in the syenites. A significant concentration of the REE-bearing minerals shows a genetic and spatial relation to an alkaline rocks, therefore the Mława igneous bodies should be the subject of further investigations.

19

Seismic wave velocities in the sedimentary cover of Poland: Borehole data compilation

Grad M., Polkowski M.

Acta Geophysica

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2012

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Vol. 60, no. 4

985-1006

EN

A knowledge of seismic wave velocities in the sedimentary cover is of great importance for interpreting reflection and refraction seismic data, deep seismic soundings and regional and global seismic tomography. This is particularly true for regions characterized by significant thicknesses and a complex sedimentary cover structure. This paper presents the results of an analysis of seismic P-wave velocities in the sedimentary cover of Poland, a complex area of juxtaposition of major tectonic units: the Precambrian East European Craton, the Palaeozoic Platform of Central and Western Europe, and the Alpine orogen represented by the Carpathian Mountains. Based on vertical seismic profiling data from 1188 boreholes, the dependence of velocity versus depth was determined for regional geological units and for successions from the Tertiary and Quaternary to the Cambrian. The data have been approximated by polynomials, and velocity-depth formulas are given down to 6000 m depth. The velocities in the sedimentary cover have been compared with those from other areas in Europe.

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Potencjał występowania złóż gazu ziemnego w łupkach dolnego paleozoiku w basenie bałtyckim i lubelsko-podlaskim

Poprawa P.

Przegląd Geologiczny

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2010

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Vol. 58, nr 3

226-249

EN

The Lower Palaeozoic basin at the western slope of the East European Craton (EEC) (Fig. 1) is currently recognized as one of the most interesting areas for shale gas exploration in Europe. The Upper Ordovician and/or Lower Silurian graptolitic shale is here the major potential reservoir formation (Figs. 2, 3) (Poprawa & Kiersnowski, 2008; Poprawa, 2009). Moreover, the Upper Cambrian to Tremadocian Alum shale is an additional target locally in the northern part of the Baltic Basin. These sediments are often rich in organic matter (Klimuszko, 2002; Poprawa & Kiersnowski, 2008; Więcław et al., 2010; Skręt & Fabiańska, 2009), as well as silica. Limited data from two wells in the western part of the Baltic Basin show silica contents up to 60-70% (Fig. 4) (Krzemiński & Poprawa, 2006). The advantage of the Lower Palaeozoic shale from the western slope of EEC is its broad lateral extend (Fig. 1) and relatively quiet tectonic setting. The later is particularly true in the case of the Baltic Basin and Podlasie Depression. Structural development becomes to some extent more complex in the case of the Lublin region, where the Lower Palaeozoic shale appears affected by late Famennian to early Visean block tectonics. Development of the organic rich Lower Palaeozoic shale at the western slope of EEC was controlled by several factors. Very important was here the rate of non-organic detritus deposition (Fig. 5). The other factors included organic productivity of the basin, its subsidence, relative sea level changes, basin bathymetry, geochemical conditions at the sea bottom (especially oxygenation), degree of bioturbation, presence of topographic barriers at the sea bottom, leading to development of isolated anoxic zones, sea currents configuration, and climate changes. Organic matter of the Lower Palaeozoic is characterized by presence of II type of kerogen. Appearance of the organic-rich shale within the Lower Palaeozoic section at the western slope of the EEC is diachronic (Fig. 6). From NW towards east and SE, the intervals richest in organic appear related to systematically younger strata, starting from the Upper Cambrian to Tremadocian, as well as the Upper Llanvirn and Caradoc in the Łeba Elevation (northern onshore Baltic Basin; Fig. 7). In central parts of the Baltic Basin and Podlasie Depression as well as NW part of the Lublin region, the intervals richest in organic matter are found in the Llandovery section, while in the eastern part of the Baltic Basin and SE part of the Lublin region the highest TOC contents are found in the Wenlock. Therefore, depending on location at the western slope of EEC, different formations are recognized as the targets for shale gas exploration. The Upper Cambrian to Tremadocian shale, present only in the northern part of the Baltic Basin, is characterized by very high contents of organic matter, with average value for individual sections usually ranging from 3 to 12% TOC. This shale formation is, however, of very limited thickness, not higher than several meters in the onshore part of the basin (Szymański, 2008; Więcław et al., 2010). In onshore part of the studied area, thickness of the Caradoc shale changes from a few meters up to more than 50 m (Modliński & Szymański, 1997, 2008). Contents of organic matter in these sediments are the highest in the Łeba Elevation zone and the basement of the Płock-Warszawa trough, where average TOC contents in individual well sections range from 1% to nearly 4%. Ashgill rocks are characterized by high TOC contents only in the Łeba Elevation zone, where average TOC values for individual well sections rise up to 4,5% at the most. Llandovery shale has high TOC contents, particularly in its lower part, throughout vast parts of the western slope of EEC. The maximum measured TOC contents in those rocks in Podlasie Depression are nearly 20%. Average TOC values for individual sections of the Llandovery are usually equal 1% do 2,5%, except for the Podlasie Depression, where they may reach as much as 6%. Thickness of the Llandovery shale generally increases from east to west to approximately 70 m at the most. However, in the major part of that area it ranges from 20 to 40 m (Modliński et al., 2006). Thickness of theWenlock sediments is also highly variable laterally, from less than 100 m in SE part of the Lublin region to over 1000 m in western part of the Baltic Basin. Average content of organic matter in individualWenlock sections in central and western parts of the Baltic Basin and the Podlasie Depression usually ranges from 0,5% to 1,3% TOC. In the eastern part of the Baltic Basin and in the Lublin region it is higher, rising to about 1-1,7% TOC. The above mentioned TOC values show the present day content of organic matter, which is lower than the primary one. The difference between the present and primary TOC contents increases along with increasing thermal maturity. It is also highly dependant on genetic type of kerogen. Taking into account the II type of kerogen from the analyzed sediments, it may be stated that in the zones located in the gas window the primary TOC was at least one-half greater than indicated by laboratory measurements. From the shale gas point of view, the basins at the western slope of EEC are characterized by a negative relation between depth at present day burial and thermal maturity (Poprawa & Kiersnowski, 2008). In the zones with burial depth small enough to keep exploration costs at very low level (Fig. 8), thermal maturity of shales is too low for gas generation (Figs. 9, 12a). Maturity increases westwards (Fig. 8) along with depth of burial (Fig. 9). Thus, the potential shale gas accumulations in the western part of the studied area occur at depths too high for commercial gas exploration and exploitation (Fig. 12b). Between of the zone of maturity too low for shale gas development and that where depth of burial is too large for its exploration, there occurs a broad zone of the Lower Palaeozoic shale with increased shale gas exploration potential (Fig. 13) (Poprawa & Kiersnowski, 2008; Poprawa, 2009). In that area, there are shale intervals of relatively high thickness and average TOC exceeding 1-2% TOC (Fig. 7, 10, 12c). Thermal maturity of these rocks appears sufficient for generation of gas (Fig. 9, 10), and results of well tests for deeper-seated conventional reservoirs suggest good quality of dry gas with no nitrogen (Fig. 12c). It should be noted that some gas shows have been recorded in the Lower Palaeozoic shale. Moreover, depth of burial is not too large for commercial shale gas exploration (Fig. 8, 10). Hydrocarbon shows and their composition in the Lower Palaeozoic are strictly related to thermal maturity of the source rock. In the zones of low maturity, these are almost exclusively oil shows documented. Further westwards, in the zone transitional to the gas window area, gas is wet and contains significant contribution of hydrocarbon gases higher than methane.Within the gas window zone, the records are almost exclusively limited to methane shows. Moreover, within the zones of low maturity high nitrogen contents were recorded (Poprawa, 2009). In the zones characterized by thermal maturity in the range from 0,8 to 1,1% Ro and very high TOC contents (over 15% at the most), there is a potential for oil shale exploration. The zones with the highest oil shale potential include eastern Baltic Basin in SW Lithuania and NE part of the Podlasie Depression. Some data necessary for entirely firm estimations of potential shale gas resources of the Lower Palaeozoic complex in Poland are still missing. However, preliminary estimates indicate that these shale gas resources may possibly be classified as gigantic (1,400-3,000 bln m3 of recoverable gas; Fig. 15). For comparison, resources of conventional gas in Poland are equal to 140,5 bln m exp.3, and annual domestic gas consumption is at the level of 14 bln m exp. 3. However, it should be noted that some characteristics of the Lower Palaeozoic complexes indicate increased exploration risk. The average TOC contents are here lower than in classic examples of gas shales, like e.g. Barnett shale. Moreover, in the zone of optimal burial depth (less than 3000–3500 m) thermal maturity is lower than in the case of the Barnett shale core area. An important risk factor is also both a limited amount and limited resources of conventional gas fields in the Lower Palaeozoic complex (Fig. 13). Amount and intensity of gas shows in the Lower Palaeozoic shale are also relatively low, and there is no evidences for presence of overpressure in this complex. In the eastern part of western slope of the EEC, there appears an additional risk factor-arelatively high content of nitrogen in gas.