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Cor re la tion of re gional litostratigraphic units (based on Jankowski et al., 2012b) in which out crops with sand injectites were doc u mented Cen tral Carpathian Paleogene: 1 -Ostrysz Beds, 2 -Chochołów Beds, 3 -Zakopane Beds, 4 -Szaflary Beds, 5 -Num mu lite Beds; Silesian Unit: 1 -Up per Krosno Beds, shale mem ber, 2 -Up per Krosno Beds, sandstone-shale mem ber, Niebylec Shales, 3 -Ostre Sand stones, 4 -Gorlice Beds, 5 -Lower Krosno Beds, sandstone mem ber (Lesko Sand stones), 6 -Lower Krosno Beds, sand stone-shale mem ber, 7 -Jasło Lime stone, 8 -Lower Krosno Beds, Otryt Sand stones, 9 -Zatwarnica Beds, 10 -Tran si tion Beds, 11 -Menilite Beds, 12 -Globigerina Marls, 13 -Green Shales, 14 -Hi ero glyphic Beds; Skole Unit: 1 -Leszczawka Diatomites, 2 -Upper Krosno Beds, sand stone-shale mem ber, 3 -Up per Krosno Beds, sand stone-shale mem ber, 4 -Niebylec Shales, 5 -Lower Krosno Beds, 6 -Tran si tion Beds, 7 -Łopianiec Beds, 8 -Menilite Beds, Kliwa Sand stones, 9 -Jasło Lime stone, 10 -Dynów Marls and Cherts, 11 -Siedliska Con glom er ates, 12 -Boryslav Sand stones, 13 -Subcherts Beds, 14 -Globigerina Marls, 15 -Popeli Beds, 16 -Pasichna Beds, 17 -Hi ero glyphic Beds; Vrancea Unit: 1 -Doftana Beds, 2 -Brebu Con glom er ates, 3 -Salt Beds, 4 -Slon Beds, 5 -Gyp sum Beds (Gura Soimului Beds, Gura Misina Beds), 6 -Up per Dysodilic Shales, 7 -Kliwa Sand stones, 8 -Lower Dysodilic Shales, Bi tu mi nous Marls, Menilite Beds, 9 -Globigerina Marls, Lucăceşti Sand stones, 10 -Bisericani Beds; Boryslav-Pokuttya Unit: 1 -Balychi Beds, 2 -Stebnik Beds, 3 -Dobrotiv Beds, 4 -Sloboda Con glom er ates, 5 -Vorotyscha Beds, 6 -Polanitsia Beds, 7 -Rusiv Con glom er ates, 8 -Menilite Beds, Boryslav Sand stone, 9 -Popeli Beds, 10 -Bystrytsia Beds, 11 -Vytkivtsi Beds
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The irregular distribution of sand injections, traditionally termed ‘dykes’ in the Polish geological literature, within individual Carpathian units and within individual lithofacies were observed during long-lasting field works. Injectites have been observed in the Magura Beds and in the Inoceramian Beds of the Polish and Romanian Carpathians, and...
Contexts in source publication
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... and in fill ing. Most of this field work was performed in the Outer Carpathians (Outer Flysch Carpathians) and within the Cen tral Carpathian Paleogene in the In ner Carpathians (Cen tral or West ern Carpathians in the Slo vak liter a ture; Fig. 1) in Po land (within the out crops of the Cen tral Carpathian Paleogene, Silesian and Skole units; Figs. 2 and 3), Ukraine (Boryslav-Pokuttya Unit; Figs. 1 and 3) and Ro ma nia (Vrancea Unit, so-called Mar ginal Folds; Figs. 1 and 3). As injectites were doc u mented in a to tal of 21 out crops (Figs. 2 and 3) over a rel a tively broad area, the amount of data col lected is large enough for a re gional-scale anal y sis and to pro pose a model that ...
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... of this field work was performed in the Outer Carpathians (Outer Flysch Carpathians) and within the Cen tral Carpathian Paleogene in the In ner Carpathians (Cen tral or West ern Carpathians in the Slo vak liter a ture; Fig. 1) in Po land (within the out crops of the Cen tral Carpathian Paleogene, Silesian and Skole units; Figs. 2 and 3), Ukraine (Boryslav-Pokuttya Unit; Figs. 1 and 3) and Ro ma nia (Vrancea Unit, so-called Mar ginal Folds; Figs. 1 and 3). As injectites were doc u mented in a to tal of 21 out crops (Figs. 2 and 3) over a rel a tively broad area, the amount of data col lected is large enough for a re gional-scale anal y sis and to pro pose a model that cor re lates the or i gin of injectites with the stages of the evo lu tion of the Carpathian orogenic belt. ...
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... cesses of short en ing and tectonization led to the for mation of sev eral tec tonic units that can be cor re lated based on litho-and biostratigraphy (Fig. 3). Sed i men tary se quences within each of these units con sis tently be come youn ger to wards the fore land area (Fig. 3). Tra di tion ally, these units have been con sid ered as tectono-fa cies units and their sed i men tary sequences were thought to have orig i nated within sep a rate basins/sub-bas ins (Ksiąkiewicz, 1972;Oszczypko ...
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... cesses of short en ing and tectonization led to the for mation of sev eral tec tonic units that can be cor re lated based on litho-and biostratigraphy (Fig. 3). Sed i men tary se quences within each of these units con sis tently be come youn ger to wards the fore land area (Fig. 3). Tra di tion ally, these units have been con sid ered as tectono-fa cies units and their sed i men tary sequences were thought to have orig i nated within sep a rate basins/sub-bas ins (Ksiąkiewicz, 1972;Oszczypko et al., 2006). How ever, some stud ies in di cate these tra di tion ally dis tinguished units are only tec tonic in na ture ...
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... re cent field work data have in di cated that, in the Outer Carpathians and in the Cen tral Carpathian Paleogene rocks, sand injectites oc cur most fre quently within the sand stone --mudstone and si li ceous-mudstone sed i men tary suc ces sions. In the Outer Carpathians their oc cur rences have been most com monly ob served within the out crops of the Menilite Beds in the Silesian and Skole units in Po land (Figs. 2 and 3), the Boryslav-Pokuttya Unit in the Ukraine, and the Vrancea Unit in Ro ma nia (Figs. 1 and 3). ...
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... al ready stated, most clastic dykes ob served dur ing this study oc cur within the Oligocene-Mio cene Menilite Beds of the sed i men tary suc ces sions of the Skole Unit and its Ro ma nian equiv a lent, the Vrancea Unit (Figs. 2 and 3). The Menilite Beds, and its east ern and west ern strati graphic equiv a lents re spec tively, con tain the most lithologically di verse suc cessions, in clud ing for ex am ple black bi tu mi nous shales, the Dysodilic Shale, Kliwa sand stones, etc. (Fig. 8A-D). ...
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... clastic injectites in ves ti gated dur ing the pres ent study oc cur typ i cally in the Skole Unit (Figs. 2 and 3) within de pos its as signed to the Menilite and Menilite-Krosno sys tems. These strata con tain much ev i dence of shal low ma rine sed i men ta tion (Jarmołowicz-Szulc and Jankowski, 2011;Matyasik et al., 2012). ...
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Citations
... On the other hand, sandstone dikes in menilite shales are interpreted here as the effects of liquefaction of unlithified sand layers caused by seismic events. We interpret the combination of these two phenomena as the earliest signals of uplift initiated in the source area (Fig. 21), accompanied by seismic shocks (Siemińska et al., 2018;Jankowski & Wysocka, 2019). A massive sandstone interval is interpreted as the result of deposition out of high-density turbidite within a distribution channel, eroded and extending into the open menilite basin. ...
Five day field trip focused on Mesozoic and Cenozoic development of the Outer (Flysch) and Inner (Pieniny Klippen Belt) Carpathians in Polish, Slovak and Czech parts of this orogen. All localities and their regional and European context are connected with Alpine-Carpathians-Dinaridic-Hellenidic-etc-etc-Himalayas recent structures and paleogeographical/paleogeodynamical relationships of the Mesozoic/Cenozoic history of the Neotethys with some comparisons between Western and Eastern Tethys – as in our IGCP 710 title – Western Tethys meets Eastern Tethys.
During the route of the trip in the Outer Carpathians the selected intervals of the classical Carpathian flysch sequence were presented. On the one hand, the trip was focused on the oldest deposits in the Carpathians, i.e. late Jurassic – Early Cretaceous in age, formed in the pre-compressional phase of the Carpathian orogen. These include black clayey or calcareous shales, pelagic limestones with turbidites (including rare example of calcareous turbidites with ooids), and other mass-movement deposits, as well as related volcanics, including basaltic pillow lavas (Early Cretaceous) related to the opening of the Silesian Basin in the Czech part of the Outer Carpathian domain. On the other hand, outcrops of much younger deposits, Oligocene in age, were visited, as they represent the final phase of development of the Carpathian sedimentary basin, i.e. (i) the Menilite Formation recording the anoxic episode of the Carpathian basin development, and known mostly from its bituminous black shales, but containing also spectacular debris flow complex, (ii) typical turbidite deposits of the Magura Formation, deformed in overturned folds. Pieniny Klippen Belt – a highly complex tectonic zone of the Carpathians, which includes diverse sedimentary successions from condensed carbonates of the submarine Czorsztyn Ridge to deep marine basinal radiolarites will be seen in this region. During the filed trip in this area the classical sections were shown: the famous succession at Biała Woda Valley near Jaworki village (type of the Czorsztyn Succession deposited on the intraoceanic submarine swell: from Bajocian crinoidal limestones, through Ammonitico Rosso-type deposits of the uppermost Bajocian to Tithonian, up to overlying calpionellid limestones), the transitional Niedzica Succession at Zaskalskie-Bodnarówka section (red radiolarites overlain by Ammonitico Rosso deposits), and the basinal Branisko Succession (Middle Jurassic spotted limestones and crinoidal cherty limestones, Middle-Upper Jurassic radiolarites, and Upper Jurassic-Lower Cretaceous Maiolica-type limestones). Finally, some post-orogenic mollase-type deposits including synsedimentary breccia deposits and small olistoliths of Paleocene coral-bearing limestones (eastern part of the Slovak Carpathians)were presented. Finally, during our return way from the Carpathians, the trip crossed Outer Carpathians again (with some outcrops of new flysch types deposits) and in the Krakow vicinity, the Upper Jurassic (Oxfordian) and Upper Cretaceous limestones paleogeoghicaly belonging to the Peri-Tethys realm were presented.
... At least a large part of the siltstones and mudstones were also deposited by gravity flows, but some thin sandstone or siltstone intercalations were deposited by bottom traction currents (Unrug, 1980). Some interpretations favoring the shallow-marine environment of the Menilite Formation within the range of storm currents or even shallower zones (e. g., Nalivkin, 1963Nalivkin, , 1967Jarmołowicz-Szulc and Jankowski, 2011;Jankowski, 2015;Jankowski and Wysocka, 2019;Filipek, 2020) are not convincing (for the discussion, see Salata and Uchman, 2019). ...
... Recent theories have questioned the traditional understanding of the origin of the Outer Carpathian basins in the context of the microplates collision and the continuous plate subduction process during the formation of the Carpathians; e.g., Jankowski (2015) and Jankowski and Wysocka (2019) suggested only one single basin zone, whose position changed over time as a result of a variable tectonic regime. According to this interpretation, the Carpathian basin was formed within the European Platform passive margin by multi-stage extension and then subjected to compression and inversion in the final, secondary tectonic deformation stage. ...
... According to this interpretation, the Carpathian basin was formed within the European Platform passive margin by multi-stage extension and then subjected to compression and inversion in the final, secondary tectonic deformation stage. Furthermore, traditionally described tecto-units should not be related to separated sub-basins due to the lack of relationship between tectonic deformation and sedimentation system in the basin (Jankowski, 2015;Jankowski and Wysocka, 2019). ...
The Oligocene Menilite Beds are considered the most important source rock for hydrocarbon accumulation in the Polish Carpathian region, whereas the Cretaceous Lgota Beds have been regarded as an additional potential source rock. Understanding their petrophysical and geochemical properties is essential for evaluating the hydrocarbon potential of these beds.
This paper presents mineral and organic porosity characterization and focuses on factors responsible for the development of organic pores as a reflection of the depositional and diagenetic processes. Mudstones were evaluated as potential source and reservoir rocks, describing their diagenetic and thermal history and examining their effective porosity and permeability. The results show that the Lgota Beds mudstone in the Huczwice quarry is thermally mature (late oil/early gas window, Tmax 460–470 °C), containing type III kerogen and TOC between 0.68 wt% and 4.2 wt%, in contrast to the Menilite Beds mudstone (Monasterzec outcrop), which is thermally immature (Tmax<426 °C), containing type II kerogen and TOC content from 1.24 wt% to 8.7 wt%. The geochemical properties show that the Lgota mudstone is currently an ineffective source rock, whereas the Menilite mudstone can be a potential source rock. SEM-identified pores include mineral pores, organic pores and microfractures. Organic porosity is observable both in immature oil-prone type II kerogen and highly mature gas-prone type III kerogen. The amount of pores in organic matter increases with maturity, and no relation between TOC and organic porosity development has been observed. Palynofacies analysis showed that the Menilite and Lgota mudstones are dominated by amorphous organic matter, and that the Lgota mudstone also contains opaque woody material. MICP measurements indicate high (up to 15%) effective porosity values for the Menilite Beds and up to 8% for the Lgota Beds, with very low permeability values (<0.1 mD) in both cases. Isotherms obtained from nitrogen adsorption are type IV for the Lgota Beds and type II for the Menilite Beds, while the BET surface areas are around 13 m²/g and 3 m²/g, respectively. The Lgota Beds demonstrate advanced diagenetic processes such as compaction, cementation, dissolution, replacement, and transformation, which contributed to the significant reduction in porosity, while the Menilite Beds represent an early stage of burial with the prevailing impact of compaction and thus less destruction of original pores. Finally, the Menilite Beds from the Monasterzec outcrop do not demonstrate sufficient conditions for shale-oil/-gas source rock due to the lack of proper thermal maturity. Such criterion is fulfilled by the Lgota Beds in the Huczwice quarry, but due to very low hydrocarbon potential, the Lgota mudstone is an ineffective source rock. However, given the other petrophysical and geochemical properties, the analysed formations may constitute a basis for further research on the occurrence of unconventional reservoirs in the entire Carpathian region.
... At least a large part of the finer deposits were deposited by gravity flows, but some thin sandstone or siltstone intercalations were deposited by bottom traction currents (Unrug, 1980). Some interpretations favouring the shallow-marine environment of the Menilite Formation within the range of storm currents or even shallower zones (e.g., Nalivkin, 1963Nalivkin, , 1967Jarmołowicz-Szulc & Jankowski, 2011;Jankowski, 2015;Jankowski & Wysocka, 2019;Filipek, 2020) are not convincing (for the discussion, see Salata & Uchman, 2019). ...
... In Europe, the mid-Miocene elevation of the Alpine-Carpathian orogenic belt and its influence on the foreland territories is well known (Ziegler and Dèzes 2007;Schmid et al. 2008;Gusterhuber et al. 2012). During this time interval, the tectonic activity of the Carpathians was also marked by the climax of vertical and lateral displacements, as well as the development of sedimentary basins in the foreland and back-arc areas, alongside volcanic phenomena (Plašienka et al. 1997;Fodor et al. 1999;Krzywiec 2001;Golonka 2004;Peryt and Piwocki 2004;Schäfer et al. 2005;Oszczypko 2006;Andreucci et al. 2013;Wysocka et al. 2016;Kováč et al. 2007Kováč et al. , 2017aWidera et al. 2008Widera et al. , 2019aJarosiński et al. 2009;Mach et al. 2013;Jankowski and Margielewski 2015;Jankowski and Wysocka 2019;Šujan et al. 2020. On the other hand, climatic changes further enhanced by tectonics have been documented in both fauna (Böhme 2003;Hernández-Ballarín and Peláez-Campomanes 2017;Holcová et al. 2018) and flora (Schneider 1992;Planderová et al. 1993;Utescher et al. 2009Doláková et al. 2021). ...
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.
... (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.) (2018), Wendorff et al. (2015Wendorff et al. ( , 2016, and Jankowski and Wysocka (2019). Also a few sedimentological studies with correlation with geochemical research in the presented area has been conducted only recently by e.g. ...
The Oligocene Menilite Beds (Formation) represent the most important hydrocarbon source rock in the Carpathian Belt. The formation is laterally uniform across long distances but it shows strong internal heterogeneity that reflects changes in depositional environments, which controls the source rock potential. The age of the Menilite Formation in the study area is Lower Oligocene – Rupellian - Lower Chattian (nannofossil zone NP22-NP24). Generally, Menilite Beds are dominated by fine-grained (claystone, mudstone, and siltstone) facies, but in some areas they are replaced by thick sandy facies or both types are present. In the study area, both types of facies are present; however, only fine-grained facies have been sedimentologically analysed here because these types can also provide good analytical material for organic geochemistry. The conducted research was aimed at verifying the concepts discussed in the literature that the Menilite Beds were formed in one or more different sedimentary basins, and thus also different palaeogeographic conditions in a small area of the Polish Carpathians, which is located on the border of three tectonic units, precisely in the research area. Therefore, a comparison of these areas was carried out both in terms of facies interpretation and geochemical characteristics. The sedimentological features of 11 different sections of the Menilite Beds from seven localities have been examined: two connected to the Magura Nappe, six to the Dukla Nappe (including tectonic windows) and three to the Silesian Nappe, and total of eight facies (F1 to F8) have been distinguished. Facies F1 from Magura Nappe shows aerobic deposition conditions for sediments with a decisive majority of terrestrial material originating from both angio- and gymnosperms, but from Dukla Nappe facies F1 biomarkers indicate a mixed type of marine-terrestrial matter, with a majority of the terrestrial substance and low-oxygen conditions of the sedimentation environment, with an indication of a lacustrine or marine-lacustrine environment, while in Silesian Nappe facies F1 shows marine and typically anoxic features of sedimentation environment. Facies F2, which is presence in all units, characterise a high content of terrestrial-type substance or there is no clear domination of a terrestrial, marine, or lacustrine component. Facies F2 in Magura Nappe has many features in common with facies F1 but differs higher share of angiosperms (high content of terrestrial-type substance), compared to in the Dukla and Silesian units. It does not show clear features or biomarkers that can be unambiguously interpreted to indicate one specific type of sedimentation condition. Facies F3, which was found in the Silesian unit, stands out due to its high deposition environment anoxicity index and a lack of markers proving a share of angiosperms with higher content of algae-type material. The structures found within these facies shows clear lamination, which frequently accompanies algae mats, hence its sedimentation environment may be similar to lacustrine conditions. Facies F4 is present only in the Dukla unit with all its geochemical features and indicates the deltaic and marine shallow-water aerobic conditions of its deposition environment, which has a share of organic matter of marine and terrestrial types. Facies F5, which is only present in the Silesian Nappe, originated in an anaerobic environment. A high input of organic matter from freshwater and terrestrial origins, indicated by biomarkers, is consistent with shallow-water deposition. Facies F6, present in the Magura Nappe, similar like in Dukla Nappe in most cases stands out due to its low generation potential and high deposition environment aerobicity indices. The origin of organic matter is typically terrestrial originating from angiosperms matter that was deposited probably in lacustrine environment, contrary to the domination of gymnosperms observed in F1 and F2 in the Dukla unit. Stratification of this facies with light and dark colours of fine-grained deposits can indicate cyclically oxidation changes in the sedimentary basin. Generally, biomarker data suggest varied types of organic matter from marine in the Silesian Nappe through mixed in the Dukla Nappe to typically terrestrial in the Magura Nappe which may indicate a deposition in separate basins with their periodical joining. Most of the geochemical parameters indicate also varying redox conditions during deposition in shallow water. Additionally, a variety of the sedimentary structures within accompanying thin-bedded sandstone beds were also recognised. These sedimentary structures provide a possibility to interpret the sedimentary environments of those facies. Most of them are connected to wide-type shallow-water sedimentary environments and are found in the zones between the storm-wave base and the fair-weather water wave base (facies F2, F4, F5 and F6). The analysis confirmed the variability of the sedimentation conditions of the Menilite Beds in terms of the deposition conditions, which can also be used to infer the paleogeographic variability of the original deposition areas.
... During the final stages of deposition in the Outer Carpathian basin along the northern margin of Paratethys, fluid expulsion, fluidization of sediments and slope instability occurred on a regional scale (e.g. Dżułyńki and Radomski, 1956;Książkiewicz, 1958;Jankowski and Wysocka, 2019) leading to emplacement of various chaotic complexes, represented for instance by the Gorlice Beds (Jankowski, 1997(Jankowski, , 2007Kopciowski, 2007;Starzec et al., 2015). Abundance of these characteristic sedimentary complexes, occurrence of seep carbonates related to dissociation of gas hydrate (DGH; Bojanowski, 2007aBojanowski, , 2012Bojanowski et al., 2015) and 13 C-depletion of dissolved inorganic carbon (DIC) in the Paratethyan water column (Köster et al., 1998;Schulz et al., 2005;Bechtel et al., 2012;Bojanowski et al., 2018) raise the question whether fluids released from DGH were responsible for this regional slope instability, which is the main goal of this work. ...
... Such phenomena may also explain the intensive submarine slumping, soft sediment deformations and fluidization of sediments that occurred on a regional scale during the synorogenic phase of the Outer Carpathian basin evolution (e.g. Dżułyńki and Radomski, 1956;Książkiewicz, 1958Książkiewicz, , 1977Jankowski and Wysocka, 2019). Similar geotectonic conditions (uplift related to accretionary prism progradation) are responsible for DGH along recent continental margins; the closest analogs include the Cascadia and Hikurangi accretionary complexes (e.g. ...
Sedimentological, biostratigraphic, petrographic, and stable C and O isotope study was carried out on chaotic complexes hosting carbonate concretions in the uppermost Oligocene successions of the Outer Carpathians. These chaotic complexes reveal a range of sedimentary features indicative of intrabasinal, submarine mass-wasting deposition, including soft-sediment deformations, brecciation, homogenization and fluidization of the parent material. Apart from carbonate concretions, they enclose blocks of rocks having lithologies typical for the underlying Oligocene strata. The concretions exhibit extremely depleted δ¹³C (by down to −51.3‰) indicating anaerobic oxidation of methane, whereas their δ¹⁸O values are strongly enriched relative to coeval brackish basin water indicating dissociation of gas hydrates as the main fluid source. These data and the geotectonic context led to the interpretation that the chaotic complexes formed as submarine slumps on a N-inclined paleoslope of the basin in consequence to tectonically-induced dissociation of gas hydrates. Hydrates were destabilized within the sediments due to synorogenic uplift, related to northward progradation of the accretionary prism. These slumps and hosted concretions were dated by the combination of calcareous nannoplankton and organic-walled dinoflagellate cysts. The age of concretions indicated by dinoflagellate cyst assemblages always overlaps with that of the surrounding slump matrix determined by both micropaleontological groups. Together with sedimentological and petrographic evidence, this confirms that the concretions formed in situ within the sediment shortly after deposition and prior to slumping. Hydrate dissociation, seepage of methane-charged fluids and the resultant slope destabilization was not an isolated event, but a continuous process occurring diachronously in front of N-prograding accretionary prism during Oligocene, at least from early NP23 to late NP25 biozones.
The stable C and O isotope analysis of carbonate concretions was crucial for this research, because the low δ¹³C and high δ¹⁸O values were the only preserved indicators of anaerobic oxidation of methane and dissociation of gas hydrates in the basin, respectively. Because, the concretions are composed of a mixture of dolomite and calcite, a semiautomatic method for measuring C and O isotope composition selectively for calcite and dolomite (Baudrand et al., 2012) was applied, which provided conclusive results. These measurements were combined with detailed petrographic investigations, which enabled assessment of isotopic composition for various carbonate constituents separately, e.g. sedimentary calcite (biogenic and detrital), early and late calcite cements, dolomite cement. They showed that the concretionary microcrystalline calcite was the main cement that precipitated due to hydrate dissociation and subsequent methane oxidation. This approach can provide valuable information when applied to other authigenic carbonates composed of a mixture of dolomite and calcite.
... In this case, the for ma tion of the Carpathian bas ins was driven mainly by decom po si tion of the East Eu ro pean Plat form mar gin. Contractional stages pin point the for ma tion of a fore land ba sin (Jankowski and Wysocka, 2019). Jankowski (2007Jankowski ( , 2015 and Jankowski and Wysocka (2019) have ad di tion ally dis tin guished an extensional stage, dur ing which sed i men ta tion took place in half-graben struc tures. ...
... Contractional stages pin point the for ma tion of a fore land ba sin (Jankowski and Wysocka, 2019). Jankowski (2007Jankowski ( , 2015 and Jankowski and Wysocka (2019) have ad di tion ally dis tin guished an extensional stage, dur ing which sed i men ta tion took place in half-graben struc tures. The pro cess of ba sin clo sure and sed imen ta tion ces sa tion was diachronous, pro gress ing from west to east; in Ro ma nia, this pro cess extended into the Pliocene (e.g., Royden and Baldi, 1988;Linzer et al., 1998;. ...
The sedimentary organic matter (SOM) assemblages and sedimentology of the Menilite Beds from the Dukla, Grybów and Vrancea units in the Slovakian and Romanian Outer Carpathians are described. Qualitative and quantitative analyses of the SOM help as certain depositional conditions, while the thermal maturity of the organic matter studied is estimated utilizing the Spore Colour Index and UV light excitation techniques. The sedimentary organic particles were grouped into ten SOM categories: marine palynomorphs (dinoflagellate cysts), sporomorphs (saccate and non-saccate, pollen and spores), freshwater algae (Botryococcus sp., and other freshwater microplankton), phytoclasts (cuticles, translucent wood, opaque wood), resin and amorphous organic matter (AOM). All samples are dominated by AOM. The presence of Botryococcus sp., Pediastrum sp., Pterospermella sp. and Campenia sp., in some samples points to deposition under hyposaline conditions. It is interpreted that the freshwater influx induced water column stratification in the basin, leading to the de velopment of dysoxic to anoxic bottom-water conditions that enhanced the preservation of AOM. Kerogen analysis in UV light and evaluation using the Spore Colour Index demonstrated different thermal maturation patterns from the Slovakian (post-mature) and Romanian (immature) sections. Integrated palynofacies analysis (notably, the presence of freshwater algae) and sedimentological observations (e.g., hummocky cross-stratification) lead to the conclusion that the deposition of the Menilite Beds in the Vrancea Unit (Romania) was relatively proximal to the shore line, above storm wave base, whereas the Slovakian units (Dukla and Grybów) were de posited in a more distal setting.
... The Central Carpathian Synclinorium probably originated as a synsedimentary tectonic graben named the Central Carpathian Depression (e.g. Klecker et al., 2001;Stefaniuk, 2003;Jankowski & Probulski, 2011;Jankowski & Wysocka, 2019). The sedimentary successions in the study area are mostly composed of sandstones and shales, derived from the different types of gravity and mass flow deposits (Jankowski & Probulski, 2011) in the Oligocene-Lower Miocene Krosno Beds. ...
... Depression. The sandstones in Nasiczne were deposited from a proximal, high-density turbidite flow from the south-west (Fig. 9C (Jankowski & Probulski, 2011;Jankowski & Wysocka, 2019) existed. Similarly, palaeoflow from the NNE in sandstones in Hoczew originated along the other margin of the depression. ...
The anisotropy of magnetic susceptibility is a well‐known geological proxy in revealing the directional tectonic and sedimentological features of rocks, although it can be ambiguous in situations where these two factors co‐occur. This paper demonstrates the usefulness of the anisotropy of magnetic susceptibility in determining palaeotransport directions in turbiditic rocks that underwent subsequent thrusting and folding. This study demonstrates that the magnetic lineation is largely unsuitable as a palaeocurrent direction proxy, and suggests that the imbrication of magnetic foliation is better in such cases. Moreover, the anisotropy of magnetic susceptibility results were analyzed in reference to a joint and fold study within the framework of the regional structural geology. Magnetic fabric investigations were conducted in the eastern part of the Outer Western Carpathians (south‐east Poland). During the study, a total of 191 oriented palaeomagnetic samples were collected from three outcrops (Nasiczne, Dwernik and Hoczew) in the Krosno Beds, Silesian Unit. For the purpose of sedimentological analysis, 121 m of turbidite successions were documented and 126 directional sedimentary structures were measured. The magnetic anisotropy of sandstones revealed typical sedimentary fabrics, often overprinted by variably intense tectonic deformation. Oblate susceptibility ellipsoids from Nasiczne showed tilt coherent with the palaeoflow direction, whereas the rocks from Dwernik and Hoczew contained triaxial magnetic fabric developed during compressional palaeostress. This paper suggests that medium‐grained and coarse‐grained sandstones, preferably with high mica content, are the most suitable for palaeotransport reconstructions among the studied lithologies.
... In the Romanian Carpathians (and Romania in general), sand intrusions are an understudied topic. Whilst some injectites have been referred to in the Eastern Carpathians (Miclaȗşet al. 2009;Jankowski & Wysocka 2019) or ECBZ (Bercea et al. 2016;Tamas et al. 2016), in this paper we provide detailed field observations of their architecture to support subsurface interpretation, infer timing and mechanism of emplacement, their relationship with regional tectonics and their impact on the petroleum system. ...
Sand intrusions are commonly associated with hydrocarbon-bearing clastic reservoirs and they can host a significant part of the reserves. They modify the depositional sandbody architecture, and can have an impact on the petroleum system elements. Their significance and complex architecture is difficult to assess in the subsurface due to limited resolution of seismic or core data. Outcrop analogues are key to better understand these complex reservoirs.
In the Eastern Carpathians Bend Zone, the Oligocene and Lower Miocene succession offer spectacular exposures of deep-water siliciclastic rocks modified by remobilisation and sand intrusion processes. These rocks are also present in producing fields in this area.
Sills can be as thick as the depositional sandstones (~4 m), and sill-dominated outcrops can provide a net-to-gross (net sandstone to shale ratio) of about 35 - 50 %. We quantified their architecture, in a study of the timing and mechanism of emplacement, their relationship to regional tectonics and their impact on reservoir connectivity. The intrusions are interpreted to be syn-tectonic, related to the major mid-Miocene compression in this part of the Carpathian Mountain Belt.
The intrusions lead to a large increase in vertical and horizontal connectivity. Our results will help to improve reservoir characterisation and production in these reservoirs.
