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    Wyświetlanie 1-85 z 85
    Tytuł:
    Litofacje formacji perspektywicznych dla gazu i ropy w łupkach w utworach ordowiku i syluru na obszarze bałtyckim i podlasko-lubelskim
    Lithofacies of the Ordovician and Silurian formations prospective for shale gas/oilin the Baltic and Podlasie-Lublin areas
    Autorzy:
    Feldman-Olszewska, A.
    Roszkowska-Remin, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075505.pdf
    Data publikacji:
    2016
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    litofacje
    ordowik
    silurian
    łupki
    lithofacies
    Ordovician
    Silurian
    shales
    Opis:
    The paper presents a sedimentological analysis of Ordovician (Sandbian–Hirnantian = Caradoc–Ashgill) and Silurian (Landovery–Wenlock, lower Ludlow) claystones and mudstones from the north-eastern (Baltic Basin) and south-eastern (Podlasie-Lublin Basin) parts of the East European Craton. In both basins, formations prospective for shale gas/oil were analyzed: the Sasino Fm., Pasłęk Fm. (including the Jantar Mb.), Pelplin Fm., Udal Fm., Wrotnów Fm. and Terespol Fm. Based on lithological and sedimentological criteria, 34 lithofacies and 11 lithofacies associations have been distinguished. The most promising lithofacies arerepresentedbytheL-1,L-3andL-4associationswhicharecharacterizedbydarkgreycolour, a very low degree or lack of bioturbation, rare sedimentary structures, and common content of small pyrite concretions. They dominate in the Sasino Fm., Pas³êk Fm. (in the Jantar Mb. only) and Pelplin Fm., but are much less common in the Udal Fm., Terespol Fm. and Pas³êk Fm. (excluding the Jantar Mb.).
    Źródło:
    Przegląd Geologiczny; 2016, 64, 12; 968--975
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Silurian rugose coral Schlotheimophyllum Smith, 1945 from the Upper Visby Beds of Gotland, Sweden
    Autorzy:
    Wrzołek, Tomasz
    Zatoń, Michał
    Powiązania:
    https://bibliotekanauki.pl/articles/24264691.pdf
    Data publikacji:
    2023
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    Rugosa
    Corals
    coloniality
    variability
    Silurian
    Opis:
    A rich (about 60 specimens) collection of Schlotheimophyllum, large rugose corals from the Silurian of Gotland, Sweden, was studied. Although the material is mostly fragmentary (beach pebbles), the presence of growth lines, clearly seen in thin sections, provides reliable numerical data. Analyzed were corallum shape, septal numbers, and aspects of coloniality. Uniformity of variability spectra of these parameters indicates that all of the material studied belongs to a single, variable species, which is Schlotheimophyllum patellatum (Schlotheim, 1820).
    Źródło:
    Annales Societatis Geologorum Poloniae; 2023, 93, 3; 251--267
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Palynology and palaeoenvironments of the Silurian Coosglass Slate and Ferriter’s Cove formations in the Dunquin Inlier (Dingle Peninsula, Ireland)
    Autorzy:
    Higgs, K. T.
    Williams, B. P. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059151.pdf
    Data publikacji:
    2011
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    palynology
    palaeoenvironments
    Silurian
    Dingle
    Ireland
    Opis:
    This study documents the first palynological data from the Silurian of the Dunquin Inlier of the Dingle Peninsula and focuses on the lower part of the succession. The previously undated Coosglass Slate Formation contains a low diversity Llandovery to early Wenlock acritarch assemblage, confirming the previously enigmatic Coosglass Slate Formation as the oldest formation in the Silurian succession. The lithofacies and acritarch biofacies suggest the mudstones of the Coosglass Slate Formation represent a low energy, offshore, muddy shelf palaeoenvironment. The Ferriter' s Cove Formation, a succession of five offshore to tidal-flat regressive marine cycles yielded more diverse palynological assemblages. Acritarchs and cryptospores from the Ferriter's Cove Formation confirm a Wenlock (Homerian) age for this formation. The integration of palynological and sedimentological data from four of the offshore to tidal-flat regressive cycles reveals three consistent palynomorph distribution trends: (1) offshore and shoreface depositional facies contain the most diverse palynological assemblages in which acritarchs with long and ramified processes dominate; (2) back-barrier tidal-flat facies are characterized by terrestrially derived palynomorphs, particularly cryptospores, together with a restricted acritarch assemblage of mainly micrhystrid and veryhachid forms with small simple processes; (3) back-barrier lagoonal facies with patch reefs are dominated by the sphaeromorph acritarch Leiosphaeridia.
    Źródło:
    Geological Quarterly; 2011, 55, 2; 95-108
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Acritarch assemblages from the Silurian Pomeranian Caledonides and their foreland
    Autorzy:
    Jachowicz, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059448.pdf
    Data publikacji:
    2000
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Pomeranian Caledonides
    Silurian
    acritarch assemblages
    Opis:
    Comprehensive palynological studies of the Silurian rocks of the Pomeranian Caledonides are described, the first since Eisenack's (1972) work. 250 clastic rock samples were analysed, all from deep boreholes. Three of these boreholes (Lębork IG 1, Gdańsk IG 1 and Kościerzyna IG 1) are located NE of the Teisseyre-Tornquist Zone (TTZ) and contain horizontal successions of the western, marginal part of the East European Craton. Other boreholes studied (Bydgoszcz IG 1, Klosnowo IG 1 and Stobno 1) penetrated folded Lower Palaeozoic sediments, and lie SE of the TTZ. The investigations included a complete Silurian profile from the Llandovery to the Poidoli, which is documented in detail by graptolites. Associations of microflora (Acritarcha, Prasinophyceae, Sporites) and microfauna (Chitinozoa, Scolecodonta) varied in quality and quantity. There was considerable variability in the preservation and thermal maturity of the organic-walled microfossils. Detailed investigations of the acritarchs are described. 7 characteristic acritarch assemblages have been distinguished, and these are correlated with the graptolite biozones. Llandovery rocks contain assemblages with Domasia, Ammonidium and Tylotopalla genera. Wenlock deposits include Tylotopalla, Leptobrachion and Cymbosphaeridium. The Upper Ludlow deposits contain well preserved assemblages with Visbysphaera, Veryhachium, Onondagella and Leoniella, accompanied by Neoveryhachium carminae, Geron gracilis, and some Deflandrastrum and Visbysphaera species generally considered characteristic of Gondwana. Throughout the Silurian profile, individual specimens of typical Ordovician genera such as Acanthodiacrodium, Frankea, Striatotheca and Coryphidium occur. The acritarch assemblages overall show mixed characters, typical of both Baltica and Gondwana.
    Źródło:
    Geological Quarterly; 2000, 44, 3; 317-331
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Early Silurian (Llandovery) graptolite assemblages of Saudi Arabia: biozonation, palaeoenvironmental significance and biogeography
    Autorzy:
    Williams, M.
    Zalasiewicz, J.
    Boukhamsin, H.
    Cesari, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/2060177.pdf
    Data publikacji:
    2016
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Saudi Arabia
    Silurian
    graptolites
    biozonation
    Opis:
    Analysis of Silurian graptolite assemblages from 1017 sample horizons in 132 cores (from 65 boreholes) through the Qusaiba Member, Qalibah Formation of Saudi Arabia, provides a refined graptolite biostratigraphy for the Arabian Peninsula comparable in its resolution to that from the British Isles and the Czech Republic. Over 150 graptolite species characterize 11 biozones from the lowermost Rhuddanian lubricus Biozone to the lower Telychian guerichi Biozone, with sub-zonal resolution for several intervals. Graptolite biozonal boundaries and the Rhuddanian-Aeronian and Aeronian-Telychian stage boundaries can be placed with high precision. Detailed analysis of graptolite spatial distribution suggests persistent depth-stratified marine assemblages across the Silurian palaeo-Arabian Plate. Near-surface-dwelling assemblages probably occupied the mixed-layer of Silurian oceans, enabling colonization of shallow shelf environments. They are low-diversity (1-2 species) assemblages characterized by Neodiplograptus, Coronograptus, Neolagarograptus and Stimulograptus species and often are preserved in strata with extensive shelly faunas. Deeper marine assemblages are of higher diversity (up to 15 species per horizon), and are characterized by dorsally curved or helically coiled species of Spirograptus, Demirastrites, Lituigraptus, Rastrites and Torquigraptus. Recognition of depth-stratified graptolite assemblages provides an important tool for establishing palaeo-basin topography and water depth at the time of sedimentary deposition. At the species level, the graptolite assemblages of Saudi Arabia are remarkably similar to contemporaneous faunas from peri-Gondwanan Europe and, from the middle Rhuddanian onwards, also to the Avalonian and Laurentian Llandovery graptolites of the UK.
    Źródło:
    Geological Quarterly; 2016, 60, 1; 3--25
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Palaeomagnetic age of remagnetizations in Silurian dolomites, Rástla quarry (Central Estonia)
    Autorzy:
    Plado, J.
    Preeden, U.
    Puura, V.
    Pesonen, L. J.
    Kirsimäe, K.
    Pani, T.
    Elbra, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/2060209.pdf
    Data publikacji:
    2008
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Estonia
    Baltica
    Silurian
    palaeomagnetism
    remagnetization
    dolomites
    Opis:
    Alternating field and thermal demagnetization of dolomite samples from the Silurian (Llandovery) horizontally-bedded sequence of central Estonia reveal two secondary magnetization components (A and B) both of chemical origin. A low-coercivity (demagnetized at -50 mT) component A (D = 60.7°, I = 7.7°, alfa95 = 16.6°) with high dispersion (k = 14.2), yields a palaeopole at 18.2°N and 139.5°E that points towards the Late Devonian — Mississipian segment of the Baltica APWP (Apparent Polar WanderPath). A high-coercivity component B (D = 13.5°, I = 60.7°, k = 67.0, alfa 95 = 4.7°) carries both normal and reversed polarities. Comparing the palaeopole (71.1°N and 173.3°E) with the European APWP reveals a Cretaceous age. These two remagnetizations are linked to mineral assemblages of magnetite and maghemite (A), and hematite (B) determined from mineralogical (X-ray, SEM and optical microscopy) and rock magnetic (acquisition and thermal demagnetization of a 3-component IRM; Lowrie-test) studies. The results suggest that the first (A) Palaeozoic remagnetization was caused by low-temperature hydrothermal circulation due to the influence of the Caledonian (more likely) or Hercynian Orogeny after the diagenetic dolomitization of carbon ates. Hematite, carrying the component B, and goethite, are the latest ferromagnetic minerals that have precipitated into the existing pore space (hematite) and walls of microscopic fractures (goethite) that opened to allow ac cess for oxygen-rich fluids during the Late Mesozoic.
    Źródło:
    Geological Quarterly; 2008, 52, 3; 213-213
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Siluro-Devonian of Podolia, Ukraine: Paleobiological, biostratigraphic, and geochemical aspects
    Autorzy:
    Szaniawski, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/20313.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Silurian
    Devonian
    Podolia
    Ukraine
    paleobiology
    biostratigraphy
    geochemistry
    Źródło:
    Acta Palaeontologica Polonica; 2012, 57, 4
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Lithologic-petrographic characterization of Silurian rocks in the Niestachów profile (Holy Cross Mountains)
    Autorzy:
    Malec, J.
    Kuleta, M.
    Migaszewski, Z. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/191848.pdf
    Data publikacji:
    2016
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    Holy Cross Mountains
    Silurian
    lithology
    petrography
    greywackes
    Opis:
    The Niestachów profile is located in the southwestern part of the Holy Cross Mountains and exposes lower Ludlovian greywacke sediments of the Niewachlów Beds that occur above graptolitic claystones of the Prągowiec Beds. Within the sequence of lithologically diversified Niewachlów Beds, more than 400 m thick, 11 characteristic lithologic complexes were identified. The lower and upper parts of the Niewachlów Beds comprise fine- and medium-grained greywacke sandstones with mudstone interbeds, whereas the middle part contains coarse-grained greywacke sandstones and conglomerates. The sediments were transported by “turbiditic currents” from the southwest. Petrographic examination of the upper part of the Prągowiec Beds and the Niewachlów Beds indicates that the greywacke conglomerates and sandstones of the Niewachlów Beds are composed primarily of volcanic and sedimentary lithoclasts, with subordinate metamorphic and scarce plutonic lithoclasts. The sandstones and conglomerates were derived from an orogen containing sandstones and mudstones as well as from the magmatic rocks of a continental volcanic arc, characterized by acidic-intermediate volcanism.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2016, 86, 1; 85-110
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Graptolite biostratigraphy and dating of the Ordovician–Silurian shale succession of the SW slope of the East European Cratond
    Autorzy:
    Podhalańska, Teresa
    Powiązania:
    https://bibliotekanauki.pl/articles/191870.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    biostratigraphy
    Ordovician
    Silurian
    graptolite
    East European Craton
    Opis:
    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.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2019, 89, 4; 429-452
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Timing of the onset of Devonian sedimentation in northwestern Poalnd: palynological evidence
    Początek dewońskiej sedymentacji w północno-zachodniej Polsce: przesłanki palinologiczne
    Autorzy:
    Turnau, E.
    Matyja, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/191429.pdf
    Data publikacji:
    2001
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    northwestern Poland
    Ordovician
    Silurian
    Devonian
    sporomorphs
    stratigraphy
    redeposition
    Opis:
    Palynomorph assemblages of low taxonomic diversity are recorded from the basal Devonian strata in three boreholes in western Pomerania and Kujawy. The palynoflora is assigned to a younger, autochtonous assemblage, and an older, redeposited one. The composition of the younger assemblage suggests lower to middle Eifelian. The older palynomorphs are derived from (1) Upper Ordovician or Lower Silurian, and (2) probably from Upper Silurian deposits.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2001, 71, No 2; 67-74
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Trace fossils from Silurian and Devonian turbidites of the Chauvay area, southern Tien Shan, Kyrgyzstan
    Autorzy:
    Warchoł, M.
    Leszczyński, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/191868.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    Tien Shan
    Kyrgyzstan
    Silurian-Devonian
    turbidites
    trace fossils
    Opis:
    The siliciclastic turbidite successions (Pul’gon and Dzhidala Formations) that crop out in the eastern part of the Chauvay River valley, are marked on geological maps as a belt of terrigenous deposits of Silurian-Devonian age. They resemble deposits of overbank areas and depositional lobes of deep sea fans, and display common trace fossils particularly on lower surfaces of sandstone beds. Sixteen ichnotaxa representing four morphological groups have been distinguished. The trace fossil assemblages suggest their affiliation to the Nereites ichnofacies. Various branched, preturbidite forms predominate in both examined units, although the assemblages of individual units differ slightly in composition. In the Pulg’on Formation, small, densely distributed burrows commonly occur on lower surfaces of sandstone beds. Shallow burrowing depth together with relatively low diversity trace fossil assemblages indicate lowered oxygenation of the sea floor.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2009, 79, No 1; 1-11
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Silurian volcanism recorded in sedimentary sections at the southwestern margin of the East European Platform: geochemical correlation and tectono-magmatic interpretation
    Autorzy:
    Kiipli, Tarmo
    Powiązania:
    https://bibliotekanauki.pl/articles/2058862.pdf
    Data publikacji:
    2021
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Silurian volcanism
    K-bentonites
    Ukraine
    Moldova
    Scythian Platform
    Opis:
    X-ray fluorescence analyses of sixty-one K-bentonite samples from the Ludlow-Pridoli sections of western Ukraine and Moldova were used for correlation and source magma interpretation. The study reveals that source magmas of K-bentonites were low-temperature (~720oC) rhyolites indicating melting of continental crust during subduction of a hydrated oceanic plate. Volcanic sources were probably located within the developing Scythian Platform embracing the southeastern margin of the East European Platform. The present study demonstrates the potential of using immobile elements for correlating volcanic ash layers between different sections.
    Źródło:
    Geological Quarterly; 2021, 65, 1; 13
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Silurian of the Nida, Holy Cross Mts. and Radom areas, Poland - a review
    Autorzy:
    Modliński, Z.
    Szymański, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059315.pdf
    Data publikacji:
    2001
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Holy Cross Mountains
    Silurian
    lithology
    biostratigraphy
    lithostratigraphy
    lithofacies
    Źródło:
    Geological Quarterly; 2001, 45, 4; 435-454
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Facies analysis of the Silurian shale-siltstone succession in Pomerania (northern Poland)
    Autorzy:
    Jaworowski, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059457.pdf
    Data publikacji:
    2000
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    northern Poland
    Silurian
    submarine silty debrites
    turbidites
    exoflysch
    Opis:
    The Silurian deposits of Pomerania occur in the foreland of the Pomeranian Caledonides which are the SE continuation of the Danish-North-German Caledonides. The Silurian sequence in Pomerania is represented largely by graptolitic clay- and mud-shales deposited in a hemipelagic environment. From the Wenlock through Late Ludlow, slow deposition of hemipelagic clays and muds was repeatedly interrupted by silty debris flows and turbidity currents. Many of the siltstone interbeds were reworked by bottom currents. Clastic material was sourced from the Caledonian accretionary prism stretching along the collision zone of Baltica and East Avalonia. The Silurian shale-siltstone succession in Pomerania represents a Caledonian exoflysch i.e. syn-collision clastics accumulated in a foredeep developed on the East European Craton. The diachronous appearance of siltstone interbeds in the graptolitic shales indicate that collision between Baltica and East Avalonia was associated with sinistral strike-slip movement along the edge of the East European Craton.
    Źródło:
    Geological Quarterly; 2000, 44, 3; 297-315
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mat-forming coccoid cyanobacteria from Early Silurian marine deposits of Sudetes, Poland
    Autorzy:
    Kremer, B
    Powiązania:
    https://bibliotekanauki.pl/articles/22597.pdf
    Data publikacji:
    2006
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    organic matter
    marine environment
    Cyanoprokaryota
    Early Silurian
    nitrogen fixation
    marine deposit
    Polska
    Silurian
    remains
    coccoid cyanobacteria
    Sudetes Mountains
    paleontology
    Opis:
    Mass occurrence of mats comprised of benthic coccoid cyanobacteria is reported from early Silurian black radiolarian cherts exposed at Żdanow village (Bardzkie Mountains, Sudetes, southwestern Poland). The cherts contain laminated organic matter representing degraded benthic coccoid cyanobacterial mats. The remains of cyanobacteria occur as laminated agglomerations of variously preserved subglobular colonies composed of spherical cells of variable size and numbers. The morphology of remnants of cells and their mucilaginous envelopes, structure of colonies, and particularly the presence of small granular structures resembling reproductive cells known in extant coccoid cyanobacteria as baeocytes, permit to compare the Silurian microbiota with modern cyanobacteria assigned to the genera Stanieria or Chroococcidiopsis.
    Źródło:
    Acta Palaeontologica Polonica; 2006, 51, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Wenlock-Ludlow carbon isotope trend in the Vidukle core, Lithuania, and its relations with oceanic events
    Autorzy:
    Martma, T.
    Brazauskas, A.
    Kaljo, D.
    Kaminskas, D.
    Musteikis, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/2058950.pdf
    Data publikacji:
    2005
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Lithuania
    Silurian
    carbon isotopes
    oceanic events
    sedimentary facies
    Opis:
    A Wenlock to Ludlow terrigenous-carbonate succession in the Vidukle core in Central Lithuania represents a deep shelf environment with a general upwards-shallowing trend, interrupted by brief deepening episodes. The carbon isotope trend, based on 115 whole-rock analyses, shows three main excursions: (1) a major excursion (δ13 C values reach 3.2‰) in the lower Wenlock, (2) low shifts (1.3‰ and 1.6‰) at two levels in the upper most Wenlock Siesartis Formation corresponding to the Monograptus ludensis Biozone, (3) the most prominent excursion (δ13 C values reach 8.2‰) occurs in the upper Ludlow Mituva Fm. The upper Ludlow excursion is dated by the last occurrences of Polygnathoides siluricus below the main shift and the appearance of Ozarkodina wimani and O. crispa above the excursion. The excursion stratigraphically coincides with the Lau oceanic Event and is correlated with the mid-Ludfordian Neocucullograptus kozlowskii-Bohemograptus bohemicus tenuis Biozone. Changes in the carbon isotope trend are in general harmony with some aspects of the rock (CaO, terrigenous component) and fossil content of the section. The data presented are consistent with an arid climate model for the Ludfordian isotope event.
    Źródło:
    Geological Quarterly; 2005, 49, 2; 223--234
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Late Wenlock biostratigraphy and the Pristiograptus virbalensis group (Graptolithina) in Lithuania and the Holy Cross Mountains
    Autorzy:
    Radzevičius, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059231.pdf
    Data publikacji:
    2006
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Holy Cross Mountains
    Silurian
    upper Wenlock
    biostratigraphy
    Graptolithina
    Opis:
    Graptolites from Lithuania and the Holy Cross Mountains comprise a succession of the lundgreni, parvus (except for the Holy Cross Mts.), nassa, praedeubeli, deubeli and ludensis biozones of the upper Wenlock, the parvus, praedeubeli and deubeli biozones being recognized for the first time in Lithuania, where a graptolite-free interval may also be distinguished. P. virbalensis Paskevicius, 1974 and the virbalensis group are not widely known, and are discussed here. Analysis of P. virbalensis shows this to be an independent taxon, closely related to P. auctus. There are three species - P. virbalensis, P.jaegeri and P. auctus - in the virbalensis group.
    Źródło:
    Geological Quarterly; 2006, 50, 3; 333-344
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Trace fossils from Silurian and Devonian turbidites of the Chauvay area, southern Tien Shan, Kyrgyzstan
    Autorzy:
    Warchoł, M.
    Leszczyński, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/191469.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    Tien Shan
    Kyrgyzstan
    Silurian-Devonian
    turbidites
    trace fossils
    Opis:
    The siliciclastic turbidite successions (Pul’gon and Dzhidala Formations) that crop out in the eastern part of the Chauvay River valley, are marked on geological maps as a belt of terrigenous deposits of Silurian–Devonian age. They resemble deposits of overbank areas and depositional lobes of deep sea fans, and display common trace fossils particularly on lower surfaces of sandstone beds. Sixteen ichnotaxa representing four morphological groups have been distinguished. The trace fossil assemblages suggest their affiliation to the Nereites ichnofacies. Various branched, preturbidite forms predominate in both examined units, although the assemblages of individual units differ slightly in composition. In the Pulg’on Formation, small, densely distributed burrows commonly occur on lower surfaces of sandstone beds. Shallow burrowing depth together with relatively low diversity trace fossil assemblages indicate lowered oxygenation of the sea floor.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2009, 79, No 2; 1-11
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Palaeoecology of corals and stromatoporoids in a Late Silurian biostrome in Estonia
    Autorzy:
    Kershaw, S.
    Motus, M.-A.
    Powiązania:
    https://bibliotekanauki.pl/articles/21971.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    paleoecology
    coral
    stromatoporoid
    Late Silurian
    biostrome
    Anthozoa
    Stromatoporoidea
    Estonia
    Opis:
    A middle Ludlow biostrome at Katri, western Estonia, the richest accumulation of corals and stromatoporoids in Estonia, is partly exposed in a coastal section. The fully marine biostrome consists of five fossiliferous layers of carbonate skeletons, grouped into Facies 1 (grainstone-packstone, Layers 1, 3, 5) and Facies 2 (wackestone, interbedded Layers 2, 4). Pressure solution degraded original sedimentary relationships and morphologies of stromatoporoids, tabulates and rugosans which constructed the biostrome, but the two facies have major faunal differences. Facies 1 is rich in stromatoporoids “Stromatopora” bekkeri and Plectostroma scaniense (low to high domical up to ca. 30 cm in basal length); and tabulate Favosites forbesi (bulbous to high domical up to ca. 25 cm wide). In Facies 2, all three taxa are less common and much smaller. Instead, the most abundant stromatoporoid is laminar Syringostromella borealis up to 30 cm basal length; the most abundant coral is erect branching Laceripora cribrosa, as scattered fragments up to 24 cm long. Neither occurs in Facies 1. Six other stromatoporoid taxa, 5 other tabulate and 5 rugosan taxa occur uncommonly in the biostrome, mostly in both facies. The Katri biostrome is slightly younger than, but facially similar to biostromes in the middle Ludlow Hemse Group on Gotland ca. 250 km WSW, with well-known stromatoporoid faunas. Corals are abundant in Hemse biostromes. Several key stromatoporoids occur in both the Hemse biostromes and Katri, but two abundant taxa in Hemse biostromes are absent in Katri and two tabulate corals abundant in Katri are missing in Hemse biostromes. Thus there was a wide distribution of such biostromes in the central Baltic large shallow marine carbonate platform, but with previously unreported variable assemblages presumed due to facies features not recognised in the sediments.
    Źródło:
    Acta Palaeontologica Polonica; 2016, 61, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On generation and regeneration of cladia in some Upper Silurian monograptids
    O rozwoju i regeneracji gałązek w koloniach pewnych górno-sylurskich Monograptidae
    O razvitii i regenereracii vetok v kolonijakh verkhne-silurijjskikh Monograptidae
    Autorzy:
    Urbanek, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/23490.pdf
    Data publikacji:
    1963
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    generation
    regeneration
    Upper Silurian
    monograptid
    Linograptinae
    structure
    development
    paleontology
    Źródło:
    Acta Palaeontologica Polonica; 1963, 08, 2
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Facies transition and biostratigraphic correlation of the Upper Silurian and Lower Devonian in West Bulgaria
    Autorzy:
    Boncheva, I.
    Sachanski, V.
    Lakova, I.
    Yaneva, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059515.pdf
    Data publikacji:
    2007
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Bulgaria
    Upper Silurian-Lower Devonian
    conodonts
    graptolites
    facies transition
    Opis:
    Upper Silurian and Lower Devonian shelf deposits in West Bulgaria are exposed in three main Alpine tectonic units: the West Balkan Unit, the Lyubash Monocline and the Morava Unit. The West Balkan and Lyubash units consist of siliciclastic deposits: black graptolitic shales, banded pale shales and black siltstones. The Ludlow, Pridoli, Lochkovian, Pragian and Emsian were recognized on the basis of graptolite and tentaculite faunas. In the Morava Unit, the Ludlow black shales are progressively replaced by clayey limestones and nodular and micritic limestones in the Pridoli and Early Devonian. Newly obtained conodonts show the presence of the siluricus, eosteinhornensis, woschmidti, postwoschmidti, delta-pesavis, sulcatus, dehiscens and gronbergi zones. Petrographic study of the Morava Unit shows an increasing carbonate content and shallowing conditions upwards. The biostratigraphical correlation and facies interpretation reveal the coeval existence of two different depositional environments within the same shelf basin as well as a gradual shift in proximal direction.
    Źródło:
    Geological Quarterly; 2007, 51, 4; 407-418
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Geochemistry and petrology of the Upper Silurian greywackes from the Holy Cross Mountains (central Poland) : implications for the Caledonian history of the southern part of the Trans-European Suture Zone (TESZ)
    Autorzy:
    Kozłowski, W.
    Domańska-Siuda, J.
    Nawrocki, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059739.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    greywackes
    provenance
    arc-continent collision
    foreland
    Silurian
    Holy Cross Mountains
    Opis:
    The Ludlovian greywackes of the Holy Cross Mountains (HCM) represent a part of the sedimentary cover of the Łysogóry and Małopolska terranes located in the Trans-European Suture Zone, central Poland. The rocks form the sedimentary infill of the Caledonian foreland basin that developed at the Tornquist margin of Laurussia and had source-areas located on the orogen side of the basin. Until the present, the source terrane of the basin has not been identified in its potential location – at the south-west margin of the East European Platform. The Ludlovian greywackes of both parts of the HCM show a lot of similarities in clast spectrum, timing, and geochemical features, which implies similar sources of the clastic material. The petrographic modal composition and geochemical features indicate recycled orogen signatures with a distinct undissected, evolved magmatic arc component. The latter is particularly evident from the extraclast spectrum that contains andesite, trachyte and dacite clasts. Beside the volcanic rocks, the source area consisted of sedimentary and metasedimentary rocks with high amounts of cherts. The geochemical and petrological features in the rock succession point to an evolution of the tectonic setting from an active to a more passive margin type indicating synorogenic formation of the studied rocks. Based on the rock record, we suggest that the Upper Silurian greywackes originated as a result of the collision of the Tornquist margin of Laurussia with a volcanic arc (here: the Teisseyre Arc) – located probably at the easternmost extent of the Avalonian Plate. In this scenario, the arc-continent orogen was composed of an uplifted filling of the forearc basin, an accretionary prism, volcanic arc rocks, and an exhumed foreland basement - analogously to the present-day Taiwan orogen. The second key issue is the palaeogeographical relation between the Małopolska (Kielce Region) and the Łysogóry terranes in the Late Silurian. Despite the analogous grain composition and clast types, the Łysogóry Region greywackes are composed of distinctly more altered detritus, which is in accordance with the more distal character of the Łysogóry Basin. The latter is manifested, e.g., in the lack of Caledonian deformations. The present-day adjacency of both domains containing correlative greywacke formations coupled with contrasting alteration and Late Silurian transport directions parallel to the terrane boundary imply small to medium-scale (below palaeomagnetic resolution) left-lateral movements of the Małopolska and Łysogóry crustal blocks along the Holy Cross Fault in post-Silurian times.
    Źródło:
    Geological Quarterly; 2014, 58, 2; 311--336
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Silurian of southwestern margin of the East European Platform (Ukraine, Moldova and Romania) : lithofacies and palaeoenvironments
    Autorzy:
    Radkovets, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059822.pdf
    Data publikacji:
    2015
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    East European Platform
    Silurian
    lithofacies
    reef
    shelf of Baltica
    palaeoenvironments
    Opis:
    Silurian strata, stretching along the western margin of the East European Platform from the Baltic to the Black Sea, represent a potential target for both conventional and unconventional hydrocarbon exploration. Distribution of the black shale facies, prospective for shale gas, and the reef facies, prospective for oil, has been studied in respect of palaeoenvironments. The Silurian sequence has been investigated in the territory of Ukraine (Volyn-Podillyan Plate, Dobrogean Foredeep) and correlated with the data on Moldova and Romania (Moldovian Platform). The occurrence of Silurian strata, their thickness, and petrographic and lithological characteristics allowed reconstructing the distribution of open-shelf, reef and lagoonal facies. The reef facies migrated during the Wenlock–Middle Pridoli, shifting towards the open sea and back towards the shore, and therefore has been termed a migrating reef facies. Correspondingly, the boundary between the open-shelf and reef facies was shifting. The facies distribution was controlled by the transgressive-regressive cycles, which caused the fluctuations of the shelf water depth in different time intervals of the Silurian. The shelf water depth of about 100 m, where the top of the oxygen-minimum layer impinged on the sea bottom, was the boundary between the open-shelf facies, represented by organic-rich sediments, and the reef buildups.
    Źródło:
    Geological Quarterly; 2015, 59, 1; 105--118
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Agastograptus, a synonym of Plectograptus [Retiolitidae, Graptolithina]
    Autorzy:
    Kozlowska-Dawidziuk, A
    Powiązania:
    https://bibliotekanauki.pl/articles/22767.pdf
    Data publikacji:
    2002
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Agastograptus robustus
    synonym
    Retiolitidae
    Graptolithina
    Silurian
    Agastograptus
    taxonomy
    Plectograptus
    paleontology
    Opis:
    Agastograptus robustus Obut and Zaslavskaya, 1983, the type species of the genus Agastograptusis herein recognized as a species of Plectograptus. Large proximal lateral orifices are one of the significant characters of Plectograptus. P. robustus differs from the type species, Plectograptus macilentus Törnquist, 1887, in possessing paired apertural processes. Other species of Agastograptus have been assigned to three different genera: Spinograptus, S. clathrospinosus (Eisenack, 1951), S. munchi (Eisenack, 1951), Neogothograptus, N. balticus (Eisenack, 1951), and Cometograptus, C. nevadensis (Berry and Murphy, 1975). The main diagnostic feature used for Agastograptus, the spinoreticular paired apertural processes, is recognized as a species feature, characteristic mostly for Spinograptus, whereas the generic features are the arrangement of the proximal end, ventral walls, and ancora sleeve of the rhabdosome. Therefore the genus Agastograptus is a synonym of Plectograptus.
    Źródło:
    Acta Palaeontologica Polonica; 2002, 47, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Veliger morphs in Pristiograptus, a robust graptoloid from the Ludlow series [Silurian] of Morocco
    Autorzy:
    Rickards, B
    Powiązania:
    https://bibliotekanauki.pl/articles/20404.pdf
    Data publikacji:
    2001
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    veliger morph
    velum
    graptolite
    Silurian
    robust graptoloid
    Pristiograptus
    Morocco
    graptoloid
    Źródło:
    Acta Palaeontologica Polonica; 2001, 46, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Silurian thelodonts from the Niur Formation, central Iran
    Autorzy:
    Hairapetian, V
    Blom, H.
    Miller, C.G.
    Powiązania:
    https://bibliotekanauki.pl/articles/20388.pdf
    Data publikacji:
    2008
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    thelodont
    Loganelliiformes
    paleontology
    Silurian
    Phlebolepidiformes
    paleobiogeography
    Thelodonti
    Niur Formation
    Iran
    Opis:
    Thelodont scales are described from the Silurian Niur Formation in the Derenjal Mountains, east central Iran. The material studied herein comes from four stratigraphic levels, composed of rocks formed in a shallow water, carbonate ramp environment. The fauna includes a new phlebolepidiform, Niurolepis susanae gen. et sp. nov. of late Wenlock/?early Ludlow age and a late Ludlow loganelliiform, Loganellia sp. cf. L. grossi, which constitute the first record of these thelodont groups from Gondwana. The phlebolepidiform Niurolepis susanae gen. et sp. nov. is diagnosed by having trident trunk scales with a raised medial crown area separated by two narrow spiny wings from the lateral crown areas; a katoporodidtype histological structure distinguished by a network of branched wide dentine canals. Other scales with a notch on a smooth rhomboidal crown and postero−laterally down−stepped lateral rims have many characters in common with Loganellia grossi. Associated with the thelodonts are indeterminable acanthodian scales and a possible dentigerous jaw bone fragment. This finding also provides evidence of a hitherto unknown southward dispersal of Loganellia to the shelves of peri−Gondwana.
    Źródło:
    Acta Palaeontologica Polonica; 2008, 53, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Pozycja stratygraficzna formacji łupków z Widełek w synklinie bardziańskiej (Góry Świętokrzyskie)
    Stratigraphical position of the Widełki Formation in the Bardo Syncline (Holy Cross Mts.)
    Autorzy:
    Malec, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075106.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Silurian
    litostratygrafia
    biostratygrafia
    Góry Świętokrzyskie
    lithostratigraphy
    biostratigraphy
    Holy Cross Mountains
    Opis:
    Results of the geological studies carried out in the western part of the Bardo Syncline have revealed the wrong stratigraphic position of the Silurian Widełki Formation, established by Stupnicka et al. (1991) in the Widełki area. This lithostratigraphic unit does not represent the youngest Silurian deposits overlying the greywackes of the Niewachlów Beds in the Kielce region of the Holy Cross Mts. In fact, the claystones with graptolites of theWidełki Formation underlie the greywackes of the Niewachlów Beds and belong to the upper part of the Prągowiec Beds.
    Źródło:
    Przegląd Geologiczny; 2014, 62, 11; 748--754
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Vitrinite equivalent reflectance of Silurian black shales from the Holy Cross Mountains, Poland
    Autorzy:
    Smolarek, Justyna
    Marynowski, Leszek
    Spunda, Karol
    Trela, Wiesław
    Powiązania:
    https://bibliotekanauki.pl/articles/127647.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Mineralogiczne
    Tematy:
    Holy Cross Mountains
    Lower Silurian
    maturation
    graptolite reflectance
    black shale
    Opis:
    A number of independent methods have been used to measure the thermal maturity of Silurian rocks from the Holy Cross Mountains in Poland. Black shales are characterized by diverse TOC values varying from 0.24-7.85%. Having calculated vitrinite equivalent reflectance using three different formulas, we propose that the most applicablevalues for the Silurian rocks are those based on Schmidt et al. (2015) equation. Based on this formula, the values range from % 0.71 VReqvVLR (the vitrinite equivalent reflectance of the vitrinite-like macerals) to % 1.96 VReqvVLR. Alternative, complementary methods including Rock Eval pyrolysis and parameters based on organic compounds (CPI, Pr/-C17, Ph/-C18, MPI1, and MDR) from extracts did not prove adequate as universal thermal maturity indicators. We have confirmed previous suggestions that Llandovery shales are the most likely Silurian source rocks for the generation of hydrocarbons in the HCM.
    Źródło:
    Mineralogia; 2014, 45, 3/4; 79-97
    1899-8291
    1899-8526
    Pojawia się w:
    Mineralogia
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Microphytoplankton from middle palaeolatitudes of the Southern Hemisphere : a record from climate change strata of Baltica’s O/S boundary
    Autorzy:
    Masiak, Monika
    Stempień-Sałek, Marzenna
    Podhalańska, Teresa
    Powiązania:
    https://bibliotekanauki.pl/articles/2058561.pdf
    Data publikacji:
    2020
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Polska
    Ordovician boundary
    Silurian boundary
    palynology
    acritarch frequency
    bathymetry
    climate
    Opis:
    In the present study, data on the diversity of acritarch and prasinophyte microphytoplankton were collected from Ordovician-Silurian transitional strata at three different geological localities in Poland: southern part of the Holy Cross Mountains (Małopolska Block, southern Poland), East European Platform (Baltica), and Koszalin-Chojnice Zone (NW Poland). The material represents the mucronata (trilobite) to vesiculosus (graptolite) biozones. The Ordovician microphytoplankton assemblages are characterized by low frequency and low diversity: up to 110 specimens and 12 genera per slide, in contrast to Silurian ones that are more frequent and more diverse - >3000 specimens and 16 genera per slide (diversity at the species level is also higher). Throughout the Ordovician part of the succession, typical Ordovician genera occur, such as Acanthodiacrodium, Ordovicidium, Orthosphaeridium and large Baltisphaeridium, together with isolated occurrences of typical Silurian genera, especially in the upper part of the Hirnantian (e.g., Diexallophasis). The Silurian assemblages are typified by high frequency of prasinophytes followed by typical Siluran acritarchs: Tylotopalla, Ammonidium, Domasia and Oppilatala. The palynological material from Poland is compared with material known from other localities: the Rapla and Valga boreholes (Estonia) and Anticosti Island (Canada), as well as others placed in different palaeocontinents and different bathymetric zones. Palynological assemblages obtained from Polish material confirm that bathymetry played the key role in taxonomic diversification of the microphytoplankton assemblage. This supports the existing models of distribution: dominance of prasinophytes (leiospheres) and cryptospores is characteristic for shallow-water environments. In deeper water, dominance of acanthomorphs is observed. In the deepest-water zones - mixed assemblages occur. For the Holy Cross Mountains, microphytoplankton frequency is compared with a TOC curve in the same interval.
    Źródło:
    Geological Quarterly; 2020, 64, 1; 86--103
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Litostratygrafia syluru polskiej części obniżenia perybałtyckiego - część lądowa i morska (N Polska)
    The silurian lithostratigraphy of the Polish part of the Peri-Baltic Depression (N Poland)
    Autorzy:
    Modliński, Z.
    Szymański, B.
    Teller, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074496.pdf
    Data publikacji:
    2006
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    sylur
    litologia
    litostratygrafia
    palaeografia
    Silurian
    lithostratigraphic units
    lithology
    petrography
    palaeogeography
    Opis:
    The Silurian rocks of the Peri-Baltic Depression area (N Poland) were penetrated by 208 boreholes (Fig. 1). Seven new formal lithostratigraphical units were recognized and defined: The Barciany Nodular Limestones Formation (Lower Llandoverian–Rhuddnian, Aeronian), the Pasłęk Bituminous Claystones Formation with the Jantar Bituminous Black Claystone Member (Llandoverian), the Pelplin Green Claystones Formation (Wenlockian–Ludlovian), the Kociewie Claystones and Siltstones Formation with the Reda Marly Siltstones Member (Wenlockian–Ludlovian) and the Puck Marly Claystones and Siltstones Formation (Ludlovian (Ludfordian)–Pridolian). Some of the units have a character of the allostratigraphical ones sensu „North American...”, (1983) because are bordered by the sedimentary or sedimentary-erosional unconformities. The lithology, stratigraphical position, thickness, paleontological data and spatial relation of the particular units are presented (Fig. 2). Their boundaries have been established and stratotypic sections are proposed. Rock sequences of different Formations have been correlated with lithostratigraphical and genetical equivalents of the adjacent regions of Lithuania and Russia (Kaliningrad District) and also with Denmark (Bornholm) and Germany (western part of the Peri-Baltic Depression).
    Źródło:
    Przegląd Geologiczny; 2006, 54, 9; 787-796
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Silurian stratigraphy of Central Iran - an update
    Autorzy:
    Hairapetian, V.
    Ghobadi Pour, M.
    Popov, L. E.
    Männik, P.
    Miller, C. G.
    Powiązania:
    https://bibliotekanauki.pl/articles/139183.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Iran
    Silurian
    biostratigraphy
    lithostratigraphy
    sedimentology
    correlation
    sylur
    biostratygrafia
    litostratygrafia
    sedymentologia
    korelacja
    Opis:
    The Silurian biostratigraphy, lithostratigraphy, and facies of Central Iran including the Kashmar (Boghu Mountains), Tabas (Derenjal Mountains, Ozbak-Kuh), Anarak (Pol-e Khavand) and Kerman regions is reviewed and updated. The current state of knowledge of the Silurian in the Zagros Basin, Alborz, Kopet-Dagh and Talysh regions, as well as in a few areas scattered across the Sabzevar Zone, and the Sanandaj-Sirjan terranes is also reviewed. Silurian volcanism in various parts of Iran is briefly discussed. The end of the Ordovician coincided with a widespread regression across Iran synchronous with the Hirnantian glaciation, and only in the Zagros Basin is there a continuous Ordovician–Silurian transition represented by graptolitic black shales of the Sarchahan Formation. In the Central-East Iranian Platform marine sedimentation re-commenced in the early to mid Aeronian. By the Sheinwoodian, carbonate platform depositional environments were established along its north-eastern margin. In other parts of Iran (e.g., Kopet-Dagh and the Sabzevar Zone), siliciclastic sedimentation continued probably into the late Silurian. The Silurian conodont and brachiopod biostratigraphy of Central Iran is significantly updated facilitating a precise correlation with the Standard Global Chronostratigraphic Scale, as well as with key Silurian sections in other parts of Iran. The Silurian lithostratigraphy is considerably revised and two new lithostratigraphical units, namely the Boghu and Dahaneh-Kalut formations, are introduced.
    Źródło:
    Acta Geologica Polonica; 2017, 67, 2; 201-233
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ordovician–Silurian boundary in the Bardo Syncline, Holy Cross Mountains, Poland—new data on fossil assemblages and sedimentary succession
    Autorzy:
    Masiak, M.
    Podhalańska, T.
    Stempień-Sałek, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2058822.pdf
    Data publikacji:
    2003
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Holy Cross Mountains
    Bardo Syncline
    Ordovician-Silurian boundary
    lithology
    graptolites
    acritarchs
    Opis:
    A gradual transition from sandy through silty to clayey strata occurs near the Ordovician–Silurian (O/S) boundary in the southern part of Holy Cross Mountains, in the Bardo Syncline. Three graptolite biozones are distinguished for the O/S boundary interval deposits: ?persculptus, ascensus-acuminatus and vesiculosus. The first, rare graptolites appear below “graptolitic shales” in the ?persculptus Biozone. The diversity of the assemblage increases in the next two biozones. An analysis of acritarch frequency shows a decrease of acritarch frequency at the O/S boundary and then a gradual increase in the lower part of the ascensus-acuminatus biozone with a maximum in the vesiculosus Biozone. The taxonomic diversity of the acritarch assemblage shows a similar trend although the maximum of acritarch frequency observed in the vesiculosus Biozone do not coincide the maximum of acritarch taxonomic diversity.
    Źródło:
    Geological Quarterly; 2003, 47, 4; 311--330
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Diversity of tissues in acanthodians with Nostolepis-type histological structure
    Autorzy:
    Valiukevicius, J
    Burrow, C.J.
    Powiązania:
    https://bibliotekanauki.pl/articles/22517.pdf
    Data publikacji:
    2005
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    histology
    acanthodian
    dentine
    Devonian
    Acanthodii
    Silurian
    bone
    Nostolepis
    tissue
    paleontology
    mesodentine
    Opis:
    Acanthodian scales with Nostolepis−type histological structure are separated into five groups based on the presence/absence and extent of stranggewebe, odontocytic and syncitial mesodentine networks, cellular unipolar mesodentine, bone−like mesodentine and durodentine in scale crowns. Two new families of acanthodians are erected, based primarily on histological structure of scales: the Vesperaliidae (stranggewebe extending throughout the scale crown) and the Acritolepidae (bone−like mesodentine in the scale crown). The latter family includes species erected for articulated fish. The families Tchunacanthidae and Lenacanthidae are united in the single family Tchunacanthidae, characterized by having scale crowns with mesodentine formed mainly by unipolar cells. A sixth group, which we exclude from the Nostolepis−type, has scale crowns composed of dentine without lacunae, plus durodentine, and bases with only rare osteocyte cavities. The new groups promote the revision and reassignment of many “nostolepid” taxa, in particular removing many species from the genus Nostolepis. Four new genera are erected: Pechoralepis (including part of Nostolepis), assigned to Acritolepidae nov.; and three genera assigned to an indeterminate family, which scales are composed of only odontocytic mesodentine without stranggewebe: Nostovicina (including part of Nostolepis), Nobilesquama (including part of Nostolepis), and Peregrinosquama (including part of Watsonacanthus). Histological structures are considered the primary characters of taxonomical value when based on isolated scales. Unfortunately, scale histology is unknown for most articulated acanthodians.
    Źródło:
    Acta Palaeontologica Polonica; 2005, 50, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The brachiopod succession through the Silurian–Devonian boundary beds at Dnistrove, Podolia, Ukraine
    Autorzy:
    Balinski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/23447.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    brachiopod
    succession
    Silurian
    Devonian
    boundary bed
    Podolia
    Ukraine
    Brachiopoda
    paleontology
    paleoenvironment
    Opis:
    In the classic section across the Silurian–Devonian boundary at Dnistrove (Podolia, Ukraine) the brachiopod fauna has never been studied in detail. This paper presents results of research on brachiopods from this important locality and time interval. Bed−by−bed collecting has enabled the detailed distribution of brachiopod taxa through the boundary beds to be revealed. Generally, the reference section at Dnistrove yields rather scarce but often well preserved brachiopods. Dayia bohemica and Dnestrina gutta can be regarded as characteristic species for the uppermost Silurian. A relatively high−diversity but low−abundance brachiopod fauna occurs in the lowest 1.8 m of the earliest Devonian. Only three forms have been found to cross the Silurian–Devonian boundary: the strophomenide Plectodonta (Plectodonta) mariae pantherae subsp. nov., the atrypide Gracianella (Sublepida) paulula sp. nov., and the spiriferide Howellella (Howellella) latisinuata. A relatively narrow brachiopod−rich interval at 5.5 m above the Silurian–Devonian boundary yields 16 brachiopod species which probably indicate a setting near the lower limit of the photic zone equivalent to the Benthic Assemblage 3–4 boundary. Two new species and one new subspecies are described: Skenidioides tatyanae, Plectodonta (Plectodonta) mariae pantherae, and Gracianella (Sublepida) paulula.
    Źródło:
    Acta Palaeontologica Polonica; 2012, 57, 4
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Palaeobiology, ecology, and distribution of stromatoporoid faunas in biostromes of the mid-Ludlow of Gotland, Sweden
    Autorzy:
    Sandstrom, O
    Kershaw, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/21659.pdf
    Data publikacji:
    2008
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    paleoecology
    deposit
    Sweden
    paleontology
    Silurian
    morphotype
    stromatoporoid fauna
    ecology
    distribution
    Gotland
    Opis:
    Six well exposed mid−Ludlow stromatoporoid−dominated reef biostromes in four localities from the Hemse Group in southeastern Gotland, Sweden comprise a stromatoporoid assemblage dominated by four species; Clathrodictyon mohicanum, “Stromatopora” bekkeri, Plectostroma scaniense, and Lophiostroma schmidtii. All biostromes investigated in this area (of approximately 30 km²) are interpreted to belong to a single faunal assemblage forming a dense accumulation of fossils that is probably the best exposed stromatoporoid−rich deposit of the Silurian. The results from this comprehensive study strengthen earlier interpretations of a combination of genetic and environmental control on growth−forms of the stromatoporoids. Growth styles are similar for stromatoporoids in all six biostromes. Differences in biostrome fabric are due to variations in the degree of disturbance by storms. The uniformity of facies and the widespread low−diversity fauna support the view that palaeoenvironmental conditions were similar across the area where these biostromes crop out, and promoted the extraordinary growth of stromatoporoids in this shallow shelf area.
    Źródło:
    Acta Palaeontologica Polonica; 2008, 53, 2
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A new type of colony in Silurian (upper Wenlock) retiolitid graptolite Spinograptus from Poland
    Autorzy:
    Kozlowska, A.
    Dobrowolska, K.
    Bates, D.E.B.
    Powiązania:
    https://bibliotekanauki.pl/articles/22266.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    new type
    colony
    Silurian
    retiolitid graptolite
    Spinograptus
    Graptoloidea
    Retiolitidae
    Polska
    paleontology
    Opis:
    The new retiolitid species, Spinograptus tubothecalis, is described from the Colonograptus praedeubeli and C. deubeli biozones from two localities in Poland: a borehole on the East European Platform and the Holy Cross Mountains. This was a recovery phase after the severe Silurian Cyrtograptus lundgreni Event. The new species has a unique, previously undescribed form of finite rhabdosome. Unlike the species Spinograptus reticulolawsoni and S. lawsoni, in which the fi− nite rhabdosomes taper distally, its rhabdosome is parallel−sided with the two distal thecae developed as isolated tubes without genicular processes, with a small appendix between them. The new species also has preserved membranes of the sicula, thecae and ancora sleeve, similar to a few species of Spinograptus from the lower Homerian. Spinograptus tubothecalis, like Spinograptus clathrospinosus and S. spinosus, has paired reticulofusellar genicular processes on the pre−thecal ventral orifices, similar to but shorter than thecal processes. Transverse rods, a rare character in post−Cyrto− graptus lundgreni Event retiolitids occur in the new species in rudimentary form.
    Źródło:
    Acta Palaeontologica Polonica; 2013, 58, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Concentrations of Silurian nautiloid cephalopods from Russia and Kazakhstan
    Autorzy:
    Bogolepova, O K
    Holland, C H
    Powiązania:
    https://bibliotekanauki.pl/articles/22316.pdf
    Data publikacji:
    1995
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Cephalopoda
    cephalopod
    Silurian
    concentration
    Russia
    living population
    Kazakhstan
    paleontology
    nautiloid cephalopod
    Opis:
    Silurian cephalopod limestones known from northern Asia are usually singular beds or horizons of nodules. They range in their taphonomic character from the Mojero river type, with postmortem concentration from rich living populations by relatively gentle bottom currents into a submarine low, to that of the Karabutak Formation of the South Urals, where there has been concentration by strong wave or current action.
    Źródło:
    Acta Palaeontologica Polonica; 1995, 40, 4
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Strophomenide and orthotetide Silurian brachiopods from the Baltic Region, with particular reference to Lithuanian boreholes
    Autorzy:
    Musteikis, P
    Cocks, L.R.M.
    Powiązania:
    https://bibliotekanauki.pl/articles/22973.pdf
    Data publikacji:
    2004
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Strophomenoidea
    brachiopod
    Plectambonitoidea
    Silurian
    Orthotetoidea
    Lithuania
    Baltic region
    Brachiopoda
    paleontology
    borehole
    Opis:
    Epeiric seas covered the east and west parts of the old craton of Baltica in the Silurian and brachiopods formed a major part of the benthic macrofauna throughout Silurian times (Llandovery to Pridoli). The orders Strophomenida and Orthotetida are conspicuous components of the brachiopod fauna, and thus the genera and species of the superfamilies Plectambonitoidea, Strophomenoidea, and Chilidiopsoidea, which occur in the Silurian of Baltica are reviewed and reidentified in turn, and their individual distributions are assessed within the numerous boreholes of the East Baltic, particularly Lithuania, and attributed to benthic assemblages. The commonest plectambonitoids are Eoplectodonta (Eoplectodonta) (6 species), Leangella (2 species), and Jonesea (2 species); rarer forms include Aegiria and Eoplectodonta (Ygerodiscus), for which the new species E. (Y.) bella is erected from the Lithuanian Wenlock. Eight strophomenoid families occur; the rare Leptaenoideidae only in Gotland (Leptaenoidea, Liljevallia). Strophomenidae are represented by Katastrophomena (4 species), and Pentlandina (2 species); Bellimurina (Cyphomenoidea) is only from Oslo and Gotland. Rafinesquinidae include widespread Leptaena (at least 11 species) and Lepidoleptaena (2 species) with Scamnomena and Crassitestella known only from Gotland and Oslo. In the Amphistrophiidae Amphistrophia is widespread, and Eoamphistrophia, Eocymostrophia, and Mesodouvillina are rare. In the Leptostrophiidae Mesoleptostrophia, Brachyprion, and Protomegastrophia are common, but Eomegastrophia, Eostropheodonta, Erinostrophia, and Palaeoleptostrophia are only recorded from the west in the Baltica Silurian. In the Eopholidostrophidae, Mesopholidostrophia is common and Eopholidostrophia rare, and within the Shaleriidae the genus Shaleria is revised and found to be the only genus within the family Shaleriidae and to contain three subgenera, S. (Shaleria), S. (Shaleriella) and S. (Janiomya). In the Strophonellidae Strophonella was widespread and Eostrophonella rare. Within the Orthotetoidea, Coolinia and Morinorhynchus(with the new Ludlow and Pridoli species M. rubeli from the Lithuanian boreholes erected) are common, and Fardenia, Saughina, and Valdaria again only known from the west Baltic. Most of the genera and many of the speciesreviewed were very widespread and many found in the adjacent Avalonia and Laurentia: a few were even more cosmopolitan.
    Źródło:
    Acta Palaeontologica Polonica; 2004, 49, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sedimentology of deposits from around the Late Caledonian unconformity in the western Holy Cross Mts.
    Autorzy:
    Malec, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059319.pdf
    Data publikacji:
    2001
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Holy Cross Mountains
    Upper Silurian-Lower Devonian
    stratigraphy
    sedimentology
    Late Caledonian unconformity
    Opis:
    The Upper Silurian-Lower Devonian section of the western part of the Holy Cross Mts. is composed of greywackes of the Niewachlów Beds, Kielce Beds and Miedziana Góra Conglomerates. They are separated from the terrestrial Gruchawka Conglomerates and Barcza Beds by an erosional surface. Depositional structures recorded in the Silurian greywackes indicate the deep-water sedimentary environment of a flysch facies. The uppermost part of the Kielce Beds and the Miedziana Góra Conglomerates accumulated on a submarine delta fan. These deposits correspond to Late Caledonian molasse and are associated with closure of the Late Silurian basin in the Holy Cross Mts. The Gruchawka Conglomerates, containing fish remains, mark the beginning of the Early Devonian marine transgression. Together with the overlying sandstones and mudstones of the Barcza Beds they form the Old Red Sandstone succession. The Late Caledonian unconformity occurs between the Upper Silurian molasse deposits and Lower Devonian Old Red Sandstone facies, and the stratigraphic gap most likely spans the Pridoli, Lochkovian and lower Pragian. Large thicknesses of Silurian greywackes in the NW part of Kielce, and the high degree of thermal maturity of organic matter, indicate a geotectonic affinity of this region with the Łysogóry Block.
    Źródło:
    Geological Quarterly; 2001, 45, 4; 397-416
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evolution of retiolitid graptolites - a synopsis
    Autorzy:
    Kozlowska-Dawidziuk, A
    Powiązania:
    https://bibliotekanauki.pl/articles/23196.pdf
    Data publikacji:
    2004
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Holoretiolites
    Ludlow
    Retiolitidae
    retiolitid graptolite
    paleobiology
    Silurian
    evolution
    Graptoloidea
    paleontology
    rhabdosome reduction
    Opis:
    Twenty million years of retiolitid evolution reflect environmental changes, the most severe being the Silurian Cyrtograptus lundgreni Event. Five biostratigraphically and morphologically constrained retiolitid faunas are distinguished and characterized according to their rhabdosomal modifications: (1) the oldest and long−ranging Llandovery group of mostly large and morphologically complex rhabdosomes, (2) the less diverse Telychian−Sheinwoodian group, (3) the Cyrtograptus lundgreni Biozone varied group of intermediate size, and two short−ranged (4) late Homerian, and (5) early Ludlow groups with small rhabdosomes. Although the evolutionary history of retiolitids was complex and not linear, a common tendency toward reduction of rhabdosome size in most lineages is observed. The greatest reduction in both number and volume of thecae, and in skeletal elements is demonstrated in the Gothograptus and Plectograptusfaunas. Contrary to the thecal decrease, a distinctive increase of sicula size is observed in retiolitids. Two types of colonies are distinguished: L−colonies with a small sicula and numerous large thecae of similar size, and S−colonies with a long sicula and a few, small thecae. These changes imply modification of the soft body: an increase in siculozooid length and a decrease in the size of the zooids. Thus, the siculozooid probably produced great amounts of morphogen inhibiting zooid growth. In consequence the phenomenon of colony reduction occurred. The most extreme stages of rhabdosome reduction in Ludlow retiolitids can be seen in Plectodinemagraptus gracilis of the Plectograptuslineage and in the new species Holoretiolites helenaewitoldi, possibly representing the last stage of skeletal reduction in the Gothograptus lineage; the next hypothetical stage would be its total loss. The sicula length of Holoretiolites, about 2 mm, is reported herein for the first time.
    Źródło:
    Acta Palaeontologica Polonica; 2004, 49, 4
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Ordovician-Silurian boundary beds between Saaremaa and Gotland, Baltic Sea, based on high resolution seismic data
    Autorzy:
    Tuuling, I.
    Flodén, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059526.pdf
    Data publikacji:
    2007
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Baltic Bas
    Ordovician-Silurian boundary
    seismostratigraphy
    carbonate buildups
    erosional features
    stratigraphic gaps
    Opis:
    New seismic profiles have been used to revise earlier interpretations of the Ordovician-Silurian bound ary beds be tween Saaremaa and Gotland. Atrans-Baltic reflector with erosional fea ures (S2) above the erosional Ordo vician-Silurian boundary reflector (S1) correlates with the bound ary between the Raikküla and Adavere stages. The sporadic reflector or2 below the S1 reflector off shore from Gotland represents the erosional boundary between the Pirgu and Porkuni stages. Three stratigraphic gaps occur in the Ordovician-Silurian boundary beds off shore from Gotland. The amount of eroded rocks between the Pirgu and Porkuni stages, the Ordovician and Silurian systems and the Raikküla and Adavere stages can change rapidly. Consequently, the thick ness and stratigraphy of the Ordovician-Silurian boundary beds around Gotland can change considerably across short distances. The O4-5-S1 unit off shore from Gotland, including carbonate build ups and erosional incisions infilled with Porkuni strata, belongs facially to the transi ional belt between the Estonian Shelf and the Livonian Tongue. The thick ness changes in the S1-S2 unit (Juuru and Raikküla stages) indicate an extensive subma rine erosional channel, streching from north of Estonia across the Baltic Sea and central Gotland, which developed in the Baltic Basin along a shelf to deep-basin transect dur ng Llandovery time.
    Źródło:
    Geological Quarterly; 2007, 51, 3; 217-229
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Rola geofizyki wiertniczej w określeniu zasobów gazu ziemnego w łupkach
    Application of wire log analysis for petrophysical evaluation and determination of shale gas reserves
    Autorzy:
    Drop, K.
    Kozłowski, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074763.pdf
    Data publikacji:
    2010
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    gaz łupkowy
    interpretacja geofizyki wiertniczej
    łupki
    shale gas
    petrophysical interpretation
    Silurian Shale
    Opis:
    The paper presents differences between conventional and shale gas plays (Tab. 1). Shale gas concept comprises a wide range of reservoirs, from the coalbed to tight gas plays. In Europe, where the shale gas rush has just started, shaly rocks were treated so far as unproductive and high quality data sets necessary for evaluating properties of those rocks are usually missing. Therefore, US shale gas plays like Barnett and Haynesville are widely used as valuable reference tools (Jacobi, 2008; Parker, 2009). Coal, where gas is essentially stored entirely by sorption, represents one end of the unconventional gas spectrum and tight gas sands, where gas is essentially stored by compression only - the other end of that spectrum. In turn, shale reservoirs with gas entrapped by sorption and compression, fill the space between the two endpoints. Differentiation of those two components is one of the primary goals of an analysis program. Shale gas reservoirs are formed by a wide variety of rock types which makes it necessary to use most appropriate technologies to characterize both coalbed and tight gas reservoirs. The current paper concentrates on tools for evaluating petrophysical parameters, most suitable for shale gas plays. In the case of old wells with old fashion Soviet logs, the uncompensated neutron gamma tool was commonly used tool. This was the only porosity reading curve in log suite, "neutron porosity curve" which could be overlaid with natural gamma ray (GR) (Fig. 1). Natural gamma ray curve is a good indicator of organic matter, which adsorbed uranium. Other hydrocarbon signatures can be traced on the basis of SP vs GR, GR vs resistivity. Some of hydrocarbon signatures can be related to TOC from core lab measurements. For contemporary good quality wire line log curves the Passey et al. (1990) method has been applied. This method is based on computation of separation between acoustic transit time and resistivity (R) (Fig. 2). The resulting difference is used to calculate TOC taking into consideration maturity of organic matter which is parameter for a bunch of relationships (TOC vs R). Local calibration R to TOC from cores are required. In order to determine reliable relationships between R, gas contents to TOC, the high technology coring service and sensitive laboratory measurements are necessary. The results of petrophysical analyses are important for estimations of gas resources in shales. The formulas for computation of conventional and unconventional gas reserves are generally similar. However, in the case of the unconventional gas reserves, instead of porosity reservoir storage the rock density is applied, and for determinations of hydrocarbon volume-the gas content is applied in place of hydrocarbon saturation. If European unconventional reservoirs turn to be profitable then continent landscape will also change. The big gas fields would require dense networks of rigs that will have some negative environmental impact. This would require a change in industry structure, as well as in public opinion and legal regulations.
    Źródło:
    Przegląd Geologiczny; 2010, 58, 3; 263-265
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Silurian synziphosurine horseshoe crab Pasternakevia revisited
    Autorzy:
    Krzeminski, W.
    Krzeminska, E.
    Wojciechowski, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/20993.pdf
    Data publikacji:
    2010
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Silurian
    horseshoe crab
    arthropod
    Pasternakevia
    paleontology
    Arthropoda
    Xiphosura
    Bunodidae
    phylogenesis
    Ukraine
    stratigraphy
    Opis:
    The synziphosurine horseshoe crab Pasternakevia was until now known only from a single specimen. Herein we describe three new specimens from the outcrop close to the type locality of monotypic P. podolica that show several features that were unknown or only assumed in this genus. These characters include: a smooth surface of the carapace; an opisthosoma composed of ten segments, the first one being a microtergite (strongly reduced first opisthosomal segment usually hidden under the carapace), two or three last segments fused into a metasoma, and the telson. Pasternakevia is included in Bunodidae due to a hypertrophied tergite 2, but it is linked to the Pseudoniscidae by the shape of the opisthosoma.
    Źródło:
    Acta Palaeontologica Polonica; 2010, 55, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Upper Homerian (Silurian) high-resolution correlation using cyclostratigraphy: an example from western Lithuania
    Autorzy:
    Radzevičius, S.
    Tumakovaitė, B.
    Spiridonov, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/139177.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Lithuania
    Silurian
    upper Homerian
    cyclostratigraphy
    graptolite biozones
    Litwa
    sylur
    górny Homerian
    cyklostratygrafia
    Opis:
    The Gėluva regional stage stratigraphically corresponds to the late Wenlock. This time interval witnessed significant graptolite extinctions and turnovers of conodont faunas, as well as a large positive Mulde carbon isotopic excursion. Thus, the development of a detailed stratigraphy is a necessary step in understanding the complex patterns of regional and global variations in the sediments accumulating during the time interval studied. Therefore, in this contribution we present a cyclostratigraphic analysis of gamma ray (GR) logs from four wells, which are located in the deep water facies belt of the Lithuanian part of the Silurian Baltic Basin of the Gėluva regional stage. The analysis was performed using REDFIT spectral estimation, continuous wavelet transform and signal filtering techniques. As a result two 4th order and five 5th order cycles were distinguished and named in all sections. The correlation of cycles between sections was calibrated with the graptolite biozones. The comparative analysis revealed that intra-basinal cyclostratigraphic correlation could achieve resolution of the order of several tens of thousands of years.
    Źródło:
    Acta Geologica Polonica; 2017, 67, 2; 307-322
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A review of Silurian fishes from north-western Hunan, China and related biostratigraphy
    Autorzy:
    Zhao, W. -J.
    Zhu, M.
    Gai, Z. -K.
    Pan, Z. -H.
    Cui, X. -D.
    Cai, J. -C.
    Powiązania:
    https://bibliotekanauki.pl/articles/139181.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    early vertebrates
    biostratigraphy
    Silurian
    north-western Hunan
    China
    kręgowce
    biostratygrafia
    sylur
    Hunan
    Chiny
    Opis:
    The Silurian fishes from north-western Hunan, China are characterised by the earliest known galeaspids Dayongaspis Pan and Zeng, 1985 and Konoceraspis Pan, 1992, and the earliest known antiarch Shimenolepis Wang J.-Q., 1991, as well as rich sinacanth fin spines. Shimenolepis from Lixian County in north-western Hunan, which was dated as the Telychian (late Llandovery), has long been regarded as the oldest representative of the placoderms in the world. As such, in addition to eastern Yunnan and the Lower Yangtze Region, north-western Hunan represents another important area in South China that yields important fossil material for the research of early vertebrates and related stratigraphy. Here we summarise the Silurian fishes known in north-western Hunan so far, and classify them into three vertebrate assemblages (i.e., the Wentang, Maoshan, and Yangtze assemblages). Based on the updated Silurian vertebrate and stratigraphic databases, the Silurian fish-bearing strata in north-western Hunan can be subdivided into the Rongxi, Huixingshao, and Xiaoxi formations in ascending chronological order, which can be correlated with the Lower Red Beds, the Upper Red Beds, and the Ludlow Red Beds in South China, respectively. A new look at the Silurian strata in Lixian suggests that the age of Shimenolepis is late Ludlow rather than late Llandovery as previously suggested. The research on Silurian fishes and biostratigraphy in north-western Hunan not only provides morphological data of early vertebrates, but also offers new palaeoichthyological evidence for the subdivision, correlation, and age assignment of the Silurian marine red beds in South China. The establishment of a related high-precision Silurian stratigraphic framework in north-western Hunan will help to elucidate the temporal and spatial distribution of Silurian fossil fishes, deepen the understanding of the evolution of early vertebrates, and unravel the coevolution between Silurian vertebrates and the palaeoenvironment.
    Źródło:
    Acta Geologica Polonica; 2018, 68, 3; 475-486
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Silurian shales of the East European Platform in Poland : some exploration problems
    Autorzy:
    Porębski, S.J.
    Prugar, W.
    Zacharski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075023.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Silurian
    black shale
    shale gas
    unconventional play
    czarne łupki
    gaz łupkowy
    niekonwencjonalna gra
    Opis:
    The pericratonic Silurian shale succession in Poland, despite its reasonably well-constrained geological framework, entails a number of contentious issues that need to be resolved before this emerging shale gas play will enter a stage of successful development. The succession is thought to have originated in a Caledonian foredeep encroaching distally onto a pericratonic shelf ramp. However, the geochemical signature of the mudrocks is consistent with a cratonic rather than orogenic sourcing, the proximal part of the foredeep basin-fill is apparently missing, and the shale succession juxtaposes in part across the Teisseyre-Tornquist Zone against suspected terranes with no evidence of Silurian tectonism. Organic-rich Llandovery– Wenlock shales form a NW-SE striking central belt that is increasingly calcareous toward the craton (NE) and more silty toward the inferred orogen (SW), with the TOC content decreasing in both directions perpendicular to the strike. The TOC trend seems consistent with the deep-downlap model of black shale deposition suggested for many Paleozoic foredeep basins, but does not quite agree with the outer neritic to upper bathyal depths assumed for the shale deposition. Preliminary results from three wells drilled by Orlen Upstream in the Lublin Basin indicate that the Llandovery–Wenlock shales were deposited on a distal shelf ramp sheltered from the craton by shelf carbonate shoals and periodically affected by weak storm-generated currents. The impact of storms on water column resulted in intermittent rises of oxygen content in the otherwise anoxic to dysoxic near-bottom conditions. The prospective interval is dominated by calcite-cemented clayey mudstones showing moderate to good reservoir qualities. It is cut locally by ENE- or NE-dipping, steep fractures favourable for fluid transmissibility, and a NE or SWdirection is most advantageous for artificial fracturing. This interval is capped with a Ludlow calcite-cemented, laminated siltstone that forms a regional correlation marker and shows soft-sediment deformations attributable to gravitational collapse on a NE-dipping paleoslope. If correct, this interpretation might imply the encroachment of orogen-fed clinothem system onto the SW-inclined craton-margin shelf ramp.
    Źródło:
    Przegląd Geologiczny; 2013, 61, 11-1; 630-638
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Phanerozoic paleoenvironment and paleolithofacies maps : Early Paleozoic
    Mapy paleośrodowiska i paleolitofacji fanerozoiku : wczesny paleozoik
    Autorzy:
    Golonka, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/183797.pdf
    Data publikacji:
    2009
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    paleogeografia
    kambr
    ordowik
    sylur
    tektonika płyt litosfery
    Cambrian
    Ordovician
    Silurian
    plate tectonics
    paleogeography
    Opis:
    The paper presents the detailed plate tectonic, paleogeographic, paleoenvironment and plaeolithofacies maps for eight Early Paleozoic time intervals. Forty maps, generated using PLATES and PALEOMAP programs, contain information about plate tectonics, paleoenvironment, and plaeolithofacies during Cambrian, Ordovician and Silurian. Disintegration of supercontinent Pannotia and origin of Gondwana, Laurentia and Baltica occur during Early Cambrian. Oceans spreading continued during Late Cambrian and Early Ordovician; vast platform flooded by shallow seas existed on the continents. The plate tectonic reorganization happened during Middle Ordovician. Silurian was a time of Caledonian orogeny, closing of Early Paleozoic oceans and origin of supercontinent Laurussia as a result of Laurentia and Baltica collision. Information contained within global and regional papers were posted on the maps and the detailed paleoenvironment and plaeolithofacies zones were distinguished within the platforms, basins and ridges.
    Artykuł przedstawia szczegółowe mapy paleogeograficzne dla ośmiu przedziałów czasowych w obrębie wczesnego paleozoiku. Czterdzieści map, skonstruowanych przy użyciu programów PLATES i PALEOMAP, zawiera informacje dotyczące tektoniki płyt, paleośrodowiska i paleolitofacji w czasie kambru, ordowiku i syluru. We wczesnym kambrze nastąpił rozpad superkontynentu Pannotia i utworzyły się kontynenty: Gondwana, Laurencja, Bałtyka i Syberia. W późnym kambrze i wczesnym ordowiku w dalszym ciągu ma miejsce spreding oceanów, istnieją też w tym czasie rozległe platformy zalane przez płytkie morza na kontynentach. Reorganizacja płyt litosfery nastąpiła w środkowym ordowiku. Sylur był okresem orogenezy kaledońskiej, zamknięciem wczesno- paleozoicznych oceanów i powstania superkontynentu Laurosji z połączenia Laurencji i Bałtyki. Informacje zawarte w szeregu globalnych i regionalnych prac zostały naniesione na mapy, a w obrębie platform, basenów i grzbietów wydzielono poszczególne strefy paleośrodowiskowe i paleolitofacjalne
    Źródło:
    Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie; 2009, 35, 4; 589-654
    0138-0974
    Pojawia się w:
    Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Assessment of hydrocarbon potential of the Lower Palaeozoic strata in the Tarnogród–Stryi area (SE Poland and western Ukraine)
    Autorzy:
    Więcław, D.
    Kosakowski, P.
    Kotarba, M.J.
    Koltun, Y. V.
    Kowalski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/191878.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    source rock
    hydrocarbon potential
    Cambrian
    Ordovician
    Silurian
    Carpathian Foredeep basement
    SE Poland
    Western Ukraine
    Opis:
    Quantity, genetic type and maturity of organic matter dispersed in the Lower Palaeozoic sequence from the Lower Cambrian to Silurian strata of the Polish and Ukrainian parts of the Carpathian Foredeep basement in the Tarnogród–Stryi area were evaluated based on the results of geochemical analyses of 475 rock samples collected from 45 wells. The best source rocks were found in the Silurian strata where the present total organic carbon (TOC) content is up to 2.6 wt%. They occur in the vicinity of Wola Obszańska, where the median of the present and the initial total organic carbon (TOC) contents in the individual wells amount to 0.98 and 1.6 wt%, respectively. The Cambrian and Ordovician strata have a poorer hydrocarbon potential and their present TOC content never exceeds 1 wt%. In all of the investigated Lower Palaeozoic strata, organic matter is represented by the oil-prone Type-II kerogen deposited in anoxic or sub-oxic conditions. The maturity of source rocks ranges from early mature (the initial phase of the low-temperature thermogenic processes) in selected zones of the Silurian strata in the vicinity of Wola Obszańska, through the middle and the final phase of “oil window” in the Ordovician and Cambrian strata in the Polish part of the study area, to the overmature stage in the Ordovician strata in the south-eastern part of the study area (Ukraine).
    Źródło:
    Annales Societatis Geologorum Poloniae; 2012, 82, 1; 65--80
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Stromatoporoid beds and flat-pebble conglomerates interpreted as tsunami deposits in the Upper Silurian of Podolia, Ukraine
    Autorzy:
    Łuczyński, P.
    Skompski, S.
    Kozłowski, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/138749.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Palaeotsunami
    Silurian
    Podolia
    Stromatoporoid beds
    Flat-pebble conglomerates
    sylur
    Podole
    warstwy stromatoporoidowe
    prefabrykaty płaskie
    Opis:
    Tsunami deposits are currently a subject of intensive studies. Tsunamis must have occurred in the geological past in the same frequency as nowadays, yet their identified depositional record is surprisingly scarce. Here we describe a hitherto unrecognized example of probable palaeotsunamites. The Upper Silurian (Pridoli) carbonate succession of Podolia (southwestern Ukraine) contains variously developed event beds forming intercalations within peritidal deposits (shallow water limestones, nodular marls and dolomites). The event beds are represented by stromatoporoid and fine-grained bioclastic limestones, in some places accompanied by flat-pebble conglomerates. The interval with event beds can be traced along the Zbruch River in separate outcrops over a distance of more than 20 km along a transect oblique to the palaeoshoreline. The stromatoporoid beds have erosional bottom surfaces and are composed of overturned and often fragmented massive skeletons. The material has been transported landward from their offshore habitats and deposited in lagoonal settings. The flat-pebble conglomerates are composed of sub-angular micritic clasts that are lithologically identical to the sediments forming the underlying beds. Large-scale landward transport of the biogenic material has to be attributed to phenomena with very high energy levels, such as tropical hurricanes or tsunamis. This paper presents a tsunamigenic interpretation. Morphometric features of redeposited stromatoporoids point to a calm original growth environment at depths well below storm wave base. Tsunami waves are the most probable factor that could cause their redeposition from such a setting. The vastness of the area covered by parabiostromal stromatoporoid beds resembles the distribution of modern tsunami deposits in offshore settings. The stromatoporoid beds with unsorted stromatoporoids of various dimensions evenly distributed throughout the thickness of the beds and with clast-supported textures most probably represent deposition by traction. In some sections, the stromatoporoids are restricted to the lowermost parts of the beds, which pass upwards into bioclastic limestones. In this case, the finer material was deposited from suspension. The coexistence of stromatoporoid beds and flat-pebble conglomerates also allows presenting a tsunami interpretation of the latter. The propagating tsunami waves, led to erosion of partly lithified thin-layered mudstones, their fragmentation into flat clasts and redeposition as flat-pebble conglomerates.
    Źródło:
    Acta Geologica Polonica; 2014, 64, 3; 261-280
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Charakterystyka petrograficzna paleozoicznych skał łupkowych basenu bałtyckiego : konsekwencje dla rozpoznawania i wydobycia gazu łupkowego
    Petrography of palaeozoic shale from Baltic basin : implications for recognition and exploitation of shale gas
    Autorzy:
    Gąsiński, A.
    Poszytek, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/394923.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
    Tematy:
    łupki sylursko-ordowickie
    gaz łupkowy
    porowatość
    mineralogia
    Silurian-Ordovician shale
    shale gas
    porosity
    mineralogy
    Opis:
    W pracy zaprezentowano wyniki szczegółowych badań mineralogicznych, które wraz z obserwacjami w wysokorozdzielczym mikroskopie skaningowym dostarczyły informacji na temat składu mineralnego, tekstur i charakteru wykształcenia porowatości w ordowicko-sylurskich skałach łupkowych basenu bałtyckiego. Głównymi składnikami tych skał są minerały ilaste oraz kwarc, kalcyt, dolomit, piryt i skalenie. Znaczna część kwarcu ma charakter diagenetyczny, co korzystnie wpływa na możliwości szczelinowania skał. Na podstawie uzyskanych wyników opisano także procesy, które w zasadniczy sposób wpłynęły na formowanie obecnie występującej porowatości. Stwierdzono, że najważniejszym procesem mającym wpływ na powstanie wtórnej porowatości było przeobrażanie minerałów ilastych (smektyt-illit), a współwystępująca wraz z tym procesem cementacja krzemionką spowodowała prawie całkowite wypełnienie powstałej przestrzeni porowej. Prawdopodobnie pory były wypełniane również przez autogeniczne ziarna chlorytów. Pory zachowane w badanych skałach łupkowych podzielono na cztery typy, biorąc pod uwagę morfologię i charakter ich występowania. Stwierdzono potencjalną możliwość występowania drobnych połączeń pomiędzy porami, co może pozwalać na powolną migrację mediów w skale.
    The paper presents the results of detailed mineralogical studies of shales in Ordovician-Silurian Baltic basin. Main constituents of these rocks are clay minerals (illite and smectite), quartz, calcite, dolomite, pyrite and feldspars. Significant part of quarz grains is of authigenic origin, which positively influences the process of hydraulic fracturing. Observations in the high-resolution scanning electron microscope gave information about the nature of porosity in the shale and the processes which significantly contributed to the formation of porosity. It was found that the most important process affecting the secondary porosity of shale was the transformation of clay minerals (smectite-illite). Created pore space was almost completely filled by silica cement. Preserved pores were divided into four types according to their morphology and nature of occurrence. There was also found the potential for occurrence of interconnections between fine pores that allow fluid migration.
    Źródło:
    Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN; 2013, 85; 79-88
    2080-0819
    Pojawia się w:
    Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Problem tsunamitów. Dlaczego tak mało jest kopalnych osadów tsunami?
    The tsunamites problem. Why are fossil tsunamites so rare?
    Autorzy:
    Łuczyński, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074917.pdf
    Data publikacji:
    2012
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    tsunami
    tsunamites
    palaeotsunamites
    stromatoporoid beds
    Upper Silurian
    Podolia
    tsunamity
    warstwy stromatoporoidowe
    górny sylur
    Podole
    Opis:
    Tsunami is a common phenomenon and one of the most dangerous natural hazards of the modern world. Taking into account the relative high frequency of tsunamis in historical times, we can expect accordingly rich geological records of similar events from fossil formations. However, palaeotsunami deposits are surprisingly rare, mainly because of the difficulty of discerning them from sediments formed by other processes, e.g. storms. Part of the problem lies in the definition of tsunamite, which refers only to the triggering process, and in a different approach while discerning modern and fossil tsunamites. Modern tsunamites are identified by connecting the deposits to a particular historical tsunami event, even if they contain no diagnostic sedimentological features - an approach, which cannot be applied to fossil formations. This can lead to an impression that modern tsunami deposits are much more common than their fossil counterparts, which in turn suggest great intensification of tsunami events in historical times. Lately, a great number ofpapers have been published on sedimentary effects of modern tsunamis. The studies concentrated on land and near-shore areas. Many authors point out that the sedimentary record left by tsunami is commonly surprisingly mean and with a very low preservation potential. When interpreting fossil successions, the most important features that might indicate their tsunamite genesis are: mixing of material derivedfrom various facial zones, evidence of deep erosion and long transport, and association with other symptoms of seismic activity. The stromatoporoid biostromal accumulations in the Upper Silurian ofPodolia are presented here as possible palaeotsunamite deposits. Thick layers of redeposited stromatoporoids within fine-grained peritidal deposits are interpreted as an effect of onshore transport of this relatively light material during high-energy sedimentary events, such as tsunami. In many ways, the stromatoporoid beds resemble modern accumulations oftsunami-derived boulders.
    Źródło:
    Przegląd Geologiczny; 2012, 60, 11; 598--604
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Waloryzacja geostanowisk na obszarze projektowanego Geoparku Łysogórskiego w Górach Świętokrzyskich
    Valorization of geosites in the projected Łysogóry Geopark in the Holy Cross Mountains
    Autorzy:
    Fijałkowska-Mader, A.
    Malec, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075050.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Cambrian
    Silurian
    Devonian
    Cenozoic
    geosite
    geodiversity
    geotourism
    kambr
    sylur
    devon
    kenozoik
    geostanowisko
    georóżnorodność
    geoturystyka
    Opis:
    The paper presents results of valorization of geosites in the Łysogóry Region of the Holy Cross Mountains, which warrant creation of the Łysogóry Geopark. Numerous geosites of different Paleozoic rocks offer a great educational potential, combining many fields of knowledge, such as geology, geomorphology, paleontology, paleoecology, ancient metallurgy industry and historical monuments. Geodiveristy makes this area very attractive for geotourism.
    Źródło:
    Przegląd Geologiczny; 2013, 61, 3; 165--171
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Łupki sylurskie platformy wschodnioeuropejskiej w Polsce : wybrane problemy poszukiwawcze
    Silurian shales of the East European Platform in Poland : some exploration problems
    Autorzy:
    Porębski, S.J.
    Prugar, W.
    Zacharski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075081.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Silurian
    black shale
    shale gas
    unconventional play
    sylur
    ciemne łupki
    gaz łupkowy
    niekonwencjonalna gra
    Opis:
    The pericratonic Silurian shale succession in Poland, despite its reasonably well-constrained geological framework, entails a number of contentious issues that need to be resolved before this emerging shale gas play will enter a stage of successful development. The succession is thought to have originated in a Caledonian foredeep encroaching distally onto a pericratonic shelf ramp. However, the geochemical signature of the mudrocks is consistent with a cratonic rather than orogenic sourcing, the proximal part of the foredeep basin-fill is apparently missing, and the shale succession juxtaposes in part across the Teisseyre-Tornquist Zone against suspected ter- ranes with no evidence of Silurian tectonism. Organic-rich Llandovery-Wenlock shales form a NW-SE striking central belt that is increasingly calcareous toward the craton (NE) and more silty toward the inferred orogen (SW), with the TOC content decreasing in both directions perpendicular to the strike. The TOC trend seems consistent with the deep-downlap model of black shale deposition suggested for many Paleozoic foredeep basins, but does not quite agree with the outer neritic to upper bathyal depths assumed for the shale deposition. Preliminary results from three wells drilled by Orlen Upstream in the Lublin Basin indicate that the Llandovery-Wenlock shales were deposited on a distal shelf ramp sheltered from the craton by shelf carbonate shoals and periodically affected by weak storm-generated currents. The impact of storms on water column resulted in intermittent rises of oxygen content in the otherwise anoxic to dysoxic near-bottom conditions. The prospective interval is dominated by calcite-cemented clayey mudstones showing moderate to good reservoir qualities. It is cut locally by ENE- or NE-dipping, steep fractures favourable for fluid transmissibility, and a NE or SW direction is most advantageous for artificial fracturing. This interval is capped with a Ludlow calcite-cemented, laminated siltstone that forms a regional correlation marker and shows soft-sediment deformations attributable to gravitational collapse on a NE-dippingpaleoslope. If correct, this interpretation might imply the encroachment of orogen-fed clinothem system onto the SW-inclined craton-margin shelf ramp.
    Źródło:
    Przegląd Geologiczny; 2013, 61, 8; 468--477
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nowelizacja stratygrafii syluru w wybranych profilach wiertniczych obniżenia bałtyckiego (Polska północna)
    Revision of the Silurian stratigraphy in selected boreholes from the Polish sector of the Baltic Depression (northern Poland)
    Autorzy:
    Szymański, B.
    Modliński, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/2063391.pdf
    Data publikacji:
    2003
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    stratygrafia
    graptolity
    sylur
    obniżenie bałtyckie
    Polska Północna
    graptolites
    stratigraphy
    Silurian
    Baltic Depression
    northern Poland
    Opis:
    Zaprezentowano wyniki rewizji podziału graptolitowego serii sylurskiej w wybranych profilach wiertniczych polskiej części obniżenia bałtyckiego. Dotychczasowy podział był oparty na autorskim schemacie E. i H. Tomczyków (1962-1990), który zawiera szereg błędnych rozwiązań. Zakres proponowanych korekt obejmuje m.in.: ujednolicenie granic systemu, dolnej - ordowik/sylur i górnej - sylur/dewon, eliminację jednostek rangi oddziału określanych jako siedlce i podlasie, zdefiniowanie granic i zasięgów standardowych oddziałów systemu (landower, wenlok, ludlow, pridoli) oraz pięter (gorst i ludford), wreszcie rezygnację z szeregu wyróżnianych dotychczas regionalnych poziomów graptolitowych. Niektóre z nich nie mają wszystkich cech umożliwiających ich identyfikację na obszarze całego basenu. Dla innych niemożliwe jest udokumentowanie ich granic i zasięgów. Jeszcze inne są niedostatecznie udokumentowane, co uniemożliwia jednoznaczne korelacje ze standardowymi poziomami graptolitowymi skali globalnej. Zmodyfikowany schemat podziału serii sylurskiej ilustrują profile otworów wiertniczych: Słupsk IG 1, Lębork IG 1, Kościerzyna IG 1, Żarnowiec IG 1, Gdańsk IG 1, Hel IG 1, Pasłęk IG 1 i Bartoszyce IG 1.
    This study revises the graptolite zonation of the Silurian System in selected boreholes from the Polish sector of the Baltic Depression. The previous zonation was based on the scheme by Tomczykowa & Tomczyk (1962-1990) and contained many errors. The revision resulted in, among others, unification of the basal and top boundaries of the Silurian System, elimination of the Siedlce series and Podlasie series, determination of limits and ranges of the standard Series (Llandovery, Wenlock, Ludlow and Pridoli) and Stages (Gorstian and Ludfordian), and relinquishment of several regional graptolite zones. Some of the zones do not posses enough attributes to allow their identification across the entire basin. For others it is impossible to dating their limits and ranges. Yet others are insufficiently documented, that makes them impossible to correlate with the standard graptolite zones. The modified stratigraphic scheme of the Silurian System is illustrated by borehole sections: Słupsk IG 1, Lębork IG 1, Kościerzyna IG 1, Żarnowiec IG 1, Gdańsk IG 1, Hel IG 1, Pasłęk IG 1 and Bartoszyce IG 1.
    Źródło:
    Biuletyn Państwowego Instytutu Geologicznego; 2003, 405; 109--138
    0867-6143
    Pojawia się w:
    Biuletyn Państwowego Instytutu Geologicznego
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Petrographic characteristics of the Ordovician and Silurian deposits in the Baltic Basin (N Poland) and their relevance for unconventional hydrocarbon accumulations
    Autorzy:
    Kuberska, Marta
    Sikorska-Jaworowska, Magdalena
    Kozłowska, Aleksandra
    Podhalańska, Teresa
    Powiązania:
    https://bibliotekanauki.pl/articles/2060104.pdf
    Data publikacji:
    2021
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    petrography
    mineralogy
    shale-type accumulations
    total organic carbon
    Ordovician rocks
    Silurian rocks
    Baltic Basin
    Opis:
    The Ordovician and Silurian deposits in the Baltic Basin are represented by siltstones, mudstones, limestones, marls, sandstones and, most commonly, claystones with a markedly shaley structure. Claystones that are particularly rich in organic matter are considered as potential reservoirs for shale gas accumulations. Samples from 11 boreholes, including core samples of the Piaśnica, Słuchowo, Kopalino, Sasino, Prabuty, Jantar, Pelplin and locally Pasłęk, Kociewie and Puck formations, were analysed by optical microscopy, cathodoluminescence (CL), scanning electron microscopy (SEM) and energy-dispersive spectrometry and X-ray diffraction analyses (XRD). The Piaśnica, Sasino, Jantar, Pasłęk and Pelplin formations are characterized locally by a dominance of black bituminous claystones with a high content of organic matter, and a generally consistent clay mineral composition. Individual samples only show variations in silt fraction and carbonate content. Very important is the negligible proportion of swelling minerals in the clay fraction; the percentage of smectite in the mixed-layered illite/smectite minerals does not exceed 15%. It is important for the rocks to have adequate [SiO2 >10%; Quartz (Q) + Feldspars (Fs) + Carbonates >40%] brittleness. The content of quartz, feldspars and carbonates (here >40%) suggests that the claystones are susceptible to hydraulic fracturing. The claystones show micropores between detrital grains, between the flakes of clay minerals, within pyrite framboids, and organic matter and secondary micropores within grains.
    Źródło:
    Geological Quarterly; 2021, 65, 3; 65: 44
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Minute Silurian oncocerid nautiloids with unusual colour patterns
    Autorzy:
    Manda, S
    Turek, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/22242.pdf
    Data publikacji:
    2009
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Silurian
    paleontology
    oncocerid nautiloid
    nautiloid
    colour pattern
    Cephalopoda
    Nautiloidea
    taxonomy
    shell size
    shell malformation
    Opis:
    A minute Silurian oncocerid Cyrtoceras pollux, from the Prague Basin is assigned here to the genus Pomerantsoceras. The only so far known species of this genus comes from the Upper Ordovician (Hirnantian) of Estonia. Pomerantsoceras thus represents, except for un−revised poorly understood taxa, the single known oncocerid genus surviving the end−Ordovician extinction events. Cyrtoceras pollux is unusual among the Silurian nautiloids because of its small shell. Colour pattern characterised by a few longitudinal bands on the entire circumference of the shell is here reported in oncocerids. Longicone and only slightly curved small shells as in Pomerantsoceras are unusual among nautiloids and resemble straight shells of orthocerids and pseudorthocerids, in which the colour pattern consists of straight colour bands. Consequently the shell shape as well as the colour pattern should be regarded as adaptive convergence with orthocerids and pseudorthocerids. It supports the hypothesis that colour pattern functioned as camouflage and its evolution was under adaptive control. In addition, several types of the shell malformations including anomalous growth of septa, shell wall and pits on an internal mould are described.
    Źródło:
    Acta Palaeontologica Polonica; 2009, 54, 3; 503-512
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An atypical Silurian myodocope ostracod from the Armorican Massif, France
    Autorzy:
    Perrier, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/22621.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Silurian
    paleontology
    myodocope ostracod
    ostracod
    Armorican Massif
    France
    Arthropoda
    Crustacea
    Ostracoda
    Myodocopa
    Entomozoidae
    taxonomy
    Opis:
    A new myodocope ostracod Sineruga insolita gen. et sp. nov. is herein described from the Armorican Massif (France). Sineruga resembles Silurian myodocopes (i.e., bolbozoids and cypridinids) in having anterior features (thinner carapace) possibly related to vision. On the other hand, it resembles entomozoid ostracods in having a bean−shaped outline along with a deep adductorial sulcus and a simple muscle spot, but lacks their characteristic ribbed ornament. The data available suggest that Sineruga insolita was probably an atypical, non−ribbed member of the entomozoids thus indicating that early entomozoids may have had smooth representatives. Comparisons with other Recent and fossils ostracods show that the presence of a rostrum and/or symmetrical vision related carapace features (i.e., indicating lateral eyes) can be used as diagnostic characters for myodocope ostracods. The position and shape of the dorsal connection and to a lesser extent that of the sulcus and the adductorial muscle scar can be used to discriminate the higher groups of Silurian myodocopes (bolbozoids, cypridinids, and entomozoids).
    Źródło:
    Acta Palaeontologica Polonica; 2012, 57, 2
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Do the available data permit clarification of the possible dependence of Palaeozoic brachiopod generic diversity dynamics on global sea-level changes? A viewpoint
    Autorzy:
    Ruban, D. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/94246.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    brachiopods
    generic diversity
    sea-level changes
    Silurian
    Devonian
    ramienionogi
    zmiany poziomu morza
    sylur
    dewon
    Opis:
    At a glance, progress in palaeontology and eustatic reconstructions in the past decade permits to prove or to disprove the possible dependence of Palaeozoic brachiopod generic diversity dynamics on global sea-level changes. However, the available diversity curve is of much lower resolution than the eustatic curve. This problem can be resolved by decreasing the resolution of the latter. The other restriction linked to the chronostratigraphical incompatibility of the available data allows to focus on the Middle Palaeozoic only. A series of mass extinctions and other biotic crises in the Silurian-Devonian does not allow to interpret correctly the results of direct comparison of the brachiopod generic diversity dynamics with global sea-level changes. With the available data, it is only possible to hypothesize that the eustatic control was not playing a major part in diversity dynamics of Middle Palaeozoic brachiopods. The resolution of the stratigraphic ranges of Palaeozoic brachiopods should be increased significantly, and these ranges should be plotted against the most up-to-date geologic time scale. Until this task will be achieved, it is impossible to judge about the existence of any dependence (either full or partial) of the Palaeozoic brachiopod diversity dynamics on global sea-level changes.
    Źródło:
    Geologos; 2014, 20, 3; 215-221
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A Cooksonia-type flora from the Upper Silurian of the Holy Cross Mountains, Poland
    Autorzy:
    Bodzioch, A
    Kozlowski, W.
    Poplawska, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/20471.pdf
    Data publikacji:
    2003
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    land plant
    stratigraphy
    Upper Silurian
    Cooksonia
    Polska
    flora
    vascular plant
    Holy Cross Mountains
    paleogeography
    paleoenvironment
    Opis:
    Silurian land plants from the Holy Cross Mts. are described for the first time. The fossil assemblage occurs in a nearshore, marine, terrigenous deposit of Ludlowian/Pridolian age. It contains Cooksonia sp., Cooksonia−related species, and some problematical forms. The flora, which needs further study, is of importance to our understanding of early vascular plants and Late Silurian palaeogeography.
    Źródło:
    Acta Palaeontologica Polonica; 2003, 48, 4
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Silurian retiolitid graptolite Plectograptus: New observations and new species
    Autorzy:
    Bates, D.E.B.
    Kozlowska, A.
    Maletz, J.
    Kirk, N.H.
    Lenz, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/20525.pdf
    Data publikacji:
    2006
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Graptoloidea
    Plectograptus
    Retiolitidae
    rhabdosome
    Silurian
    graptolite
    new species
    paleontology
    retiolitid graptolite
    Ludlow
    morphology
    terminology
    systematics
    Opis:
    The Ludlow genus Plectograptus, with the type species Retiolites macilentus Törnquist, 1887, collected from Thuringia (Germany), has been a widely−identified, monospecific, but poorly understood taxon for almost one hundred years. This was due to poor and incomplete preservation of the type material, and misidentification by subsequent authors up to 1995. The original, and only, type specimen of P. macilentus collected by Törnquist being lost, a neotype is herein selected from a small collection of Thuringian material. The genus has now been redefined and based on this, and SEM studies of isolated material, the defining characteristics of the genus are (i) the possession of a simple ancora umbrella with five radial lists with an incompletely developed rim; (ii) an ancora umbrella separated from lateral ancora sleeve walls by exceptionally large lateral orifices; (iii) the possession of mid−ventral lists; (iv) simple, orderly zigzag lateral wall ancora sleeve lists. Recently, two additional species, P. robustus and P. wimani, previously placed in different genera, were assigned to Plectograptus. This study recognizes three new species: P. mobergi, P. toernquisti, and P. trijunctus, bringing the total number of species to six. Species are distinguished by the presence or absence of genicular processes, inclination of the thecal ventral walls and mid−ventral lists, presence or absence of reticular lists, and three−way or four−way sleeve/lateral rod/apertural lip junctions.
    Źródło:
    Acta Palaeontologica Polonica; 2006, 51, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Recent studies on the Silurian of the western part of Ukraine
    Autorzy:
    Łuczyński, P.
    Skompski, S.
    Kozłowski, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/138934.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Upper Silurian
    Podolia
    facies
    stromatoporoid beds
    sedimentary environments
    górny sylur
    Podole
    facja
    warstwy stromatoporoidowe
    środowiska sedymentacyjne
    Opis:
    The paper summarises the effects of recent studies carried out by a team from the Department of Historical and Regional Geology of the Faculty of Geology, University of Warsaw on the upper Silurian of Podolia (western part of Ukraine). The sedimentary history of the Silurian succession of Podolia is characterised by its cyclic pattern, with shallowing-upward cyclothems. In the traditional interpretation, the occurrence of stromatoporoid beds within each cyclothem marks the deepest (or most open-marine) sedimentary environment within the cycle. According to the results of recent studies, their occurrence is connected rather with a relatively shallow-water environment and with high energy phenomena. A substantial reinterpretation of the main sedimentary processes governing the deposition and facies distribution on the shelf is presented. Particularly, there are recognised and described high-energy sedimentary events repeatedly punctuating the generally calm sedimentation that prevailed in the lagoonal settings, some of which are interpreted as tsunami induced. Further perspectives for studies on the Silurian successions of Podolia are also discussed. The main problem is the precise correlation of particular sections that are scattered over vast distances and developed in similar facies associations.
    Źródło:
    Acta Geologica Polonica; 2016, 66, 3; 281-297
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The use of X-ray computed microtomography for graptolite detection in rock based on core internal structure visualization
    Autorzy:
    Kaczmarek, Ł.
    Kozłowska, A.
    Maksimczuk, M.
    Wejrzanowski, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/139097.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    computed microtomography
    visualization
    graptolites
    Silurian
    Baltic Basin shale
    mikrotomografia komputerowa
    wizualizacja
    graptolity
    sylur
    łupki basenu bałtyckiego
    Opis:
    This paper presents for the first time X-ray computed microtomography (μCT) analysis as a technique for Silurian graptolite detection in rocks. The samples come from the Jantar Bituminous Claystones Member of the Opalino core, Baltic Basin, northern Poland. Images were obtained with spatial resolution of 25 μm, which enabled the authors to create a 3-D visualization and to calculate the ratio of fissure and graptolite volume to the total sample volume. A set of μCT slices was used to create a 3-D reconstruction of graptolite geometry. These μCT slices were processed to obtain a clearly visible image and the volume ratio. A copper X-ray source filter was used during exposure to reduce radiograph artifacts. Visualization of graptolite tubaria (rhabdosomes) enabled Demirastrites simulans to be identified. Numerical models of graptolites reveal promising applications for paleontological research and thus for the recognition and characterization of reservoir rocks.
    Źródło:
    Acta Geologica Polonica; 2017, 67, 2; 299-306
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Convergent evolution of two Silurian graptolites
    Autorzy:
    Lenz, A C
    Melchin, M.J.
    Powiązania:
    https://bibliotekanauki.pl/articles/21551.pdf
    Data publikacji:
    2008
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    taxonomy
    biostratigraphy
    paleontology
    Graptoloidea
    nomenclature
    graptolite species
    convergent evolution
    Cochlograptus veles
    Testograptus testis
    Silurian graptolite
    Monograptidae
    Opis:
    The two graptolite speciesCochlograptus veles(Telychian, Upper Llandovery) and Testograptus testis(lower Homerian, upper Wenlock) are remarkably and uniquely similar in being strongly ventrally and planispirally coiled and in demonstrating an abrupt deflection in the immediate post−sicular regions of their rhabdosomes. The two species, however, are separated by a relatively large biostratigraphic gap and a global mass extinction, and they differ morphologically in the proportion of thecal overlap, different angles of inclination of the interthecal septa, relative proportions of the widths occupied by the free metathecae, the position of the sharp dorsal flexure relative to the tip of the sicula, and the presence of a distinctive, keel−like structure on T. testis. It is suggested therefore, that in spite of the strong proximal morphological parallelism between the two species, their origin is best explained as a remarkable example of convergent evolution. It is suggested that C. veles perhaps evolved from some modified monograptid such as Stimulograptus, whereas the small Testograptus group may have derived from some monograptid such as Monograptus flemingii. Cladistic analysis fully supports the independent derivation the two species. If correct, this hypothesis supports the validity of separate generic names for the two species, despite the close and unique rhabdosomal similarities, including proximal metathecal form.
    Źródło:
    Acta Palaeontologica Polonica; 2008, 53, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Trepostome bryozoans encrusting Silurian gastropods: A taphonomic window and its implications for biodiversity
    Autorzy:
    Buttler, C.J.
    Cherns, L.
    McCobb, L.M.E.
    Powiązania:
    https://bibliotekanauki.pl/articles/31341406.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    trepostome bryozoan
    bryozoan
    Silurian
    gastropod
    biodiversity
    Gastropoda
    Bryozoa
    symbiosis
    overgrowth
    aragonite
    taphonomy
    Shropshire county
    United Kingdom
    Źródło:
    Acta Palaeontologica Polonica; 2022, 67, 3; 569-577
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Coexistence of algae and a graptolite-like problematicum: a case study from the late Silurian of Podolia (Ukraine)
    Autorzy:
    Skompski, Stanisław
    Kozłowski, Wojciech
    Łuczyński, Piotr
    Kozłowska, Anna
    Powiązania:
    https://bibliotekanauki.pl/articles/27323966.pdf
    Data publikacji:
    2023
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    Dasycladales
    Graptolite-like epibionts
    Silurian
    Ludlow
    Ukraine
    periti dal environment
    glony
    graptolity
    epibionty
    sylur
    ludlow
    Ukraina
    Opis:
    This contribution presents the record of an abundant assemblage of well-preserved, thallophytic noncalcified algae and of an epibiotic form that has been recognised as a putative graptolite from the upper Silurian (Ludlow, Gorstian–Ludfordian) of Podolia (western part of Ukraine). The sediments represent a shallow peritidal zone of the shelf. A new genus and species, Voronocladus dryganti, belonging to the Dasycladales Pascher, 1931, is established. Most of the specimens representing the algal thallus are overgrown by problematical epibiotic graptolites, described as Podoliagraptus algaeoides gen. et sp. nov. This phenomenon is explained as an epiphytic mode of life of the putative graptolite on algae, and is herein compared to recently known coexistences of algae with other organisms. The excellent state of preservation, and the abundance of studied Dasycladales algae and epibiotic problematics indicate that the investigated mudstone layer can be treated as a ‘Konservat Lagerstätte’ sensu Seilacher (1970).
    Źródło:
    Acta Geologica Polonica; 2023, 73, 2; 115--133
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Graptolites – stratigraphic tool in the exploration of zones prospective for the occurrence of unconventional hydrocarbon deposits
    Autorzy:
    Podhalańska, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075025.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    graptolites
    black shale
    stratigraphy
    Ordovician
    Silurian
    East European Craton
    graptolity
    czarne łupki
    stratygrafia
    ordowik
    Kraton wschodnioeuropejski
    Opis:
    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.
    Źródło:
    Przegląd Geologiczny; 2013, 61, 11-1; 621--629
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A new genus of Late Ordovician-Early Silurian pentameride brachiopods and its phylogenetic relationships
    Autorzy:
    Jin, J
    Popov, L.E.
    Powiązania:
    https://bibliotekanauki.pl/articles/22557.pdf
    Data publikacji:
    2008
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    pentameride brachiopod
    brachiopod
    paleontology
    new genus
    Siberia
    Late Ordovician
    Canada
    Brachiopoda
    Early Silurian
    Protanastrophia repanda
    Parastrophinidae
    Opis:
    Protanastrophia repanda gen. et sp. nov. is a reef−dwelling parastrophinid brachiopod in the Lower Silurian (uppermost Telychian) Attawapiskat Formation of the Hudson Bay region of Canada. It is characterized by a small, quasi−smooth shell with gentle anterior costae, a tendency towards an asymmetrical, sigmoidal anterior commissure, and widely separate, subparallel inner hinge plates. Protanastrophia first appeared in the marginal seas of Siberia (Altai, Mongolia) during the Late Ordovician, retaining the primitive character of discrete inner hinge plates in the superfamily Camerelloidea, and preferred a carbonate mound depositional environment. It survived the Late Ordovician mass extinction and subsequently spread to Baltica and Laurentia during Early Silurian (Llandovery) time. Superficially similar asymmetrical shells of Parastrophina portentosa occur in the Upper Ordovician carbonate mound facies of Kazakhstan but differ internally from the new genus in having a septum−supported septalium. Phylogenetic analysis indicates that, within the Camerelloidea, asymmetrical shells with a sigmoidal anterior commissure evolved in Protanastrophia repanda and Parastrophina portentosa independently during the Late Ordovician as a case of homoplasy. The two species belong to separate parastrophinid lineages that evolved in widely separate palaeogeographic regions.
    Źródło:
    Acta Palaeontologica Polonica; 2008, 53, 2
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Graptolity : narzędzie stratygraficzne w rozpoznaniu stref perspektywicznych dla występowania niekonwencjonalnych złóż węglowodorów
    Graptolites : stratigraphic tool in the exploration of zones prospective for the occurrence of unconventional hydrocarbon deposits
    Autorzy:
    Podhalańska, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075084.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    graptolites
    black shale
    stratigraphy
    Ordovician
    Silurian
    East European Craton
    graptolity
    ciemne łupki
    stratygrafia
    ordowik
    sylur
    platforma wschodnioeuropejska
    Opis:
    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.
    Źródło:
    Przegląd Geologiczny; 2013, 61, 8; 460--467
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The late Silurian-Middle Devonian long-term eustatic cycle as a possible control on the global generic diversity dynamics of bivalves and gastropods
    Autorzy:
    Ruban, Dmitry A.
    Powiązania:
    https://bibliotekanauki.pl/articles/94693.pdf
    Data publikacji:
    2013
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    bivalves
    gastropods
    diversity dynamics
    origination
    extinction
    eustatic changes
    Silurian
    Devonian
    małże
    ślimaki
    powstawanie
    wyginięcie
    zmiany eustatyczne
    Dewon
    Opis:
    A long-term eustatic cycle (fall and subsequent rise of the global sea level) embraced the late Silurian-Middle Devonian time interval. Potentially, these sea-level changes could drive global biodiversity. The stratigraphic ranges of 204 bivalve genera and 279 gastropod genera included into the famous Sepkoski database allow reconstructing changes in the total diversity and the number of originations and extinctions of these important groups of marine benthic macro- -invertebrates during this interval. None of the recorded parameters coincided with the long-term global sea-level cycle. It cannot be not excluded, however, that the global sea-level changes did not affect the regions favourable for bivalve and gastropod radiation because of regional tectonic mechanisms; neither can it be excluded that the eustatic control persisted together with many other extrinsic and intrinsic controls. Interestingly, the generic diversity of gastropods increased together with a cooling trend, and vice versa. Additionally, the Ludlow, Eifelian, and Givetian biotic crises affected, probably, both fossil groups under study. There was also a coincidence of the relatively high bivalve generic diversity, initial radiation of gastropods and the entire biota, and the diversification of brachiopods with the Early Devonian global sea-level lowstand, and this may be interpreted as evidence of a certain eustatic control on the marine biodiversity.
    Źródło:
    Geologos; 2013, 19, 3; 193-200
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Regressive-transgressive cyclothem with facies record of the re-flooding window in the Late Silurian carbonate succession (Podolia, Ukraine)
    Autorzy:
    Łuczyński, P.
    Kozłowski, W.
    Skompski, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/138684.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    re-flooding window
    spectral gamma ray record
    shallow water carbonates
    late Silurian
    Podolia
    wody płytkie
    węglan
    sylur
    Podole
    Opis:
    The term “re-flooding window” was recently proposed as a time-interval connected with the transgressive stage of present day peri-reefal development. In the analysis presented here, a fossil record of a re-flooding window has been recognized. Nine Late Silurian carbonate sections exposed on the banks of the Dnister River in Podolia (Ukraine) have been correlated base on bed-by-bed microfacies analysis and spectral gamma ray (SGR) measurements. Correlated were sections representing settings ranging from the inner part of a shallow-water carbonate platform to its slope, through an organic buildup. The reconstructed depositional scenario has been divided into six development stages, with the first three representing a regressive interval and the latter three a transgressive interval of the basin’s history. The re-flooding window has been identified at the beginning of a transgressive part of the succession. Surprisingly, it is characterized by an extremely fast growth of a shallow, tide-dominated platform and by deposition of calciturbiditic layers in a more basinal area. The interpreted succession is a small-scale model illustrating the reaction of carbonate depositional sub-environments to sea level changes and determining the facies position of the stromatoporoid buildups within the facies pattern on a Silurian shelf. The use of SGR analyses in shallow water, partly high-energy, carbonate facies, both for correlation purposes and for identifying depositional systems, is a relatively new method, and thus can serve as a reference for other studies of similar facies assortment.
    Źródło:
    Acta Geologica Polonica; 2015, 65, 3; 297-318
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A giant boring in a Silurian stromatoporoid analysed by computer tomography
    Autorzy:
    Beuck, L
    Wisshak, M.
    Munnecke, A.
    Freiwald, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/20045.pdf
    Data publikacji:
    2008
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    Upper Visby Formation
    computer tomography
    Sweden
    Densastroma pexisum
    paleontology
    Gotland Island
    Silurian
    stromatoporoid
    trace fossil
    Osprioneides kampto
    analysis
    Opis:
    This study describes the largest known Palaeozoic boring trace, Osprioneides kampto igen. et isp. nov., found within a stromatoporoid Densastroma pexisum from the Upper Visby Formation (lower Wenlock, Silurian) on the island of Gotland, Sweden. Differences between the physical properties of the stromatoporoid and the dense micritic infilling of the borings allowed the application of the CT−scan technology for the 2D and 3D−visualisation of this rare trace. The additional application of a stereoscopic technique on these CT images and movies enhances its value for unravelling spatial orientations. This non−destructive method has a great potential for future macroas well as microboring analyses. The trace maker, most likely a worm, infested the hosting colony post−mortem with up to 120 mm long borings measuring 5–17 mm in diameter. Smaller forms of Trypanites and Palaeosabella within the same stromatoporoid preferentially occur in the outer coenosteum and occasionally in abandoned borings of O. kampto. The stratigraphic position of O. kampto follows the “Great Ordovician Biodiversification Event” in time, and reflects the increase in diversity of boring species. Borings with penetration depths of 120 mm are, however, unique findings for the Palaeozoic and were not exceeded until some 260 million years later (Bajocian, Middle Jurassic) when the “Mesozoic Marine Revolution” led to convergent reinventions as a result of enhanced predation, grazing pressure, and ecospace competition.
    Źródło:
    Acta Palaeontologica Polonica; 2008, 53, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    New location of the known Silurian graptolite Monograptus uncinatus Tullberg, 1883 in the Mineral Raw Materials Mine in Mielenko Drawskie, West Pomeranian Province, Poland
    Autorzy:
    Tomasz, Borowski
    Powiązania:
    https://bibliotekanauki.pl/articles/1031473.pdf
    Data publikacji:
    2021
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    Graptolites
    Mielenko Drawskie
    Mineral Raw Materials Mine in Mielenko Drawskie
    Monograptus
    Monograptus uncinatus
    post-glacial materials
    the Silurian period
    Opis:
    This paper presents the new location of the known graptolite genus – Monograptus Geinitz, 1852, in the Mineral Raw Materials Mine in Mielenko Drawskie, West Pomeranian Province, Poland. This specimen of the genus Monograptus was obtained as a result of many years of exploration in this mine, by searching individual lots of post-glacial materials extracted by this mine.
    Źródło:
    World News of Natural Sciences; 2021, 35; 56-67
    2543-5426
    Pojawia się w:
    World News of Natural Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Crinoids from the Silurian of Western Estonia
    Autorzy:
    Ausich, W.I.
    Wilson, M.A.
    Vinn, O.
    Powiązania:
    https://bibliotekanauki.pl/articles/21031.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    crinoid
    Silurian
    Western Estonia
    Estonia
    Echinodermata
    Crinoidea
    Pridoli
    paleontology
    new species
    Calceocrinus balticensis
    Desmidocrinus laevigatus Eucalyptocrinites tumidus
    Saaremaacrinus estoniensis
    Opis:
    The Silurian crinoids of Estonia are re−evaluated based on new collections and museum holdings. Nineteen species−level crinoid taxa are now recognized. All crinoid names applied to Estonian Silurian crinoids during the middle 19th century are disregarded. Especially significant is the fauna reported herein from the Pridoli because coeval crinoids are very poorly known from the Baltic region and elsewhere. One new genus and four new species are described from Estonia, namely Calceocrinus balticensis sp. nov., Desmidocrinus laevigatus sp. nov., Eucalyptocrinites tumidus sp. nov., and Saaremaacrinus estoniensis gen. et sp. nov.
    Źródło:
    Acta Palaeontologica Polonica; 2012, 57, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Potencjał występowania złóż gazu ziemnego w łupkach dolnego paleozoiku w basenie bałtyckim i lubelsko-podlaskim
    Shale gas potential of the Lower Palaeozoic complex in the Baltic and Lublin-Podlasie basins (Poland)
    Autorzy:
    Poprawa, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074759.pdf
    Data publikacji:
    2010
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    gaz łupkowy
    górny ordowik
    dolny sylur
    zachodni skłon kratonu wschodnioeuropejskiego
    EEC
    shale gas
    Upper Ordovician
    Lower Silurian
    East European Craton
    Opis:
    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.
    Źródło:
    Przegląd Geologiczny; 2010, 58, 3; 226-249
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    New and unusual upper Llandovery graptolites from Arctic Canada
    Autorzy:
    Lenz, A C
    Kozlowska, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/20163.pdf
    Data publikacji:
    2007
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    graptolite
    Mirorgraptus arcticus
    Silurian
    Llandovery
    skeleton
    morphology
    Arctic Canada
    Pseudoplegmatograptus cf.obesus
    stratigraphy
    systematics
    Giganteograptus giganteus
    biostratigraphy
    paleontology
    Graptoloidea
    Pileograptus pileatus
    Opis:
    Three isolated and well−preserved retiolitid taxa, two of them new, and one taxon of unknown affinity, are described from the upper Llandovery of Arctic Canada. All taxa display unusual characteristics The three retiolitids display extraordinary morphological features: Pseudoplegmatograptus cf. obesus preserves very delicate and lacey or cobweb−like list structures external to the main skeletal lists, structures previously seen only rarely on flattened material; Pileograptus pileatus gen. et sp. nov. possesses a thecal framework typical of retiolitines, particularly Stomatograptus, but its thecal orifices possess broad, meshwork genicular hoods similar to those in the plectograptines; and Giganteograptus giganteus, formerly attributed to Pseudoplegmatograptus, with its very coarse and relatively simple skeletal framework, well−developed paired thecal apertural spines, and a pustulose micro−ornamentation on the lists. The latter feature suggests an assignment to the subfamily Plectograptinae, rather than to the Retiolitinae as has been previously presumed. The presence of pustulose lists in Giganteograptus adds a further complication to understanding of retiolitid evolution. Mirorgraptus arcticus gen. et sp. nov., the fourth taxon and of unknown systematic affinity, lacks the proximal end, but preserves lists with seams and some fusellar material suggestive of some type of new retiolitid. Unlike known retiolitids or other graptolites, however, the skeletal list development is apparently confined to a narrow region along one side of the nema.
    Źródło:
    Acta Palaeontologica Polonica; 2007, 52, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Petrologiczne rozpoznanie materii organicznej rozproszonej w sylurskich łupkach Gór Bardzkich (Sudety)
    Petrological identification of dispersed organic matter in Silurian shales of the Bardo Mts. (Sudetes)
    Autorzy:
    Nowak, Grzegorz J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075962.pdf
    Data publikacji:
    2019
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Góry Bardzkie
    Sylur
    łupki
    rozproszona materia organiczna
    bituminy stałe
    refleksyjność bituminów
    Bardo Mts.
    Silurian
    shales
    dispersed organic matter
    solid bitumen
    bitumen reflectance
    Opis:
    The present paper is focused on the petrological characteristics of dispersed organic matter of the Silurian part of the Graptolite Shales from the Bardo Mts. (Sudetes). The most abundant organic component is secondarily altered organic matter represented by solid bitumen. Based on the results obtained by optical microscopy, it was possible to distinguish several types of solid bitumen. They were determined as granular, porous, coke-like, mosaic andfluidal types. All bitumen types are optically isotropic. Bitumen reflectance varies between 1.37 and 1.62%. Based on the % reflectance values, the solid bitumen identified in the studied samples are classified as pyrobitumen.
    Źródło:
    Przegląd Geologiczny; 2019, 67; 183--185
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Faunal dynamics across the Silurian-Devonian positive isotope excursions (delta13C, delta18O) in Podolia, Ukraine: Comparative analysis of the Ireviken and Klonk events
    Autorzy:
    Racki, G.
    Balinski, A.
    Wrona, R.
    Malkowski, K.
    Drygant, D.
    Szaniawski, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/20924.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    fauna dynamics
    Silurian
    Devonian
    isotope excursion
    Podolia
    Ukraine
    comparative analysis
    Ireviken event
    Klonk event
    Brachiopoda
    Conodonta
    Chitinozoa
    carbon isotope
    oxygen isotope
    geochemistry
    Opis:
    Two global isotopic events, the early Sheinwoodian (early Wenlock) and that at the Silurian–Devonian transition, have been comprehensively studied in representative carbonate successions at Kytayhorod and Dnistrove, respectively, in Podolia, Ukraine, to compare geochemistry and biotic changes related correspondingly to the Ireviken and Klonk events. These two large−scale isotope excursions reveal different regional ecosystem tendencies. The well−defined increasing trend across the Llandovery–Wenlock boundary in siliciclastic input, redox states and, supposedly, bioproductivity, was without strict correlative relations to the major ¹³C enrichment event. The environmental and biotic evolution was forced by eustatic sea−level fluctuations and two−step climate change toward a glaciation episode, but strongly modified by regional epeirogeny movements due to location near the mobile Teisseyre−Törnquist Fault Zone. Thus, the global early Sheinwoodian biogeochemical perturbation was of minor depositional significance in this epeiric sea, as in many other Laurussian domains. Conversely, the Podolian sedimentary record of the Klonk Event exhibits temporal links to the abrupt δ¹³C anomaly, overprinted by a tectonically driven deepening pulse in the crucial S–D boundary interval. This carbon cycling turnover was reflected in the regional carbonate crisis and cooling episodes, paired with a tendency towards eutrophication and recurrent oxygen deficiency, but also with major storms and possible upwelling. Faunal responses in both Podolian sections follow some characters of the Silurian pattern worldwide, as manifested by conodont changeover prior to the major early Sheinwoodian isotopic/climatic anomaly. This contrasts with the relative brachiopod and chitinozoan resistances in the course of the Ireviken Event. Also, during the Klonk Event, a moderate faunal turnover, both in benthic and pelagic groups, occurred only near the very beginning of the prolonged ¹³C−enriched timespan across the system boundary, possibly due to progressive dysoxia and temperature drop. The characters point to a peculiarity of the Klonk Event by comparison with the Silurian global events, and some similarity already to the succeeding Devonian transgressive/anoxic episodes.
    Źródło:
    Acta Palaeontologica Polonica; 2012, 57, 4
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Kirkigraptus, a new retiolitid graptolite from Poland
    Autorzy:
    Kozlowska, A
    Bates, D.E.B.
    Powiązania:
    https://bibliotekanauki.pl/articles/21786.pdf
    Data publikacji:
    2008
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    deposit
    Polska
    systematics
    paleontology
    Silurian
    Kirkigraptus inexpectans
    retiolitid skeleton
    Retiolitidae
    graptolite
    Graptolithina
    retiolitid graptolite
    new species
    new aspect
    East European Platform
    evolution
    Opis:
    The new retiolitid graptolite Kirkigraptus inexpectans gen. et sp. nov., from the Neodiversograptus nilssoni Biozone of the Bartoszyce borehole, Poland is described. It is unique among the retiolitids not having a preserved virgella or ancora. Instead the most proximal structures are two round proxi−lateral lists, joining the two genicular lists of the first thecae, connecting the two sides of the rhabdosome. The lists are interpreted as a possible homologue of the distal edge of the ancora umbrella in typical retiolitids. The size of rhabdosome with large proximal lateral orifices, and the ventral panels of thecae with mid−ventral lists, are similar to those of Plectograptus, whereas the two ancora sleeve panels consisting of spaced horizontal lists only, resemble those of Valentinagraptus. It is possible that the new retiolitid may represent a new pattern of development of the proximal end of the rhabdosome, different from that in all other retiolitids.
    Źródło:
    Acta Palaeontologica Polonica; 2008, 53, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evolution of the retiolitid Neogothograptus [Graptolithina] and its new species from the upper Wenlock of Poland, Baltica
    Autorzy:
    Kozlowska, A
    Lenz, A.
    Melchin, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/20789.pdf
    Data publikacji:
    2009
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    evolution
    retiolitid
    Neogothograptus
    Graptolithina
    new species
    Upper Wenlock
    Polska
    Wenlock
    Ludlow
    Silurian
    Retiolitidae
    Gothograptus
    biostratigraphy
    ocean current
    Colonograptus praedeubeli
    Lobograptus progenitor
    Neogothograptus reticulatus
    Opis:
    Neogothograptus reticulatus sp. nov. from the upper Homerian Colonograptus praedeubeli Biozone, and N. thorsteinssoni and N. alatiformis from the Lobograptus progenitor Biozone, are described for the first time from three localities: borehole, Baltic erratic boulder of East European Platform and Holy Cross Mountains of Poland. N. reticulatus, presently the oldest known species of Neogothograptus, is also tentatively identified from upper Homerian strata of southeastern Australia. The two other species are previously known only from Arctic Canada, and possibly China. The morphology of the Neogothograptus reticulatus rhabdosome, its appendix, thecal profile, densely reticulated rhabdosome and genicular hoods suggest a close relationship to N. eximinassa from Colonograptus ludensis Biozone. N. reticulatus and N. eximinassa are most similar to Gothograptus nassa, the earliest−known retiolitid to appear immediately following the Cyrtograptus lundgreni extinction event. The biostratigraphic position of N. reticulatus suggests it might be considered as a potential ancestor to all younger (Ludlow) species of Neogothograptus. Cladistic analysis, however, provides no direct support for such an interpretation and, instead, suggests that Baculograptus batesi may be the ancestor. The occurrences of Neogothograptus, as well as G. nassa, from a number of Silurian terranes mostly from low paleolatitude regions, but also from high paleolatitudes, demonstrate their tolerance to a broad range of paleoenvironments.
    Źródło:
    Acta Palaeontologica Polonica; 2009, 54, 3; 423-434
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    New Wenlock-Pridoli [Silurian] acanthodian fishes from Lithuania
    Autorzy:
    Valiukevicius, J
    Powiązania:
    https://bibliotekanauki.pl/articles/21880.pdf
    Data publikacji:
    2004
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    histology
    fish
    Ischnacanthiformes
    acanthodian
    Vesperalia perplexa
    Silurian
    Acanthodii
    Arenaceacanthus arcuatacanalis
    Bracteatacanthus assiduus
    morphology
    Fecundosquama basiglobosa
    Rohonilepis breviornatus
    acanthodian fish
    new species
    Climatiiformes
    Lithuania
    paleontology
    Opis:
    Five new monotypic acanthodian genera and five new species are described from the Silurian (Wenlock to Pridoli) of Lithuania. Two new genera and species, Vesperalia perplexa and Fecundosquama basiglobosa, belong to climatiiform and three, Arenaceacanthus arcuatacanalis, Bracteatacanthus assiduus, and Rohonilepis breviornatus, to ischnacanthiform acanthodians. Vesperalia perplexa has high−crowned scales with ridges that cross the entire surface or frequently fade mid−crown and after a smooth area continue on the posterior edge. Stranggewebe in the crowns of V. perplexa scales has large oriented lacunae and a well−developed system of main vascular canals. Fecundosquama basiglobosa scales have an undeveloped neck, a crown with only marginal sculptural incisions and have an unusually large deep base. Simple bone−like mesodentine in the crowns of F. basiglobosa scales lacks principal vascular canals. Arenaceacanthus arcuatacanalis has diagnostic scales with anterior ridges that fade out at one−third of crown length, and crowns composed of simple acellular mesoand durodentine with the original arcuate radial vascular canals over the base. Bracteatacanthus assiduus scale crowns have short ridges of asymmetric profile and an antero−median sulcus, whereas scales of Rohonilepis breviornatus have sharp symmetric subradial crown ridges sloping towards the base. Scale crowns of B. assiduus and R. breviornatus are composed of dentine and durodentine, but the former is distinguished by a second area of multibranched radial vascular canals positioned high in the neck.
    Źródło:
    Acta Palaeontologica Polonica; 2004, 49, 1
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analiza petrofizyczna łupków sylurskich z synklinorium lubelskiego
    Petrophysical analysis of Silurian shales from the Lublin synclinorium
    Autorzy:
    Krakowska, P.
    Puskarczyk, E.
    Jędrychowski, M.
    Habrat, M.
    Madejski, P.
    Jarzyna, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/972364.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
    Tematy:
    petrofizyka
    łupki sylurskie
    synklinorium lubelskie
    spektrometria magnetycznego rezonansu jądrowego
    rentgenowska tomografia komputerowa
    petrophysics
    Silurian shales
    Lublin synclinorium
    nuclear magnetic resonance
    X-ray computed tomography
    Opis:
    Wyniki badań laboratoryjnych formacji sylurskich pozwalają na uzyskanie szczegółowych informacji na temat złożoności przestrzeni porowej, występowania mikroszczelin, a także obecności pirytu w skale. Trzy próbki mułowców sylurskich pochodzące z różnych głębokości, z jednego otworu zlokalizowanego w synklinorium lubelskim, zostały przebadane pod kątem wyznaczenia właściwości sprężystych, czyli prędkości fal podłużnych P i poprzecznych S, dynamicznych modułów: sprężystości podłużnej (Younga), odkształcenia postaci, odkształcenia objętości, współczynnika Poissona oraz zbiornikowych, z wykorzystaniem spektrometrii magnetycznego rezonansu jądrowego (porowatość całkowita i efektywna, zawartość wody wolnej, kapilarnej i nieredukowalnej). W ramach dodatkowych analiz przeprowadzono badania laboratoryjne przepuszczalności absolutnej w skali nano-Darcy, a także granulometrii. Rentgenowska tomografia komputerowa dała możliwość interpretacji jakościowej wykształcenia przestrzeni porowej oraz mikroszczelin, a także formy występowania pirytu w skale. Interpretacja ilościowa obrazów tomograficznych dostarczyła parametrów geometrycznych porów, pirytów i mikroszczelin, tj. wielkości porów i kryształów pirytów, mikroszczelin itp. Komplementarna analiza petrofizyczna skał łupkowych, wykonana przy wykorzystaniu różnorodnych metod badawczych, stała się kluczem do zrozumienia budowy wewnętrznej tego typu skał, które wykazują silną heterogeniczność parametrów fizycznych i chemicznych szkieletu ziarnowego i przestrzeni porowej.
    The results of laboratory measurements of the Silurian formations allow detailed information on the complexity of pore space, the occurrence of microcracks, as well as the presence of pyrite in the rock to be obtained. Three samples of Silurian mudstones from different depths, from one well located in the Lublin synclinorium, were tested for elastic properties, i.e. the longitudinal waves P and transverse S, the dynamic moduli: Young, shear, bulk, Poisson ratio and reservoir using nuclear magnetic resonance spectrometry (total and effective porosity, free water, capillary and irreducible water). Additional laboratory analyses of the absolute permeability on a nano-Darcy scale as well as granulometry were performed. X-ray computed tomography provided an opportunity to interpret the qualitative development of porous space as well as the microscopic and forms of pyrite in the rock. The quantitative interpretation of tomographic images provided the geometric parameters of pores, pyrites and microcracks, i.e. the size of pores, pyrite crystals and microcracks. The complementary petrophysical analysis of shale gas deposits, made using a variety of research methods, became the key to understanding the internal structure of this type of rock, which exhibits strong heterogeneity in physical and chemical parameters of the particle's skeleton and pore space.
    Źródło:
    Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN; 2017, 101; 293-301
    2080-0819
    Pojawia się w:
    Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Palaeo-earthquake events during the late Early Palaeozoic in the central Tarim Basin (NW China): evidence from deep drilling cores
    Autorzy:
    He, B.
    Qiao, X.
    Jiao, C.
    Xu, Z.
    Cai, Z.
    Guo, X.
    Zhang, Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/94300.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    soft-sediment deformation structures
    seismites
    palaeo-seismicity
    Late Ordovician
    Silurian
    Tazhong 1 Fault
    Tarim Basin
    struktury deformacji
    osady miękkie
    sejsmity
    ordowik późny
    sylur
    Kotlina Kaszgarska
    Opis:
    Various millimetre-, centimetre- and metre-scale soft-sediment deformation structures (SSDS) have been identified in the Upper Ordovician and Lower-Middle Silurian from deep drilling cores in the Tarim Basin (NW China). These structures include liquefied-sand veins, liquefaction-induced breccias, boudinage-like structures, load and diapir- or flame-like structures, dish and mixed-layer structures, hydroplastic convolutions and seismic unconformities. The deformed layers are intercalated by undeformed layers of varying thicknesses that are petrologically and sedimentologically similar to the deformed layers. The SSDS developed in a shelf environment during the early Late Ordovician and formed initially under shear tensile stress conditions, as indicated by boudinage-like structures; during the latest Ordovician, SSDS formed under a compressional regime. The SSDS in the Lower-Middle Silurian consist mainly of mixed layers and sand veins; they formed in shoreline and tidal-flat settings with liquefaction features indicating an origin under a compressional stress regime. By Silurian times, the centre of tectonic activity had shifted to the south-eastern part of the basin. The SSDS occur at different depths in wells that are close to the syn-sedimentary Tazhong 1 Fault (TZ1F) and associated reversed-thrust secondary faults. Based on their characteristics, the inferred formation mechanism and the spatial association with faults, the SSDS are interpreted as seismites. The Tazhong 1 fault was a seismogenic fault during the later Ordovician, whereas the reversed-direction secondary faults became active in the Early-Middle Silurian. Multiple palaeo-earthquake records reflect pulses and cyclicity, which supports secondary tectonic activity within the main tectonic movement. The range of SSDS structures reflects different developments of tectonic activity with time for the various tectonic units of the centralbasin. The effects of the strong palaeo-earthquake activity coincide with uplift, fault activity and syn-tectonic sedimentation in the study area during the Late Ordovician to Middle Silurian.
    Źródło:
    Geologos; 2014, 20, 2; 105-123
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wyznaczanie całkowitej zawartości węgla organicznego TOC w skałach łupkowych z wykorzystaniem profilowań geofizyki otworowej na przykładzie danych z basenu bałtyckiego
    Use of empirical methods based on well logging to calculate the total organic carbon content in Baltic Basin’s shale gas reservoir
    Autorzy:
    Waszkiewicz, S.
    Karczewski, J.
    Krakowska, P.
    Jarzyna, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1835137.pdf
    Data publikacji:
    2018
    Wydawca:
    Instytut Nafty i Gazu - Państwowy Instytut Badawczy
    Tematy:
    całkowita zawartość węgla organicznego TOC
    profilowania geofizyki otworowej
    metoda Passeya
    metody empiryczne
    łupki ordowickie i sylurskie
    total organic carbon – TOC
    well logs
    Passey method
    empirical methods
    Ordovician and Silurian shales
    Opis:
    Wyznaczenie całkowitej zawartości węgla organicznego (TOC) jest ważnym elementem procesu oceny skał łupkowych jako niekonwencjonalnych złóż węglowodorów. TOC to podstawowy wskaźnik perspektywiczności skały. Jego pomiar w laboratorium przy zastosowaniu pirolizy Rock-Eval dostarcza jedynie informacji punktowej. Zwiększenie liczby próbek wiąże się ze znacznym wzrostem kosztów prowadzonych badań. W pracy dopasowano wybrane metody statystyczne do obliczania TOC w utworach syluru i ordowiku w basenie bałtyckim, wykorzystując profilowania geofizyki otworowej. Zastosowana metodyka pozwoliła na uzyskanie wartości tego parametru w sposób ciągły bez wzrostu kosztów prowadzonych badań. Wykorzystano aplikację TOC systemu GeoWin, będącą narzędziem do automatycznego obliczania zawartości węgla organicznego. Aplikacja ta stosuje metodę Passeya, a także znane z literatury wzory empiryczne, w których współczynniki zostały wyliczone na podstawie wielowymiarowych analiz statystycznych. Wykorzystano profilowania geofizyki otworowej, takie jak: spektrometryczne profilowanie gamma (K, U, TH), profilowanie gęstości objętościowej (RHOB), profilowanie porowatości neutronowej (NPHI) oraz profilowanie oporności elektrycznej w strefie niezmienionej (LLD). Analizie poddano także wyniki badań laboratoryjnych próbek z rdzeni wiertniczych z pięciu otworów leżących w obrębie syneklizy perybałtyckiej i wyniesienia Łeby, będących strukturalną częścią kratonu wschodnioeuropejskiego. Z punktu widzenia poszukiwania gazu w badanych profilach geologicznych interesujące są dwie formacje: sylurska (landower) formacja iłowców z Pasłęka z ogniwem z Jantaru w spągowej części oraz ordowicka (karadok/lanwirn) formacja iłowców z Sasina. W związku z położeniem otworów w obrębie różnych jednostek geologicznych akumulacja węglowodorów przebiegała w odmiennych warunkach, co odzwierciedla się w wyznaczonych na podstawie profilowań geofizyki otworowej parametrach. Obliczenia statystyczne wykonano dla badanych formacji w poszczególnych otworach. Wyznaczono również ogólne współczynniki równań dla analizowanego obszaru, pozwalające na szybką estymację całkowitej zawartości węgla organicznego.
    Calculations of total organic carbon (TOC) is one of the most important parts of interpretation in shale gas reservoirs and it is one of main indicators of perspective zones. Laboratory methods to measure total organic carbon such as Rock-Eval pyrolysis, give only the point data results. Increase in the number of samples causes a significant increase in the cost of surveys. This article fits the selected methods of total organic carbon determination based on well logging data, which allows to calculate TOC in all measured intervals without an increase in costs. In order to estimate TOC, different mathematical equations were used, such as that implemented in TOC application in the GeoWin system, which is a tool for automatic total organic carbon estimation based on the Passey method and other empirical equations. All factors were calculated using multidimensional statistical analysis made on well logs such as spectral gamma ray (K, U, TH), bulk density (RHOB), neutron porosity (NPHI), electric resistivity (LLD). Wells are placed in Poland, on the Łeba Elevation and the Peri-Baltic Syneclise, which is located on the onshore part of the Baltic Basin. The analysis was carried out on well logs and core data from five wells located within the Peri-Baltic Syneclise and the Łeba Elevation being a structural part of the East European Platform. The most perspective gas-bearing sediments are thought to be Silurian member of bituminous shales from Jantar and Ordovician level of the Sasino claystone formation, rich in organic matter. Due to the location of wells in different geological units, accumulation of hydrocarbons took place in different conditions, which is reflected in the calculated parameters. The Authors, using the calculations, have tried to fit the general coefficient of equations for the whole analyzed area, allowing for fast estimation of TOC.
    Źródło:
    Nafta-Gaz; 2018, 74, 11; 789-795
    0867-8871
    Pojawia się w:
    Nafta-Gaz
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Marine snow and epipelagic suspensoids in the Reda carbonates and a pronounced mid-Ludfordian (Silurian) CIE in the axis of the Baltic Basin (Poland)
    Autorzy:
    Kozłowski, Wojciech
    Powiązania:
    https://bibliotekanauki.pl/articles/1835581.pdf
    Data publikacji:
    2020
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    pelagic carbonates
    Sparoids
    marine snow
    algal blooms
    eolian dust
    carbonate supersaturation
    euxinia
    Baltic basin
    Reda Member
    ludlow
    Silurian
    węglany pelagiczne
    sparoidy
    śnieg morski
    zakwit glonów
    osady eoliczne
    basen bałtycki
    sylur
    Opis:
    The mid-Ludfordian pronounced, positive carbon isotope excursion (CIE), coincident with the Lau/kozlowskii extinction event, has been widely studied so far in shallow-water, carbonate successions, whereas its deep-water record remains insufficiently known. The aim of this research is to reconstruct the sedimentary environments and the palaeoredox conditions in the axial part of the Baltic-Podolian Basin during the event. For these purposes, the Pasłęk IG-1 core section has been examined using microfacies analysis, framboid pyrite diameter and carbon isotope measurements. The prelude to the event records an increased influx of detrital dolomite interpreted as eolian dust, coupled with a pronounced decrease in the diameter of the pyrite framboids, indicating persistent euxinic conditions across the event. The event climax is recorded as the Reda Member and consists of calcisiltites, composed of calcite microcrystals (‘sparoids’), which are interpreted as suspensoids induced by phytoplankton blooms in the hipersaturation conditions present in the epipelagic layer of the basin. Both the prelude and climax facies show lamination, interpreted as having resulted from periodical settling of marine snow, combined with hydraulic sorting within a ‘benthic flocculent layer’, which additionally may be responsible for a low organic matter preservation rate due to methanogenic decomposition. Contrary to the observed basinward CIE decline in the benthic carbonates in the basin, the Reda Member records an extremely positive CIE (up to 8.25‰). Given the pelagic origin of the sparoids, the CIE seems to record surface-water carbon isotope ratios. This points to a large carbon isotope gradient and kinetic fractionation between surface and bottom waters during the mid-Ludfordian event in a strongly stratified basin. The Reda facies-isotope anomaly is regarded as undoubtedly globally triggered, but amplified by the stratified and euxinic conditions in the partly isolated, Baltic-Podolian basin. Hence, the common interpretation of the basin record as representative for the global ocean needs to be treated with great caution.
    Źródło:
    Acta Geologica Polonica; 2020, 70, 4; 529-567
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Phyletic evolution and iterative speciation in the persistent Pristiograptus dubius lineage
    Autorzy:
    Urbanek, A.
    Radzevicius, S.
    Kozlowska, A.
    Teller, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/22649.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    phyletic zob.phylogenetic
    phylogenetic evolution
    iterative speciation
    Pristiograptus dubius
    lineage
    graptolite
    Graptolithina
    stem lineage
    new subspecies
    Pristiograptus dubius magnus
    Pristiograptus dubius paezerensis
    Pristiograptus dubius praelodenicensis
    Pristiograptus dubius postfrequens
    Pristiograptus dubius postmagnus
    Silurian
    East European Platform
    Polska
    Lithuania
    Opis:
    The paper focuses on patterns of the evolution of the simplest and longest−ranging (approximately 18 Ma) Silurian graptolite Pristiograptus dubius. The Pristiograptus dubius species group consists of the P. dubius stem lineage represented by a sequence of a number of subspecies displaying only small morphological changes as well as derivative species produced from the stem lineage by means of iterative speciation. This long raging graptolite lineage is the only one, apart of one retiolitid, which survived the most severe environmental event for graptolites, the Cyrtograptus lundgreni Event. Based on three−dimensional, isolated material two P. dubius groups taxa are distinguished. One group has an obtuse angle between the thecal lip and the succeeding thecal wall, the second group has a right or acute angle. Other characters differentiating P. dubius forms are: the shape of the apertural lips, differences in rhabdosome shape and size, and a different number of sicular rings. Sixteen species and subspecies of Pristiograptus from the East European Platform, Poland and Lithuania are discussed. Five new subspecies P. dubius magnus, P. dubius paezerensis, P. dubius praelodenicensis, P. dubius postfrequens, and P. dubius postmagnus are proposed.
    Źródło:
    Acta Palaeontologica Polonica; 2012, 57, 3
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-85 z 85

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