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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
Wyświetlanie 1-25 z 85

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