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Wyszukujesz frazę "cenomanian" wg kryterium: Temat


Tytuł:
Zróżnicowanie warunków geotermalnych cenomańskiego systemu wodonośnego w rejonie Buska-Zdroju na przykładzie danych z nowych wierceń
Diversification of geothermal conditions of the cenomanian water-bearing system on the example of new drillings from the Busko-Spa region
Autorzy:
Gągulski, T.
Gorczyca, G.
Powiązania:
https://bibliotekanauki.pl/articles/203553.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
wody geotermalne
Busko-Zdrój
system wodonośny
cenoman
gradient geotermiczny
geothermal waters
water-bearing system
cenomanian
geothermal degree
Opis:
Niecka miechowska stanowi obszar perspektywiczny pod względem występowania wód geotermalnych w obrębie cenomańskiego systemu wodonośnego. Wody takie zostały nawiercone w rejonie Buska-Zdroju w latach 2016–2017 trzema otworami OB-I, OB-II oraz OB-V. Otwory te zlokalizowane są po obu stronach dużej regionalnej dyslokacji zwanej uskokiem radzanowskim. Stwierdzona głębokość występowania wód geotermalnych w tym rejonie wynosi od 732,5 m (otw. OB-I) do 344,0 (otw. OB-II). Maksymalne temperatury wody na wypływie z otworów OB-I, OB-II i OB-V jakie uzyskiwano podczas badań wynoszą odpowiednio 27,2, 22,3 i 23,5°C. Są to wody chlorkowo-sodowe i chlorkowo-siarczanowo-sodowe, często jodkowe oraz siarczkowe. Pomimo tego, iż występują w obrębie utworów cenomanu, nie zawsze zawierają siarkowodór. Analiza wyników wykazała, że wyższy gradient geotermiczny występuje po południowej stronie uskoku Radzanowa. Jednak to obszar po północnej jego stronie, tj. rejon otworu OB-I, jest bardziej perspektywiczny pod kątem wykorzystania wód geotermalnych choćby do celów balneologicznych.
The Miechów Basin is a prospective area in terms of geothermal water occurrence within the Cenomanian aquifer. Three hydrogeological drillings (OB-I, OB-II, and OB-V) were made in the Busko-Zdrój area in 2016–2017. These geothermal water boreholes are located on both sides of a large regional dislocation called the Radzanów Fault. The geothermal water in this area occurs within the depth interval between 732.5 to 344.0 m, and the maximal temperatures at the outflow range from 21.5 to 27.2°C. These are chloride-sodium and chloride-sulfatesodium waters, often with iodide and sulphide. Despite the fact that these waters occur within the Cenomanian formations, they do not always contain hydrogen sulphide. The results of the studies showed that better geothermal conditions take place on the southern side of the Radzanów Fault.
Źródło:
Technika Poszukiwań Geologicznych; 2018, R. 57, nr 1, 1; 73-85
0304-520X
Pojawia się w:
Technika Poszukiwań Geologicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wzbogacenie w REE utworów osadowych w wybranych rejonach obrzeżenia mezozoicznego Gór Świętokrzyskich : obiecujące dane wstępne i potrzeba dalszych badań
REE enrichment of sedimentary formations in selected regions of the Mesozoic margin of the Holy Cross Mountains : promising preliminary data and more research needed
Autorzy:
Mikulski, Stanisław Z.
Brański, Paweł
Pieńkowski, Grzegorz
Małek, Rafał
Zglinicki, Karol
Chmielewski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2076190.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
rzadkie elementy ziemi
osady krzemoklastyczne
górny trias
dolna jura
fosforyty dolnokredowe
fosforyty albsko-cenomańskie
rare earth elements
siliciclastic deposits
Upper Triassic
Lower Jurassic
Lower Cretaceous phosphorites
Albian-Cenomanian phosphorites
Opis:
The main task of research was a quantitative and qualitative identification of rare earth elements within various Mesozoic sediments in the surroundings of the Holy Cross Mountains. Over 100 samples from archive boreholes, outcrops and mining waste were analysed using modern methods, like portable XRF, geochemical analysis (ICP-MS), electron microprobe and SEM. Results show enrichments of REE concentrations in sedimentary rock samples from the Niektań PIG-1 borehole (LREE up to 0.95%), Miedary outcrop (LREY up to 0.4%) and Lower Cretaceous phosphorites from mining waste in Chałupki and Annopol (LREE ~0.2%). Further investigation is strongly recommended in order to explain the distribution of REE in the study areas.
Źródło:
Przegląd Geologiczny; 2021, 69, 6; 379--385
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vertebral morphology, dentition, age, growth, and ecology of the large lamniform shark Cardabiodon ricki
Autorzy:
Newbrey, M.G.
Siversson, M.
Cook, T.D.
Fotheringham, A.M.
Sanchez, R.L.
Powiązania:
https://bibliotekanauki.pl/articles/21003.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
morphology
dentition
age
growth
ecology
large lamniform shark
Cardabiodon ricki
Cardabiodon venator
Chondrichthyes
Lamniformes
Archaeolamna
Squalicorax
Cretaceous
Cenomanian
Turonian
Australia
Opis:
Cardabiodon ricki and Cardabiodon venator were large lamniform sharks with a patchy but global distribution in the Cenomanian and Turonian. Their teeth are generally rare and skeletal elements are less common. The centra of Cardabiodon ricki can be distinguished from those of other lamniforms by their unique combination of characteristics: medium length, round articulating outline with a very thick corpus calcareum, a corpus calcareum with a laterally flat rim, robust radial lamellae, thick radial lamellae that occur in low density, concentric lamellae absent, small circular or subovate pores concentrated next to each corpus calcareum, and papillose circular ridges on the surface of the corpus calcareum. The large diameter and robustness of the centra of two examined specimens suggest that Cardabiodon was large, had a rigid vertebral column, and was a fast swimmer. The sectioned corpora calcarea show both individuals deposited 13 bands (assumed to represent annual increments) after the birth ring. The identification of the birth ring is supported in the holotype of Cardabiodon ricki as the back-calculated tooth size at age 0 is nearly equal to the size of the smallest known isolated tooth of this species. The birth ring size (5-6.6 mm radial distance [RD]) overlaps with that of Archaeolamna kopingensis (5.4 mm RD) and the range of variation of Cretoxyrhina mantelli (6-11.6 mm RD) from the Smoky Hill Chalk, Niobrara Formation. The revised, reconstructed lower jaw dentition of the holotype of Cardabiodon ricki contains four anterior and 12 lateroposterior files. Total body length is estimated at 5.5 m based on 746 mm lower jaw bite circumference reconstructed from associated teeth of the holotype.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Upper Albian, Cenomanian and Upper Turonian ammonite faunas from the Fahdène Formation of Central Tunisia and correlatives in northern Algeria
Autorzy:
Kennedy, William James
Powiązania:
https://bibliotekanauki.pl/articles/138843.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Ammonites
Cretaceous
Albian
Cenomanian
Turonian
Algeria
Tunisia
amonity
kreda
Alb
cenoman
Turon
Algieria
Tunezja
Opis:
Over 130 species are documented from the Upper Albian, Cenomanian and Upper Turonian Fahdène Formation and correlatives in Central Tunisia and northern Algeria, based on material described by Henri Coquand (1852, 1854, 1862, 1880), Léon Pervinquière (1907, 1910), Georges Dubourdieu (1953), Jacques Sornay (1955), and new collections. The material consists predominantly of limonitic nuclei, together with adults of micromorphs. There is no continuous record, and a series of faunas are recognised that can be correlated with the zonation developed in Western Europe. These are the Upper Albian Ostlingoceras puzosianum fauna, Lower Cenomanian Neostlingoceras carcitanense and Mariella (Mariella) harchaensis faunas, the upper Lower to lower Middle Cenomanian Turrilites scheuchzerianus fauna, Middle Cenomanian Calycoceras (Newboldiceras) asiaticum fauna, Upper Cenomanian Eucalycoceras pentagonum fauna, and the Upper Turonian Subprionocyclus neptuni fauna. Two new micromorph genera are described, Coquandiceras of the Mantelliceratinae and Cryptoturrilites of the Turrilitinae. Most of the taxa present have a cosmopolitan distribution, with a minority of Boreal, North American and endemic taxa.
Źródło:
Acta Geologica Polonica; 2020, 70, 2; 147-272
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two bone fragments of ornithocheiroid pterosaurs from the Cenomanian of Volgograd region, Southern Russia
Autorzy:
Averianov, A O
Kurochkin, E.N.
Pervushov, E.M.
Ivanov, A.V.
Powiązania:
https://bibliotekanauki.pl/articles/21981.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Volgograd Region
Cenomanian
Cretaceous
Pterosauria
Russia
Ornithocheiroidea
bone fragment
ornithocheiroid pterosaur
pterosaur
paleontology
Opis:
Two pterosaur bone fragments, a distal humerus and a distal femur, from the upper Cenomanian of the Volgograd Region in the Don River basin of southern Russia are reported. Although fragmentary, these bones come from mature individuals and are exceptionally well and three−dimensionally preserved, allowing a detailed description of their anatomy. Both specimens can be referred to a middle−sized ornithocheiroid pterosaur with a reconstructed wingspan of about 4 m. The humerus shows affinities with Istiodactylus from the Barremian of England, whereas the femur fragment is not identifiable beyond Ornithocheiroidea indet.
Źródło:
Acta Palaeontologica Polonica; 2005, 50, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trans-Tethyan correlation of the Lower-Middle Cenomanian boundary interval; southern England (Southerham, near Lewes, Sussex) and Douar el Khiana, northeastern Algeria
Autorzy:
Kennedy, W. J.
Gale, A. S.
Powiązania:
https://bibliotekanauki.pl/articles/139255.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Trans-Tethyan correlation
Cenomanian
ammonites
Algeria
England
cenoman
amonity
Algieria
Anglia
Opis:
A 480 m section of marls with widely separated levels of nodular limestone in the Fahdene Formation north of Bou Khadra in Tebessa Province, northeastern Algeria, spans the Lower/Middle Cenomanian boundary. A total of 30 ammonite species are present, of which two: Forbesiceras reversum and Calycoceras (Newboldiceras) algeriense are new. The fauna allows recognition of the Northwest European upper Lower Cenomanian Mantelliceras dixoni Zone, the succeeding lower Middle Cenomanian Cunningtoniceras inerme Zone, the Acanthoceras rhotomagense Zone and its subzones of Turrilites costatus and Turrilites acutus. The sequence of index species occurs in the same order in both north-eastern Tunisia and the Southerham Grey Pit in Sussex (and indeed elsewhere in North-west Europe), indicating these to be robust assemblage zones and subzones that can be recognised on both the north and south sides of the Tethys. Other occurrences of taxa that are common in both sections and regions are markedly different, and include the co-occurrence of Cunningtoniceras inerme (Pervinquière, 1907) with Acanthoceras rhotomagense (Brongniart, 1822) in the costatus Subzone in north-eastern Algeria and central Tunisia, the extension of Acompsoceras renevieri (Sharpe, 1857) into the lower Middle Cenomanian in north-eastern Tunisia, whilst the acme of Turrilites scheuchzerianus Bosc, 1801, is in the dixoni Zone in Northwest Europe, and in the inerme Zone in northeasten Algeria and adjacent parts of Central Tunisia. These differences are not a result of collection failure or non-preservation, but must rather reflect environmental controls on occurrence and abundance.
Źródło:
Acta Geologica Polonica; 2017, 67, 1; 75-108
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thin-bedded strata and tuning effect as causes of seismic data anomalies in the top part of the Cenomanian sandstone in the Grobla–Rajsko–Rylowa area (Carpathian foreland, Poland)
Autorzy:
Marzec, P.
Pietsch, K. J.
Powiązania:
https://bibliotekanauki.pl/articles/2060481.pdf
Data publikacji:
2012
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Polska
Carpathian Foreland
Cenomanian
direct hydrocarbon indicators
seismic amplitude analysis
tuning effect
Opis:
A high-amplitude anomaly in seismic signal, i.e. a bright-spot, which is the main direct hydrocarbon indicator, may also occur due to interference between the reflected signals from the top and base of a thin bed (the tuning effect). In such settings the main problem is to distinguish amplitude anomalies associated with lithological changes or changes in gas saturation from anomalies originating from the tuning effect. We provide a method of interpreting the composite seismic signal produced by the interference between reflections. Such reflections occur along the top of the Cenomanian sandstone in the area of the Grobla–Rajsko–Rylowa 3-D seismic dataset (southern Poland). The non-standard method presented here is based on interpretation of seismic data which was rotated by 270°. The results of seismic modelling were used to develop criteria for interpretation of such data. These criteria are based on the difference between information carried by the peak-to-trough amplitude and that by the total amplitude of rotated seismic data. The difference was used to define the transfer function and to remove the high-amplitude anomalies caused by the constructive interference between the reflected signals from the top and bottom of the thinning stratum. The final outcome of the study was a map showing the seismic amplitude response at the top Cenomanian reflector unaffected by the tuning effect. The map shows the extent of the area where high-amplitude anomalies do not correspond with changes in thickness and petrophysical parameters within the top part of the Cenomanian. These anomalies are caused by a lateral increase in thickness of the Turonian and/or an increase in the velocity within the bottom part of the Senonian (Coniacian) strata. The map can be used to determine precisely the boundaries of the Rajsko and Rylowa gas reservoirs as well as to locate the potential extension of the reservoir zone to the east of the Rylowa 6 borehole.
Źródło:
Geological Quarterly; 2012, 56, 4; 691--710
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The stratigraphy of the mid Cretaceous (Albian) Upper Greensand Formation of the Wessex Basin and South West England, UK
Autorzy:
Gallois, R.
Owen, H.
Powiązania:
https://bibliotekanauki.pl/articles/139028.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
stratigraphy
Upper Greensand Formation
Cretaceous
Devon
Dorset
Wessex
Albian Stage
Cenomanian Stage
sequence stratigraphy
stratygrafia
formacja
kreda
dewon
alb
cenoman
Opis:
The Upper Greensand Formation, mostly capped by the Chalk, crops out on the edges of a broad, dissected plateau in Devon, west Dorset and south Somerset and has an almost continuous outcrop that runs from the Isle of Purbeck to the Vale of Wardour in south Wiltshire. The Formation is well exposed in cliffs in east Devon and the Isle of Purbeck, but is poorly exposed inland. It comprises sandstones and calcarenites with laterally and stratigraphically variable amounts of carbonate cement, glauconite and chert. The sedimentology and palaeontology indicate deposition in marginal marine-shelf environments that were at times subject to strong tidal and wave-generated currents. The formation of the Upper Greensand successions in the region was influenced by penecontemporaneous movements on major fault zones, some of which are sited over E-W trending Variscan thrusts in the basement rocks and, locally, on minor faults. Comparison of the principal sedimentary breaks in the succession with the sequence boundaries derived from world-wide sea-level curves suggests that local tectonic events mask the effects of any eustatic changes in sea level. The preserved fauna is unevenly distributed, both laterally and stratigraphically. Bivalves, gastropods and echinoids are common at some horizons but are not age-diagnostic. Ammonites are common at a few stratigraphically narrowly defined horizons, but are rare or absent throughout most of the succession. As a result, the age of parts of the succession is still poorly known.
Źródło:
Acta Geologica Polonica; 2018, 68, 2; 161-180
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The oldest Brazilian snakes from the Cenomanian (early Late Cretaceous)
Autorzy:
Hsiou, A.S.
Albino, A.M.
Medeiros, M.A.
Santos, R.A.B.
Powiązania:
https://bibliotekanauki.pl/articles/945877.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Reptilia
Squamata
Ophidia
snake
Cenomanian
Late Cretaceous
Cretaceous
Brazil
Opis:
South American Mesozoic snake diversity is mostly represented by genera from the Cenomanian (Najash), Santonian–Campanian (Dinilysia), and Campanian–Maastrichtian (Alamitophis, Patagoniophis, Rionegrophis, and Australophis) of Patagonia, Argentina. In this paper, we describe a new snake genus and species, Seismophis septentrionalis, from the Cenomanian (early Late Cretaceous) of the Alcântara Formation, Maranhão, northeastern Brazil. The new snake comprises a posteriormost trunk vertebra and possibly a poorly preserved midtrunk vertebra. Both vertebrae share small size, zygosphene moderately thick with a rectilinear roof, absence of paracotylar foramina, presence of parazygantral foramina, and strongly marked parasagittal ridges of the neural arch. The new snake is here considered of uncertain systematic affinities, but probably close to the limbed snake Najash rionegrina. Although the material is very fragmentary and the systematic assignment is still unresolved, this snake represents the oldest, as well as probably the most primitive snake from Brazil.
Źródło:
Acta Palaeontologica Polonica; 2014, 59, 3; 635-642
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The late Cenomanian oyster Lopha staufferi (Bergquist, 1944) – the oldest ribbed oyster in the Upper Cretaceous of the Western Interior of the United States
Autorzy:
Hook, S. C.
Cobban, W. A.
Powiązania:
https://bibliotekanauki.pl/articles/138617.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cenomanian
oysters
U.S. Western Interior
Taxonomy
paleogeography
biostratigraphy
Sweepstake Routes
Zigzag Commissure
Twowells Tongue
Dakota Sandstone
cenoman
ostrygi
Środkowo-Zachodnie Stany Zjednoczone
systematyka
paleogeografia
biostratygrafia
Dakota
piaskowiec
Opis:
Lopha staufferi (Bergquist, 1944) is a medium-sized, ribbed, Late Cretaceous oyster with a slightly curved axis and a zigzag commissure; it appears suddenly and conspicuously in upper Cenomanian rocks in the Western Interior Basin of the United States. At maturity, the ribs on both valves thicken into steep flanks that allow the oyster to increase interior volume without increasing its exterior footprint on the seafloor. Lopha staufferi is the first (earliest) ribbed oyster in the Late Cretaceous of the Western Interior, but has no ancestor in the basin. It disappears from the rock record as suddenly as it appeared, leaving no direct descendent in the basin. In the southern part of the basin where it is well constrained, L. staufferi is restricted stratigraphically to the upper Cenomanian Metoicoceras mosbyense Zone (= Dunveganoceras conditum Zone in the north). Lopha staufferi has an unusual paleogeographic distribution, occurring in only two, widely scattered areas in the basin. It has been found at several localities near the western shoreline of the Late Cretaceous Seaway in west-central New Mexico and adjacent Arizona, and in localities 1,900 km (1,200 mi) to the northeast near the eastern shoreline in northeastern Minnesota, but nowhere in between. In west-central New Mexico and adjacent Arizona, L. staufferi is a guide fossil to the Twowells Tongue of the Dakota Sandstone.
Źródło:
Acta Geologica Polonica; 2016, 66, 4; 609-626
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The early angiosperm Pseudoasterophyllites cretaceus from Albian-Cenomanian of Czech Republic and France revisited
Autorzy:
Kvacek, J.
Gomez, B.
Zetter, R.
Powiązania:
https://bibliotekanauki.pl/articles/22816.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
angiosperm
Pseudoasterophyllites cretaceus
Cenomanian Peruc Korycany Formation
Czech Republic
France
Magnoliopsida
Pseudoasterophyllites
Tucanopollis
Cretaceous
Albian
Cenomanian
Bohemia
paleontology
Opis:
The early halophytic angiosperm Pseudoasterophyllites cretaceus from the Cenomanian Peruc Korycany Formation of the Bohemian Cretaceous Basin and from the Late Albian of the Northern Aquitanian Basin is redescribed. The plant is characterized by semi−whorled linear, and heavily cutinized leaves with paracytic stomata. Stamens associated with P. cretaceus possess an apically emerging connective that possesses the same epidermal cell pattern as the leaves. The stamens are massive, tetrasporangiate, and contain Tucanopollis pollen, thus clearly indicating affinities of P. cretaceus to the basal angiosperms. The plants that co−occur with P. cretaceus in semi−autochtonous taphocoenoses include the conifer Frenelopsis alata, which was likely a halophyte or halo−tolerant glycophyte growing in habitats close to the sea.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Cenomanian heterozoan carbonates in the north-central Alborz, north-east Kelardasht, north Iran
Autorzy:
Kavoosi, Mohammad Ali
Ezoji, Neda
Powiązania:
https://bibliotekanauki.pl/articles/2060116.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
heterozoan carbonates
condensed
Cenomanian
north-east Kelardasht
Opis:
Detailed field surveys, petrographic investigation and SEM and EDS analyses have been used to evaluate Cenomanian glauconitic heterozoan carbonates in north-east Kelardasht, north-central Alborz, north Iran. Lithofacies and microfacies analyses led to recognition of six microfacies types related to the inner-, mid- and outer-ramp facies belts of a carbonate ramp. The heterozoan nature of these carbonates is inferred from a predominance of echinoderms associated with calcispheres, planktonic foraminifers, a lack of ooid grains, and a low carbonate production rate, together with a high content of glauconite grains and prevailing high-Mg calcite mineralogy. Petrographic and SEM studies reveal that glauconite filling skeletal grains retains the shape and morphology of host grains, signifying an authigenic origin at low sedimentation rates and slightly reducing conditions. SEM images show cauliflower and rosette structures associated with well-developed lamellae indicating an authigenic origin of evolved glauconite grains. Our findings are compatible with a nutrient-rich waters and palaeoecological stress related to relative sea-level rise and eutrophic conditions, which contributed to the generation of these heterozoan carbonates despite the hot greenhouse conditions during the Cenomanian in the north-central Alborz Mountains.
Źródło:
Geological Quarterly; 2021, 65, 3; 65: 37
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Taxonomy and taphonomy of Cenomanian (Upper Cretaceous) nautilids from Annopol, Poland
Autorzy:
Machalski, M.
Wilmsen, M.
Powiązania:
https://bibliotekanauki.pl/articles/139221.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nautilids
condensed deposits
taphonomy
cenomanian
Cretaceous
Annopol
Polska
tafonomia
cenoman
kreda
Polska
Opis:
A nautilid faunule of seven specimens, comprising Eutrephoceras bouchardianum (d’Orbigny, 1840), Cymatoceras deslongchampsianum (d’Orbigny, 1840), and Cymatoceras tourtiae (Schlüter, 1876) is described from a condensed middle Cenomanian interval at Annopol, Poland. C. tourtiae is recorded for the first time in Poland. The studied material consists of reworked phosphatised internal moulds of phragmocones, which may be of early or middle Cenomanian age, given the stratigraphic range of the associated ammonites. The nautilid moulds vary in inferred mode of infilling, and in intensity of abrasion, bioerosion and mineralisation. The sediment entered the phragmocones in two ways: 1) through punctures in the shell, the result of bioerosion or mechanical damage; 2) through siphonal openings by intracameral currents. In contrast to the fossil moulds from the Albian phosphorites of Annopol, which originated via direct precipitation of apatite around and/or inside fossils, the present nautilid moulds seem to have originated through secondary phosphatisation of the initially calcareous moulds. Diversity of taphonomic signatures in nautilid material from the middle Cenomanian interval at Annopol is compatible with the complex, multievent depositional scenario proposed for this level.
Źródło:
Acta Geologica Polonica; 2015, 65, 4; 495-506
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Successive stages of calcitization and silicification of Cenomanian spicule-bearing turbidites based on microfacies analysis, Polish Outer Carpathians
Autorzy:
Bąk, B.
Górny, Z.
Bąk, K.
Wolska, A.
Stożek, B.
Powiązania:
https://bibliotekanauki.pl/articles/191355.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
calcitization
silicification
sponge spicules
spicule-bearing turbidites
cherts
Cenomanian
Outer Carpathians
Opis:
Mid-Cretaceous turbidites with large proportions of sponge spicules are widely distributed in the Silesian Nappe of the Outer Carpathians, giving rise to diversified types of sediments, from spiculites to spicule-bearing siliciclastics and calcarenites. Part of this succession, Middle–Late Cenomanian in age, was transformed into cherts. A microfacies study showed that these turbidite sediments underwent several stages of calcitization and silicification, which took place during Mid-Cretaceous times in different sedimentary environments, i.e., on a northern shelf bordering the Silesian Basin and on a deep sea floor. The first diagenetic changes were related to changes to the biotic components of the turbidite layers, dominated by siliceous sponge spicules. This process, which took place in the spiculitic carbonate mud on the shelves, was related to the calcitization of sponge spicules. Calcareous clasts and calcified skeletal elements also were corroded by bacteria. After transportation down the slope, the biogenic and siliciclastic particles were deposited below the carbonate compensation depth. Taphonomic processes on the basin floor and alternating phases of carbonate and silica cementations, recrystallization and dissolution occurred in these sediments and were related to the diversification in composition of successive turbidite layers. Silicification was related to the formation of quartz precipitates as fibrous chalcedony or microcrystalline quartz, which were derived from the earlier dissolution of amorphous silica, originating mostly from siliceous sponge spicules and radiolarian skeletons. However, a source of silica from hydrothermal vents was also possible. The initial silica precipitation could have taken place in a slightly acidic environment, where calcite was simultaneously dissolved. A number of silicification stages, visible as different forms of silica precipitate inside moulds after bioclasts, occur in the particular turbidite layers. They were related to changes in various elements of the pore-water profile after descending turbidity-current flows. A very low sedimentation rate during the Middle–Late Cenomanian in the Silesian Basin may have favoured the sequence of initial calcitization and silicification stages of the turbidite sediments.
Źródło:
Annales Societatis Geologorum Poloniae; 2015, 85, 1; 187-203
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stratigraphy of the Albian-Cenomanian boundary interval in the Agadir Basin, Morocco: ammonites, microcrinoids, planktonic foraminifera
Autorzy:
Gale, Andrew Scott
Kennedy, William James
Petrizzo, Maria Rose
Powiązania:
https://bibliotekanauki.pl/articles/2024048.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Albian/Cenomanian boundary
Agadir
planktonic foraminifera
ammonites
granica alb/cenoman
otwornice planktoniczne
amonity
Opis:
The uppermost Albian and lowermost Cenomanian succession at Abouda Plage, north of Agadir, in the Agadir Basin, western Morocco, is described in detail, and ammonites, microcrinoids and planktonic foraminifera are recorded and illustrated. The lower part of the Aït Lamine Formation yields ammonites indicative of the Pervinquieria (Subschloenbachia) rostrata and P. (S.) perinflata ammonite zones, and the Thalmanninella appenninica planktonic foraminiferan Zone. The base of the Cenomanian is identified at 42.2 m above the base of the Aït Lamine Formation, based on the lowest occurrence of the planktonic foraminiferan Thalmanninella globotruncanoides Sigal, 1948. Lower Cenomanian ammonites of the Graysonites adkinsi Zone enter 3 m higher in the succession. Microcrinoid zones AlR11 and AlR12 are identified in the Upper Albian, and the base of the CeR1 Zone coincides with the lowest occurrence of Cenomanian ammonites. The ammonite and microcrinoid occurrences and detailed distributions are very similar to those found in north central Texas, which, in the Cenomanian, was 5,300 km to the west. The new records suggest that the G. adkinsi Zone is equivalent to the uppermost (Lower Cenomanian) part of the Pleurohoplites briacensis Zone of the Global Stratotype Section for the base of the Cenomanian stage. An hiatus, of global extent, immediately underlies the base of the G. adkinsi Zone and is represented in the Agadir Basin by an erosion surface containing bored and encrusted hiatus concretions.
Źródło:
Acta Geologica Polonica; 2021, 71, 4; 453--480
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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