Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Lower Cretaceous" wg kryterium: Temat


Tytuł:
Foraminifera from the Late Jurassic and Early Cretaceous carbonate platform facies of the southern part of the Crimea Mountains, Southern Ukraine
Autorzy:
Krajewski, M.
Olszewska, B.
Powiązania:
https://bibliotekanauki.pl/articles/191714.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
foraminifers
dinoflagellata
Upper Jurassic
Lower Cretaceous
Crimea
Opis:
Upper Jurassic and Lower Cretaceous deposits of the Crimea Peninsula are rich in microfossils frequently used for stratigraphic interpretations. In case of foraminifera, the research has been carried predomi- nantly on assemblages obtained by washing the rock samples. The present paper is based on investigations of thin sections from the more indurated sediments that seldom were objects of study. Its goal was to obtain additional information on age and environment of sediments studied. Over 250 thin sections from 16 surface outcrops yielded abundant foraminifera from which over fourty are described herein. Many foraminiferal species (e.g., Labirynthina mirabilis, Parurgonina caelinensis, Neokilianina rahonensis, Amijella amiji, Anchispirocyclina lusitanica) are stratigraphically significant and known from the Kimmeridgian-Tithonian of the Mediterranean Tethys. The Early Cretaceous fauna is represented by Protopeneroplis ultragranulata, Everticyclammina kelleri, Nautiloculina bronnimanni, Monsalevia salevensis, and Mayncina bulgarica. Generally, the investigated fauna is typical for paleoenvironment of the carbonate platform. Older (Kimmeridgian-Tithonian) assemblages represent the inner, and younger (Berriasian) outer parts of the platform. Palaeogeographic distribution of many species described from the studied area indicates their affiliation with cosmopolitan biota known from the north Tethyan shelf. Additionally, few calcareous cysts of Dinoflagellata have been identified and described.
Źródło:
Annales Societatis Geologorum Poloniae; 2007, 77, No 3; 291-311
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research history, taphonomy, and age structure of a mass accumulation of the ornithopod dinosaur Dysalotosaurus lettowvorbecki from the Upper Jurassic of Tanzania
Autorzy:
Hubner, T.R.
Foth, C.
Heinrich, W.-D.
Schwarz, D.
Bussert, R.
Powiązania:
https://bibliotekanauki.pl/articles/2082333.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Crocodylomorpha
Thalattosuchia
Metriorhynchidae
Lower Cretaceous
Valanginian
Czech Republic
Opis:
Metriorhynchid crocodylomorphs were an important component in shallow marine ecosystems during the Middle Jurassic to Early Cretaceous in the European archipelago. While metriorhynchids are well known from western European countries, their central and eastern European record is poor and usually limited to isolated or fragmentary specimens which often hinders a precise taxonomic assignment. However, isolated elements such as tooth crowns, have been found to provide informative taxonomic identifications. Here we describe two isolated metriorhynchid tooth crowns from the upper Valanginian (Lower Cretaceous) of the Štramberk area, Czech Republic. Our assessment of the specimens, including multivariate analysis of dental measurements and surface enamel structures, indicates that the crowns belong to two distinct geosaurin taxa (Plesiosuchina? indet. and Torvoneustes? sp.) with different feeding adaptations. The specimens represent the first evidence of Metriorhynchidae from the Czech Republic and some of the youngest metriorhynchid specimens worldwide.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 2; 357-367
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A mixed assemblage of deep-sea and shelf trace fossils from the Lower Cretaceous (Valanginian) Kamchia Formation in the Troyan region, central Fore-Balkan, Bulgaria
Autorzy:
Uchman, A.
Tchoumatchenco, P.
Powiązania:
https://bibliotekanauki.pl/articles/973639.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
trace fossils
ichnology
Lower Cretaceous
Fore-Balkan
Bulgaria
Opis:
Trace fossils collected from the best outcrop of the Kamchia Formation have been analysed. There are thirteen ichnotaxa (Curvolithus simplex, Gyrochorte isp., ?Helminthoidichnites tenuis, Multina minima [second occurrence], Palaeophycus tubularis, ?Palaeophycus isp., Phycodes bilix, Phycosiphon incertum, Planolites cf. reinecki, Spongeliomorpha ?chevronensis, Squamodictyon tectiforme, Thalassinoides suevicus, Zoophycos isp.) representing different ethologic, toponomic and preservational types, and produced at different depths in the sediment. The ichnoassemblage contains a mixture of forms typical of flysch (Squamodictyon) and shelf deposits (Curvolithus, Gyrochorte). Probably, sediments of the Kamchia Formation were deposited in an offshore or deeper basin with storm deposition of sand beds and background marly sedimentation. It is possible that storm currents transported trace makers of the shelf trace fossils to the deeper sea. It is not excluded that the trace maker of Gyrochorte migrated to the deep-sea after the Jurassic. However, the simplest explanation is that the Kamchia ichnofauna represents an ecological transition between shelf and slope communities.
Źródło:
Annales Societatis Geologorum Poloniae; 2003, 73, No 1; 27-34
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two ammonites from the Early Cretaceous deep-sea sediments of the Silesian Nappe, Polish Carpathians, and stratigraphic problems resulted from micropalaeontological dating of their sites
Autorzy:
Vašíček, Z.
Gedl, E.
Kędzierski, M.
Uchman, A.
Powiązania:
https://bibliotekanauki.pl/articles/191914.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
ammonites
nannoplankton
dinocysts
biostratigraphy
Lower Cretaceous
flysch Carpathians
Opis:
Two ammonites Teschenites subflucticulus Reboulet and Criosarasinella mandovi Thieuloy have been found for the first time in the Flysch Carpathians. They occur in the so far poorly dated Early Cretaceous flysch deposits of the Silesian Nappe at Poznachowice Dolne, in the Upper Cieszyn Shale and the Hradiště (Grodziszcze) beds lithotypes, respectively. Teschenites subflucticulus points to Late Valanginian (Furcillata Zone), but nanno- plankton points to Late Hauterivian-Late Barremian and dinocysts to Late Hauterivian, all analyzed from the same sample. Criosarasinella mandovi points also to Late Valanginian (Furcillata Zone), what is not in contra-diction with the nannoplankton assemblage (Early Valanginian-Early Barremian) analyzed from the same bed, but dinocysts suggest Late Hauterivian. Preservation of the ammonites and sedimentary features of their host beds exclude redeposition. The difference in age by almost 3 Ma years between the ammonites and microfossils cannot be satisfactorily explained according to the current knowledge on their biostratigraphic meaning; it is left as it is as a dilemma.
Źródło:
Annales Societatis Geologorum Poloniae; 2010, 80, No 1; 25-37
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Origin of "cannon-ball" concretions in the Carolinefjellet Formation (Lower Cretaceous), Spitsbergen
Autorzy:
Krajewski, Krzysztof P.
Luks, Bartłomiej
Powiązania:
https://bibliotekanauki.pl/articles/2052073.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
Svalbard
Lower Cretaceous
"cannon-ball" concretions
diagenesis
Źródło:
Polish Polar Research; 2003, 24, 3-4; 217-242
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evidence of two lineages of metriorhynchid crocodylomorphs in the Lower Cretaceous of the Czech Republic
Autorzy:
Madzia, D.
Sachs, S.
Young, M.T.
Lukeneder, A.
Skupien, P.
Powiązania:
https://bibliotekanauki.pl/articles/2082332.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Crocodylomorpha
Thalattosuchia
Metriorhynchidae
Lower Cretaceous
Valanginian
Czech Republic
Opis:
Metriorhynchid crocodylomorphs were an important component in shallow marine ecosystems during the Middle Jurassic to Early Cretaceous in the European archipelago. While metriorhynchids are well known from western European countries, their central and eastern European record is poor and usually limited to isolated or fragmentary specimens which often hinders a precise taxonomic assignment. However, isolated elements such as tooth crowns, have been found to provide informative taxonomic identifications. Here we describe two isolated metriorhynchid tooth crowns from the upper Valanginian (Lower Cretaceous) of the Štramberk area, Czech Republic. Our assessment of the specimens, including multivariate analysis of dental measurements and surface enamel structures, indicates that the crowns belong to two distinct geosaurin taxa (Plesiosuchina? indet. and Torvoneustes? sp.) with different feeding adaptations. The specimens represent the first evidence of Metriorhynchidae from the Czech Republic and some of the youngest metriorhynchid specimens worldwide.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 2; 357-367
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New cupedid beetles from the Lower Cretaceous of Spain and the palaeogeography of the family
Autorzy:
Soriano, C
Delclos, X.
Powiązania:
https://bibliotekanauki.pl/articles/23502.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Lower Cretaceous
Cretaceous
beetle
cupedid beetle
Coleoptera
paleobiogeography
Spain
paleontology
Cupedidae
Opis:
Thirteen new species of the family Cupedidae (Coleoptera: Archostemata) from Las Hoyas (Cuenca province) and El Montsec (Lleida province) fossil sites from the Barremian (Lower Cretaceous) of Spain are described. Ten of them belong to subfamily Ommatinae: Tetraphalerus ponomarenkoi, Tetraphalerus penalveri, Cionocoleus longicapitis, Brochocoleus indibili, Zygadenia viridis, Zygadenia oculata, Zygadenia martinclosas, Zygadenia longicoxa, and Zygadenia siniestri. Three of them are assigned to subfamily Cupedinae: Priacma sanzii, Anaglyphites zherikhini, and Anaglyphites pluricavus. Placement of genus Cionocoleus among subfamily Ommatinae is proposed. These new species extend the record of genera Zygadenia, Cionocoleus, Brochocoleus, Priacma, and Anaglyphites to the western part of Barremian European deposits. Nowadays the family Cupedidae is considered to be a relic group, restricted to few genera and species on Asia, Africa, Australia, and America, with limited geographical distribution, while during the Mesozoic the cupedids were distributed all over Laurasia. The Mesozoic cupedid−bearing localities are mostly interpreted as warm temperate to subtropical environments.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Provenance of Lower Cretaceous deposits of the western part of the Silesian Nappe in Poland (Outer Carpathians): evidence from geochemistry
Autorzy:
Wójcik-Tabol, P.
Ślączka, A.
Powiązania:
https://bibliotekanauki.pl/articles/191335.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Silesian Nappe
Lower Cretaceous
mineral composition
geochemistry
provenance
diagenesis
Opis:
The turbiditic to hemipelagic, fine-grained deposits of the Hradiště Formation (Hauterivian, 132 Ma) to the Lhoty Formation (Albian–Cenomanian, 99 Ma) in the western part of the Silesian Nappe (Polish Outer Car- pathians) were studied mineralogically and geochemically to determine if the main factors controlling the chemistry of the sedimentary material can be attributed to provenance, or to post-depositional processes. A high degree of weathering of the source rocks is indicated by the chemical index of alteration (CIA) that varies from 75.98 to 89.86, and Th/U ratios (~4 with outliers at 1.85 and >6). The cooccurrence of rounded and unabraded grains of zircon and rutile, the enrichment in Zr and Hf, as well as the high Zr/Sc ratios suggest that the Hradiště and Veřovice Formations contain recycled material. Plots of La/Th versus Hf and Th against Sc show that samples occur in the field of felsic and mixed felsic/basic sources. On a ternary La–Th–Sc diagram, all of the sediments studied are referable to the continental island-arc field. The European Plate, as an alimentary area, has a mosaic structure consisting of Cadomian and Variscan elements. The Proto-Silesian Ridge was detached from the continent, because of rifting. Therefore, it could have corresponded to a continental island arc. The concentrations of Fe and trace metals (e.g., Mo, Au, Cu) in the Veřovice Formation and silica and potassium additions to the Veřovice and Lhoty Formations, as well as the fractionation of REE, and Nb, Ta, Zr, Hf, and Y can be explained by the action of basinal brines. The fluids were of hydrothermal origin and/or were released, owing to the dewatering of clay minerals. Diagenetic processes could have exerted a greater influence on sedimentary rock chemistry than the provenance and sedimentary processes. A distinction between primary, terrigenous elements and those changed diagenetically is necessary for the reliable determination of provenance.
Źródło:
Annales Societatis Geologorum Poloniae; 2013, 83, 2; 113--132
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First report on dinosaur tracks from the Burro Canyon Formation, San Juan County, Utah, USA : evidence of a diverse, hitherto unknown Lower Cretaceous dinosaur fauna
Autorzy:
Milàn, J.
Chiappe, L. M.
Loope, D. B.
Kirkland, J. I.
Lockley, M. G.
Powiązania:
https://bibliotekanauki.pl/articles/191615.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
dinosaur tracks
Lower Cretaceous
Barremian
Utah
pathology
dinosaur fauna
Opis:
The newly discovered White Mesa tracksite in the Burro Canyon Formation represents a snapshot of a diverse, Lower Cretaceous dinosaur fauna from south-eastern Utah. The tracks were found at a construction site where the sandstone had been bulldozed and broken up. All tracks were found as deep, well-preserved natural casts on the underside of the sandstone slabs. Individual theropod tracks are 19–57 cm in length; one peculiar track shows evidence of a possible pathological swelling in the middle of digit III and an apparently didactyl track is tentatively assigned to a dromaeosaurid. Individual sauropod tracks are found with pes lengths of 36–72 cm, and interestingly, three distinct shapes of manus tracks, ranging from wide banana shaped to rounded and hoof-like. Ornithopods are represented with individual tracks 18–37 cm in length; a sin gle track can possibly be attributed to the thyreophoran ichnogenus Deltapodus. Zircon U-Pb dating places the track-bearing layer in the Barremian, contemporary to the lower Yellow Cat Member of the Cedar Mountain Formation, which has a similar faunal composition based on both tracks and body fossils. This new track-fauna demonstrates the existence of a diverse dinosaurian assemblage in the lower part of the Burro Canyon Formation, which hitherto is not known to yield skeletalre mains.
Źródło:
Annales Societatis Geologorum Poloniae; 2015, 85, 3; 515-525
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Double alignments of ammonoid aptychi from the Lower Cretaceous of Southeast France: Result of a post-mortem transport or bromalites?
Autorzy:
Reboulet, S
Rard, A.
Powiązania:
https://bibliotekanauki.pl/articles/21005.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Cretaceous
Valanginian
predation
coprolite
ammonoid
paleontology
taphonomy
France
aptychus
Ammonoidea
Lower Cretaceous
Opis:
A new preservation of aptychi is described from the Valanginian limestone−marl alternations of the Vergol section (Drôme), located in the Vocontian Basin (SE France). Aptychi are arranged into two parallel rows which are generally 50 mm in length and separated by 4 mm. The alignments are very often made by entire aptychi (around 10 mm in length), oriented following their harmonic margin. Aptychi show the outside of valve to the viewer: they are convex−up. This fossilization of aptychi is successively interpreted as the result of post−mortem transport by bottom currents (taphonomicresedimentation process) or the residues (bromalites: fossilized regurgitation, gastric and intestinal contents, excrement) from the digestive tract of an ammonoid−eater (biological processes). Both the parallel rows of aptychi are more likely interpreted as a coprolite (fossil faeces) and they could be considered as both halves (hemi−cylindrical in shape) of the same cylindrical coprolite which would have been separated in two parts (following the long axis) just after the animal defecated. Considering this hypothesis, a discussion is proposed on the hypothetical ammonoid−eater responsible for them.
Źródło:
Acta Palaeontologica Polonica; 2008, 53, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new short-bodied salamander from the Upper Jurassic-Lower Cretaceous of China
Autorzy:
Wang, Y
Evans, S.E.
Powiązania:
https://bibliotekanauki.pl/articles/20232.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Lower Cretaceous
Cretaceous
China
Upper Jurassic
Pangerpeton sinensis
deposit
Jurassic
salamander
paleontology
Opis:
Abundant well−preserved salamander fossils have recently been recovered from localities across northeastern China. Pangerpeton sinensis gen. et sp. nov. is represented by a nearly complete skeletal impression of a postmetamorphosed salamander from the Late Jurassic/Early Cretaceous locality of Wubaiding, Liaoning Province. It is characterised by a short wide skull and only 14 presacral vertebrae. Associated soft tissue impressions suggest a warty skin and a broad body outline. Phylogenetic analysis indicates a basal position within Caudata, either just within or just outside crown−group Urodela.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Actinaraeopsis ventosiana, a new scleractinian species from the Lower Cretaceous of Provence (SE France)
Nowy gatunek koralowca sześciopromiennego (scleractinia) z wczesnej kredy Prowansji (Se Francja)
Autorzy:
Morycowa, E.
Masse, J.P.
Powiązania:
https://bibliotekanauki.pl/articles/191716.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Scleractinian corals
Haplaraeidae
Actinaraeopsis ventosiana sp. nov.
Lower Cretaceous
France
Opis:
Actinaraeopsis ventosiana is a new scleractinian coral species from the Lower Cretaceous shallow- water limestones of the Mont Ventoux (Provence, SE France). To date only two Late Jurassic species of this genus have been known, i.e. Actinaraeopsis araneola Roniewicz and A. exilis Roniewicz. The new species shows some similarity to the Jurassic species A. araneola, but differs in microstructure details and morphometric parameters.
W pracy opisano nowy gatunek koralowca kolonijnego Actinaraeopsis ventosiana, pochodzącego z płytkowodnych wapieni górnobarremskich Prowansji (SE Francja). Dotychczas tylko dwa gatunki tego rodzaju są znane z jury górnej, A. araneola Roniewicz i A. exilis Roniewicz. Nowy gatunek Actinaraeopsis ventosiana wykazuje pewne podobieństwo do jurajskiego gatunku A. araneola, ale różni się od niego parametrami morfometrycznymi i szczegółami budowy mikrostrukturalnej szkieletu.
Źródło:
Annales Societatis Geologorum Poloniae; 2007, 77, No 2; 141-145
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Aptian Gura Râului conglomerates (Southern Carpathians) : remains of an extended subaqueous gravity flow deposit from the eastern flank of the Getic Nappe
Autorzy:
Ungureanu, Răzvan
Săsăran, Emanoil
Bucur, Ioan I.
Mircescu, Cristian Victor
Ungureanu, Alexandra
Ungur, Ciprian Gheorghiţă
Powiązania:
https://bibliotekanauki.pl/articles/2058596.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
conglomerates
gravity flow deposits
fan-deltas
Lower Cretaceous
Piatra Craiului Massif
Romania
Opis:
The Getic Nappe belongs to the Central Dacides or Dacia Mega Unit. Gravity flow deposits were generated by the Lower Cretaceous overthrust and uplift of this unit over the External Dacides. In the Piatra Craiului Syncline (part of the Getic Nappe), such detrital deposits are represented by the Aptian conglomerates and the uppermost Albian-Cenomanian conglomerates. Part of the infill of the syncline consists of a thick pile of NW-SE oriented conglomerates. Sedimentological study documents the presence of an association which consists of three distinct facies types, represented by: massive conglomerates; alternating conglomerates, sandstones and microconglomerates; and fining- and coarsening-upwards conglomerates. These deposits were accumulated through a series of debris flows, and hyperconcentrated or concentrated flows. The entire assemblage represents a complex routing system within submarine channels, an interpretation made by interpreting facies associations, palaeoflow directions and clast fabrics. A large part of this succession was removed by post-Albian erosion. Thus, the interpretation of the depositional system could be as a series of feeder channels or the submarine sector of a fan-delta system representing a foreland basin fill.
Źródło:
Geological Quarterly; 2019, 63, 1; 88--105
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Facies of the Upper Jurassic–Lower Cretaceous deposits from the southern part of the Carpathian Foredeep basement in the Kraków–Rzeszów area (southern Poland)
Autorzy:
Krajewski, M.
Matyszkiewicz, J.
Król, K.
Olszewska, B.
Powiązania:
https://bibliotekanauki.pl/articles/191393.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
facies
microfacies
dolomitization
Upper Jurassic
Lower Cretaceous
Carpathian Foredeep basement
southern Poland
Opis:
A comparative sedimentological analysis of the Upper Jurassic–Lower Cretaceous deposits carried out on drill-cores from the southern part of the Carpathian Foredeep allowed us to distinguish thirteen main microfacies types. The results of microfacies analyses and stratigraphical data made it possible to propose a lithological subdivision of the southern part of the Upper Jurassic and Lower Cretaceous sediments of the Carpathian Foredeep basement between Kraków and Rzeszów. In the analysed wells, three main sedimentary complexes were distinguished, embracing the following intervals: (i) Callovian–Oxfordian, (ii) Kimmeridgian and (iii) Tithonian– Berriasian–Valanginian. The Oxfordian, Kimmeridgian and Tithonian deposits represent the outer – mid homoclinal ramp facies, whereas the Berriasian and Valanginian deposits belong to the inner homoclinal ramp facies. Complexes of microbial-sponge reefs, with a distinct relief, could be recognised in the Upper Oxfordian sediments only. The development of these buildups took place in a basin typified by diversified morphology, determined by the block-type structure of the Palaeozoic basement and synsedimentary tectonics, which brought about substantial variability in thickness of the Oxfordian sediments. At the end of the Oxfordian, large complexes of the reef facies were replaced mainly by microbial-sponge and microbial-coral biostromes developed during the Kimmeridgian and Tithonian. In the principal part of the studied area (except the western part of the described fragment of the Carpathian Foredeep; Kraków area) during the Kimmeridgian, Tithonian, Berriasian and Valanginian, sedimentation occurred in a basin typified by homogeneous morphology, which resulted in a wide extent and comparable thicknesses of the distinguished facies types. In the studied sections, indications of partial or complete dolomitization were observed in a large part of the sediments. Four generations of dolomite document a complex diagenetic history with multiple episodes of dolomite formation: from early diagenetic environment to late burial conditions.
Źródło:
Annales Societatis Geologorum Poloniae; 2011, 81, No 3; 269-290
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calcareous nannofossil biostratigraphy and sedimentary environment of Valanginian–Hauterivian rhythmites (Silesian Nappe, Polish Carpathians)
Autorzy:
Kędzierski, M.
Ochabska, A.
Powiązania:
https://bibliotekanauki.pl/articles/191763.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
calcareous nannofossils
biostratigraphy
Lower Cretaceous
Silesian Nappe
Polish Carpathians
Tethyan-Boreal influences
Opis:
The results of semi-quantitative and qualitative studies of nannofossil assemblages in dark to light grey, rhythmically bedded, calcareous mudstones of the Upper Cieszyn Beds, Silesian Nappe of the Outer Carpathians are presented. The vertical variation in the carbonate content of these mudstones and changes in the composition of nannofossil assemblages, as well as the Shannon diversity index (SI), result from humid-arid climate changes, driving the trophic conditions of surface waters and nannoplankton biocalcification. These changes were control- led by the variable influences of both the Tethyan and Boreal provinces. The light grey mudstones were deposited during the dominance of warm waters from the Tethyan realm and some nannoconids, typical of the warm, stratified water of lower palaeolatitudes, occur here. The dark grey mudstones represent influences of the Boreal province, indicated by the appearance of Crucibiscutum sp. and a generally higher biodiversity demonstrated by SI. Climatic changes affected the stratification of surface water, expressed also by different linear fits for pairs of SI, Watznaueria barnesiae and Rhagodiscus asper. On the basis of the presence of Eiffellithus striatus, E. windii and signals of both Tethyan and Boreal influences. the section studied represents the uppermost Valanginian– lowermost Hauterivian boundary interval, i.e., the upper part of the BC5/BC6 nannofossil zones, related to the furcillata-radiatus ammonite zones.
Źródło:
Annales Societatis Geologorum Poloniae; 2012, 82, 3; 225--237
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies