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Wyszukujesz frazę "Cretaceous palaeogeography" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Provenance of Albian to Cenomanian exotics-bearing turbidites in the Western Carpathians : a heavy mineral analysis
Autorzy:
Aubrecht, Roman
Bellová, Simona
Mikuš, Tomáš
Powiązania:
https://bibliotekanauki.pl/articles/2060270.pdf
Data publikacji:
2020
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ophiolites
Cr-spinel
blue amphibole
tourmaline
pyroxene
Cretaceous palaeogeography
Opis:
Throughout the Cretaceous, Tethyan oceanic branches gradually closed, and various ophiolites became obducted and eroded. Their remnants, however, provide an abundance of exotic clasts of unknown origin. Sandstone samples from the oldest, Albian exotics-bearing strata of the Pieniny Klippen Belt and Central Western Carpathians were analysed for heavy minerals. These samples were dominated by a high content of chrome-spinels, zircon, tourmaline, apatite and rutile. Titanite, kyanite, monazite, epidote, sillimanite and staurolite were much less abundant. Garnet was generally also rare; however, it was locally common, as were blue amphiboles, pyroxenes and kyanite. The spinels found in the samples were predominantly derived from harzburgites (supra-subduction peridotites and volcanic rocks). The blue amphiboles represented glaucophanes to ferroglaucophanes, and were derived from HP/LT metabasites. Pyroxenes (enstatite, less commonly augite and diopside) most likely came from coeval volcanics. Most of the tourmalines were derived from metasedimentary rocks and locally from granitoids. Furthermore, some have a complex zonation with two phases of tourmaline, or tourmaline intergrown with quartz. These were likely derived from ophiolitic sources. The results from our analysis indicate a dominance of ophiolites and older sediments with local input of continental crust metamorphic rocks. A resulting palaeogeographic reconstruction involves secondary doubling of the Neotethys suture zone and its lateral shift north of the Central Western Carpathians, which formed a common source for exotics in the Pieniny Klippen Belt and the Central Western Carpathians.
Źródło:
Geological Quarterly; 2020, 64, 3; 658--680
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Upwelling regime in the Carpathian Tethys: a Jurassic-Cretaceous palaeogeographic and paleoclimatic perspective
Autorzy:
Golonka, J.
Krobicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/2059324.pdf
Data publikacji:
2001
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Tethys
Carpathians
Jurassic
Cretaceous
palaeogeography
palaeoclimate
palaeoecology
upwelling
Opis:
Jurassic and Cretaceous global palaeogeographic reconstructions show a changing configuration of mountains, land, shallow seas and deep ocean basins, and these are used as input for paleoclimatic modelling. We have generated Oxfordian-Kimmeridgian, Tithonian-Berriasian and Barremian-Hauterivian paleoclimatic maps, showing air pressure, wind directions, humidity zones and areas favourable to upwelling conditions, modelled by the PALEOCLIMATE program and plotted on the palaeogeographic background. Paleoclimate modelling suggests that prevailing Jurassic-Cretaceous winds in the northern Tethys area came from south-south-west, and may have been parallel to the Czorsztyn Ridge, uplifted as a result of extension during the Jurassic supercontinental breakup. Upwelling may have been induced at the southeastern margin of the ridge. The model is consistent with the rock records within the earliest Cretaceous deposits. The presence of phosphates and a palaeoenvironmental analysis of benthic fauna support the upwelling model.
Źródło:
Geological Quarterly; 2001, 45, 1; 15-32
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Cretaceous inversion and salt tectonics in the Koszalin-Chojnice and Drawno-Człopa-Szamotuły zones, Pomeranian sector of the Mid-Polish Trough
Autorzy:
Leszczyński, K.
Powiązania:
https://bibliotekanauki.pl/articles/2059905.pdf
Data publikacji:
2002
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Mid-Polish Trough
Upper Cretaceous
salt structures
inversion
palaeogeography
facies and thickness analysis
Opis:
Late Cretaceous inversion processes and their relation to salt movements in the Pomeranian sector of the Mid-Polish Trough are described, based on deep boreholes. Two tectonic zones, inverted in the Late Cretaceous, located in the Mid-Polish Trough, were selected for study: the Koszalin-Chojnice Zone situated NE of the present-day Mid-Polish Swell in the Pomeranian Trough, within an area of non-salt anticlines, and the Drawno-Człopa-Szamotuły Zone located in the Szczecin Trough, SW of the Mid-Polish Swell, in an area of strong salt tectonics. The stratigraphic gaps present indicate that the first pulse of Late Cretaceous inversion might have occurred in the Coniacian-early Santonian in this area. Another pulse can be dated at late Campanian-early Maastrichtian. Intra-Cretaceous stratigraphic gaps reached their maximum areal extent in the Coniacian (Inoceramus involutus Zone) and Upper Campanian (Koszalin-Chojnice Zone). Over large areas, Santonian (mostly upper Santonian) deposits rest upon Turonian (including Inoceramus schloenbachi Zone), and locally on older rocks. The lithofacies maps show that thickness and lithofacies distribution in the Cenomanian was independent of the strike of the Koszalin-Chojnice Zone. Such a dependence began and was accentuated in the Coniacian. Santonian and Campanian clastic deposits, extending along the SW boundary of the Mid-Polish Swell and absent in the SW part of the Pomeranian Trough, suggest local tectonic inversion within the central part of the Mid-Polish Trough.
Źródło:
Geological Quarterly; 2002, 46, 3; 347-362
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Upper Cretaceous (Maastrichtian) charophyte gyrogonites from the Lameta Formation of Jabalpur, Central India: palaeobiogeographic and palaeoecological implications
Autorzy:
Khosla, A.
Powiązania:
https://bibliotekanauki.pl/articles/138589.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
charophyta
palaeobotany
palaeogeography
biogeography
Cretaceous-Paleogene boundary
Charophyta
paleobotanika
paleogeografia
biogeografia
kreda
paleogen
granica
Opis:
A charophyte gyrogonite assemblage consisting of Platychara cf. sahnii, Nemegtichara grambastii and Microchara sp. is reported herein from two localities (Bara Simla Hill and Chui Hill sections) of the Lameta Formation at Jabalpur. The Lameta Formation locally underlying the Deccan traps has been shown to be pedogenically modified alluvial plain deposits containing one of the most extensive dinosaur nesting sites in the world. They are associated with dinosaur bones and freshwater ostracod assemblages that suggest a Late Cretaceous (Maastrichtian) age. This is the first detailed systematic account of charophyte gyrogonites from the Lameta Formation. This charophyte assemblage is compatible with the biostratigraphic attribution provided by the ostracods. From a biogeographic viewpoint, it exhibits considerable similarity to other infratrappean assemblages of the Nand, Dongargaon, and Dhamni-Pavna sections (Maharashtra), and some intertrappean assemblages of Kora in Gujarat, Rangapur in Andhra Pradesh and Gurmatkal in South India. Globally, the genus Microchara is well distributed throughout Eurasia, whereas the genus Platychara occurs richly in the Upper Cretaceous deposits of Europe, Asia, America and Africa. However, at the specific level, Platychara cf. sahnii shows close affinities with charophytes from the Maastrichtian of Iran whilst Nemegtichara grambastii shows distinct affinities with two species of Early Palaeogene deposits of China and Mongolia. The presence of charophyte gyrogonites in the Lameta sediments is attributed to local lacustrine and palustrine conditions within a flood plain environment.
Źródło:
Acta Geologica Polonica; 2014, 64, 3; 311-323
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The erratic rocks of the Upper Cretaceous Chalk of England: how did they get there, ice transport or other means?
Autorzy:
Jeans, Christopher V.
Platten, Ian M.
Powiązania:
https://bibliotekanauki.pl/articles/1835594.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cretaceous
chalk
erratics
gastroliths
fast ice
palaeogeography
NW Europe
kreda
eratyk
stały lód brzegowy
paleogeografia
Europa północno-zachodnia
Opis:
Rare erratic clasts - extraneous rock types - occur in the Upper Cretaceous Chalk, including a local basal facies, the Cambridge Greensand. The underlying Upper Albian Gault Clay and the Hunstanton Red Chalk Formations have also yielded erratics. The discovery of these erratics, their description and the development of hypotheses to explain their origins and significance are reviewed. They became the subject of scientific interest with the interpretation of a particularly large example “The Purley Boulder” by Godwin-Austen (1858) as having been transported to its depositional site in the Chalk Sea by drifting coastal ice. Thin section petrography (1930–1951) extended knowledge of their diverse provenance. At the same time the Chalk Sea had become interpreted as warm, so drifting ice was considered out of context, and the preferred agents of transport were entanglement in the roots of drifting trees, as holdfasts of floating marine algae, or as stomach stones of marine reptiles or large fish. Reconsideration of their occurrence, variable nature and sedimentary setting suggests that there are three zones in the English Chalk where erratics may be less rare (1) near the base of the Cenomanian in the Cambridge area, (2) the Upper Cenomanian-Middle Turonian in Surrey, and (3) the Upper Coniacian and Lower Santonian of Kent. The assemblage from each level and their sedimentary setting is subtly different. Present evidence suggests that the erratics found in the Upper Albian-Lower Cenomanian and the Upper Cenomanian-Middle Turonian zones represent shallow water and shoreline rocks that were transported into the Chalk Sea by coastal ice (fast-ice) that enclosed coastal marine sediments as it froze. The Upper Coniacian and Lower Santonian erratics from Rochester and Gravesend in Kent are gastroliths.
Źródło:
Acta Geologica Polonica; 2021, 71, 3; 287-304
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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