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Wyświetlanie 1-5 z 5
Tytuł:
Palaeoenvironmental interpretation of echinoderm assemblages from Bathonian ore-bearing clays at Gnaszyn (Kraków-Silesia Homocline, Poland)
Autorzy:
Boczarowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/138733.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
baton
iły rudonośne
jura środkowa
paleośrodowisko
Polska
szkarłupnie
Bathonian
echinoderms
Middle Jurassic
ore-bearing clays
palaeoenvironment
Polska
Opis:
This paper presents the results of an investigation into the variability of echinoderm assemblages from Bathonian ore-bearing clays from Gnaszyn. Remains of Crinoidea, Asteroidea, Ophiuroidea, Echinoidea, and Holothuroidea have been studied from 38 rock samples. The most common echinoderms represented are the crinoids Balanocrinus berchteni and Chariocrinus andreae and a few species of the holothurian genera Priscopedatus, Calclamna, Staurocaudina, Eocaudina, Achistrum, Theelia and Hemisphaeranthos. The echinoderms from Gnaszyn show various life strategies: benthic or epibenthic forms, sessile sestonophages (Crinoidea), motile macrophages (Asteroidea) and detritivores (Asteroidea, Ophiuroidea, Echinoidea), infaunal and epifaunal detritus feeders, sediment feeders or rake-feeders (Holothuroidea). Their presence suggests well oxygenated and presumably relatively cold bottom marine waters. The parts of the Gnaszyn section around concretion horizons and characterized by the ubiquitous occurrence of the holothurian Theelia and echinoids were deposited during phases of optimal living conditions with sufficient influx of plant detritus and good oxygenation of the sea bottom. These parts commonly host echinoderm associations dominated by crinoid remains, which occasionally are still articulated (or disarticulated but remaining intact) - this points to a quiet environment with normal oxygenation of the bottom waters but anaerobic/dysaerobic conditions in the sediment.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 351-366
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An introduction to the palaeoenvironmental reconstruction of the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland
Autorzy:
Gedl, P.
Kaim, A.
Powiązania:
https://bibliotekanauki.pl/articles/138596.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
baton
iły rudonośne
jura środkowa
monoklina śląsko-krakowska
osady
Polska
Bathonian ore-bearing clays
Dark deposits
Kraków-Silesia Homocline
Middle Jurassic
Polska
Opis:
This paper provides introductory data for multidisciplinary studies on palaeoenvironmental reconstructions of the Bathonian (Middle Jurassic) ore-bearing clays exposed at Gnaszyn, southern Poland. These dark-coloured fine-clastic deposits have been studied for micropalaeontology, sedimentology and geochemistry (published in separate papers within this volume). Brief outlines of the Middle Jurassic palaeogeography of the Polish epicontinental basin and the geology of the Kraków-Silesia Homocline are given. A description of the ore-bearing clays succession exposed in the clay-pit at Gnaszyn is provided, including locations of the sections studied, their ammonite biostratigraphy, brief lithology and macrofossil distribution. The sample positions collected for micropalaeontological and geochemical studies are specified.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 267-280
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Palynofacies from Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland, with special emphasis on sporomorph eco-groups
Autorzy:
Gedl, P.
Ziaja, J.
Powiązania:
https://bibliotekanauki.pl/articles/138745.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
baton
epikontynentalny zbiornik
iły rudonośne
jura środkowa
paleogegrafia
palinofacja
Polska
sporomorf
Bathonian
epicontinental basin
Middle Jurassic
ore-bearing clays
palaeogeography
palynofacies
Polska
sporomorphs
Opis:
The palynological organic matter of dark clays from Bathonian ore-bearing clays exposed at Gnaszyn (Częstochowa, Kraków-Silesia Homocline, Poland) consists of high proportions of land-derived particles; aquatic elements (mainly dinoflagellate cysts) are comparatively rare. Terrestrial particles include black opaque phytoclasts, dark brown phytoclasts, cuticle remains and subordinate sporomorphs. The latter are represented by eighty-four taxa of spores and pollen grains. They represent various groups of plants, including Bryophyta, Sphenophyta, Lycophyta, Pteridophyta, Pteridospermophyta, Cycadophyta or Ginkgophyta and Coniferophyta. The most frequent sporomorphs in almost all samples from Gnaszyn are Callialasporites (Araucariaceae), Cerebropollenites and Perinopollenites elatoides (Taxodiaceae) pollen grains, fern spores with triradiate tetrad mark, bisaccate pollen grains belonging to conifers (Pinaceae or Podocarpaceae) and also to Pteridospermophyta. Quantitative analysis of the palynofacies shows fluctuations of particular element ratios, which correlate with lithology. Clay intervals that contain siderite concretion levels yielded lower amounts of cuticles in relation to sporomorphs (mainly pollen grains) and dinoflagellate cysts. Intervals of monotonous clays and silts are characterized by a higher ratio of cuticles in relation to other elements, especially dinoflagellate cysts. Also, quantitative analysis of the sporomorphs shows changes in frequency of the representatives of various plant communities, which coexisted during the Jurassic: Upland, Lowland, River, Pioneer, Coastal and Tidally-influenced. These changes might have reflected sealevel fluctuations, which affected vegetation growing on adjacent land. However, the dominance of Callialasporites pollen grains, which belong to the Coastal community, indicates that the Gnaszyn assemblage was mainly influenced by the seashore vegetation. The high frequency of Araucariaceae pollen grains and the presence of ferns representing the Osmundaceae, Cyatheaceae, Dicksoniaceae, Schizeaceae, Gleicheniaceae and Matoniaceae indicate a warm climate without large seasonal amplitudes during the deposition of the Gnaszyn succession.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 325-349
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Organic-walled dinoflagellate cysts from the Bathonian ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland - a palaeoenvironmental approach
Autorzy:
Gedl, P.
Powiązania:
https://bibliotekanauki.pl/articles/138764.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
baton
dinocysty
iły rudonośne
jura środkowa
monoklina śląsko-krakowska
paleośrodowisko
Polska
Bathonian
dinoflagellate cysts
Kraków-Silesia Homocline
Middle Jurassic
ore-bearing clays
palaeoenvironment
Polska
Opis:
A succession of Middle-Upper Bathonian (Subcontractus.Retrocostatum zones) ore-bearing clays exposed at Gnaszyn has been investigated for the presence of dinoflagellate cysts. The assemblages are dominated by Ctenidodinium. However, analysis of diversity shows some subtle differences throughout the succession, possibly related to the palaeoenvironmental conditions in the photic zone. Impoverished assemblages, dominated by Ctenidodinium, occur mainly in monotonous muddy intervals. More diverse assemblages, albeit also dominated by Ctenidodinium, occur in intervals which contain siderite concretion levels. The taxonomic composition of the former assemblage seems to reflect slightly restricted conditions in the photic zone, possibly related to a minor reduction in salinity and/or increase in nutrient availability. More diverse dinoflagellate cyst assemblages reflect periods of less intense terrigenous influx and relatively higher, possibly normal, salinity. These changes were possibly caused by variable intensity of freshwater influx into the basin, controlled by sea-level fluctuations. Sea-level changes may be related to migrations of Tethyan water masses, which were probably partly responsible for the composition of the dinoflagellate cyst assemblages.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 439-461
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sedimentology and ichnology of Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland
Autorzy:
Leonowicz, P.
Powiązania:
https://bibliotekanauki.pl/articles/138978.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ciemnoszare mułowce
iły rudonośne
jura środkowa
monoklina śląsko-krakowska
Polska
zespół skamieniałości śladowych
Dark grey mudstones
Kraków-Silesia Homocline
Middle Jurassic
ore-bearing clays
Polska
Trace fossil tiering
Opis:
The lithology, sedimentary structures and trace fossil association from the Bathonian organic-rich mudstones from Kraków-Silesia Homocline (SW Poland) are described and a preliminary interpretation of the palaeoenvironment is presented. The ore-bearing clays exposed in the Gnaszyn clay-pit are developed as dark grey claysilt deposits with a few horizons of sideritic concretions. Sedimentological analysis has revealed that these deposits originated in the offshore part of a marine basin, below the fair weather wave base. Relict parallel lamination suggests that the predominant mechanism of deposition was quiet settling from suspension. However, locally preserved storm deposits indicate that the sea bottom was affected by offshore flows, deriving coarser material from the nearshore area. The degree of bioturbation is high but the diversity of the trace-fossil association is low. It consists mainly of Chondrites, Trichichnus, pyritized burrows and less common Palaeophycus. Other traces, including Thalassinoides, Planolites, Taenidium and some undetermined burrows, occur mainly in the lower part of the succession. This ichnoassociation combines features of distal Cruziana and Zoophycos ichnofacies, suggesting poor oxygenation of the bottom sediment. Temporary improvements in bottom oxygenation, linked with more intense mixing of water during major storms, resulted in the more diverse trace fossil suite that is found in some intervals of the succession.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 281-296
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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