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Tytuł:
Evidence that the fossil insect trackway Bifurculapes laqueatus Hitchcock, 1858 was made underwater
Autorzy:
Getty, Patrick R.
Powiązania:
https://bibliotekanauki.pl/articles/138699.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aquatic
ichnology
arthropods
mesozoic
Jurassic
wodny
ichnologia
stawonogi
mezozoik
jura
Opis:
Three trackways attributable to the ichnospecies Bifurculapes laqueatus Hitchcock, 1858 found in Lower Jurassic rocks of the Newark Supergroup in northeastern North America are preserved in association with current lineations. Each trackway takes turns so that parts of the trackway parallel the current lineations. This parallelism is interpreted as evidence that the trackmakers were entrained in flowing water and had to change course due to the current. If this interpretation is correct, then morphological differences between B. laqueatus and terrestrial insect trackways could be explained by the trackmaker moving subaqueously. Further, B. laqueatus would constitute only the second insect trackway from this region to be recognized as being made subaqueously. From an ecological standpoint, the aquatic insects that made B. laqueatus were probably near the base of the local food chain, the apex predators of which were piscivorous theropod dinosaurs.
Źródło:
Acta Geologica Polonica; 2020, 70, 1; 125-133
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A monograph of the Polish Oxfordian echinoids: Part 2, Subclass Euechinoidea Bronn, 1860
Autorzy:
Radwańska, U.
Powiązania:
https://bibliotekanauki.pl/articles/139022.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Euechinoidea
taxonomy
Hemicidaris
Trochotiara
Juvenile echinoids
Upper Jurassic
Polska
taksonomia
jura
Polska
Opis:
The non-cidaroid echinoids (subclass Euechinoidea Bronn, 1860) from the Oxfordian epicontinental sequence of Poland (Polish Jura, Holy Cross Mountains, Mid-Polish Anticlinorium) are assigned to the genera Hemipedina Wright, 1855, Hemicidaris L. Agassiz, 1838, Hemitiaris Pomel, 1883, Pseudocidaris Étallon, 1859, Stomechinus Desor, 1856, Eucosmus L. Agassiz in Agassiz and Desor, 1846, Glypticus L. Agassiz, 1840, Pleurodiadema de Loriol, 1870, Diplopodia McCoy, 1848, Trochotiara Lambert, 1901, Desorella Cotteau, 1855, and Heterocidaris Cotteau, 1860, plus one acropeltid taxon, and one taxon left in open nomenclature. Within the genus Hemicidaris L. Agassiz, 1838, the relationship between Hemicidaris intermedia (Fleming, 1828), Hemicidaris crenularis L. Agassiz, 1839 [non Lamarck, nec Goldfuss] and Hemicidaris quenstedti Mérian, 1855, all with confused taxonomy, is discussed. Based on test structure, the genera Polydiadema Lambert, 1883, and Trochotiara Lambert, 1901, of the family Emiratiidae Ali, 1990, are proved to be separate; the common species mamillana of F.A. Roemer (1836) is a typical Trochotiara. An attention is paid to the morphology of the tiny, juvenile specimens, common in Eucosmus decoratus L. Agassiz in L. Agassiz and Desor, 1846, and in Pleurodiadema stutzi (Moesch, 1867).
Źródło:
Acta Geologica Polonica; 2014, 64, 3; 352-349
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Palaeoenvironmental reconstruction of Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland
Autorzy:
Gedl, P.
Kaim, A.
Leonowicz, P.
Boczarowski, A.
Dudek, T.
Kędzierski, M.
Rees, J.
Smoleń, J.
Szczepanik, P.
Sztajner, P.
Witkowska, M.
Ziaja, J.
Powiązania:
https://bibliotekanauki.pl/articles/138742.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
beton
iły rudonośne
jura
paleośrodowisko
Polska
Bathonian
Jurassic
ore-bearing clays
palaeoenvironment
Polska
Opis:
Multidisciplinary studies of the Middle-Upper Bathonian ore-bearing clays at Gnaszyn revealed variable palaeoenvironmental conditions during the deposition of this seemingly monotonous sequence. We interpret the conditions in the bottom environment and the photic zone, and also evaluate the influence of the adjacent land areas, based on sedimentology, geochemistry, sporomorphs and palynofacies composition, benthic (foraminifera, gastropods, bivalves, scaphopods, echinoderms), planktonic (calcareous nannoplankton, dinoflagellate cysts), and nektonic (sharks) fossils. The Gnaszyn succession originated relatively close to the shore, within reach of an intense supply of terrestrial fine clastic and organic particles. The latter are mainly of terrestrial origin and range from 1.5 to 2.5 wt.%. The precise water depth is difficult to estimate but most likely ranges from several tens of metres to a few hundred metres. All fossil groups show minor changes throughout the succession. As the climate seems to have been quite stable during this period we consider sea-level fluctuations to have been the main factor responsible for the changes. The terrestrial input, including freshwater and land-derived clastic and organic particles (sporomorphs and cuticles), increased during periods of sea-level lowstand. As a consequence, stress conditions (lower salinity, higher nutrient availability, lower water transparency) in the photic zone caused blooms of opportunistic planktonic taxa. Furthermore, a faster sedimentation rate led to oxygen depletion and deterioration of the living conditions in the bottom environment due to an increased accumulation of organic matter. As a result, the benthic biota became taxonomically impoverished and commonly dominated by juvenile forms. During periods of high sea level, the source areas were shifted away from the basin, resulting in a decrease in the terrestrial influx, increase in the salinity of surface waters, the appearance of more diverse phytoplankton assemblages, a lower sedimentation rate, and an improvement of living conditions at the bottom.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 463-484
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Triassic-Jurassic flora of Poland; floristical support of climatic changes
Autorzy:
Barbacka, M.
Pacyna, G.
Feldman-Olszewska, A.
Ziaja, J.
Bodor, E.
Powiązania:
https://bibliotekanauki.pl/articles/138615.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Triassic
Jurassic
Polska
macroflora
Desmiophyllum harrisii sp. nov.
palaeoclimate
trias
jura
Polska
mikroflora
paleoklimat
Opis:
Plant macroremains from five boreholes in Poland were studied. Two of them (Huta OP-1 and Studzianna) from the northern margin of the Holy Cross Mountains, yielded several taxa. In the other three boreholes determinable fossil plants were sporadic, albeit important. Most of the taxa from the Huta OP-1 and Studzianna boreholes are typical of the European Early Jurassic (Hettangian and Sinemurian). Both localities, although close to one another, show quite different taxonomic floral compositions. The Huta OP-1 flora is fern-dominated with the presence of ginkgophytes and conifers (a new species incertae sedis, Desmiophyllum harrisii Barbacka et Pacyna is herein proposed), which would suggest rather wet and warm conditions. This flora is typical of the European Province of the Euro-Sinian Region. In Studzianna the Siberian elements dominate, gymnosperms, mainly Czekanowskiales, which indicate a drier and colder environment.The palaeobotanical data correspond to the results of clay mineral studies, in particular the kaolinite/illite ratio in the source formations. The kaolinite content confirms a decrease in temperature and a reduction in rainfall in the late Early Hettangian and the latest Hettangian in the area.
Źródło:
Acta Geologica Polonica; 2014, 64, 3; 281-309
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asteroidea from the lower Kimmeridgian of Wapienno/Bielawy, Kuyavia region, north-central Poland
Autorzy:
Loba, Michał
Radwańska, Urszula
Powiązania:
https://bibliotekanauki.pl/articles/2023989.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Asteroidea
taxonomy
Upper Jurassic
Lower Kimmeridgian
Polska
rozgwiazda
taksonomia
jura górna
dolny kimeryd
Polska
Opis:
A relatively rich assemblage of starfish is recognised from the talus facies of an Upper Jurassic (lower Kimmeridgian) biohermal, sponge-cyanobacterial build-up from the Wapienno/Bielawy succession exposed in a salt-dome anticline in Kuyavia region, north-central Poland. The paper presents 8 taxa belonging to 4 genera (one new to science): Boxaster gen. nov., Noviaster Valette, 1929, Tylasteria Valette, 1929, Valettaster Lambert, 1914, and 4 families: Astropectinidae Gray, 1840, Goniasteridae Forbes, 1841, Sphaerasteridae Schöndorf, 1906 and Stauranderasteridae Spencer, 1913. Only a very few representatives of some of these taxa have formerly been reported from the Jurassic of Poland. Two species are new: Valettaster planus sp. nov. and Boxaster wapienensis gen. et sp. nov. The Jurassic starfish assemblage recognised from the Wapienno/Bielawy succession is interpreted as an offshore starfish fauna with the admixture of allochtonous shallow-water taxa. The lithology of the source deposits indicates their transport by storm agitation and/or mass movements. This fact strongly influenced the preservation state, all collected plates being disarticulated and most of them abraded.
Źródło:
Acta Geologica Polonica; 2022, 72, 1; 89--106
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pinnidae (Bivalvia) from the Reuchenette Formation (Kimmeridgian, Upper Jurassic) of northwestern Switzerland
Autorzy:
Koppka, J.
Powiązania:
https://bibliotekanauki.pl/articles/138674.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
taxonomy
Bivalvia
Pinnidae
Pinna (Cyrtopinna)
Stegoconcha
Kimmeridgian
Jurassic
Switzerland
taksonomia
małże
kimeryd
jura
Szwajcaria
Opis:
The shallow-marine carbonate deposits of the Reuchenette Formation (Kimmeridgian, Upper Jurassic) in northwestern Switzerland and adjacent France yield highly diverse bivalve associations, but only rarely contain remains of pinnid bivalves. The three occurring taxa Pinna (Cyrtopinna) socialis d’Orbigny, 1850, Stegoconcha granulata (J. Sowerby, 1822) and Stegoconcha obliquata (Deshayes, 1839) have been revised. A lectotype for Pinna (C.) socialis was designated and the taxon is assigned herein to P. (Cyrtopinna) Mörch, 1853, the first record of the subgenus from the Jurassic. A brief review of Stegoconcha Böhm, 1907 revealed two species groups within the genus. Species close to the type species S. granulata are characterized by a nearly smooth anterior shell, followed posteriorly by deep radial furrows and rows of pustules covering the dorsal flank. Another group comprises radially ribbed species related to S. neptuni (Goldfuss, 1837). It includes among others the Paleogene species S. faxensis (Ravn, 1902), extending the known range of Stegoconcha from the Middle Jurassic into the Paleogene. The paper suggests a relationship between Stegoconcha and the Cretaceous Plesiopinna Amano, 1956, with S. obliquata as a possible intermediate species leading to Plesiopinna during the Early Cretaceous. Furthermore, a possible relationship between Stegoconcha and Atrina Gray, 1842 is discussed.
Źródło:
Acta Geologica Polonica; 2018, 68, 1; 21-51
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High (ultrahigh) pressure metamorphic terrane rocks as the source of the detrital garnets from the Middle Jurassic sands and sandstones of the Cracow Region (Cracow-Wieluń Upland, Poland)
Autorzy:
Meres, S.
Aubrecht, R.
Gradziński, M.
Sykora, M.
Powiązania:
https://bibliotekanauki.pl/articles/139271.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analiza proweniencji
jura
Polska Platforma
detrital garnets
detrytyczne granaty
Jurassic
Polish platform
provenance analysis
Opis:
The Middle Jurassic (Upper Bathonian/Lower Callovian) sands and sandstones of the Cracow.Wieluń Upland contain detrital garnets with high contents of the pyrope molecule (30.73 mol %). The predominance of detrital pyrope garnets, and inclusions represented mainly by omphacite and kyanite, show that the garnets were derived from high (ultrahigh) pressure (H/UHP) metamorphic terrane rocks (garnet peridotites, eclogites and granulites). Their source is unknown. The Moldanubian Zone of the Bohemian Massif is closely comparable. However, the terranes between this zone and the Cracow-Wieluń Upland are dominated by almandine garnets. The relatively low proportion of almandine garnets in the examined samples indicates that transport of the detrital material could not have been from a far distant source as the garnet assemblage would otherwise be strongly dominated by almandine. A less distant possible source could have been the Góry Sowie Mts., which incorporate UHP/HP metamorphic rocks, but the exposed areal extent of these rocks is too small. It is possible that larger portions of these metamorphic rocks are buried beneath the Cenozoic cover and might have earlier represented a larger source area. Reworking of the entire heavy mineral spectra from older clastics is improbable because of the low maturity of the heavy mineral assemblages (higher proportion of less stable minerals). The source area therefore remains unknown. Most probably it was formed by primary crystalline complexes of lower crust to mantle origin, outcrops of which were not far distant from the area of deposition. Similar detrital garnet compositions were also recorded in the Outer Western Carpathians (Flysch Zone, Pieniny Klippen Belt), i.e. the crustal segments which formed the Silesian and Magura cordilleras; the Czorsztyn Swell was also formed by similar rocks.
Źródło:
Acta Geologica Polonica; 2012, 62, 2; 231-245
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calcareous nannofossils from the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn as palaeoenvironmental indicator, Kraków-Silesia Homocline, Poland
Autorzy:
Kędzierski, M.
Powiązania:
https://bibliotekanauki.pl/articles/139434.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
baton
jura
monoklina śląsko-krakowska
paleośrodowisko
Bathonian
calcareous nannofossils
Jurassic
Kraków-Silesia Homocline
palaeoenvironment
Polska
Opis:
Qualitative and quantitative studies on calcareous nannofossils have been carried out on the Middle-Upper Bathonian succession of Gnaszyn (Kraków-Silesia Homocline, Częstochowa region). The nannofossil assemblages are moderately or well-preserved and are dominated by Watznaueria britannica; also common are Staurolithites lumina and Zeugrhabdotus erectus. The presence of delicate nannofossil forms together with dissolution-resistant taxa shows that the changes in composition of some of the nannoplankton assemblages reflect original variations. The frequency and diversity changes of the calcareous nannofossil assemblages have been interpreted in relation to fluctuations of sedimentation rate versus changes in trophic conditions within the photic zone. The highest diversity assemblages contain a high percentage of palaeofertility indicators, and are impoverished in the genus Watznaueria. This is interpreted as a reflection of a lower sedimentation rate and more stable, possibly mesotrophic conditions within the photic zone. On the other hand, W. britannica-dominated assemblages with low species diversity may represent more unstable environments with a high influx of terrestrial material related to a high sedimentation rate and a high nutrient influx, i.e. eutrophic conditions in the photic zone.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 421-437
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Faunal dynamics of gastropods in the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland
Autorzy:
Kaim, A.
Powiązania:
https://bibliotekanauki.pl/articles/138635.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
baton
Gnaszyn
iły rudonośne
jura
paleoekologia
Polska
ślimaki
Bathonian
gastropods
Jurassic
ore-bearing clays
palaeoecology
Polska
Opis:
The succession of gastropods in the Gnaszyn section is quite monotonous and shows significant changes only in the proximity of concretion layers, at least partially because of diagenetic reasons. Otherwise, the section is dominated by gastropods (cylidrobullinids, bullinids, and mathildids) most of which preyed probably on sedentary organisms (polychaetes and/or coelenterates) that possibly flourished on the sea bottom at that time. The other groups of gastropods are represented by larval or juvenile shells. Their presence shows that the environmental conditions that were probably unfavourable for gastropods living directly on the sea bottom most likely because of a soupy substrate consistency, possible oxygen deficiency near the sediment-water interface and/or oxygen content fluctuations. Adult and/or subadult individuals of these gastropods occur only in the higher part of the section, reflecting a time when these conditions improved. A new heterostrophic gastropod species, Promathildia gedli, is described.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 367-380
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Palaeoecological implications of neoselachian shark teeth from the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland
Autorzy:
Rees, J.
Powiązania:
https://bibliotekanauki.pl/articles/138736.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
baton
Gnaszyn
jura
monoklina śląsko-krakowska
paleoekologia
Polska
Bathonian
Jurassic
Kraków-Silesia Homocline
Neoselachii
palaeoecology
Polska
Opis:
Systematic sampling through the Middle and Upper Bathonian strata at Gnaszyn has resulted in the discovery of 13 neoselachian teeth. Systematically, the teeth represent five taxa including Sphenodus sp., Protospinax sp. 1, Protospinax sp. 2, Palaeobrachaelurus sp. and another, indeterminate orectolobiform. The presence of two species of the flattened and bottom-dwelling Protospinax and two different orectolobiforms that are likely to have lived near the bottom, is a strong indication of oxygenated bottom conditions at the time of deposition. The dietary preferences of these taxa included a wide variety of benthic invertebrates. The synechodontiform Sphenodus may have been the first pelagic predatory neoselachian in the Jurassic, equipped with high and slender piercing teeth that formed a tearing-type dentition. The diet of Sphenodus probably included bony fish, smaller sharks and cephalopods.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 397-402
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Faunal dynamics of foraminiferal assemblages in the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland
Autorzy:
Smoleń, J.
Powiązania:
https://bibliotekanauki.pl/articles/138629.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
jura
monoklina śląsko-krakowska
morfogrupa
otwornice
paleoekologia
utlenianie
foraminifera
Jurassic
Kraków-Silesia Homocline
Morphogroups
oxygenation
palaeoecology
Opis:
The faunal dynamics of benthic foraminifera in the Middle Jurassic ore-bearing clays of Gnaszyn (Kraków-Częstochowa Upland, south-central Poland) are used to reconstruct sedimentary environments. Two types of foraminiferal assemblages, distinct in their quantitative and qualitative composition, were distinguished; type I assemblages, characterizing intervals between horizons with sideritic concretions; and type II assemblages, characterising horizons with sideritic concretions. Benthic foraminifers were further subdivided into eight ecological morphogroups, based on their morphological features and micro-habitats. Type I assemblages consist mostly of plano/concavo-convex, small-sized epifaunal morphotypes, with a restricted occurrence of shallow infaunal forms and a scarcity of deep infaunal taxa, which suggests low-oxygen conditions in both sediment and bottom waters, and a high sedimentation rate in an outer shelf environment. Type II assemblages are characterized by high taxonomic diversity, high specimen abundance and variability of epifaunal and infaunal morphotypes representing a mixed group of specialized feeding strategies. This suggests optimum living conditions controlled by a lower sedimentation rate, relatively well-oxygenated bottom waters and sufficient or high food supply.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 403-419
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Neptunian dykes penetrating the Lower Jurassic Dudziniec Formation in the autochthonous High-Tatric succession, Tatra Mountains, Western Carpathians, Poland
Autorzy:
Łuczyński, P.
Jezierska, A.
Powiązania:
https://bibliotekanauki.pl/articles/139207.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
neptunian dykes
Dudziniec Formation
Lower Jurassic
High-Tatric Succession
Tatra Mountains
dajki neptuniczne
formacja Dudzińca
jura dolna
Tatry
Opis:
The Lower Jurassic to Aalenian carbonate-clastic Dudziniec Formation exposed in the autochthonous unit of the Tatra Mountains (Kościeliska Valley) hosts neptunian dykes filled with various deposits. The development of the fissures took place in multiple stages, with the same fractures opening several times, as is indicated by their architecture, occurrence of internal breccias and arrangement of the infilling sediments. Various types of internal deposits were derived in a different manner and from different sources. Fine carbonate sediments, represented by variously coloured pelitic limestones, calcilutites and fine calcarenites, most probably come from uplifted and corroded carbonate massifs (possibly from the allochthonous units of the High-Tatric succession). Products of weathering, both in dissolved form and as small particles, were washed into the sedimentary basin of the autochthonous unit, and redeposited within the dykes. The sandy varieties of the infillings, represented by red, ferruginous calcareous sandstones, come directly from the host rocks or from loose sediments present on the sea bottom at the time of fracturing. The most probable age of the infilling sediments is Sinemurian to Pliensbachian. The occurrence of dykes of this age is yet another feature confirming that the sedimentary development of the Lower Jurassic sandy-carbonate facies in the autochthonous unit was strongly influenced by synsedimentary tectonic activity, such as block-faulting.
Źródło:
Acta Geologica Polonica; 2018, 68, 4; 555-570
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Faunal dynamics of bivalves and scaphopods in the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland
Autorzy:
Kaim, A.
Sztajner, P.
Powiązania:
https://bibliotekanauki.pl/articles/138633.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
baton
Gnaszyn
iły rudonośne
jura
łódkonogi
małże
paleoekologia
Polska
ślimaki
Bathonian
bivalves
gastropods
Jurassic
ore-bearing clays
palaeoecology
Polska
Scaphopods
Opis:
The environment at the Gnaszyn section - as deduced from bivalve and scaphopod dynamics - was controlled by the substrate consistency and possibly oxygen deficiency near the sediment-water interface and/or oxygen content fluctuations. The middle part of the section dominated by nuculoid and corbulid bivalves and Laevidentalium-type scaphopods probably reflects a soupy substrate and possibly oxygen deficiency in the sediment. Slightly coarser and better-oxygenated silts in the upper and lower parts of the section offered a less soupy substrate consistency, allowing the development of communities dominated by astartids, byssate bivalves, and Dentalium- and Plagioglypta-type scaphopods.
Źródło:
Acta Geologica Polonica; 2012, 62, 3; 381-395
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A unique fossil record from neptunian sills: the worlds most extreme example of stratigraphic condensation (Jurassic, western Sicily)
Autorzy:
Wendt, J.
Powiązania:
https://bibliotekanauki.pl/articles/139227.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Sicily
Jurassic
biostratigraphy
synsedimentary tectonics
Neptunian sills
condensation
ammonite fauna
sea level
Sycylia
jura
biostratygrafia
tektonika synsedymentacyjna
kondensacja
amonity
poziom morza
Opis:
Neptunian sills at Rocca Busambra, a fragment of the Trapanese/Saccense Domain in western Sicily, host the most abundant ammonite and gastropod fauna which has ever been recorded from the Jurassic of the western Tethys. The fauna is dominated by parautochthonous organisms which were swept into the sills by gentle transport. Ammonites are characterized by perfect preservation and small size, a feature which is due to the predominance of microconchs but also of stunting. The most complete sill is 0.7 m thick and could be separated into 17 levels which range in age from the early Toarcian into the late Kimmeridgian, thus representing the most extreme case of palaeontologically and depositionally documented stratigraphic condensation in Earth history. The unique feature of the Rocca Busambra sills is due to the interaction of three processes: extreme stratigraphic condensation on the sea floor, weak tectonic fracturing of the host rock and repeated reopening on top of already existing sills. Contrasting percentages of gastropods in individual levels reflect sea-level oscillations which correspond to long known low- and highstands during the Jurassic of the western Tethys. Comparisons with other ammonite-bearing sill faunas reveal several similarities, but represent only short-timed phases of tectonic pulses and deposition.
Źródło:
Acta Geologica Polonica; 2017, 67, 2; 163-199, [6]
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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