Informacja

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

Wyszukujesz frazę "conodont biostratigraphy" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
New upper Givetian to basal Frasnian conodont faunas from the Tafilalt (Anti-Atlas, Southern Morocco)
Autorzy:
Aboussalam, Z.S.
Becker, R.T.
Powiązania:
https://bibliotekanauki.pl/articles/2059516.pdf
Data publikacji:
2007
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Morocco
Frasnes Event
Givetian
Frasnian
conodont taxonomy
conodont biostratigraphy
Opis:
Conodont faunas, mostly from previously unsampled sections of the Tafilalt (eastern Anti-Atlas, Morocco) and spanning the upper Givetian to basal Frasnian, include first records of species for the region and NW Gondwana as well as new taxa: "Ozarkodina" maroccanica n. sp., Polygnathus aequidivisus n. sp., Po. dengleri sagitta n. ssp., Po. jorfensis n. sp., Po. saevus n. sp., Po. tafilensis n. sp., and Schmidtognathus longicavus n. sp. The morphology of Tortodus subsymmetricus n. sp. suggests relation ships of Tortodus with Frasnian ancyrognathids. Other taxa are described in open nomenclature: Po. cristatus n. ssp., Icriodus aff. I. symmetricus, Skeletognathus aff. Sk. norrisi, and enigmatic supposed Pb elements (Gen. et sp. indet.). Ctenopolygnathus lanei Kuzmin (1995) is emended and distinctive morphotypes are recognized in Ct. angustidiscus and Po. collieri. Mesotaxis falsiovalis Sandberg et al. (1989) is a subjective junior synonym of the widely over looked M. guanwushanensis (Tian, 1988). There vised regional lithostratigraphy and conodont sequences allow to refine the upper Givetian zonation. The former Upper disparilis Zone is subdivided into succes sive Po. dengleri sagitta and Po. dengleri dengleri subzones. The basalmost Frasnian Ancyrodella rotundiloba pristina Zone (= MN 1 Zone) is preserved as a thin, condensed lime stone just at one locality (Bine Jebilet). The over lying Frasnes Event Beds (Lower Styliolinites) seem to fall in the subsequent Ad. rotundiloba soluta Zone (MN 2 Zone). Records of rare taxa, such as Po. paradecorosus, Po. Pollocki Morphotype 1, old est Po. webbi, Ct. angustidiscus, and Ct. lanei may be help ful for correlation into distant areas or shallower facies.
Źródło:
Geological Quarterly; 2007, 51, 4; 345-374
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conodont biostratigraphy and biofacies across the Devonian-Carboniferous boundary in the Kule section (Uzbekistan)
Autorzy:
Narkiewicz, Katarzyna
Corradini, Carlo
Abdiev, Nuriddin
Narkiewicz, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2058722.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
DCB
carbonate facies
conodont biostratigraphy
biofacies analysis
deep marine environment
Opis:
New conodont data provide further constraints on the occurrence of the Devonian-Carboniferous boundary in the Kule section through the carbonate Novchomok Formation (Kitab Reserve, Uzbekistan). The stratigraphically condensed section includes the interval from the uppermost Famennian Pseudopolygnathus granulosus–lowermost Protognathodus kockeli zones to the middle Tournaisian Siphonodella crenulata Zone. In addition to revision of earlier published taxonomic and biostratigraphic data, two previously unreported taxa are described: Polygnathus sp. n. A and a peculiar form probably representing a new genus (gen. et sp. indet.). The biofacies analysis documents a succession of polygnathid, siphonodellid-polygnathid, polygnathid-siphonodellid to polygnathid-bispathodid, and again polygnathid-siphonodellid biofacies. The generic composition of the samples and relative abundance of Polygnathus purus reflect deep marine environments of the continental slope and rise.
Źródło:
Geological Quarterly; 2021, 65, 1; 17
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conodont faunas with Lenodus variabilis in the upper Arenigian to lower Llanvirnian of Sweden
Autorzy:
Lofgren, A
Powiązania:
https://bibliotekanauki.pl/articles/20607.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
ecology
fauna
Lenodus variabilis
Sweden
Kundan Stage
conodont
biostratigraphy
paleontology
Opis:
Lenodus variabilis occurs in an interval in the lower to middle Kundan Stage which includes the Arenig–Llanvirn boundary. The lower part of its range constitutes the L. variabilis Zone,the upper part,where it co−occurs with Yangtze−placognathus crassus,making up the Y. crassus Zone. The conodont faunas of these two consecutive conodont biozones have been investigated in 14 sections from south,south−central and central Sweden,the faunal differences between the areas being mainly expressed in shifts in relative abundance. The taxon which is generally the most abundant, Baltoniodus, has comparable abundance maxima at localities representing shallow parts of the basin as well as in deeper parts,indicating that some environmental factor other than water depth has influenced its distribution. Drepanodus and Protopanderodus rectus prefer areas representing deeper parts of the epicontinental sea. Scalpellodus is most abundant at the sites representing intermediate depths. Semiacontiodus cornuformis was adapted to shallow water and is lacking at levels representing maximum depths, but at some places (for instance in Skåne) it is replaced by Semiacontiodus davidi.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lanea carlsi conodont apparatus reconstruction and its significance for subdivision of the Lochkovian
Autorzy:
Slavik, L.
Powiązania:
https://bibliotekanauki.pl/articles/20418.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Lanea carlsi
conodont
apparatus reconstruction
significance
Lochkovian
Conodonta
taxonomy
phylogenesis
biostratigraphy
Barrandian
Opis:
A cosmopolitan spathognathodontid taxon “Ancyrodelloides carlsi” is not regarded in this paper as one of the earliest known representatives of Ancyrodelloides according to former concepts, but is considered as conspicuous member of the genus Lanea. The taxon shows distinct morphological innovation of the upper surface of the Pa element within the Lanea lineage which makes it easily recognizable worldwide and suitable for global correlation. Presented stratigraphic correlation using conodonts and other faunal groups qualifies a short−lived Lanea carlsi as probably the best marker of the middle Lochkovian base. This paper presents reconstruction of the apparatus of L. carlsi which is the first complete reconstruction in the genus Lanea. The comparison of the Lanea apparatus and assumed apparatus of early Ancyrodelloides from the Požáry Quarries (Barrandian, Czech Republic) resulted to proposal of an alternative concept of evolution of these two genera. The relatively short−lived genus Ancyrodelloides is considered to split off from the Lanea clade in the late middle Lochkovian by the entry of Ancncyrodelloides transitans.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Frasnian-Famennian events in a deep-shelf succession, Subpolar Urals: biotic, depositional, and geochemical records
Autorzy:
Yudina, A B
Racki, G.
Savage, N.M.
Racka, M.
Malkowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/21692.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Famennian
biotic record
Frasnian
geochemical record
depositional record
geochemistry
Kellwasser crisis
conodont
biostratigraphy
paleontology
lithostratigraphy
carbon isotope
Opis:
The Frasnian–Famennian (F–F) boundary is well biostratigraphically documented in the Palmatolepis−rich deposits exposed along the Syv’yu River in the lower slopes of the Subpolar Urals. The thin−bedded calcareous−clayey−siliceous deep−slope succession of the Vorota Formation appears to represent continuous Domanic−type deposition throughout the world−wide carbonate crisis time, without evidence for the basal Famennian hiatus or a large−scale sedimentary perturbation within a regressive setting. The northernmost Laurussian sequence exhibits many well known signatures throughout the broad F–F timespan: the appearance of organicand clay−rich deposits, icriodontid and radiolarian blooms, and a correlative shift of several geochemical proxies towards hypoxic and high−productivity regimes, perfectly recorded by positive 13Ccarb excursions of +3.5‰. Integrative biotic, microfacies and geochemical data substantiate a longer−term oceanographic destabilization, attributable to multiple Earth−bound triggering factors in (episodically enhanced?) greenhouse climate and punctuated eustatic sea−level highstands, superimposed on the elevated deposition of organic carbon−rich sediments during the Upper Kellwasser Event. Unsteady eutrophicated, and oxygen−depleted ecosystems during the F–F biotic crisis interval could be assumed, especially when intensified by various spasmodic tectono−volcanic phenomena in the incipiently closing Ural Ocean.
Źródło:
Acta Palaeontologica Polonica; 2002, 47, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conodont-based event stratigraphy of the Early-Middle Frasnian transition on the South Polish carbonate shelf
Autorzy:
Pisarzowska, A
Sobstel, M.
Racki, G.
Powiązania:
https://bibliotekanauki.pl/articles/22673.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
conodont association
stratigraphy
Early-Middle Frasnian
Frasnian
Polska
carbonate shelf
biostratigraphy
carbon isotope
paleoecology
Devonian
Palmatolepis transitans
Palmatolepis punctata
Opis:
Early to Middle Frasnian (E–MF) epicontinental sequences are investigated in five representative localities of the Holy Cross Mountains and Cracow region, with emphasis on conodont biostratigraphy, to evaluate the regional stratigraphic and biotic context of a major biogeochemical perturbation in global carbon cycling. Conodont associations from the Palmatolepis transitans to Palmatolepis punctata Zone boundary beds are dominated by the shallow−water polygnathid and ancyrodellid fauna in the South Polish epicontinental successions, and first appearances of index palmatolepid species are delayed due to facies control of pelagic environments during intermittent drowning of the carbonate shelf. Thus, identification of the zonal boundary is based mainly on species of Ancyrodella, and five distinctive ancyrodellid levels in the succession across the E–MF interval enable refined correlation of the sections studied, especially when paired with chemostratigraphic proxies. Prominent conodont biofacies shifts coincided with eustatic deepening, which is correlated with the Timan, Middlesex, and early Rhinestreet events, respectively. Trends in the conodont dynamics, mortality and diversity, partly replicated by the benthic biota (especially shelly faunas and crinoids), indicate that the faunal turnovers correlate also with the main δ¹³C excursions and related changes in trophic conditions. The E–MF transitional interval, marked by short−term sea−level fluctuations, is distinguished by a change from relatively diversified biofacies to more homogenous, mostly impoverished faunas. The latter change is a biotic response to the beginning of a prolonged (ca. 0.5 Ma) positive δ¹³C anomaly, probably paired with unsteady eutrophic and partly anoxic regimes. The late Pa. punctata Zone negative carbon isotope anomaly is synchronous with the second large−scale pelagic biofacies remodelling, including mesotaxid extinction. A stabilization of the carbon cycle and its return to normal background values at the start of the Early Palmatolepis hassi Zone coincide with conodont biofacies diversification and recovery of reef−related biofacies. With the exception of collapsed, endemic Kadzielnia−type mud−mound biota and a moderate biodiversity depletion due to overall ecosystem stagnation, no significant extinction events can be demonstrated, even if the large−scale changes in carbon cycling during the E–MF timespan are of higher−amplitude than the celebrated carbon isotopic anomalies related to the Frasnian–Famennian mass extinction. Thus, this regional succession in detail confirms that the large−scale punctata Isotopic Event (= Pa. punctata Event) is correlated neither with catastrophic enviromental nor radical biotic changes.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 4; 609-646
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

    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