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Wyświetlanie 1-15 z 26
Tytuł:
Brachiopods and stratigraphy of the Upper Devonian (Frasnian) succession of the Radlin Syncline (Holy Cross Mountains, Poland)
Autorzy:
Baliński, A.
Racki, G.
Halamski, A. T.
Powiązania:
https://bibliotekanauki.pl/articles/139163.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Devonian
Frasnian
stratigraphy
carbon isotope stratigraphy
punctata Event
brachiopods
Holy Cross Mountains
dewon
fran
stratygrafia
stratygrafia izotopowa węgla
zdarzenie punctata
ramienionogi
Góry Świętokrzyskie
Opis:
The lower part of the Frasnian succession in the Radlin Syncline (Kielce–Łagów Synclinorium, southern region of the Holy Cross Mountains), in the two studied successions: Józefka at Górno and (for the first time) Radlin, consists of the rhythmic marly Szydłówek Beds, the fossil-rich limestones of the Wietrznia Beds (locally) and the atypically developed, calcareous Kostomłoty Beds. The carbon isotope chemostratigraphic pattern overall corresponds well to the global Early–Middle Frasnian biogeochemical perturbation, even if the major punctata positive excursion is only fragmentarily recorded in the Kostomłoty intrashelf basin. Two brachiopod assemblages are abundantly represented in both sections: the Phlogoiderhynchus polonicus Assemblage, typical of the Szydłówek Beds, and the Biernatella lentiformis Assemblage, limited to the middle part of the Wietrznia Beds. Both are highly dominated by the index species. Twenty nine lower Frasnian brachiopod species (Craniida – 1 species, Strophomenida – 1, Productida – 2, Protorthida – 1, Orthida – 5, Pentamerida – 1, Rhynchonellida – 4, Atrypida – 4, Athyridida – 3, Spiriferida – 4, Spiriferinida – 3) are described from the Szydłówek and Wietrznia Beds. Seven new species are introduced: Skenidioides cretus Halamski sp. nov., Biernatium minus Baliński sp. nov., Monelasmina montisjosephi Baliński sp. nov., Atryparia (Costatrypa) agricolae Halamski and Baliński sp. nov., Davidsonia enmerkaris Halamski sp. nov., Leptathyris gornensis Baliński sp. nov., and Echinocoelia parva Baliński sp. nov. Davidsonia enmerkaris Halamski sp. nov. is intermediate between Davidsonia Bouchard-Chantereaux, 1849 and Rugodavidsonia Copper, 1996 and is the youngest known representative of the suborder Davidsonioidea Copper, 1996. Skenidioides cretus Halamski sp. nov. is the last representative of the genus. Statistical investigation of a large sample of Spinatrypina (Exatrypa) explanata did not confirm the existence of two dimorphic forms, coarse- and fine-ribbed. The high-diversity Biernatella lentiformis Assemblage is quite dissimilar to coeval brachiopod assemblages described heretofore from the Holy Cross Mountains region. It is interpreted as consisting of mostly parautochthonous dwellers of deep-slope muddy habitats and a local, occasionally storm-agitated, intra-basin brachiopod-crinoid-coral shoal. The fauna was adapted probably to cooler and nutrient-poor waters during an initial phase of the severe carbon cycle perturbation.
Źródło:
Acta Geologica Polonica; 2016, 66, 2; 125-174
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Brachiopods and their response to the Early-Middle Frasnian biogeochemical perturbations on the South Polish carbonate shelf
Autorzy:
Balinski, A
Powiązania:
https://bibliotekanauki.pl/articles/20277.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
brachiopod
brachiopod response
paleontology
Early-Middle Frasnian
Frasnian
biogeochemical perturbation
Southern Poland
Polska
carbonate shelf
Brachiopoda
Flabellulirostrum
Thomasaria
carbon isotope
diversity dynamics
Opis:
The brachiopod faunas from deposits recording the Early–Middle Frasnian transition of Poland are poorly known. The present report describes these faunas that were recovered from Wietrznia and Kostomłoty (Holy Cross Mountains) and Dębnik (Silesian−Cracow Upland) regions positioned on the southern Polish carbonate shelf. The brachiopod distribution was analysed relative to a significant δ¹³C excursion, referred recently to as Palmatolepis punctata Event. The sporadic occurrence of brachiopods at Dębnik makes it difficult to analyse the biotic response to this geochemical anomaly. However, higher brachiopod frequency in the topmost part of the section coincides with a gradual decrease of δ¹³C down to the Frasnian background values. At two studied sections at Wietrznia the greatest taxonomic diversity and abundance of brachiopods (Flabellulirostrum–Coeloterorhynchus assemblage) are confined to the Palmatolepis transitans Zone. In the following Pa. punctata Zone brachiopods are rare (Biernatella lentiformis assemblage) or absent, which suggests a serious deterioration of the environmental conditions linked probably with periods of benthic anoxia−dysoxia and oligotrophic conditions in the basin. In two Kostomłoty sections brachiopods faunas of this age are members of the mostly monospecific rhynchonellid−dominated Phlogoiderhynchus polonicus assemblage which inhabited deeper−water environments characteristic of intrashelf oxygen−depleted basins of ŁysogóryKostomłoty region. In some horizons large shells of P. polonicus were frequently colonised by discinoid Romerella? sp. Among 28 species described in this report new forms include: Flabellulirostrum kielcensis sp. nov., F. rackii sp. nov., and Thomasaria ventosa sp. nov.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 4; 647-678
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New observations on rhynchonelloid brachiopod Dzieduszyckia from the Famennian of Morocco
Autorzy:
Balinski, A
Biernat, G.
Powiązania:
https://bibliotekanauki.pl/articles/21704.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Dziaduszyckia
Famennian
fossil
brachiopod
Halorellidae
rhynchonellid brachiopod
Morocco
distribution
Brachiopoda
paleontology
carbon isotope
Opis:
The genus Dzieduszyckia is especially well represented and diverse in the Famennian strata of the Middle Atlas, Morocco. In this paper we re−study and re−illustrate the rich collection of Dzieduszyckia from Morocco, described by Henri and Genevive Termier, and originally referred to Halorella or Eoperegrinella. New data on the internal shell structure of D. crassicostata, D. intermedia, and D. tenuicostata indicate great intraspecific variability in morphology. The structure of crura of three studied species demonstrates that subfamily Dzieduszyckiinae is better placed within the family Halorellidae, instead of Peregrinellidae. Type specimens (lectotypes) of the three species were also selected. An analysis of the stable isotopes of carbon and oxygen of the shell material of Dzieduszyckia and carbonate sediment was used to investigate the presumed chemosynthetic nature of its paleoenvironments. The analyses of the Moroccan and Polish material do not show any signature of unusual environmental conditions: they fall in the range of the mean values of δ¹³C for the Late Devonian.
Źródło:
Acta Palaeontologica Polonica; 2003, 48, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carbon isotope distribution along pine needles [Pinus nigra Arnold]
Autorzy:
Barszczowska, L
Jedrysek, M.O.
Powiązania:
https://bibliotekanauki.pl/articles/57836.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
Croatia
pine
inhomogeneity
needle
growth
distribution
kinetic isotope effect
black pine
Spain
Pinus nigra
carbon isotope
Opis:
In this paper we show spatial carbon isotope variations in black pine (Pinus nigra Arnold) needles, collected in spring 2001 and autumn 2003, from trees at the coast of south-western Croatia island (Žirje) and southern Spain (Benalmadena near Malaga), respectively. Needles were segmented perpendicularly to the longer axis (base, middle and top) and each segment was analysed separately. d13C values in needles from Croatia varied between -26.65‰ to -24.43‰ (2 months old needles) and from -28.25‰ to -25.21‰ (1 year old needles), while d13C values in needles from Spain varied from -27.58‰ to -25.27‰. The difference between d13Cb (base) and d13Ct (top) in the same needle (D13Cb-t) varied from 1.85 to 2.05‰ (in young needles from Croatia), from 0,02 to 1,80‰ (young needles from Spain), and 1.16 to 2.32‰, (in old needles from Croatia). The average D13Cb-t values were 0.78‰ and 1.73‰ in Spain and Croatia, respectively. In each needle the base of the needle was always 13C-enriched as compared to the top of the same needle. This evidences that carbon isotopes are not retranslocated after its fixation into the leaf structure (after the growth process is over). Temperature variation was most probably negligible for the discovered intraneedle carbon isotope distribution. Although, the intraneedle carbon isotope inhomogeneity can be partly the result of seasonal variation in d13C of atmospheric CO2, most probably the remarkably high D13Cb-t values, and regular pattern, are predominantly resulting from isotopic and chemical composition of primary and secondary products contained in the growin part of needle and kinetic isotope fractionation during decomposition of storage materials at the base.
Źródło:
Acta Societatis Botanicorum Poloniae; 2005, 74, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tritium kinetic isotope effects on enzymatic decomposition of L-tryptophan
Autorzy:
Boroda, E.
Kański, R.
Kańska, M.
Powiązania:
https://bibliotekanauki.pl/articles/148533.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
carbon-14
isotope effect
tritium
tryptophan
tryptophanase
Opis:
The tritium kinetic isotope effect on position 2 has been determined in the reaction of decomposition of L-tryptophan, L-Trp, catalyzed by enzyme TPase, (EC 4.1.99.1). The numerical values of isotope effects in the course of reaction were obtained by the competitive method using [1-14C]-L-tryptophan as internal radiometric standard.
Źródło:
Nukleonika; 2006, 51,suppl.2; 17-19
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carbon-14 kinetic isotope effects in the debromination of p-nitrodibromocinnamic acid
Autorzy:
Bukowski, J.
Kanski, R.
Kanska, M.
Powiązania:
https://bibliotekanauki.pl/articles/147051.pdf
Data publikacji:
2002
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
bromine
carbon-14
elimination
kinetic isotope effect
mechanism
p-nitrodibromocinnamic acid
Opis:
The kinetic isotope effect (KIE) method was applied to study the mechanism of elimination of bromine from p-nitro-erythro-alfa,beta-dibromocinnamic acid labeled at the alfa-carbon. This compound was obtained starting from [2-14C]malonic acid via [2-14C]cinnamic acid and subsequent addition of bromide. The value of 14C KIE determined for alfa-position of side chain of p-nitro-erythro-alfa,beta-dibromocinamic acid proves that elimination of bromine leading to formation of (E)-p-nitrocinnamic acid proceeds via E2 mechanism.
Źródło:
Nukleonika; 2002, 47, 4; 133-136
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A revised inoceramid biozonation for the Upper Cretaceous based on high-resolution carbon isotope stratigraphy in northwestern Hokkaido, Japan
Autorzy:
Hayakawa, T.
Hirano, H.
Powiązania:
https://bibliotekanauki.pl/articles/139392.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
carbon isotope stratigraphy
inoceramid biozones
Yezo Group
Upper Cretaceous
Hokkaido
Japan
stratygrafia izotopowa węgla
górna kreda
Japonia
Opis:
Biostratigraphic correlations of inoceramid bivalves between the North Pacific and Euramerican provinces have been difficult because the inoceramid biostratigraphy of the Japanese strata has been based on endemic species of the northwest Pacific. In this study, carbon stable isotope fluctuations of terrestrial organic matter are assembled for the Upper Cretaceous Yezo Group in the Haboro and Obira areas, Hokkaido, Japan, in order to revise the chronology of the inoceramid biozonation in Japan. The carbon isotope curves are correlated with those of marine carbonates in English and German sections with the aid of age-diagnostic taxa. According to the correlations of the carbon isotope curves, 11 isotope events are recognised in the sections studied. As a result of these correlations, the chronology of the inoceramid biozones of the Northwest Pacific has been considerably revised. The revised inoceramid biozones suggest that the timing of the origination and extinction of the inoceramids in the North Pacific biotic province is different from the stage/substage boundaries defined by inoceramids, as used in Europe and North America.
Źródło:
Acta Geologica Polonica; 2013, 63, 2; 239-263
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The rank of climatic oscillations during MIS 11c (OHO and YHO) and post-interglacial cooling during MIS 11b and MIS 11a in eastern Poland
Autorzy:
Hrynowiecka, Anna
Żarski, Marcin
Drzewicki, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/2058672.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
substages of MIS 11
Mazovian interglacial
Holsteinian Interglacial
MIS 12 and MIS 10 glaciation range
palaeoclimate changes
E Poland palaeolakeland
Carbon isotope
Opis:
Lacustrine sediments representing Marine Isotope Stage 11 (MIS 11) were found in Hermanów (SE Poland) in a present-day closed depression under a thin cover of Weichselian and Holocene deposits (1.4 m). These sediments filled a palaeolake created as a result of melting of a dead-ice block at the end of MIS 12. Geological research has excluded the presence of an ice sheet during MIS 12 in this area. The lobe of the ice sheet of this glaciation was located several kilometres to the west of Hermanów. The palaeolake was part of a larger palaeolakeland in southeastern Poland, formed during MIS 11. The palaeomorphology of this interglacial is evident in the contemporary relief of the area and the outline of the lakes corresponds to the pattern of the closed palaeodepressions. Based on the record of sediments from Hermanów, a new perspective regarding the sub-division of MIS 11 is presented. Two regressive phases are observed in the Holsteinian Interglacial (MIS 11c) - OHO and YHO. The subsequent substages with five cold fluctuations according to the newest stratigraphic standards should be assigned to MIS 11b with a very clear cooling and a slightly warmer MIS 11a. Carbon isotopic composition of organic matter corroborates geological and environmental analysis. The isotopic composition suggests two cooling periods: OHO and MIS 11b. Stable climatic conditions with little temperature fluctuations persisted between the cooling periods.
Źródło:
Geological Quarterly; 2019, 63, 2; 375--394
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skład izotopowy dwutlenku węgla w atmosferze Krakowa
Isotopic composition of carbon dioxide in the atmosphere of Kraków
Autorzy:
Jasiek, Alina
Zimnoch, Mirosław
Różański, Kazimierz
Powiązania:
https://bibliotekanauki.pl/articles/578341.pdf
Data publikacji:
2016
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
izotopy trwałe
dwutlenek węgla
izotopowy bilans masy
stable isotopes
carbon dioxide
isotope mass balance
Opis:
Izotopy trwałe stanowią doskonałe narzędzie do analizy źródeł pochodzenia gazów cieplarnianych. Znając specyficzne sygnatury izotopowe poszczególnych źródeł dwutlenku węgla można określić pochodzenie CO2 nagromadzonego w miejskiej atmosferze. Kwasi-ciągłe pomiary stężenia i składu izotopowego węgla w atmosferycznym CO2 prowadzone w 2013 roku w Krakowie pozwoliły na dokonanie analizy ich zmienności sezonowej oraz synoptycznej. Źródłem obserwowanych zimą zwiększonych stężeń CO2 w atmosferze Krakowa było spalanie, w głównej mierze gazu ziemnego w celach grzewczych. Latem zaobserwowano wpływ suszy na stężenie CO2 w miejskiej atmosferze – z powodu obumierania lokalnej biosfery zmalała jej wydajność fotosyntetyczna, prowadząc do wyższych niż normalnie stężeń tego gazu w miesią - cach letnich. Przeprowadzono również dyskusję przyczyn krótkoterminowych wzrostów stężenia dwutlenku węgla, wykorzystując pomiary jego składu izotopowego oraz analizy trajektorii wstecznych mas powietrza. Zaprezentowane dwa przypadki ilustrują sytuacje, w których za chwilowy wzrost stężenia CO2 odpowiadają źródła przemysłowe oraz komunikacyjne.
Stable isotopes constitute a powerful tool to study the sources of greenhouse gases, especially CO2. Carbon dioxide derived from the burning of fossil fuels has a distinct 13C isotopic composition depending on the type of fuel. Therefore, one can attribute contributions of different emission sources to the total CO2 load in the urban atmosphere. Quasi-continuous measurements of the mixing ratio of atmospheric CO2 and its 13C signature were performed in Krakow in 2013 to analyze its seasonal and synoptic variability. High CO2 mixing ratios were observed in winter due to intensified burning of fossil fuels for heating purposes (mostly methane). During the summer of 2013, a slight increase in atmospheric CO2 was observed following a drought event and a subsequent suppression of the photosynthetic activity of the local biosphere. A high temporal resolution of the measurements allowed to analyze short-term increases of the measured CO2 mixing ratios. Two such events are presented and discussed. Isotopic mass balance combined with air backward trajectory analysis allowed to attribute local traffic and industry as potential sources of these events.
Źródło:
Acta Geographica Lodziensia; 2016, 104; 113-122
0065-1249
Pojawia się w:
Acta Geographica Lodziensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tracing the signature of various frontal systems in stable isotopes (oxygen and carbon) of the planktonic foraminiferal species Globigerina bulloides in the Southern Ocean (Indian Sector)
Autorzy:
Khare, N.
Chaturvedi, S.K.
Powiązania:
https://bibliotekanauki.pl/articles/48922.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Foraminifera
Globigerina bulloides
stable isotope
frontal system
oxygen
carbon
foraminiferal species
water mass
Southern Ocean
Opis:
Twenty-five surficial sediment samples, collected on board ORV Sagar Kanya during her 199th and 200th cruises along a north-south transect between latitudes 9.69◦N and 55.01◦S, and longitudes 80◦E and 40◦ E were studied for isotopic variations (values of δ18O and δ13C) of the indicator planktonic species Globigerina bulloides. The results indicate that from latitudes 9.69◦N to 15◦ S both these isotopes (δ18O and δ13C) fluctuated significantly. Between latitudes from around 15◦S to 30–35◦S δ18O values steadily increased, whereas δ13C showed a decreasing trend. However, to the south of latitudes 30–35◦S, both isotope values showed a similar response with a gradual increase up to latitude 50◦S, beyond which δ18O continued to increase while δ13C declined. The characteristic patterns of the values of both isotopes indicates that the signatures of different water masses are associated with various frontal systems and/or water masses across the transect. The signature of the Polar Front at around latitude 50◦S shows the specific response of the isotopic values (δ18O and δ13C) of G. bulloides. Such a response beyond 50◦S latitude is ascribable to the general decrease in the ambient temperature, resulting in a continuous increase in δ18O values, while δ13C values decrease as a result of reduced photosynthesis in regions approaching higher latitudes owing to low light penetration. To further corroborate our results, those of many such transects from geographically distinct regions need to be studied for isotopic variations in the calcareous shells of planktonic foraminiferal species. The results have the potential to be used as a proxy to assess the movement of frontal systems in southern high latitude regions.
Źródło:
Oceanologia; 2012, 54, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elucidation of reaction mechanisms using kinetic isotope effects of short-lived radionuclides
Autorzy:
Matsson, O.
Powiązania:
https://bibliotekanauki.pl/articles/146955.pdf
Data publikacji:
2002
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
carbon-11
fluorine-18
kinetic isotope effect
reaction mechanism
short-lived radionuclide
Opis:
The use of the short-lived radionuclides 11C and 18F for the elucidation of organic reaction mechanisms is described. Examples of the different mechanistic problems that are discussed include concerted vs. stepwise base catalysed elimination (E2 or E1cB) and finding the rate limiting step for nucleophilic aromatic substitution (SNAr). The use of radionuclides to learn details about transition state structure for concerted nucleophilic aliphatic substitution (SN2) is also described.
Źródło:
Nukleonika; 2002, 47,suppl.1; 43-45
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trophic connectivity between intertidal and offshore food webs in Mirs Bay, China
Autorzy:
Ning, J.
Du, F.
Wang, X.
Wang, L.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/47613.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
intertidal zonation
offshore zone
food web
different habitat
trophic interaction
stable isotope
carbon isotope composition
Mirs Bay
China
Źródło:
Oceanologia; 2019, 61, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Limitation of lignin derivatives as biomarkers of land derived organic matter in the coastal marine sediments
Autorzy:
Pempkowiak, J.
Powiązania:
https://bibliotekanauki.pl/articles/2079190.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
lignin oxidation
biomarker
stable carbon isotope
nonlinear analysis
Gdansk Bay
Southern Baltic Sea
coastal sediment
Opis:
Lignin oxidation products (vanillyl, syringil and cummaryl phenols), and δ13C were measured in a variety of land and marine samples collected in Inner Puck Bay – dominated by marine vascular plants, small river run-off, and shallow bottom, and in Gdańsk Bay – characterized by large river run-off, small marine vascular plants population, and the average depth exceeding euphotic zone. Both study areas are parts of the Gdańsk Basin, Southern Baltic. Typical δ13C values (δ13C = -28‰) and both composition and concentrations of lignin phenols were measured in samples originating from land. Small, yet easily measurable amounts of lignin phenols were found in marine vascular plants biomass (Σ8 = 90 µg/100 mg organic matter). The biomass was characterized by exceptionally high δ13C values (-12‰). No lignin phenols and typical δ13C values (-22‰) were measured in marine phytoplankton biomass. δ13C and both composition and content of lignin phenols in organic matter of surface sediments collected in the study area fall in the range marked by the end members. The proportion of land derived organic matter calculated using lignin phenols, or δ13C in Gdańsk Bay were comparable, while in Puck Bay they differed substantially. It was concluded that a) in areas with substantial bottom coverage with vascular plants the two end members approach, usually employed to establish the contribution of organic matter sources, is insufficient, b) organic matter originating from three sources: riverine, phytoplankton, and vascular plants contribute to sedimentary organic matter in Puck Bay with the respective proportion 30:40:30.
Źródło:
Oceanologia; 2020, 62, 3; 374-386
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carbon isotope stratigraphy of the basal Zechstein (Lopingian) strata in Northern Poland and its global correlation
Autorzy:
Peryt, T. M.
Durakiewicz, T.
Kotarba, M. J.
Oszczepalski, S.
Peryt, D.
Powiązania:
https://bibliotekanauki.pl/articles/2058984.pdf
Data publikacji:
2012
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Upper Permian
Zechstein
organic geochemistry
Kupferschiefer
carbon isotope stratigraphy
Opis:
The Kupferschiefer (T1) records a period of basin-wide euxinic conditions, and is thus considered an excellent time-marker in the Zechstein (Lopingian) basin. Previous studies indicated that both the Kupferschiefer and Marl Slate and the overlying Zechstein Limestone (Magnesian Limestone) show remarkable changes in carbon isotopic composition towards higher 131313131313
Źródło:
Geological Quarterly; 2012, 56, 2; 285-298
1641-7291
Pojawia się w:
Geological Quarterly
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 1-15 z 26

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