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Maslo Martin - One of the best experts on this subject based on the ideXlab platform.
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Jurassic-Cretaceous Radiolarian-bearing strata from the Gresten Klippen Zone and the St. Veit Klippen Zone (Wienerwald, Eastern Alps, Austria) : implications for stratigraphy and paleogeography
'Austrian Geological Society (OGG)', 2018Co-Authors: Ślączka Andrzej, Bąk Marta, Pfersmann Clemens, Koukal Veronika, Wagreich Michael, Kowalik Szymon, Maslo MartinAbstract:Two sections of the klippen zones in the Wienerwald area have been investigated for their stratigraphy: (1) The Gern section of the Main Klippen Zone, a part of the Gresten Klippen Zone, and (2) the St. Veit Klippen Zone in the Lainz Tunnel and the neighboring outcrops in western Vienna. New biostratigraphic data are based on Radiolaria from siliceous intervals and a few findings of calcareous nannofossils from marlstones. In the Gresten Klippen Zone, Radiolarian assemblages from limestones of the Gern locality indicate a middle Oxfordian to early Kimmeridgian age of the Scheibbsbach Formation. Radiolarian and nannofossil data from the St. Veit Klippen Zone in the Lainz railway tunnel locality, as well as correlated outcrops from the Lainzer Tiergarten and the Gemeindeberg in the southwest of Vienna, indicate the presence of mainly Bajocian to lower Oxfordian red radiolarites and cherts (Rotenberg Formation). Siliceous, grey limestones and cherts of the Fasselgraben Formation range from the upper Oxfordian Kimmeridgian to the Valanginian-Barremian. The Main Klippen Zone was derived from the European margin to the north, and this zone is regarded as a Helvetic paleogeographic unit. The St. Veit Klippen Zone in the Lainz Tunnel section contains no ophiolitic material and shows a tectonic contact with the surrounding Rhenodanubian nappe system, which indicates no primary sedimentary contact of the St. Veit Klippen Zone with the Flysch units, as well as demonstrating the presence of two structurally separated Alpine tectonic units. Thus, a direct correlation with the Ybbsitz Zone is not supported, and an original paleogeographic position in the transition from the Penninic Ocean to the Austroalpine continental fragment is proposed
Maslo, Martin Of Palaeontology, Faculty Of Earth Sciences, Geography And Astronomy, University Of Vienna) - One of the best experts on this subject based on the ideXlab platform.
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Jurassic–Cretaceous Radiolarian-bearing strata from the Gresten Klippen Zone and the St. Veit Klippen Zone (Wienerwald, Eastern Alps, Austria): Implications for stratigraphy and paleogeography
'Austrian Geological Society (OGG)', 2018Co-Authors: Ślączka, Andrzej Of Geological Sciences, Faculty Of Geography And Geology, Jagiellonian University), Bąk, Marta Of Geology, Geophysics And Environmental Protection, Agh University Of Science And Technology), Pfersmann, Clemens Of Geodynamics And Sedimentology, Faculty Of Earth Sciences, Geography And Astron Vienna), Koukal, Veronika Of Geodynamics And Sedimentology, Faculty Of Earth Sciences, Geography And Astronom Vienna), Wagreich, Michael Of Geodynamics And Sedimentology, Faculty Of Earth Sciences, Geography And Astrono Vienna), Kowalik, Szymon Of Geography, Faculty Of Geography And Biology, Pedagogical University Of Cracow), Maslo, Martin Of Palaeontology, Faculty Of Earth Sciences, Geography And Astronomy, University Of Vienna)Abstract:Two sections of the klippen zones in the Wienerwald area have been investigated for their stratigraphy: (1) The Gern section of the Main Klippen Zone, a part of the Gresten Klippen Zone, and (2) the St. Veit Klippen Zone in the Lainz Tunnel and the neighboring outcrops in western Vienna. New biostratigraphic data are based on Radiolaria from siliceous intervals and a few findings of calcareous nannofossils from marlstones. In the Gresten Klippen Zone, Radiolarian assemblages from limestones of the Gern locality indicate a middle Oxfordian to early Kimmeridgian age of the Scheibbsbach Formation. Radiolarian and nannofossil data from the St. Veit Klippen Zone in the Lainz railway tunnel locality, as well as correlated outcrops from the Lainzer Tiergarten and the Gemeindeberg in the southwest of Vienna, indicate the presence of mainly Bajocian to lower Oxfordian red radiolarites and cherts (Rotenberg Formation). Siliceous, grey limestones and cherts of the Fasselgraben Formation range from the upper Oxfordian–Kimmeridgian to the Valanginian–Barremian. The Main Klippen Zone was derived from the European margin to the north, and this zone is regarded as a Helvetic paleogeographic unit. The St. Veit Klippen Zone in the Lainz Tunnel section contains no ophiolitic material and shows a tectonic contact with the surrounding Rhenodanubian nappe system, which indicates no primary sedimentary contact of the St. Veit Klippen Zone with the Flysch units, as well as demonstrating the presence of two structurally separated Alpine tectonic units. Thus, a direct correlation with the Ybbsitz Zone is not supported, and an original paleogeographic position in the transition from the Penninic Ocean to the Austroalpine continental fragment is proposed.© 2018 Andrzej ŚLĄCZKA et al
Takahito Ikenoue - One of the best experts on this subject based on the ideXlab platform.
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flux variations and vertical distributions of siliceous rhizaria Radiolaria and phaeodaria in the western arctic ocean indices of environmental changes
Biogeosciences, 2015Co-Authors: Kjell R. Bjørklund, Svetlana B Kruglikova, Takahito Ikenoue, Jonaotaro Onodera, Katsunori Kimoto, Naomi HaradaAbstract:Abstract. The vertical distribution of Radiolarians was investigated using a vertical multiple plankton sampler (100–0, 250–100, 500–250, and 1000–500 m water depths, 62 μm mesh size) at the Northwind Abyssal Plain and southwestern Canada Basin in September 2013. To investigate seasonal variations in the flux of Radiolarians in relation to sea ice and water masses, a time-series sediment trap system was moored at Station NAP (75°00´ N, 162°00´ W; bottom depth 1975 m) in the western Arctic Ocean during October 2010–September 2012. The Radiolarian flux was comparable to that in the North Pacific Ocean. Amphimelissa setosa was dominant during the season with open water as well as at the beginning and end of the seasons with sea-ice cover. During the sea-ice-cover season, however, oligotrophic and cold-water-tolerant actinommids were dominant, productivity of Radiolaria was lower, and species diversity was greater. These suggest that the dynamics of sea ice are a major factor affecting the productivity, distribution, and composition of the Radiolarian fauna.
David A. Caron - One of the best experts on this subject based on the ideXlab platform.
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Video plankton recorder reveals high abundances of colonial Radiolaria in surface waters of the central North Pacific
Journal of Plankton Research, 2002Co-Authors: Mark R. Dennett, David A. Caron, Anthony F. Michaels, Scott M. Gallager, Cabell S. DavisAbstract:Colonial spumellarian Radiolaria are heterotrophic protists that form large (up to several meters in length), gelatinous structures in the surface waters of all tropical and subtropical oceanic ecosystems. These species are morphologically and trophically complex and some, but not all, produce silica skeletal structures of considerable paleontological significance. Skeletonless species of Radiolaria are poorly sampled by plankton nets, which can severely damage these delicate organisms. Therefore, abundances of colonial Radiolaria typically have been underestimated in quantitative studies of zooplankton abundance and biomass. Here we document the abundances of colonial Radiolaria in the central North Pacific based on analysis of video images from a miniaturized video plankton recorder. We observed abundances of Radiolarian cells in colonies that exceeded previous reports of total Radiolaria by more than ten-fold, and counts of skeleton-bearing Radiolaria by more than two to three orders of magnitude. Biomass (carbon) within these colonies was similar to or greater than the total Radiolarian biomass (i.e. including all solitary species) previously reported for the Pacific. Symbiont productivity within colonial Radiolaria was estimated to constitute a modest but significant fraction of total primary productivity (up to 9%) in the upper 150 m. These findings indicate an important contribution of skeletonless spumellaria to food webs and biogeochemical cycles of these communities.
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towards a molecular phylogeny of colonial spumellarian Radiolaria
Marine Micropaleontology, 1999Co-Authors: Linda Amaral A Zettler, O. R. Anderson, David A. CaronAbstract:Gene sequence data from the small-subunit ribosomal RNA coding region were used to explore evolutionary relationships among the colonial spumellarian Radiolaria (Polycystinea). Representatives from the two spumellarian families known to form colonies were considered including the following taxa: Sphaerozoidae: Collozoum pelagicum; Collozoum serpentinum; Rhaphidozoum acuferum ; Sphaerozoum punctatum ; and Collosphaeridae: Collosphaera globularis‐huxleyi ; Acrosphaera (circumtexta?); and Siphonosphaera cyathina. Our molecular analyses support the monophyly of the Collosphaeridae in all analyses used, but only distance analyses support the monophyly of the Sphaerozoidae. Within the Sphaerozoidae, two species of Collozoum (C. serpentinum and C. pelagicum) failed to branch together, indicating a more distant relationship than first suggested, a conclusion further supported by recent ultrastructural studies (see adjoining paper). Branching patterns within the Collosphaeridae indicate that Siphonosphaera diverged prior to the split between Collosphaera and Acrosphaera, a result which challenges evidence based on data from the Radiolarian fossil record. © 1999 Elsevier Science B.V. All rights reserved.
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molecular phylogeny of symbiotic dinoflagellates from planktonic foraminifera and Radiolaria
Molecular Biology and Evolution, 1996Co-Authors: Rebecca J Gast, David A. CaronAbstract:Recent analyses of the small subunit ribosomal DNA (srDNA) from dinoflagellate symbionts of cnidaria have confirmed historical descriptions of a diverse but well-defined clade, Symbiodinium, as well as several other independent symbiont lineages (Rowan 1991; Rowan and Powers 1992; Sadler et al. 1992; McNally et al 1994). Dinoflagellates also occur as intracellular symbionts in a number of pelagic protistan taxa, but the srDNA of these symbionts has not been examined. We analyzed the srDNA sequences of the symbiotic dinoflagellates from four planktonic foraminiferal species and six Radiolarian species. The symbionts from these sarcodines formed two distinct lineages within the dinoflagellates. Within each lineage, symbionts obtained from different host species showed few, if any, srDNA sequence differences. The planktonic foraminiferal symbionts were most closely related to Gymnodinium simplex and the Symbiodinium clade, whereas the Radiolarian symbionts were most closely related to the dinoflagellate symbiont from the oceanic chondrophore, Velella velella. Therefore, although the dinoflagellate symbionts of foraminifera appear to be a sister taxon of the symbionts from benthic foraminifera and invertebrates, the symbionts of Radiolaria are distinct and arose from an independent lineage of dinoflagellate symbionts that shares common ancestry with the symbiont of at least one pelagic metazoan. The lack of srDNA variability within the sarcodine symbiont lineages suggests that coevolution of host and symbiont has not occurred.
Ślączka Andrzej - One of the best experts on this subject based on the ideXlab platform.
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Jurassic-Cretaceous Radiolarian-bearing strata from the Gresten Klippen Zone and the St. Veit Klippen Zone (Wienerwald, Eastern Alps, Austria) : implications for stratigraphy and paleogeography
'Austrian Geological Society (OGG)', 2018Co-Authors: Ślączka Andrzej, Bąk Marta, Pfersmann Clemens, Koukal Veronika, Wagreich Michael, Kowalik Szymon, Maslo MartinAbstract:Two sections of the klippen zones in the Wienerwald area have been investigated for their stratigraphy: (1) The Gern section of the Main Klippen Zone, a part of the Gresten Klippen Zone, and (2) the St. Veit Klippen Zone in the Lainz Tunnel and the neighboring outcrops in western Vienna. New biostratigraphic data are based on Radiolaria from siliceous intervals and a few findings of calcareous nannofossils from marlstones. In the Gresten Klippen Zone, Radiolarian assemblages from limestones of the Gern locality indicate a middle Oxfordian to early Kimmeridgian age of the Scheibbsbach Formation. Radiolarian and nannofossil data from the St. Veit Klippen Zone in the Lainz railway tunnel locality, as well as correlated outcrops from the Lainzer Tiergarten and the Gemeindeberg in the southwest of Vienna, indicate the presence of mainly Bajocian to lower Oxfordian red radiolarites and cherts (Rotenberg Formation). Siliceous, grey limestones and cherts of the Fasselgraben Formation range from the upper Oxfordian Kimmeridgian to the Valanginian-Barremian. The Main Klippen Zone was derived from the European margin to the north, and this zone is regarded as a Helvetic paleogeographic unit. The St. Veit Klippen Zone in the Lainz Tunnel section contains no ophiolitic material and shows a tectonic contact with the surrounding Rhenodanubian nappe system, which indicates no primary sedimentary contact of the St. Veit Klippen Zone with the Flysch units, as well as demonstrating the presence of two structurally separated Alpine tectonic units. Thus, a direct correlation with the Ybbsitz Zone is not supported, and an original paleogeographic position in the transition from the Penninic Ocean to the Austroalpine continental fragment is proposed