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Wyszukujesz frazę "stromatoporoid" wg kryterium: Temat


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Tytuł:
Palaeoecology of corals and stromatoporoids in a Late Silurian biostrome in Estonia
Autorzy:
Kershaw, S.
Motus, M.-A.
Powiązania:
https://bibliotekanauki.pl/articles/21971.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleoecology
coral
stromatoporoid
Late Silurian
biostrome
Anthozoa
Stromatoporoidea
Estonia
Opis:
A middle Ludlow biostrome at Katri, western Estonia, the richest accumulation of corals and stromatoporoids in Estonia, is partly exposed in a coastal section. The fully marine biostrome consists of five fossiliferous layers of carbonate skeletons, grouped into Facies 1 (grainstone-packstone, Layers 1, 3, 5) and Facies 2 (wackestone, interbedded Layers 2, 4). Pressure solution degraded original sedimentary relationships and morphologies of stromatoporoids, tabulates and rugosans which constructed the biostrome, but the two facies have major faunal differences. Facies 1 is rich in stromatoporoids “Stromatopora” bekkeri and Plectostroma scaniense (low to high domical up to ca. 30 cm in basal length); and tabulate Favosites forbesi (bulbous to high domical up to ca. 25 cm wide). In Facies 2, all three taxa are less common and much smaller. Instead, the most abundant stromatoporoid is laminar Syringostromella borealis up to 30 cm basal length; the most abundant coral is erect branching Laceripora cribrosa, as scattered fragments up to 24 cm long. Neither occurs in Facies 1. Six other stromatoporoid taxa, 5 other tabulate and 5 rugosan taxa occur uncommonly in the biostrome, mostly in both facies. The Katri biostrome is slightly younger than, but facially similar to biostromes in the middle Ludlow Hemse Group on Gotland ca. 250 km WSW, with well-known stromatoporoid faunas. Corals are abundant in Hemse biostromes. Several key stromatoporoids occur in both the Hemse biostromes and Katri, but two abundant taxa in Hemse biostromes are absent in Katri and two tabulate corals abundant in Katri are missing in Hemse biostromes. Thus there was a wide distribution of such biostromes in the central Baltic large shallow marine carbonate platform, but with previously unreported variable assemblages presumed due to facies features not recognised in the sediments.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Palaeobiology, ecology, and distribution of stromatoporoid faunas in biostromes of the mid-Ludlow of Gotland, Sweden
Autorzy:
Sandstrom, O
Kershaw, S.
Powiązania:
https://bibliotekanauki.pl/articles/21659.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleoecology
deposit
Sweden
paleontology
Silurian
morphotype
stromatoporoid fauna
ecology
distribution
Gotland
Opis:
Six well exposed mid−Ludlow stromatoporoid−dominated reef biostromes in four localities from the Hemse Group in southeastern Gotland, Sweden comprise a stromatoporoid assemblage dominated by four species; Clathrodictyon mohicanum, “Stromatopora” bekkeri, Plectostroma scaniense, and Lophiostroma schmidtii. All biostromes investigated in this area (of approximately 30 km²) are interpreted to belong to a single faunal assemblage forming a dense accumulation of fossils that is probably the best exposed stromatoporoid−rich deposit of the Silurian. The results from this comprehensive study strengthen earlier interpretations of a combination of genetic and environmental control on growth−forms of the stromatoporoids. Growth styles are similar for stromatoporoids in all six biostromes. Differences in biostrome fabric are due to variations in the degree of disturbance by storms. The uniformity of facies and the widespread low−diversity fauna support the view that palaeoenvironmental conditions were similar across the area where these biostromes crop out, and promoted the extraordinary growth of stromatoporoids in this shallow shelf area.
Źródło:
Acta Palaeontologica Polonica; 2008, 53, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stromatoporoid beds and flat-pebble conglomerates interpreted as tsunami deposits in the Upper Silurian of Podolia, Ukraine
Autorzy:
Łuczyński, P.
Skompski, S.
Kozłowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/138749.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Palaeotsunami
Silurian
Podolia
Stromatoporoid beds
Flat-pebble conglomerates
sylur
Podole
warstwy stromatoporoidowe
prefabrykaty płaskie
Opis:
Tsunami deposits are currently a subject of intensive studies. Tsunamis must have occurred in the geological past in the same frequency as nowadays, yet their identified depositional record is surprisingly scarce. Here we describe a hitherto unrecognized example of probable palaeotsunamites. The Upper Silurian (Pridoli) carbonate succession of Podolia (southwestern Ukraine) contains variously developed event beds forming intercalations within peritidal deposits (shallow water limestones, nodular marls and dolomites). The event beds are represented by stromatoporoid and fine-grained bioclastic limestones, in some places accompanied by flat-pebble conglomerates. The interval with event beds can be traced along the Zbruch River in separate outcrops over a distance of more than 20 km along a transect oblique to the palaeoshoreline. The stromatoporoid beds have erosional bottom surfaces and are composed of overturned and often fragmented massive skeletons. The material has been transported landward from their offshore habitats and deposited in lagoonal settings. The flat-pebble conglomerates are composed of sub-angular micritic clasts that are lithologically identical to the sediments forming the underlying beds. Large-scale landward transport of the biogenic material has to be attributed to phenomena with very high energy levels, such as tropical hurricanes or tsunamis. This paper presents a tsunamigenic interpretation. Morphometric features of redeposited stromatoporoids point to a calm original growth environment at depths well below storm wave base. Tsunami waves are the most probable factor that could cause their redeposition from such a setting. The vastness of the area covered by parabiostromal stromatoporoid beds resembles the distribution of modern tsunami deposits in offshore settings. The stromatoporoid beds with unsorted stromatoporoids of various dimensions evenly distributed throughout the thickness of the beds and with clast-supported textures most probably represent deposition by traction. In some sections, the stromatoporoids are restricted to the lowermost parts of the beds, which pass upwards into bioclastic limestones. In this case, the finer material was deposited from suspension. The coexistence of stromatoporoid beds and flat-pebble conglomerates also allows presenting a tsunami interpretation of the latter. The propagating tsunami waves, led to erosion of partly lithified thin-layered mudstones, their fragmentation into flat clasts and redeposition as flat-pebble conglomerates.
Źródło:
Acta Geologica Polonica; 2014, 64, 3; 261-280
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problem tsunamitów. Dlaczego tak mało jest kopalnych osadów tsunami?
The tsunamites problem. Why are fossil tsunamites so rare?
Autorzy:
Łuczyński, P.
Powiązania:
https://bibliotekanauki.pl/articles/2074917.pdf
Data publikacji:
2012
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
tsunami
tsunamites
palaeotsunamites
stromatoporoid beds
Upper Silurian
Podolia
tsunamity
warstwy stromatoporoidowe
górny sylur
Podole
Opis:
Tsunami is a common phenomenon and one of the most dangerous natural hazards of the modern world. Taking into account the relative high frequency of tsunamis in historical times, we can expect accordingly rich geological records of similar events from fossil formations. However, palaeotsunami deposits are surprisingly rare, mainly because of the difficulty of discerning them from sediments formed by other processes, e.g. storms. Part of the problem lies in the definition of tsunamite, which refers only to the triggering process, and in a different approach while discerning modern and fossil tsunamites. Modern tsunamites are identified by connecting the deposits to a particular historical tsunami event, even if they contain no diagnostic sedimentological features - an approach, which cannot be applied to fossil formations. This can lead to an impression that modern tsunami deposits are much more common than their fossil counterparts, which in turn suggest great intensification of tsunami events in historical times. Lately, a great number ofpapers have been published on sedimentary effects of modern tsunamis. The studies concentrated on land and near-shore areas. Many authors point out that the sedimentary record left by tsunami is commonly surprisingly mean and with a very low preservation potential. When interpreting fossil successions, the most important features that might indicate their tsunamite genesis are: mixing of material derivedfrom various facial zones, evidence of deep erosion and long transport, and association with other symptoms of seismic activity. The stromatoporoid biostromal accumulations in the Upper Silurian ofPodolia are presented here as possible palaeotsunamite deposits. Thick layers of redeposited stromatoporoids within fine-grained peritidal deposits are interpreted as an effect of onshore transport of this relatively light material during high-energy sedimentary events, such as tsunami. In many ways, the stromatoporoid beds resemble modern accumulations oftsunami-derived boulders.
Źródło:
Przegląd Geologiczny; 2012, 60, 11; 598--604
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent studies on the Silurian of the western part of Ukraine
Autorzy:
Łuczyński, P.
Skompski, S.
Kozłowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/138934.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Upper Silurian
Podolia
facies
stromatoporoid beds
sedimentary environments
górny sylur
Podole
facja
warstwy stromatoporoidowe
środowiska sedymentacyjne
Opis:
The paper summarises the effects of recent studies carried out by a team from the Department of Historical and Regional Geology of the Faculty of Geology, University of Warsaw on the upper Silurian of Podolia (western part of Ukraine). The sedimentary history of the Silurian succession of Podolia is characterised by its cyclic pattern, with shallowing-upward cyclothems. In the traditional interpretation, the occurrence of stromatoporoid beds within each cyclothem marks the deepest (or most open-marine) sedimentary environment within the cycle. According to the results of recent studies, their occurrence is connected rather with a relatively shallow-water environment and with high energy phenomena. A substantial reinterpretation of the main sedimentary processes governing the deposition and facies distribution on the shelf is presented. Particularly, there are recognised and described high-energy sedimentary events repeatedly punctuating the generally calm sedimentation that prevailed in the lagoonal settings, some of which are interpreted as tsunami induced. Further perspectives for studies on the Silurian successions of Podolia are also discussed. The main problem is the precise correlation of particular sections that are scattered over vast distances and developed in similar facies associations.
Źródło:
Acta Geologica Polonica; 2016, 66, 3; 281-297
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Astrorhizae-like structures on epitheca of rugose corals from the Carboniferous of Laos
Autorzy:
Hung, N H
Powiązania:
https://bibliotekanauki.pl/articles/23243.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Carboniferous
astrorhizae-like structure
Laos
stromatoporoid
Hydractinia echinata
rugose coral
Calceola sandalina
coral
Clionolithes reptans
paleontology
Opis:
Stellate patterns, called astrorhizae, occurring in some Paleozoic stromatoporoids are by most authors regarded as integral elements of these enigmatic fossils. The finding of stellate structures on epithecae of rugose corals from the Lower Carboniferous of Central Laos seems to support, however, the idea that astrorhizae in Paleozoic stromatoporoids may represent traces of foreign organisms.
Źródło:
Acta Palaeontologica Polonica; 2001, 46, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Famennian stromatoporoids from Debnik Anticline, southern Poland
Autorzy:
Wolniewicz, P
Powiązania:
https://bibliotekanauki.pl/articles/19981.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Famennian
Late Famennian
stromatoporoid
Polska
Porifera
ontogenesis
Quasiendothyra communis
Clathrodictyida
Gerronostroma
Stylostroma
Labechiida
Gerronostroma raclaviense
Stromatoporoidea
Opis:
Famennian Stromatoporoidea from the Quasiendothyra communis Foraminiferal Zone and slightly younger strata from the Dębnik anticline, southern Poland, form a succession of three consecutive assemblages. Assemblages 1 and 3 consist of representatives of the order Clathrodictyida, while assemblage 2 is dominated by the order Labechiida. The clathrodictyids are represented by the genus Gerronostroma, and labechiids are represented by the genus Stylostroma. Species assigned here to the genus Gerronostroma show a network of amalgamated pillars in the central part of the columns, a feature regarded by previous authors as typical of the genus Clavidictyon. Two new species, Stylostroma multiformis sp. nov. and Gerronostroma raclaviense sp. nov., are described. Stromatoporoids from southern Poland differ from the Famennian fauna of western Europe, showing affinity to eastern European and Siberian Stromatoporoidea.
Źródło:
Acta Palaeontologica Polonica; 2009, 54, 2; 337-350
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A giant boring in a Silurian stromatoporoid analysed by computer tomography
Autorzy:
Beuck, L
Wisshak, M.
Munnecke, A.
Freiwald, A.
Powiązania:
https://bibliotekanauki.pl/articles/20045.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Upper Visby Formation
computer tomography
Sweden
Densastroma pexisum
paleontology
Gotland Island
Silurian
stromatoporoid
trace fossil
Osprioneides kampto
analysis
Opis:
This study describes the largest known Palaeozoic boring trace, Osprioneides kampto igen. et isp. nov., found within a stromatoporoid Densastroma pexisum from the Upper Visby Formation (lower Wenlock, Silurian) on the island of Gotland, Sweden. Differences between the physical properties of the stromatoporoid and the dense micritic infilling of the borings allowed the application of the CT−scan technology for the 2D and 3D−visualisation of this rare trace. The additional application of a stereoscopic technique on these CT images and movies enhances its value for unravelling spatial orientations. This non−destructive method has a great potential for future macroas well as microboring analyses. The trace maker, most likely a worm, infested the hosting colony post−mortem with up to 120 mm long borings measuring 5–17 mm in diameter. Smaller forms of Trypanites and Palaeosabella within the same stromatoporoid preferentially occur in the outer coenosteum and occasionally in abandoned borings of O. kampto. The stratigraphic position of O. kampto follows the “Great Ordovician Biodiversification Event” in time, and reflects the increase in diversity of boring species. Borings with penetration depths of 120 mm are, however, unique findings for the Palaeozoic and were not exceeded until some 260 million years later (Bajocian, Middle Jurassic) when the “Mesozoic Marine Revolution” led to convergent reinventions as a result of enhanced predation, grazing pressure, and ecospace competition.
Źródło:
Acta Palaeontologica Polonica; 2008, 53, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Revised classification and terminology of Palaeozoic stromatoporoids
Autorzy:
Stearn, C W
Webby, B D
Nestor, H
Stock, C W
Powiązania:
https://bibliotekanauki.pl/articles/23457.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Stromatoporida
Paleozoic
Labechiida
stromatoporoid
Stromatoporellida
morphology
taxonomy
carbonate skeleton
geographic distribution
stratigraphy
Clathrodictyida
classification
fossil
Syringostromatida
Amphiporida
catalogue number
terminology
Actinostromatida
paleontology
Opis:
Palaeozoic stromatoporoids comprise an extinct class of non-spiculate poriferans that are represented as fossils by their basal carbonate skeleton. A revised terminology for the description of these fossils is presented. Seven orders (Labechiida, Clathrodictyida, Actinostromatida, Stromatoporellida, Stromatoporida, Syringostromatida, Amphiporida) are recognized. The following is recorded for each genus: (1) type species, catalogue number and depository of the primary holotype; (2) synonyms and their type species; (3) diagnosis; (4) stratigraphic range; (5) estimate of the number of species assigned to the genus; (6) stratigraphic and geographic distribution of the genus. Problems in the definition and recognition of the genus are briefly discussed in annotations. One hundred and nine genera are considered valid, or doubtfully valid. Fifty three genera are placed in synonymy. An additional 14 genera are considered to be of uncertain placement in the classification.
Źródło:
Acta Palaeontologica Polonica; 1999, 44, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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