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1.
Foraminifera have proven to be reliable biostratigraphic indicators. Accordingly, Triassic and Early Jurassic benthic Foraminifera allow us to define a biostratigraphic zonation within the carbonate platform of Kayseri (Yahyal?), Göksun (Kahramanmara?) and Sivas (Delikta?) regions in the Eastern Taurus (Ceviz, Alada?, Kaman and Felfan Mountains). Seven new stratigraphic sections are described in detail and the first precise inventory and illustration of the benthic foraminifer assemblages from the Triassic successions are presented over a large geographic area. The stratigraphic and palaeontological features of the Lower Mesozoic carbonate units of these mountains include several synchronous transgressive–regressive events that suggest continuity of the Lower Mesozoic environments over a large parautochthonous Taurus zone. Palaeogeographic considerations about the Eastern Taurus carbonates are given, evidencing three stages of development underwent by the studied area: 1) a stable continental margin from Lower Triassic to Lower Cretaceous; 2) a dismantling of the continental margin and first emplacement of ophiolites in the Upper Cretaceous; and 3) a deformation of the continental margin and emplacement of the Peridotite Nappe in the uppermost Cretaceous (Maastrichtian).  相似文献   

2.
Twenty-eight species of scleractinian corals were collected between 55 and 2,291 m depth during INDEMARES 2010–2012 expeditions to the Avilés Canyon System and the near continental shelf (Bay of Biscay). Most interesting species are described and all depicted. All species were already known from the northeast Atlantic, although some are seldom reported. Deltocyathus eccentricus and Flabellum chunii are northernmost records in the eastern Atlantic, and species first collected from the Bay of Biscay. From a literature review and new records given herein, 31 species of Scleractinia are known from the Avilés Canyon System. Live specimens of six species were recorded outside their previously known bathymetric ranges in the Bay of Biscay and nearby areas, either at shallower depths (Caryophyllia sarsiae, Monomyces pygmaea, Stephanocyathus nobilis), or deeper depths (C. atlantica, C. sarsiae, Enallopsammia rostrata, Solenosmilia variabilis). Desmophyllum cristagalli has the widest bathymetric range (551–2,291 m), and Lophelia pertusa is the most widely distributed species (24 stations). Tabulating the number of live species occurring in each 100-m depth interval of the canyon system, highest species richness occurs in the 700–800-, 800–900-, and 1,400–1,500-m depth intervals (11 species). The habitat-forming species L. pertusa and Madrepora oculata were abundant in some stations building well-developed coral banks. Live colonies of the big-sized species S. variabilis and E. rostrata co-occurred at the deepest station sampled that yielded scleractinia (2,291 m).  相似文献   

3.
The authors study the microfauna of small benthonic and planktonic Foraminifera from the Aquitanian stratotype and of a few exposures in the stratotype vicinity.Benthonic microfauna is rich: more than 150species have been collected; among them Miliolidae mainly belonging to the genera Quinqueloculina and Miliola.Planktonic Foraminifera are much less abundant:only 20 species. They authorize to place the stratotype at the boundary of N4–N5 Blow's zones.The figurations of many species are made withthe scanning electronic microscope.  相似文献   

4.
Geographic surveys of allozymes, microsatellites, nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) have detected several genetic subdivisions among European anchovy populations. However, these studies have been limited in their power to detect some aspects of population structure by the use of a single or a few molecular markers, or by limited geographic sampling. We use a multi-marker approach, 47 nDNA and 15 mtDNA single nucleotide polymorphisms (SNPs), to analyze 626 European anchovies from the whole range of the species to resolve shallow and deep levels of population structure. Nuclear SNPs define 10 genetic entities within two larger genetically distinctive groups associated with oceanic variables and different life-history traits. MtDNA SNPs define two deep phylogroups that reflect ancient dispersals and colonizations. These markers define two ecological groups. One major group of Iberian-Atlantic populations is associated with upwelling areas on narrow continental shelves and includes populations spawning and overwintering in coastal areas. A second major group includes northern populations in the North East (NE) Atlantic (including the Bay of Biscay) and the Mediterranean and is associated with wide continental shelves with local larval retention currents. This group tends to spawn and overwinter in oceanic areas. These two groups encompass ten populations that differ from previously defined management stocks in the Alboran Sea, Iberian-Atlantic and Bay of Biscay regions. In addition, a new North Sea-English Channel stock is defined. SNPs indicate that some populations in the Bay of Biscay are genetically closer to North Western (NW) Mediterranean populations than to other populations in the NE Atlantic, likely due to colonizations of the Bay of Biscay and NW Mediterranean by migrants from a common ancestral population. Northern NE Atlantic populations were subsequently established by migrants from the Bay of Biscay. Populations along the Iberian-Atlantic coast appear to have been founded by secondary waves of migrants from a southern refuge.  相似文献   

5.
The present work deals with the microfauna of small benthonic and planktonic Foraminifera from the Burdigalian stratotype of Aquitaine basin (France) and from a few outcrops in the stratotype vicinity showing the upper or lower boundary of the stratotype.Benthonic fauna is rich: more than 250 species divided in 92 genera have been collected. The most frequent are hyaline Foraminifera (Pararotalia, Elphidium, Asterigerina, Florilus, Virgulopsis, Bolivina). The miocene feature is more pronounced than in the Aquitanian stratotype.Planktonic Foraminifera are much less abundant:only 20 species. However, some of them authorize to place the stratotype (or its equivalent l. s.) in N5 Blow's zone and perhaps in the basel N6 zone.The figurations of many species are made withthe scanning electronic microscope.  相似文献   

6.
Etienne Steurbaut 《Geobios》1980,13(1):111-114
The continental Aquitanian of Southern France has yielded an otolith fauna containing seven species pertaining to the Umbridae and Cyprinodontoidei. One new species is here introduced: genus Cyprinodontidarum feistae. Such an assemblage indicates lacustrine deposition with possibly lagoonal influence. Two zones have been established: a first one, corresponding to the Lower and Middle Aquitanian is characterized by Prolebias praecursor; the second one, representing the Upper Aquitanian, is more diversified and characterized by genus Cyprinodontidarum angulosus.  相似文献   

7.
Micropaleontological studies of Tertiary shales and carbonates of the continental shelf of northeast Brazil have shown the existence of several levels rich in scolecodnts, even in areas in which other taxa are absent. A systematic analysis of the vertical distribution of these worm remains in relation to the Eocene/Oligocene stratigraphical subdivision based on pollen and spores, dinoflagellates, nannoplankton and foraminifera leads to the possibility of establishing a scolecodont zonation that can be traced into areas in which other microfossils are rarely preserved. This possibility, which may be a new stratigraphical tool in the exploration for petroleum in Brazil, is applied to the off-shore Maranhão basin.  相似文献   

8.
How rich is the deep-sea Antarctic benthic hydroid fauna?   总被引:3,自引:3,他引:0  
The bathymetric distribution of the 155 known species of Antarctic benthic hydroids has been studied with the aim of determining bathymetric groups and estimating the richness of the deep-sea Antarctic benthic hydroid fauna. Six bathymetric groups could be recognized on the basis of vertical zonation patterns. Most species have wide bathymetric ranges, but must nevertheless be considered shelf species. Although 62 species of benthic hydroids have been found in the Antarctic deep-sea, only 10 are strict inhabitants of that area. An inverse relative dominance between anthoathecate and leptothecate hydroids has been observed, with the former being more frequent in shallow waters.  相似文献   

9.
A bottom trawl survey was conducted over all of the shelf and continental slope in the Russian waters of the Sea of Japan, from Peter the Great Bay to the La Perouse Strait, from March 31 to July 8, 2015. The species composition and biomass of demersal fish were determined for Peter the Great Bay, waters of southern and northern Primorye, and the West Sakhalin subzone. The bulk of the biomass (over 90% of the estimated biomass in the study areas) was formed by four families: Gadidae, Pleuronectidae, Cottidae, and Clupeidae. The highest biomass, 218000 t, was recorded from the West Sakhalin subzone; the lowest, 77400 t, was found from Peter the Great Bay. The proportions of biomasses of the considered species varied substantially between areas: walleye pollock and plain sculpin dominated by biomass in Peter the Great Bay; walleye pollock and scale-eye plaice dominated off southern Primorye; herring dominated off northern Primorye; and scale-eye plaice and speckled founder were dominant in the West Sakhalin subzone. The density of the fish concentration was determined for several bathymetric ranges in the considered areas. In the period of studies, the pattern of distribution of fish in Peter the Great Bay was still of the winter type, which is characterized by high concentrations over the continental slope. There was some shift towards shallower depths in Primorye waters; however, taking the great latitudinal span of the area of the research and the early spring into account, these migrations were not so clearly pronounced, as would be observed in later periods. The most distinct differences in the bathymetric distribution were found in the West Sakhalin subzone, where the distribution pattern corresponded mostly to the summer type with its high concentrations in shallow waters and low ones over the continental slope. According to the estimates in 2015, the biomass of demersal fish slightly increased as compared to the values of the 1980s–1990s.  相似文献   

10.
Foraminifera are documented from the type section of the Quinnanie Shale in order to interpret their bathymetric distributions in a shallow high-latitude interior sea during the Kungurian. The marine setting was a narrow elongate half-graben (Merlinleigh Sub-Basin of the Southern Carnarvon Basin) in the Western Australian portion of eastern Gondwana. The Quinnanie Shale is part of the Byro Group of formations that display pronounced shale–sand cyclicity recording frequent changes in bathymetry. The type section of the Quinnanie Shale shows an overall progradational pattern in lithofacies, and consists of five ‘cycles’, each culminating in a prominent sandstone bed. Foraminifera are abundant in the shale and are almost entirely siliceous (organic-cemented) agglutinated types that probably dominated the original fauna of the interior sea. Hierarchical cluster analysis of samples taken every meter through the 162-m-thick type section is used to distinguish ten biofacies, each defined by a different set of dominant agglutinated species. Although biofacies frequently change up-section, there is an overall trend that is related to the progradational trend suggested by the lithofacies. Based on comparisons between lithofacies and biofacies, a palaeobathymetric zonation is established for the foraminifera. This zonation, the sparse macrofauna, and the lithofacies suggest that the interior sea was stratified in terms of salinity and dissolved oxygen levels, and the water was generally hyposaline. Most of the agglutinated foraminiferal species have analogous morphotypes present in modern confined estuaries and interior seas and this points to great conservatism in the evolutionary and ecological development of this component of interior-sea faunas. Aaptotoichus quinnaniensis sp. nov., an organic-cemented agglutinated foraminifer, is described from the Quinnanie Shale type section.  相似文献   

11.
Phage-host cross-reaction tests were performed with 774 bacterial strains and 298 bacteriophages. The bacteria (bacteriophages) were isolated at different times from water samples collected in the Atlantic Ocean between the European continental shelf and the Sargasso Sea: 733 (258) strains; in the North Sea near Helgoland: 31 (31) strains; and in the Bay of Biscay: 10 (9) strains. Of the Atlantic Ocean bacteria 326 were found to be susceptible to one or more Atlantic Ocean bacteriophage(s). The bacteriophage sensitivity patterns of these bacteria vary considerably, placing 225 of them in two large clusters of bacteriophage-host systems. Taking all into account, 250 of the 326 Atlantic Ocean bacteria are different from each other. This high degree of variation among the bacteria distinguishes microbial populations derived from widely separated eastern and western regions of the Atlantic Ocean. It also sets apart from each other the populations derived from samples collected at successive stations some 200 miles apart, although to a lesser degree. With bacterial populations found from samples collected on the way back and forth between Europe and the Sargasso Sea a gradual change was observed from "western" phage sensitivity patterns to "eastern" ones. Sixty-nine Atlantic Ocean bacteria are sensitive to bacteriophages isolated from the North Sea and the Bay of Biscay; of these only 26 strains are also susceptible to Atlantic Ocean phages. The interpretation of the results is based on the hydrographical conditions prevailing in the northern Atlantic Ocean including the North Sea, and on the assumption that the microbial populations investigated have undergone genetic changes while being transported within water masses from west to east.  相似文献   

12.
The distribution of scleractinian corals in the Bay of Biscay, NE Atlantic   总被引:1,自引:0,他引:1  
Studies on the distribution of scleractinian corals in the Bay of Biscay were relatively numerous during the nineteenth and the first half of the twentieth century. Yet, recent reports are scattered, sometimes unpublished, and therefore knowledge about the current coral occurrence in the area is limited. This study aims at compiling the available historical and more recently collected information on the occurrence of scleractinian corals in the Bay of Biscay. Data from two recent cruises are included and compared with previous explored coral sites from as early as 1830 up to 1995. A database of 347 records including 34 described species of scleractinians highlights that the slope of the Bay of Biscay is an important habitat for scleractinians. This could be expected due to the high topographic relief providing the necessary hard substrate and accelerated bottom current flow that corals require. Further exploration of the occurrence and ecology of corals in the area is recommended to support the conservation of cold-water coral reefs along the European margin. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

13.
The mesozooplankton community was monitored at both coastaland offshore sites of the Basque shelf (inner Bay of Biscay)during 1988–1990 This was considered of interest becausethe local climate change toward dry conditions was found tobe responsible for changes in shelf-water properties. In additionto seasonal changes, interannual variations in mesozooplanktonabundance and composition were evident, and primarily relatedto the year-to-year increase in water temperature and salinity.The increasing trends in copepod dominance, coupled with theincreasing abundance of species with oceanic affinity (e.g.Euchaeta hebes), were presumably a response to the increasein oceanic features in the shelf area. In the same way, thesubstantial year-to-year increase in the abun dance of specieswith summer-autumn development was attributed to the progressivewarming. Among these species, the case of Temora stylifera isdiscussed specifically because this species was very scarcein 1988, but showed unusual high abundances for the study area,and dominated the summer-autumn assemblage in 1990. We thinkthat T.stylifera can be a key species in monitoring climate-oceanologicalchanges affecting the Bay of Biscay. Results are also discussedin the context of the long climate-oceanological series forthe Bay of Biscay, and its biogeographical status.  相似文献   

14.
Jean-Pierre Suc 《Geobios》1976,9(6):741-767
The present study illustrates clearly how pollen analysis may be applied to stratigraphy from a botanical point of view. Within a chronologically reliable frame (Middle Pliocene for the marine deposits on the basis of Foraminifera record; two subzones for continental deposits on the basis of Mammals record: Hautimagne for Terrats fauna, Sète for Serrat-d'en-Vacquer fauna), palynology provides a good stratigraphical boundary: the extinction of the Taxodiaceae. In a remblayage area, it is established that a continental level is not necessarily younger than a marine one unless they are superposed. Many profiles are replaced according to the «progradation of the pliocene gulf of Roussillon. The boundary between marine and continental deposits cuts through the chronological line of the Taxodiaceae extinction. The flora investigated (93 taxa) is the first known for the Pliocene of this area. The extinction of the Taxodiaceae in southern France has a climatic cause: the setting in of a mediterranean rhythm (dry summers). This extinction is much older than the one which took place in Italy (Tiberian boundary) and in the Netherlands (Reuverian-Pretiglian boundary).  相似文献   

15.
The taxonomic composition and quantitative distribution of the meiobenthos were studied in materials collected from one of the former nuclear test sites by the Novaya Zemlya Archipelago in Chernaya Guba (Barents Sea) and from the grounds of nuclear waste disposal along the east coast of the Archipelago from Abrosimov Bay to Stepovoi Bay and the region of Novozemel'skaya Hollow (Kara Sea). Foraminifera and free living nematodes were the most numerous groups, and foraminifera prevailed in terms of biomass in the entire area studied. No correlation of the parameters of the meiobenthic communities with varying depth and type of ground was revealed. It was established that the taxonomic diversity increased and population density decreased with an increase in the concentration of 137Cs. It was suggested that meiobenthic communities are able to respond quickly to the deterioration of environmental radioactivity, varying their taxonomic composition and parametrical indexes.  相似文献   

16.
The objective of this work is to characterise the variations of the quality of the glass eels recruitment during a season of migration, from November till March and before and after the transition from marine to continental environment. The emaciation state measured from the ratio DNA/Dry weight and percentage of body water is analysed from a sampling of glass-eels collected at sea and in estuary, in the South of the Bay of Biscay during the migration period 1999/2000. The length and the mass are taken into account, they decrease during the season while the individuals are more and more pigmented. However, our work shows that groups of glass eels arriving on the coasts of the Bay of Biscay are homogeneous from the point of view of their energetic and hydride reserves with a high individual variability within these groups. Also no significant difference in losses of water and energetic reserve were observed among the individuals migrating at the beginning and during tide stream. Fluctuations of the biochemical indication and the percentage of water between the glass eels caught in sea and in estuary show that the transition between maritime and continental environment is not a mobilising event of a lot of energy for glass eels. Differences were only observed in December.  相似文献   

17.
 Composition and distribution of megabenthic communities around Svalbard were investigated in June/July 1991 with 20 Agassiz trawl and 5 bottom trawl hauls in depths between 100 and 2100 m. About 370 species, ranging from sponges to fish, were identified in the catches. Species numbers per station ranged from 21 to 86. Brittle stars, such as Ophiacantha bidentata, Ophiura sarsi and Ophiocten sericeum, were most important in terms of constancy and relative abundance in the catches. Other prominent faunal elements were eunephthyid alcyonarians, bivalves, shrimps, sea stars and fish (Gadidae, Zoarcidae, Cottidae). Multivariate analyses of the species and environmental data sets showed that the spatial distribution of the megabenthos was characterized by a pronounced depth zonation: abyssal, bathyal, off-shore shelf and fjordic communities were discriminated. However, a gradient in sediment properties, especially the organic carbon content, seemed to superimpose on the bathymetric pattern. Both main factors are interpreted as proxies of the average food availability, which is, hence, suggested to have the strongest influence in structuring megabenthic communities off Svalbard. Received: 28 April 1995/Accepted: 18 November 1995  相似文献   

18.
Digenean metacercariae of 0 year group common sole Solea solea ( n = 70) were more abundant in the embayed nursery of the Pertuis Charentais than in the Tagus estuary nursery. Macroparasite assemblages of adult sole ( n = 119) displayed only one species in common between the Bay of Biscay and the Portuguese coast continental shelves. These data highlighted the potential use of macroparasites as biological tags in various aspects of common sole ecology.  相似文献   

19.
Although foraminifers have been extensively used for biochronology, no quantitative evaluation of the quality of their application is available. In this work we apply a quantitative approach – the Unitary Association (UA) method – to evaluate the relative quality of planktic and benthic foraminifers in biostratigraphy. Based on 12,321 specimens belonging to 65 planktic and 132 benthic foraminifer species in 117 samples from the Paleocene–Eocene strata of the Kharga-Baris Oases (Western Desert, Egypt), the potential stratigraphic resolution power of benthic foraminifers is quantitatively assessed and compared to planktic foraminifers. The UA method accounts for superpositional contradictions between sets of coexisting taxa and generates unitary associations, which are conceptually similar to Oppel zones. The analysis produced fifteen unitary associations for the Paleocene–Eocene benthic Foraminifera of the studied sections, instead of three classical zones; most of these unitary associations are easily identified by the restricted occurrence of a single species. Although planktic Foraminifera have a higher seriation reality leading to a more robust biozonation, benthic Foraminifera have a higher stratigraphic resolution, at least at such regional scale. Furthermore, there was a significant positive correlation between the number of unitary associations and the number of species (R = 0.78 for planktic and 0.70 for benthic foraminifers; both with p < 0.001). These results corroborate that quantitative techniques may lead to a higher resolution in biochronology, even when applied to poor biochronological markers. Moreover, in contrast to simple spatiotemporal analyses, the Unitary Association method can accurately assess the stratigraphic potential of a given taxonomic group.  相似文献   

20.
Recent data generally substantiate the most recent incarnation of the Cenozoic time-scale (Berggren, 1969c). Newly obtained dates in the type section of the Chattian (Upper Oligocene) support a previous suggestion that a hiatus may separate the top of the stratotype Chattian from the base of the stratotype Aquitanian. The Orbulina Datum is placed at 16 my and the Globigerina nepenthes at 13.5 my. The junction of Eurasia and Africa in the early Miocene (ca. 18 my ago) and of Europe and Africa in the middle Miocene (ca. 15 my ago) markedly affected the Tethyan paleogeography and, concomitantly, the biogeographic dis tribution of larger and smaller Foraminifera, as well as various land mammal groups, including hominoids.  相似文献   

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