Palaeoenvironmental reconstruction of the Oligocene Afales Basin, Ithaki island, western Greece

2009 ◽  
Vol 1 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Hara Drinia
Keyword(s):  
Environmental Conditions ◽  
Benthic Foraminifera ◽  
Bottom Water ◽  
Marine Environments ◽  
Palaeoenvironmental Reconstruction ◽  
Basin Morphology ◽  
Palaeoenvironmental Conditions ◽  
Western Greece ◽  
High Diversity ◽  
Undisturbed Flow

AbstractAssemblages of benthic foraminifera from one clastic succession in the Afales Basin (Ithaki Island, western Greece) were investigated to reconstruct palaeoenvironmental conditions during the Oligocene. The section consists of alternating hemipelagic marls and detrital deposits, designated as flysch-like beds, attributed to biostratigraphic Zones P20 and P21. Planktic percentages are mostly high (66–80%). Benthic foraminiferal assemblages comprise calcareous and agglutinated taxa (up to 15%). The prevalence of epifaunal foraminifera indicates good ventilation of the bottom water resulting from basin morphology, which enabled the undisturbed flow of water throughout the basin. Palaeodepth estimates imply bathyal deposition, from about 800 to 1200 m deep. The benthic foraminiferal fauna is of high diversity along the section, as is expected in deep marine environments. The abundances of the most common foraminiferal taxa (Cibicidoides spp., Oridorsalis umbonatus, Gyroidinoides spp., Stilostomella spp., Nodosariidae, Nuttallides umbonifera) are quite variable and imply generally oligotrophic to mesotrophic environmental conditions with variable organic flux.

scholarly journals New Approaches for the Observation of Transient Phenomena in Critical Marine Environment

2021 ◽  
Vol 9 (6) ◽  
pp. 578
Author(s):  
Roberta Ferretti ◽  
Massimo Caccia ◽  
Massimo Coltorti ◽  
Roberta Ivaldi
Keyword(s):  
Mediterranean Sea ◽  
Marine Environment ◽  
Environmental Conditions ◽  
Marine Environments ◽  
Transient Phenomena ◽  
New Approaches ◽  
Marine Vehicles ◽  
New Methodologies ◽  
Biogeochemical Parameters ◽  
Very High

This paper focuses on the development of new approaches to observe transient phenomena in critical marine environments using autonomous marine vehicles (AMVs) for the acquisition of physical and biogeochemical parameters of water and seabed characterization. The connection with metrological principles, together with the adoption of observing methodologies adjustable according to the specific marine environment being studied, allows researchers to obtain results that are reliable, reproducible, and comparable with those obtained through the classic monitoring methodologies. Tests were executed in dramatically dynamic, sensitive, and fragile areas, where the study and application of new methodologies is required to observe phenomena strongly localized in space and requiring very high resolutions, in time. Moreover, the harsh environmental conditions may present risks not only for the quality and quantity of the acquired data but also for the instrumentation and the operators. This is the case, for instance, in polar marine environments in proximity of tidal glaciers and in the Mediterranean Sea in areas characterized by seabed degassing activities, where AMV-supported monitoring procedures can allow for the safe observation of not repeatable and not completely predictable events.

scholarly journals SEDIMENTOLOGICAL AND PALAEOENVIRONMENTAL CHARACTER OF LAKE KORONIA SEDIMENTS

2017 ◽  
Vol 50 (1) ◽  
pp. 295
Author(s):  
S. Doani ◽  
K. Albanakis ◽  
O. Koukousioura ◽  
K.K. Koliadimou
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Environmental Conditions ◽  
Water Body ◽  
Fine Sand ◽  
Lake Bottom ◽  
Bottom Sampling ◽  
Palaeoenvironmental Conditions ◽  
Freshwater Ostracods ◽  
Ostracod Species

The aim of the present study is to investigate the sedimentological characteristics of Lake Koronia down to a depth of 3.5m below lake bottom. Sampling operations took advandage of a season that the lake bottom was exposed to subaerial conditions. The sedimentological analysis proved that sediments consist of mud to sandy mud, with 2 phases of very fine sand fractions. The proportion of dry organic matter contained into sediment, appears to be generally small while the rates of moisture and volatiles are relatively high. Furthermore, this study examines the distribution of ostracod populations in the sediments of the lake in relation to depth, grain size and other environmental conditions of this water body. Four ostracod species were identified: Candona neglecta, Darwinula stevensoni, Heterocypris spp. and Limnocythere inopinata. The study of freshwater ostracods provides information for the palaeoecological/palaeoenvironmental conditions during the sedimentation.

scholarly journals Pleistocene Branchiopods (Cladocera, Anostraca) from Transbaikalian Siberia Demonstrate Morphological and Ecological Stasis

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3063
Author(s):  
Anton A. Zharov ◽  
Anna N. Neretina ◽  
D. Christopher Rogers ◽  
Svetlana A. Reshetova ◽  
Sofia M. Sinitsa ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Seasonal Variations ◽  
Environmental Changes ◽  
Daphnia Pulex ◽  
Steppe Zone ◽  
Water Bodies ◽  
Large Branchiopods ◽  
Community Types ◽  
High Diversity

Pleistocene water bodies have been studied using the paleolimnological approach, which traces environmental changes using particular subfossils as ecological proxies, rather than analysis of the paleocommunities themselves. Within a given taphocoenosis, the presence and quantity of animals are related to environmental conditions rather than to community types where relationships between taxa are stabilized during their long-term co-occurrence and are (at least partially) more important than the particular environmental conditions at the time of deposition, which may have experienced significant seasonal and inter-seasonal variations. Here, we analyze Branchiopoda (Crustacea) of two paleolocalities in the Transbaikalian Region of Russia: Urtuy (MIS3) and Nozhiy (older than 1.5 million years). Cladocerans Daphnia (Ctenodaphnia) magna, D. (C.) similis, D. (Daphnia) pulex, Ceriodaphnia pulchella-reticulata, C. laticaudata, Simocephalus sp., Moina cf. brachiata, M. macropopa clade, Chydorus cf. sphaericus, Capmtocercus sp. and anostracans Branchinecta cf. paludosa, and Streptocephalus (Streptocephalus) sp. are found in two localities. With the exception of the last taxon, which now occurs in the southern Holarctic, all other taxa inhabit the Transbaikalian Region. Within Eurasia, the steppe zone has the greatest diversity of large branchiopods and a high diversity of some cladocerans, such as subgenus Daphnia (Ctenodaphnia) and Moina sp. Here we demonstrated that the branchiopod community in shallow steppe water bodies has been unchanged since at least the Pleistocene, demonstrating long-term morphological and ecological stasis.

The genus Dolichopoda in Greece. A description of new species from the Ionian Regions and Peloponnisos (Orthoptera, Rhaphidophoridae)

Zootaxa ◽  
2008 ◽  
Vol 1923 (1) ◽  
pp. 1-17 ◽  
Author(s):  
MAURO RAMPINI ◽  
CLAUDIO DI RUSSO ◽  
FRANCESCA PAVESI ◽  
MARINA COBOLLI
Keyword(s):  
New Species ◽  
Central Area ◽  
The Other ◽  
The North ◽  
North Eastern ◽  
Western Greece ◽  
High Diversity

Description of five new Dolichopoda species from the Ionian area of Western Greece together with a description of the female for D. pavesii from Kefalonia island and the male of D. dalensi from North-eastern Peloponnisos are reported. Considering the other 6 species already documented in the area (including the North of the Peloponnisos), there is now a total of 11 recorded species of Dolichopoda which currently inhabit the underground areas of this zone. These new data, therefore, help better define the already high diversity of the genus in the Hellenic region (25 species in all) reinforcing the hypothesis that there was a central area of dispersion of the Dolichopoda in the ancient Aegean plate.

THE GEOLOGICAL EXPRESSION OF EUSTACY IN THE EARLY TERTIARY OF THE GIPPSLAND BASIN

1976 ◽  
Vol 16 (1) ◽  
pp. 73 ◽  
Author(s):  
A. D. Partridge
Keyword(s):  
Sea Level ◽  
Time Interval ◽  
Marine Environments ◽  
Fine Grained ◽  
Sedimentary Sequences ◽  
Seismic Records ◽  
Basin Morphology ◽  
The Times ◽  
Sequence Boundaries ◽  
Gippsland Basin

In the non-marine to marginal marine environments of the Latrobe Group, distinct sedimentary sequences are recognised on seismic records and these sequences are often expressed in wells by palynological zones, changes in E-log character and lithology.The succession of sequences represents variations in sea level, many of which are interpreted aseustatic. Eustatic falls are represented by unconformities and channel formation along the seaward margin and by hiatuses (frequently with dolomite cementation of underlying sands) landward in deltaic and non-marine sections. Eustatic rises are represented by dinoflagellate ingressions over truncated surfaces at sequence boundaries, followed by outbuilding of deltaic environments at the stillstand towards the end of each cycle.During the Paleocene and Eocene very little sediment was deposited beyond the limits of the marginal marine environments except within channels where the Flounder and Turrum Formations are found. In this time interval they was an overall landward encroachment of successive sequences reflecting an overall sea level rise. The interaction of rising sea level and limited deposition beyond the marginal marine edge meant that successive sequences became more restricted seaward such that within the marine environment the area of non-deposition increased. The surface thus defined, modified locally by channel erosion, constitutes the unconformity at the top of the Latrobe Group. This unconformity surface was preserved when deposition of fine-grained open marine sediments of the Lakes Entrance Formation commenced in the Oligocene.In the Tasman Sea a succession of terrigenous silts and clays present in the Deep Sea Drilling Project (DSDP) Site 283 can be correlated with periods when fine-grained sediments bypassed the Gippsland shelf. The stratigraphy of this site can be interpreted as a record of availability of sediment from the southeastern Australian continental shelf. The times of commencement and termination of stratigraphic units and disconformities at Site 283 correlate with timing of eustatic cycles. Thus the stratigraphy of Site 283 is a record, as is the Latrobe Group, of how eustacy interacts with basin morphology to modify distribution of sediments.

I/Ca in epifaunal benthic foraminifera: A semi-quantitative proxy for bottom water oxygen in a multi-proxy compilation for glacial ocean deoxygenation

2020 ◽  
Vol 533 ◽  
pp. 116055 ◽  
Author(s):  
Wanyi Lu ◽  
Rosalind E.M. Rickaby ◽  
Babette A.A. Hoogakker ◽  
Anthony E. Rathburn ◽  
Ashley M. Burkett ◽  
...  
Keyword(s):  
Benthic Foraminifera ◽  
Bottom Water ◽  
Water Oxygen ◽  
Ocean Deoxygenation

scholarly journals Mg/Ca-Temperature Calibration of Polar Benthic foraminifera species for reconstruction of bottom water temperatures on the Antarctic shelf

2020 ◽  
Vol 283 ◽  
pp. 54-66
Author(s):  
Elaine M. Mawbey ◽  
Katharine R. Hendry ◽  
Mervyn J. Greaves ◽  
Claus-Dieter Hillenbrand ◽  
Gerhard Kuhn ◽  
...  
Keyword(s):  
Benthic Foraminifera ◽  
Bottom Water ◽  
Temperature Calibration ◽  
Antarctic Shelf ◽  
The Antarctic

Environmental factors affecting recent benthic foraminiferal distribution in the south-eastern Baltic Sea

Baltica ◽  
2020 ◽  
Vol 33 (1) ◽  
pp. 58-70
Author(s):  
Ekaterina Ponomarenko ◽  
Viktor Krechik ◽  
Evgenia Dorokhova
Keyword(s):  
Organic Carbon ◽  
Baltic Sea ◽  
Benthic Foraminifera ◽  
Bottom Water ◽  
Environmental Parameters ◽  
Organic Carbon Content ◽  
The South ◽  
The Baltic Sea ◽  
South Eastern ◽  
The Baltic

The Baltic Sea is characterized by a restricted exchange of deep waters due to permanent stratification of the water column. The aim of the present study is to investigate the distribution of benthic foraminifera in the south-eastern part of the Baltic Sea in relation to environmental parameters. The distribution of benthic foraminifera was analyzed in 26 surface sediment samples collected in the south-eastern part of the Baltic Sea and in the Bornholm Basin during springtime and wintertime 2016. Foraminiferal diversity in the studied region was extremely low. Agglutinated specimens dominated the assemblages and were represented by small-sized individuals which belong to Psammosphaera, Pseudothurammina, Saccammina, and Reophax genera. Calcareous foraminifera were dominated by Cribroelphidium genus. Micropaleontological data were compared to the environmental parameters characterizing bottom water (temperature, salinity, and dissolved oxygen content) and substrate conditions (grain size composition and total organic carbon content). Higher foraminiferal concentrations and diversity were found in deeper parts of the study region where fine-grained sediments with a higher total organic carbon content were accumulated under stable hydrographical conditions. Calcareous tests were found only at the stations with elevated salinity, indicating that bottom water salinity is the main factor limiting the distribution of calcareous foraminifera. On the other hand, substrate parameters and hydrodynamic conditions appear to play a major role in the distribution of agglutinated foraminifera.

Long-term monitoring of benthic foraminiferal assemblages from Asia's largest tropical coastal lagoon, Chilika, India

2018 ◽  
Vol 99 (2) ◽  
pp. 311-330
Author(s):  
Vandana Kumari Gupta ◽  
Areen Sen ◽  
Ajit K. Pattnaik ◽  
Gurdeep Rastogi ◽  
Punyasloke Bhadury
Keyword(s):  
Coastal Lagoon ◽  
Benthic Foraminifera ◽  
Taxonomic Composition ◽  
Spatial Patterning ◽  
Pattern Diversity ◽  
Significant Seasonal Variation ◽  
Lagoon Environment ◽  
Term Monitoring ◽  
High Diversity

The present study undertaken in the largest coastal lagoon of Asia, Chilika, deals with monthly monitoring of benthic foraminifera assemblages in terms of distribution pattern, diversity and variations in taxonomic composition spanning over a period of 20 months. In total, 13 species of benthic foraminifera represented by eight families were identified in the lagoon. The stations in the Southern sector of the lagoon showed relatively low foraminifera abundance yet high diversity whereas higher abundance and lower diversity were observed in stations located in the Central sector which indicates the spatial patterning of the assemblage. Live foraminifera abundance was sparse in the study area indicating the stressed nature of the lagoon environment. The dissolved nutrient concentration of bottom water reflected significant seasonal variation. The stressed nature of the lagoon is further indicated by the dominance of the genus Ammonia across the inner sectors of the lagoon, a genus known to inhabit impacted habitats. Overall these data can serve as a baseline proxy for understanding palaeontological assemblages of foraminifera in similar shallow-water settings globally.

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