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A record of the Messinian salinity crisis in the eastern Ionian tectonically active domain (Greece,eastern Mediterranean) 
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下载免费PDF全文 Vasileios Karakitsios Marco Roveri Stefano Lugli Vinicio Manzi Rocco Gennari Assimina Antonarakou Maria Triantaphyllou Konstantina Agiadi George Kontakiotis Nefeli Kafousia Marc de Rafelis 《Basin Research》2017,29(2):203-233
This integrated study (field observations, micropalaeontology, magnetostratigraphy, geochemistry, borehole data and seismic profiles) of the Messinian–Zanclean deposits on Zakynthos Island (Ionian Sea) focuses on the sedimentary succession recording the pre‐evaporitic phase of the Messinian salinity crisis (MSC) through the re‐establishment of the marine conditions in a transitional area between the eastern and the western Mediterranean. Two intervals are distinguished through the palaeoenvironmental reconstruction of the pre‐evaporitic Messinian in Kalamaki: (a) 6.45–6.122 Ma and (b) 6.122–5.97 Ma. Both the planktonic foraminifer and the fish assemblages indicate a cooling phase punctuated by hypersalinity episodes at around 6.05 Ma. Two evaporite units are recognized and associated with the tectonic evolution of the Kalamaki–Argassi area. The Primary Lower Gypsum (PLG) unit was deposited during the first MSC stage (5.971–5.60 Ma) in late‐Messinian marginal basins within the pre‐Apulian foreland basin and in the wedge‐top (<300 m) developed over the Ionian zone. During the second MSC stage (5.60–5.55 Ma), the PLG evaporites were deeply eroded in the forebulge–backbulge and the wedge‐top areas, and supplied the foreland basin's depocentre with gypsum turbidites assigned to the Resedimented Lower Gypsum (RLG) unit. In this study, we propose a simple model for the Neogene–Pliocene continental foreland‐directed migration of the Hellenide thrusting, which explains the palaeogeography of the Zakynthos basin. The diapiric movements of the Ionian Triassic evaporites regulated the configuration and the overall subsidence of the foreland basin and, therefore, the MSC expression in this area. 相似文献
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In Europe the process of agricultural engagement or disengagement is attributed to the economic factor and mainly on the level
of alternative employment source development. It is the relational quality of economic, social and environmental factors that
determine sustainability of agricultural holdings and, hence, households. In regions of poor agricultural structures and of
many employment opportunities as well as in regions suffering from agricultural depression, households exhibit stronger tendencies
towards agricultural disengagement. Remarkably in southern Europe a stable agricultural engagement and not disengagement is
observed, even though in recent years there are limited possibilities of alternative income sources and prevailing agricultural
depression. This article highlights the factors which lead households to stable engagement with agriculture in a region of
southern Europe, the island of Lesvos. The island is characterised by traditional olive grove mono-culture, poor agricultural
structures and limited employment opportunities. The investigation of the economic, social and environmental farm household
characteristics concluded that in regions where poor agricultural infrastructure and lack of employment prevail, all three
factors of sustainability contribute to stability and/or low agricultural disengagement. Among these, the economic factor
is the most sensitive and hence highly influential. The social factor is highlighted as a quality and consistent factor due
to the respect for tradition. The environmental factor, finally, is characterised by mild cultivation practices, contributing
to environment conservation. 相似文献
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M. V. Triantaphyllou A. Antonarakou K. Kouli M. Dimiza G. Kontakiotis M. D. Papanikolaou P. Ziveri P. G. Mortyn V. Lianou V. Lykousis M. D. Dermitzakis 《Geo-Marine Letters》2009,29(4):249-267
Quantitative analyses of coccolithophores, planktonic foraminifers, dinoflagellate cysts and pollen assemblages were carried
out on shallow (NS-14) and deeper (NS-40) sediment cores from the south-eastern Aegean Sea. Nine coccolithophore (ACE 1–9)
and nine planktonic foraminifer (APFE 1–9) ecozones, correlated with dinoflagellate cyst evidence, have been defined for the
last ~14.5 cal. ka. Additionally, eight pollen assemblage zones (PAZ 1–8) have been recognised and correlated with the plankton
ecozones. Although generally consistent with existing schemes for the central and eastern Mediterranean, the established high-resolution
ecostratigraphy has led to an expanded palaeoecological reconstruction of the Late Glacial–Holocene archive in the south-eastern
Aegean Sea, defining two warm and humid phases at 9.3–8.6 and 7.6–6.4 cal. ka b.p., associated with the deposition of the early Holocene sapropel S1, and a third one between 5.2 and 4.2 cal. ka b.p. The high sedimentation rates which characterise the study area enabled the detection of even minor and brief climatic events
in the Aegean Sea during S1 deposition times.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Maria V. Triantaphyllou Assimina Antonarakou Margarita Dimiza Christos Anagnostou 《Geo-Marine Letters》2010,30(1):1-13
In core ADE3-23 collected in the Libyan Sea, the nannofossil species Coccolithus pelagicus, Coronosphaera spp., Helicosphaera spp., Syracosphaera spp., Calcidiscus spp., small Gephyrocapsa spp., and the planktonic foraminifers Globigerina bulloides, Neogloboquadrina pachyderma, Globorotalia scitula, Turborotalita quinqueloba and Neogloboquadrina dutertrei prevail in sapropel S6 (midpoint at 172 ka b.p.), indicative of cold and highly productive surface conditions. Warm and highly stratified water-column conditions are recorded
by the characteristic assemblage of Globigerinoides ruber, Globoturborotalita rubescens, Florisphaera profunda, Rhabdosphaera spp. during the sapropel S5 depositional interval (midpoint at 124 ka b.p.). Compared with S5, Globigerinita glutinata, Globorotalia inflata, Globigerinella siphonifera, Globorotalia truncatulinoides and the calcareous nannofossil Emiliania huxleyi characterise less stratified conditions within sapropel S1 (midpoint at 8.5 ka b.p.). Multivariate statistical analyses of calcareous nannofossil and planktonic foraminifers in core ADE3-23 identify planktonic
assemblages which typify sapropels S6, S5 and S1 in the Libyan Sea. A warmer interval is recognised in the middle part of
the cold S6, and can be associated with an influx of less saline waters and the occurrence of a faint, temporary deep chlorophyll
maximum. Evidence for enhanced surface productivity and breakdown of stratification is observed in the middle–upper part of
the warm S5, associated with climatic deterioration. Moreover, an increase in surface productivity in the upper S1 implies
weak stratification. Our combined calcareous nannofossil and planktonic foraminiferal data add to the evidence that climate
variability was more pronounced than commonly considered to date for all the three studied Eastern Mediterranean sapropel
depositional intervals. 相似文献
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An integrated faunal and geochemical dataset has been generated by the study of a late Miocene (early Tortonian) sedimentary
section outcropping at Manassi, Levkas Island (eastern Mediterranean). Quantitative analysis of benthic foraminifers from
the 25-m-thick section indicates changes of bottom palaeoecological conditions in this part of the eastern Mediterranean,
during the analyzed time interval. Benthic foraminifer assemblages are typical of a bathyal environment and testify to relatively
oxygenated conditions with low to moderate food supply alternating with periods with an increase in organic matter content.
The long-term palaeoceanographic analyses indicate an anti-estuarine circulation model based on the benthic foraminifer and
stable isotope results, which evolved in a strong estuarine circulation. The positive relationship existing between the plankton
δ18O and δ13C, in most of the record, agrees well with the hypothesis of a variable contribution of runoff. In three stratigraphic levels,
samples record heavy bottom water δ18O and δ13C values and light surface δ18O values, representing a wet, warm, estuarine climate with a stratified water column. In two stratigraphic levels, samples
have depleted δ13C and δ18O values for both surface and bottom waters. These two samples represent wet, warm climates with some ocean mixing and stratification.
The stable isotope signal of foraminifer tests from the Manassi section was influenced by the global temperature changes,
but the local factors also played an important role. The palaeoenvironments derived from stable isotope analysis in this study
are interpreted as responses to the local tectonic instability together with monsoon intensities that enhanced continental
runoff, characteristic for the time interval studied in the study area. Due to the limited data available from this study,
no correlations with the precessional, obliquity, or eccentricity cycles can be made. 相似文献
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Karpouza Maria Chousianitis Konstantinos Bathrellos George D. Skilodimou Hariklia D. Kaviris George Antonarakou Assimina 《Natural Hazards》2021,109(1):637-669
Natural Hazards - The present study aims to suggest an approach that allows the simultaneous hazard zonation mapping of earthquake-induced secondary effects. The modeling process of the applied... 相似文献
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