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Roban R.-D.,University of Bucharest | Melinte-Dobrinescu M.C.,National Institute of Marine Geology and Geo ecology
Cretaceous Research | Year: 2012

Lower Cretaceous deposits of the Tarcâu Nappe, central part of the Eastern Carpathians, were studied, aiming to point out their lithofacies and to reconstruct the changes in depositional palaeoenvironment of those times. The investigated deposits extend within the NC5-NC10 calcareous nannoplankton biozones, covering the Late Barremian-Late Albian. Based on sedimentological, petrographical and geochemical features, ten lithofacies were identified, grouped in three categories, such as shaly, siliciclastic and carbonate. The shaly lithofacies consist of black and grey shales, as well as carbonate shales yielding an average of organic matter content around 3%. The organic matter and pigments of iron, such as hydrotroillite are responsible for the occurrence of the black colour. Preservation of the organic matter is due to anoxic environments induced by reduced current flow and intensified water density stratification. The siliciclastic lithofacies are mainly composed of quartz arenites, quartzwackes, and subordinately sublitharenites and lithic graywackes. The carbonate lithofacies include predominantly marls and siderites, originating by diagenetical processes of the shaly lithofacies, and subordinately calcarenites with terrigenous material and sponge spicules. The petrography and geochemistry indicate that the main sources of the sandy detrital material are the basement and sedimentary cover of the Central (Scythian) and East European platforms. The black and grey shale deposition, in the Barremian-Late Aptian interval, reflects suspension settling of the hemipelagic and pelagic material. Thin sandy beds, with parallel lamination and current ripples, suggest low-density turbidity currents, while the Albian thick sandy beds with massive or normal grading and parallel lamination are interpreted as high-density turbidity currents or even sandy debris flows. The shaly depositional intervals are linked to the basinal plain, while the sandy dominated sequences are associated with turbiditic lobes. © 2012 Elsevier Ltd. Source

Popescu S.-M.,GeoBioStratData Consulting | Dalibard M.,GeoBioStratData Consulting | Suc J.-P.,CNRS Institute of Earth Sciences | Barhoun N.,Hassan II University | And 9 more authors.
Marine and Petroleum Geology | Year: 2015

We present a high-resolution analysis of planktonic foraminifers, calcareous nannofossils, ostracods, dinoflagellate cysts and pollen grains in four sequences from DSDP-ODP holes in the southwestern Mediterranean Alboran and Balearic basins (976B, 977A, 978A and 134B) encompassing the previously defined Messinian-Zanclean boundary. The study focuses on (1) the marine reflooding, which closed the Messinian Salinity Crisis prior to the Zanclean GSSP; (2) the nature of the Lago Mare in the deep basins (indicated by Paratethyan dinoflagellate cysts), which appears to comprise several Paratethyan influxes without climatic control; and (3) the depositional context of the youngest Messinian evaporites which accumulated in a marine environment relatively close to the palaeoshoreline. Isolation of the Aegean Basin during the paroxysmic second step of the crisis is considered to have stored Paratethyan waters, which may then have poured into the Mediterranean central basins after deposition of the evaporitic sequence. © 2015 Elsevier Ltd. Source

Melinte-Dobrinescu M.C.,National Institute of Marine Geology and Geo ecology | Bojar A.-V.,University of Graz
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

This study presents carbon and oxygen isotope fluctuations identified in marine red marlstones and claystones of the Fizeşti Formation from the SE Haţegeg area (Southern Carpathians, Romania). Biostratigraphy based on calcareous nannoplankton allow the identification of nannofossil standard zones and subzones CC16-CC17 up to CC20, and respectively UC11c up to UC15b, indicating that the investigated deposits are latest Coniacian-late Early Campanian in age. Throughout the studied succession, Δ13C values fluctuate between 1.4% and 2.65%, while Δ18O values are between -3% and -4%.In the middle Santonian (within the UC12 calcareous nannofossil zone), we found a slight positive carbon isotope excursion, with values increasing by 0.3%, up to a value of 2.44%, which we assume to represent the regional expression of the Horseshoe Bay Event, originally recognized in the English Chalk. In the uppermost Santonian, just below the first occurrence of the crinoid Marsupites testudinarius (within the UC13 calcareous nannofossil zone), we recorded a Δ13C increase, from 2.38% up to 2.63%, correlative with the Hawks Brow Event, firstly described in UK. The most significant Δ13C increase identified by us, up to 2.63%, is coincident with the last occurrence of the crinoid Marsupites testudinarius (=the Santonian-Campanian boundary) and represents the regional expression of the worldwide distributed Santonian/Campanian Boundary Event. The Santonian-Campanian boundary is associated with a slight positive excursion for Δ18O. In the lower part of the Campanian stage, Δ13C values progressively decrease to around 1.5%.A decrease of the water surface temperature in the region is suggested for the lower part of the Santonian, an assumption based on the significant shift to less negative values of Δ18O and on the mixed (Tethyan and Boreal) character of the identified nannofloras. From the Santonian-Campanian boundary interval upwards, the temperatures were rising, leading to an arid and warm climate in the region. This climate mode continued probably into the Maastrichtian, when the Haţeg area became part of an island situated in the Northern Tethys Realm. © 2009 Elsevier B.V. Source

Melinte-Dobrinescu M.C.,National Institute of Marine Geology and Geo ecology
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

This paper presents the lithological and biostratigraphical (mainly based on calcareous nannofossils) record of the marine sediments which crop out in the NW and SE Haţeg regions. Upper Cretaceous marine deposition starts in these two regions in the Early Cenomanian (both in the CC9 calcareous nannofossil zone, and within UC1-UC2 biozones, respectively). In NW Haţeg, a hemipelagic sequence composed of red shales and marlstones, followed by white marlstones, probably associated with a deep-water paleoenvironment, marked the beginning of Upper Cretaceous marine sedimentation. In the SE, marine deposition started with sandstones and calcarenites, interlayered with Actaeonella and Ytruvia coquina, indicating an infralittoral paleoenvironment. From the Cenomanian up to the Coniacian, the marine setting becomes progressively shallower in the two Upper Cretaceous marine depositional Haţeg areas; this change is marked by the occurrence of outer shelf deposits in the NW and inner shelf sediments up to infralittoral ones in the SE. These deposits are followed by lower Santonian-upper Campanian turbidites in the NW, and by Lower Santonian-Campanian pro parte red marlstones and Upper Campanian turbidites, in the SE. The marine sedimentation ends, in NW Haţseg, with distal turbidites, Late Campanian in age (placed in the CC22 calcareous nannofossil zone, in the UC15d subzone respectively, slightly above the first occurrence of the nannofossil Uniplanarius trifidus). Towards the end of the Campanian, conglomerates and sandstones with Actaeonella and Ytruvia coquina, yielding reworked nannofloras (including Late Campanian taxa), occur in SE Haţeg. Associated with the paroxysmal Laramian tectonic phase, continental deposition started, probably within the Campanian/Maastrichtian boundary interval, both in the NW and SE parts of the Haţeg region. During the Late Cretaceous interval, different paleoenvironmental settings may be distinguished in the NW Haţeg (where a deep marine basin developed for most of the Early Cenomanian up to the Late Campanian interval), and in the SE Haţeg (characterised by an outer oscillating basin with an episodic shallow-water deposition in the same interval). Despite the various backgrounds of the two regions, some common regional events, such as the Early-Middle Cenomanian and the Early Santonian-Early Late Campanian sea level highstand, as well as the Late Cenomanian-Coniacian sea-level lowstand were recognised in both investigated areas. © 2009 Elsevier B.V. Source

Sano M.,University of Cantabria | Sano M.,Griffith University | Jimenez J.A.,Polytechnic University of Catalonia | Jimenez J.A.,International Center for Coastal Resources Research | And 5 more authors.
Ocean and Coastal Management | Year: 2011

Coastal erosion and storms represent a source of risk for settlements and infrastructure along the coast. At the same time, coastal natural assets, including landscape, are threatened by increasing development mainly driven by tourism. The Mediterranean coast is especially vulnerable to these processes, considering its high biological and cultural diversity. An additional challenge is represented by climate change, as it will force coastal communities to apply more or less drastic adaptation strategies. Coastal setbacks, used to protect coastal communities and infrastructure from storms and erosion, and to preserve coastal habitats and landscapes from degradation, is one of the main instruments suggested by the Protocol on Integrated Coastal Zone Management of the Barcelona Convention, entered into force on the 24 of March 2011. Its implementation has the potential to influence coastal policies in other regions, such as the neighbouring Black Sea.The CONSCIENCE project has formalized concepts and conducted specific studies to provide new tools for coastal erosion management practice. The objective of this paper is to present a synthesis of the research conducted into coastal setbacks for coastal erosion management and climate change adaptation. This is done by analysing the requirement of the Protocol, current processes and management practices in two case study areas (Costa Brava Bays in Spain and Danube Delta, in Romania) and the new challenges posed by climate change. © 2011 Elsevier Ltd. Source

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