scholarly journals The Miocene–Pliocene hiatus in the southern North Sea Basin (northern Belgium) revealed by dinoflagellate cysts

2010 ◽  
Vol 147 (5) ◽  
pp. 760-776 ◽  
Author(s):  
STEPHEN LOUWYE ◽  
STIJN DE SCHEPPER
Keyword(s):  
North Sea ◽  
Time Interval ◽  
Dinoflagellate Cysts ◽  
Depositional History ◽  
Southern Boundary ◽  
Accommodation Space ◽  
The North ◽  
The North Sea ◽  
Southern Border ◽  
First Time

AbstractA palynological analysis with marine palynomorphs (dinoflagellate cysts, acritarchs, green algae) and terrestrial palynomorphs (pollen and spores) of the Kasterlee and Poederlee formations provides new insights in the depositional history at the southern border of the North Sea basin (northern Belgium) around the Miocene–Pliocene transition. Dinoflagellate cyst stratigraphy constrains the age of the Kasterlee Formation in the Oud-Turnhout borehole between 7.5 and 5.32 Ma. The upper boundary of the formation can be correlated with sequence boundary Me2 at 5.73 Ma of Hardenbol and co-workers, which further constrains its age to the time interval 7.5–5.73 Ma. The palynomorph assemblages reflect a near-coast depositional environment. Where present, the Kasterlee Formation thus terminates the Miocene series in northern Belgium. The overall shallow nature of the latest Miocene deposits is related to a sea-level lowering caused by the onset of globally cooling conditions. For the first time, palynology is applied to estimate the age of the Poederlee Formation, suggesting it was deposited during the Mid-Pliocene warm period. Dinoflagellate cysts and sequence stratigraphy together constrain the age of the unit between 3.21 and 2.76 Ma, and possibly even between 3.21 and 3.15 Ma. The Poederlee Formation was deposited in neritic environments, which shoaled in the upper part of the unit as a consequence of the decreasing availability of accommodation space. We demonstrate that the magnitude of the hiatus between the Miocene and Pliocene series varies strongly at the southern boundary of the North Sea Basin, and lasts in the Antwerp area c. 3.2 million years and c. 2.52 million years in the Campine area.

Offshore Claims and Problems in the North Sea

1965 ◽  
Vol 59 (3) ◽  
pp. 505-522 ◽  
Author(s):  
Richard Young
Keyword(s):  
North Sea ◽  
Large Scale ◽  
Geneva Convention ◽  
Legal Principles ◽  
The North ◽  
Legal Problems ◽  
The North Sea ◽  
The Subject ◽  
First Time ◽  
Economic Considerations

The possible presence of very large petroleum and natural gas reserves in the area beneath the North Sea is currently the subject of intense investigation. If confirmed, as seems likely in at least some localities, this occurrence will raise legal problems of considerable interest and complexity. For the North Sea is not merely an oilfield covered by water: for centuries it has been one of the world's major fishery regions and the avenue to and from the world's busiest seaports. Thus all three of the present principal uses of the sea—fishing, navigation, and the exploitation of submarine resources—promise to meet for the first time on a large scale in an area where all are of major importance. The process of reconciling the various interests at stake will provide the first thoroughgoing test of the adequacy and acceptability of the general principles laid down in the 1958 Geneva Convention on the Continental Shelf and should add greatly to the practice and precedents available in this developing branch of the law. In the present article an attempt is made to review some of the geographical and economic considerations involved in the North Sea situation, to note some of the technical and legal developments that have already taken place, and to consider these elements in the light of the various interests and legal principles concerned.

scholarly journals Different bottom trawl fisheries have a differential impact on the status of the North Sea seafloor habitats

2020 ◽  
Vol 77 (5) ◽  
pp. 1772-1786 ◽  
Author(s):  
A D Rijnsdorp ◽  
J G Hiddink ◽  
P D van Denderen ◽  
N T Hintzen ◽  
O R Eigaard ◽  
...  
Keyword(s):  
North Sea ◽  
Management Strategies ◽  
Demersal Fish ◽  
Time Interval ◽  
The North ◽  
The Status ◽  
Fisheries Conservation ◽  
The North Sea ◽  
The Impact ◽  
Trawl Fisheries

Abstract Fisheries using bottom trawls are the most widespread source of anthropogenic physical disturbance to seafloor habitats. To mitigate such disturbances, the development of fisheries-, conservation-, and ecosystem-based management strategies requires the assessment of the impact of bottom trawling on the state of benthic biota. We explore a quantitative and mechanistic framework to assess trawling impact. Pressure and impact indicators that provide a continuous pressure–response curve are estimated at a spatial resolution of 1 × 1 min latitude and longitude (∼2 km2) using three methods: L1 estimates the proportion of the community with a life span exceeding the time interval between trawling events; L2 estimates the decrease in median longevity in response to trawling; and population dynamic (PD) estimates the decrease in biomass in response to trawling and the recovery time. Although impact scores are correlated, PD has the best performance over a broad range of trawling intensities. Using the framework in a trawling impact assessment of ten métiers in the North Sea shows that muddy habitats are impacted the most and coarse habitats are impacted the least. Otter trawling for crustaceans has the highest impact, followed by otter trawling for demersal fish and beam trawling for flatfish and flyshooting. Beam trawling for brown shrimps, otter trawling for industrial fish, and dredging for molluscs have the lowest impact. Trawling is highly aggregated in core fishing grounds where the status of the seafloor is low but the catch per unit of effort (CPUE) per unit of impact is high, in contrast to peripheral grounds, where CPUE per unit of impact is low.

Shallow marine Lower and Middle Miocene deposits at the southern margin of the North Sea Basin (northern Belgium): dinoflagellate cyst biostratigraphy and depositional history

2000 ◽  
Vol 137 (4) ◽  
pp. 381-394 ◽  
Author(s):  
S. LOUWYE ◽  
J. DE CONINCK ◽  
J. VERNIERS
Keyword(s):  
North Sea ◽  
Depositional Environment ◽  
Middle Miocene ◽  
Depositional History ◽  
Shallow Marine ◽  
Dinoflagellate Cyst ◽  
Southern North Sea ◽  
The North ◽  
Southern Margin ◽  
The North Sea

Detailed dinoflagellate cyst analysis of the Lower–Middle Miocene Berchem Formation at the southernmost margin of the North Sea Basin (northern Belgium) allowed a precise biostratigraphical positioning and a reconstruction of the depositional history. The two lower members of the formation (Edegem Sands and decalcified Kiel Sands) are biostratigraphically regarded as one unit since no significant break within the dinocyst assemblages is observed. The base of this late (or latest) Aquitanian–Burdigalian unit coincides with sequence boundary Aq3/Bur1 as defined by Hardenbol and others, in work published in 1998. A hiatus at the Lower–Middle Miocene transition separates the upper member (the Antwerpen Sands) from the underlying member. The greater part of the Antwerpen Sands were deposited in a Langhian (latest Burdigalian?)–middle Serravallian interval. The base of this unit coincides with sequence boundary Bur5/Lan1. Biostratigraphical correlation points to a diachronous post-depositional decalcification within the formation since parts of the decalcified Kiel Sands can be correlated with parts of the calcareous fossil-bearing section, up to now interpreted as Antwerpen Sands. The dinoflagellate cyst assemblages are dominated by species with a inner neritic preference, although higher numbers of oceanic taxa in the upper part of the formation indicate incursions of oceanic watermasses into the confined depositional environment of the southern North Sea Basin.

scholarly journals First record of the rare crab Asthenognathus atlanticus Monod, 1933 (Crustacea: Brachyura: Varunidae) in the North Sea

2021 ◽  
Vol 50 (3) ◽  
pp. 352-358
Author(s):  
Marco Faasse ◽  
Hendrik Gheerardyn ◽  
Rob Witbaard ◽  
Joël Cuperus
Keyword(s):  
North Sea ◽  
First Record ◽  
Western Mediterranean ◽  
Distribution Range ◽  
Marine Waters ◽  
The West ◽  
The North ◽  
The North Sea ◽  
Northward Expansion ◽  
First Time

Abstract Several species new to the area were collected while monitoring Dutch marine waters using a dredge. The varunid crab Asthenognathus atlanticus Monod, 1933 was recorded for the first time in the North Sea. Until 2008, this relatively rare crab was known from the west coast of Africa and the western Mediterranean to northern Brittany in the north. In recent years, its distribution range has expanded, as indicated by records from the Bay of the Seine and the area around Dieppe-Le Tréport. Our finding from Brown Bank (southern North Sea) indicates a further, northward expansion of its distribution range. We list the hosts with which the crab is associated. Earlier arguments for climate change as an explanation for the northward range expansion are supported.

scholarly journals FerryBox Data in the North Sea from 2002 to 2005

2018 ◽  
Author(s):  
Wilhelm Petersen ◽  
Susanne Reinke ◽  
Gisbert Breitbach ◽  
Michail Petschatnikov ◽  
Henning Wehde ◽  
...  
Keyword(s):  
Time Series ◽  
North Sea ◽  
Daily Basis ◽  
Time Interval ◽  
The North ◽  
The North Sea ◽  
Flow Through ◽  
Data Portal ◽  
Data Gap ◽  
Biogeochemical Parameters

Abstract. From 2002 to 2005 a FerryBox system was installed aboard two different ferries travelling between Cuxhaven (GE) and Harwich (UK) on a daily basis. The FerryBox system is an automated flow-through monitoring system for measuring oceanographic and biogeochemical parameters installed on ships of opportunity. The variables were recorded in a time interval of 10–20 seconds corresponding to a spatial resolution of about 100 m. The dataset provides the parameters water temperature, salinity, dissolved oxygen and chlorophyll-a fluorescence. There is a longer data gap between November 2002 and August 2003 in the time series due to a change of the vessel in October 2002. The data are available at doi:10.1594/PANGAEA.883824 and as part of the COSYNA data portal CODM at http://codm.hzg.de/codm or doi:10.17616/R3K02T.

scholarly journals Lactuca tatarica (Asteraceae) in embryonic dunes on Wolin Island (NW Poland)

2015 ◽  
Vol 39 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Wojciech Kowalski W. A. ◽  
Andrzej Łysko ◽  
Agnieszka Popiela
Keyword(s):  
Baltic Sea ◽  
19Th Century ◽  
North Sea ◽  
Natural Habitat ◽  
The North ◽  
The North Sea ◽  
The 19Th Century ◽  
First Time ◽  
Nw Poland

Abstract By the end of the 19th century, Lactuca tatarica was reported for the first time from an adventive occurrence on the North Sea and Baltic Sea coasts. In Wolin Island, the species has become established in the natural habitat and is clearly spreading in recent years. The community with L. tatarica was studied currently on the western point of Wolin Island along the stretch between the mouth of the Świna (Swine) River and a newly constructed breakwater of the external harbour. The taxon occupies relatively low parts of the sandy elevations of dune ridges, in patches of the Honckenyo-Agropyretum juncei association (habitat 2110). Furthermore, L. tatarica has been reported in recent years from some locations in Świnoujście (Usedom (Uznam) Island), Międzyzdroje, Wisełka and Międzywodzie.

Continuous Trawl Protection of Heating Cable for Direct Electric Heating of Flowlines

2005 ◽  
Author(s):  
Ha˚var Ilstad ◽  
Svein Harald Sa˚tendal ◽  
Bjo̸rn Melve ◽  
Atle Harald Bo̸rnes ◽  
Lars Henning ◽  
...  
Keyword(s):  
North Sea ◽  
Electric Heating ◽  
Full Length ◽  
Electrical Heating ◽  
Reservoir Temperature ◽  
The North ◽  
Heating Cable ◽  
Analytical Work ◽  
The North Sea ◽  
First Time

The following paper describes the experimental and analytical work that was carried out in the development of a continuous external trawling protection for the Direct Electrical Heating cables for the subsea flowlines on the Kristin Field in the North Sea. The developed trawl protection was able to absorb the required 5.0 kJ energy without damage to the cable. The Kristin field is the most extreme HP/HT subsea field developed in Norway to date (170 degC reservoir temperature and 911 barg pressure). This is the first time that a continuous trawl protection is applied to the full length of a flowline. The normal approach would be burying to avoid interaction with fishing activities, however since this is a HP/HT subsea flowline it was necessary with an extra cooling from unburied pipelines to reduce the riser temperatures.

Tectonostratigraphic framework and depositional history of the Cretaceous–Danian succession of the Danish Central Graben (North Sea) – new light on a mature area

2017 ◽  
Vol 8 (1) ◽  
pp. 9-46 ◽  
Author(s):  
F. S. P. van Buchem ◽  
F. W. H. Smit ◽  
G. J. A. Buijs ◽  
B. Trudgill ◽  
P.-H. Larsen
Keyword(s):  
North Sea ◽  
Depositional Facies ◽  
Depositional History ◽  
Sequence Stratigraphic ◽  
Stratigraphic Analysis ◽  
The North ◽  
Economic Significance ◽  
History Of ◽  
The North Sea ◽  
Depositional Systems

AbstractAn integrated tectonic and sequence stratigraphic analysis of the Cretaceous and Danian of the Danish Central Graben has led to significant new insights critical for our understanding of the chalk facies as a unique cool-water carbonate system, as well as for the evaluation of its potential remaining economic significance.A major regional unconformity in the middle of the Upper Cretaceous chalk has been dated as being of early Campanian age. It separates two distinctly different basin types: a thermal contraction early post-rift basin (Valanginian–Santonian), which was succeeded by an inversion tectonics-affected basin (Campanian–Danian). The infill patterns for these two basin types are dramatically different as a result of the changing influence of the tectonic, palaeoceanographic and eustatic controlling factors.Several new insights are reported for the Lower Cretaceous: a new depositional model for chalk deposition along the basin margins on shallow shelves, which impacts reservoir quality trends; recognition of a late Aptian long-lasting sea-level lowstand (which hosts lowstand sandstone reservoirs in other parts of the North Sea Basin); and, finally, the observation that Barremian–Aptian sequences can be correlated from the Boreal to the Tethyan domain. In contrast, the Late Cretaceous sedimentation patterns have a strong synsedimentary local tectonic overprint (inversion) that influenced palaeoceanography through the intensification of bottom currents and, as a result, the depositional facies. In this context, four different chalk depositional systems are distinguished in the Chalk Group, with specific palaeogeography, depositional features and sediment composition.The first formalization of the lithostratigraphic subdivision of the Chalk Group in the Danish Central Graben is proposed, as well as an addition to the Cromer Knoll Group.

Distribution of the Cirratulid Polychaetes Dodecaceria Fimbriata, D. Concharum and D. Diceria in European Waters Between Latitudes 48°N and 70°N

1996 ◽  
Vol 76 (3) ◽  
pp. 625-635 ◽  
Author(s):  
Peter H. Gibson
Keyword(s):  
North Sea ◽  
Coastal Waters ◽  
Northern Europe ◽  
English Channel ◽  
The North ◽  
The North Sea ◽  
Firth Of Forth ◽  
First Time

The distribution of Dodecaceria in northern Europe was found for samples borrowed from museums and other collections. Dodecaceria fimbriata was present in the coastal waters of mainland Britain and the Continent from the English Channel northwards. Dodecaceria concharum was only found in British mainland coastal waters and on the French coast at the western end of the English Channel. It was absent where salinities were below ~34%0. The two species were sampled along the Lothian and Borders coasts and the numbers of D. concharum fell with decreasing salinity as the Firth of Forth was approached. Dodecaceria diceria was found for the first time in the North Sea at depths of 100–200 m. The benthic salinity here is ~35%0.

Sign in / Sign up

Export Citation Format

Share Document