scholarly journals Organic-walled dinoflagellate cyst stratigraphy in an expanded Oligocene–Miocene boundary section in the eastern North Sea Basin (Frida-1 Well, Denmark) and correlation from basinal to marginal areas

2007 ◽  
Vol 26 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Karen Dybkjær ◽  
Erik Skovbjerg Rasmussen

Abstract. The organic-walled dinoflagellate cyst (dinocyst) assemblages in an unusually thick (>800m) Oligocene–Miocene boundary succession from the eastern North Sea Basin (the Frida-1 Well) were studied. Six successive dinocyst assemblages are described: the Wetzeliella gochtii Assemblage (early Chattian), the Distatodinium biffii Assemblage (Chattian), the Deflandrea phosphoritica Assemblage (latest Chattian), the Homotryblium spp. Assemblage (early Aquitanian), the Caligodinium amiculum Assemblage (Aquitanian) and the Cordosphaeridium cantharellus Assemblage (latest Aquitanian to early Burdigalian). The dinocyst assemblages are compared with informal dinocyst zonations proposed for the southern North Sea Basin (Germany, Belgium and the Netherlands).A correlation of the expanded basinal succession in Frida-1 with the marginal marine succession found onshore Jylland, based on the dinocyst stratigraphy combined with well logs and seismic data, is proposed. This correlation confirms earlier proposed datings of the onshore deposits and the presence of several hiati. Furthermore, the correlation made it possible to subdivide the succession in Frida-1 into the sequences A–C, as defined onshore. The Mi-1 glaciation event and thus the Oligocene–Miocene boundary are proposed to correlate to the boundary between sequences A and B.

2004 ◽  
Vol 83 (4) ◽  
pp. 267-285 ◽  
Author(s):  
D.K. Munsterman ◽  
H. Brinkhuis

AbstractAn integrated stratigraphical analysis emphasizing organic-walled dinoflagellate cyst (dinocyst) distribution has been carried out on multiple boreholes penetrating the Miocene in the subsurface of the Netherlands (southern North Sea Basin). The bulk of the investigated successions is attributed to the Breda Formation, a regional lithostatigraphical unit most complete in the south-eastern part of the Netherlands. In concert with a first regional integrated bio (chrono) sequence-stratigraphical framework, fourteen informal dinocyst zones for the southern North Sea Miocene (SNSM), and three subzones are proposed for the Breda Formation. By also integrating (chrono)stratigraphic information from Mediterranean and North Atlantic dinocyst studies a first ever detailed age-model is here proposed for the Miocene in the subsurface of the Netherlands.


Geotectonics ◽  
2020 ◽  
Vol 54 (6) ◽  
pp. 807-820
Author(s):  
M. A. F. Miraj ◽  
A. Ali ◽  
N. Ahsan ◽  
Sh. Afgan ◽  
R. F. Saleem

2000 ◽  
Vol 137 (4) ◽  
pp. 381-394 ◽  
Author(s):  
S. LOUWYE ◽  
J. DE CONINCK ◽  
J. VERNIERS

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.


Geophysics ◽  
2020 ◽  
Vol 85 (1) ◽  
pp. B9-B21
Author(s):  
Filipe Borges ◽  
Martin Landrø ◽  
Kenneth Duffaut

On 7 May 2001, a seismic event occurred in the southern North Sea in the vicinity of the Ekofisk platform area. Analysis of seismological recordings of this event indicated that the epicenter is likely within the northern part of the field and its hypocenter lies in the shallow sedimentary layer. Further investigation in this same area revealed a small seabed uplift and identified an unintentional water injection in the overburden. The injection presumably caused the seabed uplift in addition to stress changes in the overburden. To better understand the consequences of this water injection, we analyze marine seismic data acquired before and after the seismological event. The 4D analysis reveals a clear traveltime shift close to the injection well, as well as a weak amplitude difference. We find that these measured time shifts correspond reasonably well with modeled time shifts based on a simple geomechanical model. The modeling also correlates well with the observed bathymetry changes at the seabed and with global positioning system measurements at the platforms. Although no explicit amplitude sign of the seismic event could be detected in the seismic data, the modeled stress changes, combined with the effect of decades of production-induced reservoir compaction, suggest a source mechanism for the far-field seismological recordings of the May 7th event.


2021 ◽  
Author(s):  
Hector Barnett ◽  
Mark T. Ireland ◽  
Sanem Acikalin

<p>The energy industry in the UK faces a challenge to decarbonize to support reaching net zero CO2 emissions by 2050. In nearly all scenarios emission reductions are characterized not only by energy demand reductions, but also the decarbonization of electricity and heating. The use of hydrogen as a replacement for natural gas is one proposed solution, where renewable hydrogen is either blended into the gas grid or used directly. To ensure continuity of supply large scale hydrogen storage will be needed to meet this demand.</p><p>Hydrogen has been stored in small volumes (<25GWh) in salt caverns at various locations onshore in the United Kingdom since 1959. These caverns store hydrogen for industrial usage. In order to meet the demand for energy related hydrogen storage an increasing number of new and potentially larger storage options will be needed. Engineering of larger salt caverns for a hydrogen energy system will require thick salt formations which are optimally located with respect to both the hydrogen production facility and the end use. The Permian and Triassic salts deposits of both the Southern North Sea and the East Irish Sea offer vast areas for potential cavern development. Previous studies have described the landscape of underground gas storage onshore and offshore the UK, but to date there have been few detailed geophysical and geological studies on the hydrogen storage potential offshore.</p><p>The identification of suitable storage sites requires an understanding of the subsurface geology including potential structural discontinuities which could compromise the integrity of storage sites and be pathways for leakage. This analysis of hydrogen storage sites will utilise extensive existing modern 3D seismic data and well data taken from the Southern North Sea. We describe the geological setting of the Permo-triassic salt in the SNS in relation to the potential to develop salt cavern storage and develop play risk assessment maps. These risk assessment maps form part of a play fairway analysis workflow in order to identify the optimal storage sites for hydrogen on the UCKS.</p>


2004 ◽  
Vol 141 (3) ◽  
pp. 353-378 ◽  
Author(s):  
STEPHEN LOUWYE ◽  
MARTIN J. HEAD ◽  
STIJN DE SCHEPPER

Dinoflagellate cysts and other palynomorphs from the Pliocene Kattendijk and Lillo formations, exposed in two temporary outcrops in northern Belgium, provide new information on the biostratigraphic position and sequence stratigraphic interpretation of these units. Dinoflagellate cysts from the Kattendijk Formation indicate an age between about 5.0 Ma and 4.7–4.4 Ma (early Early Pliocene) in our sections, confirming a correlation with standard sequence 3.4 and implying a slightly greater age than the Ramsholt Member of the Coralline Crag Formation of eastern England. The unconformity at the base of the Kattendijk Formation was not seen, but presumably correlates with sequence boundary Me2 at 5.73 Ma. The overlying Lillo Formation is late Early Pliocene or early Late Pliocene (c. 4.2–2.6 Ma) in age, and the unconformity at its base may be correlated with sequence boundary Za2 at 4.04 Ma or Pia1 at 3.21 Ma. The Oorderen Sands and superjacent Kruisschans Sands members (Lillo Formation) are both part of the same depositional cycle. They were probably deposited before 2.74 Ma, and certainly before the onset of Northern Hemisphere cooling at c. 2.6 Ma. Evidence from dinoflagellate cysts indicates that both a shelly unit at the base of the Lillo Formation and the lower part of the overlying Oorderen Sands were deposited during a conspicuously cool climatic phase, with warmer temperatures returning during later deposition of the Oorderen Sands and Kruisschans Sands members. Many dinoflagellate cyst and acritarch species are reported here for the first time from the southern North Sea Basin. Selenopemphix conspicua (de Verteuil & Norris, 1992) stat. nov. is proposed.


GFF ◽  
2000 ◽  
Vol 122 (1) ◽  
pp. 154-157 ◽  
Author(s):  
Etienne Steurbaut ◽  
Jan De Coninck ◽  
Christian Dupuis ◽  
Chris King

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