Lower pleistocene dinoflagellate cyst, foraminiferal and pollen assemblages in four boreholes in the Southern North Sea

1984 ◽  
Vol 121 (2) ◽  
pp. 85-97 ◽  
Author(s):  
T.D.J. Cameron ◽  
A.P. Bonny ◽  
D.M. Gregory ◽  
R. Harland
Keyword(s):  
North Sea ◽  
Forest Cover ◽  
Early Pleistocene ◽  
Pollen Record ◽  
Seismic Profiles ◽  
East Anglia ◽  
Southern North Sea ◽  
Lower Pleistocene ◽  
Regional Forest ◽  
Warm Temperate

AbstractNeogene and Lower Pleistocene stratigraphy in the Southern North Sea has been investigated in four I.G.S. boreholes between East Anglia and the Netherlands. The foraminifera of the Red Crag Formation in Borehole 81/51 are closely similar to Upper Pliocene assemblages in Holland. The overlying succession is clearly punctuated by unconformities in seismic profiles, separating four early Pleistocene formations in the boreholes, and indicating intervals of significant stratigraphic hiatus offshore. The Westkapelle Ground and Smith's Knoll Formations correlate with Thurnian and Antian Stage deposits in East Anglia. Pollen spectra in the Winterton Shoal and Yarmouth Roads Formations are similar to Baventian and Bramertonian assemblages in Britain. The autochthonous marine and allochthonous terrestrial microfauna and flora provide conflicting evidence of early Pleistocene palaeoclimate. The dinoflagellate cysts and foraminifera indicate that each formation was deposited in a warm temperate neritic environment. The pollen record, containing evidence of fluctuation between boreal and mixed coniferous–deciduous regional forest cover, suggests alternation between cool and warm temperate palaeoclimate.

The Guinevere Field, Block 48/17b, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 723-730 ◽  
Author(s):  
M. Lappin ◽  
D. J. Hendry ◽  
I. A. Saikia
Keyword(s):  
Fault Zone ◽  
North Sea ◽  
Production System ◽  
Early Permian ◽  
Gas Field ◽  
East Anglia ◽  
Southern North Sea ◽  
Fault Block ◽  
Sandstone Formation ◽  
The Uk

AbstractThe Guinevere Gas Field was discovered in January 1988 by the Mobil-operated well 48/17b-5. The field lies in the UK Sector of the Southern North Sea and occupies Block 48/17b. The field is located within the footwall of the Dowsing Fault Zone on the western flank of the Sole Pit Basin. Guinevere is a compressional northwesterly-trending fault block that comprises Early Permian Leman Sandstone Formation (Rotliegend Group) reservoir, sourced from the Carboniferous below and sealed by Later Permian Zechstein evaporates above.The Guinevere Gas Field is estimated to contain 90 BCF of recoverable gas reserves and was brought on-stream in June 1993 using a single not-normally-manned minimum facilities platform. Field life is predicted to be 13 years. Gas and condensate are evacuated though the Lancelot Area Production System (LAPS) to the onshore Bacton gas terminal in East Anglia.

Coast erosion and sediment circulation on the coast of eastern England

1972 ◽  
Vol 272 (1221) ◽  
pp. 171-171
Keyword(s):  
Recent Work ◽  
North Sea ◽  
Dynamic Topography ◽  
East Anglia ◽  
Thames Estuary ◽  
Dutch Coast ◽  
Southern North Sea ◽  
The North ◽  
The North Sea

Sediment is considered to travel southward along the English coast and northward along the Dutch coast and this has been interpreted as being part of a counter clockwise circulation in the North Sea. There is evidence that the transport along the English coast is interrupted at a number of places, e.g. the Wash and the Thames Estuary, placing major traps in its path and there are discontinuities in the bank formations due to reversal of movement off East Anglia. Recent work suggests that there are some well defined sediment streams in the southern North Sea with very restricted means of transfer from one stream to another. It is possible that in some sandwave fields we are observing fossil topography rather than present dynamic topography, e.g. in areas such as the Sandettie.

scholarly journals Land–sea coupling of early Pleistocene glacial cycles in the southern North Sea exhibit dominant Northern Hemisphere forcing

2018 ◽  
Vol 14 (3) ◽  
pp. 397-411 ◽  
Author(s):  
Timme H. Donders ◽  
Niels A. G. M. van Helmond ◽  
Roel Verreussel ◽  
Dirk Munsterman ◽  
Johan ten Veen ◽  
...  
Keyword(s):  
Surface Water ◽  
Sea Level ◽  
Northern Hemisphere ◽  
North Sea ◽  
River Flow ◽  
Meridional Overturning Circulation ◽  
Early Pleistocene ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Southern North Sea

Abstract. We assess the disputed phase relations between forcing and climatic response in the early Pleistocene with a spliced Gelasian (∼2.6–1.8 Ma) multi-proxy record from the southern North Sea basin. The cored sections couple climate evolution on both land and sea during the intensification of Northern Hemisphere glaciation (NHG) in NW Europe, providing the first well-constrained stratigraphic sequence of the classic terrestrial Praetiglian stage. Terrestrial signals were derived from the Eridanos paleoriver, a major fluvial system that contributed a large amount of freshwater to the northeast Atlantic. Due to its latitudinal position, the Eridanos catchment was likely affected by early Pleistocene NHG, leading to intermittent shutdown and reactivation of river flow and sediment transport. Here we apply organic geochemistry, palynology, carbonate isotope geochemistry, and seismostratigraphy to document both vegetation changes in the Eridanos catchment and regional surface water conditions and relate them to early Pleistocene glacial–interglacial cycles and relative sea level changes. Paleomagnetic and palynological data provide a solid integrated timeframe that ties the obliquity cycles, expressed in the borehole geophysical logs, to Marine Isotope Stages (MIS) 103 to 92, independently confirmed by a local benthic oxygen isotope record. Marine and terrestrial palynological and organic geochemical records provide high-resolution reconstructions of relative terrestrial and sea surface temperature (TT and SST), vegetation, relative sea level, and coastal influence. During the prominent cold stages MIS 98 and 96, as well as 94, the record indicates increased non-arboreal vegetation, low SST and TT, and low relative sea level. During the warm stages MIS 99, 97, and 95 we infer increased stratification of the water column together with a higher percentage of arboreal vegetation, high SST, and relative sea level maxima. The early Pleistocene distinct warm–cold alterations are synchronous between land and sea, but lead the relative sea level change by 3000–8000 years. The record provides evidence for a dominantly Northern Hemisphere-driven cooling that leads the glacial buildup and varies on the obliquity timescale. Southward migration of Arctic surface water masses during glacials, indicated by cool-water dinoflagellate cyst assemblages, is furthermore relevant for the discussion on the relation between the intensity of the Atlantic meridional overturning circulation and ice sheet growth.

Sclerochronological evidence of pronounced seasonality from the Pliocene of the southern North Sea Basin, and its implication

2021 ◽  
Author(s):  
Andrew Johnson ◽  
Annemarie Valentine ◽  
Melanie Leng ◽  
Bernd Schöne ◽  
Hilary Sloane ◽  
...  
Keyword(s):  
Surface Temperature ◽  
North Sea ◽  
High Surface ◽  
Time Averaging ◽  
Arctica Islandica ◽  
Late Pliocene ◽  
Southern North Sea ◽  
Winter Temperatures ◽  
Cool Temperate ◽  
Warm Temperate

<p>Various elements of the biota of the early Pliocene Coralline Crag Formation (southern North Sea Basin, eastern England) have been taken to indicate a warm temperate marine climate, with summer surface temperatures above 20 °C and winter temperatures above 10 °C [1]. However, summer and winter temperature estimates from oxygen-isotope (δ<sup>18</sup>O) sclerochronology of benthic invertebrates are typically in the respective cool temperate range when calculated using a plausible modelled value for water δ<sup>18</sup>O of +0.1‰. For instance, examples of the bivalve mollusc <em>Aequipecten opercularis</em> from the Ramsholt Member indicate summer maximum temperatures of 11.0–15.7 °C and winter minimum temperatures of 4.4–7.1 °C [2]. Amongst other evidence, the pattern of microgrowth-increment variation in Ramsholt-Member <em>A. opercularis</em> points to a depth below the summer thermocline, hence the temperatures recorded for that season provide an underestimate of surface temperature; this may well have been in the warm temperate summer range [2], as suggested by the pelagic dinoflagellate biota [3]. However, the cool temperate benthic winter temperatures indicated by isotopic data are likely also to have obtained at the surface, pointing to a greater seasonal range in surface temperature (perhaps > 15 °C) than in the modern North Sea (< 13 °C) [2]. This conclusion is not changed by adoption of a different (invariant) value for water δ<sup>18</sup>O and also follows from data for a specific late Pliocene interval (Mid-Piacenzian Warm Period) elsewhere in the southern North Sea Basin (Belgium, Netherlands [4]). Here we present isotopic evidence of a seasonal range in surface temperature higher than now at other times in the late Pliocene. Examples of <em>A. opercularis</em> from several horizons in the Lillo Formation (Belgium) and the Oosterhout Formation (Netherlands) indicate seasonal ranges in benthic temperature of 10–14 °C. Seasonal variation in water δ<sup>18</sup>O can only plausibly account for about 1 °C of these ranges. Taking into consideration microgrowth-increment evidence of a setting below the summer thermocline, the seafloor ranges imply that the surface seasonal range was sometimes 17 °C or more. Other bivalves (<em>Atrina fragilis</em>, <em>Arctica islandica,</em> <em>Pygocardia rustica</em>, <em>Glycymeris radiolyrata</em>) do not indicate such a high seasonal range in benthic (and hence surface) temperature but this can be attributed to inadequate sampling—time-averaging or a failure to recover evidence of seasonal extremes because of growth breaks. The high surface temperature range could reflect a reduction in vigour of the North Atlantic Current and hence diminished oceanic supply of heat in winter.</p><p>References:</p><p>[1] Vignols et al. (2019), Chem. Geol. 526, 62–83. https://doi.org/10.1016/j.chemgeo.2018.05.034.</p><p>[2] Johnson et al. (2020), Palaeogeogr. Palaeoclimatol. Palaeoecol. 561. https://doi.org/10.1016/j.palaeo.2020.110046.</p><p>[3] Head (1997), J. Paleontol. 71, 165–193. https://doi.org/10.1017/S0022336000039123.</p><p>[4] Valentine et al. (2011), Palaeogeogr. Palaeoclimatol. Palaeoecol. 309, 9–16. https://doi.org/10.1016/j.palaeo.2011.05.015.</p>

Foraminiferal isoleucine epimerization determinations from the Nar Valley Clay, Norfolk, UK: implications for Quaternary correlations in the southern North Sea basin

1999 ◽  
Vol 136 (5) ◽  
pp. 543-560 ◽  
Author(s):  
J. D. SCOURSE ◽  
W. E. N. AUSTIN ◽  
H. P. SEJRUP ◽  
M. H. ANSARI
Keyword(s):  
Amino Acid ◽  
Oxygen Isotope ◽  
North Sea ◽  
Middle Pleistocene ◽  
Series Data ◽  
East Anglia ◽  
Oxygen Isotope Stage ◽  
Southern North Sea ◽  
Pollen Stratigraphy ◽  
Valley Area

Fully temperate freshwater, brackish and marine sediments overlying Anglian till and glacilacustrine sediments in the Nar Valley area of northwest Norfolk, UK, have been attributed to the Middle Pleistocene Hoxnian temperate stage on palynological grounds, and basal peats associated with this sequence have been recently correlated with oxygen isotope stage 9 on the basis of a series of 230Th/238U dates (mean 317±14 ka). At Tottenhill these sediments (Nar Valley Freshwater Beds, Nar Valley Clay) underlie a deltaic complex attributed to the Wolstonian ice margin. The lithostratigraphical relations between the major formations in the Nar Valley, and the pollen stratigraphy of the fully temperate sequence, are very similar to the Pleistocene sequence in the Inner Silver Pit area of the southern North Sea, and correlation has been proposed between the successions described from these two localities. However, the Inner Silver Pit sequence has yielded aminostratigraphic data consistent with isotopic stage 11.Benthic foraminiferal assemblages and foraminiferal amino-acid determinations have been investigated from the Nar Valley Clay in order to test further the palaeoenvironmental setting of the sequence and to help resolve the age of the sequence and correlation with the Inner Silver Pit interglacial. The foraminiferal assemblages support previous sedimentological and palaeontological evidence for a transgressive tendency within this sequence. Multiple isoleucine epimerization determinations on Ammonia beccarii and Aubignyna perlucida from five levels within the Nar Valley Clay give mean aIle/Ile ratios of 0.135 and 0.111, respectively. The A. beccarii ratios are much lower than mean aIle/Ile ratios on equivalent species from the interglacial sequence in the Inner Silver Pit (upper Sand Hole Formation), which are close to 0.2, and the two datasets fail to overlap at the 1σ level. The new aminostratigraphic ratios indicate correlation of the Nar Valley Clay with oxygen isotope stage 9, and therefore support the pre-existing 230Th/238U data.These results suggest that two temperate stages of Hoxnian palynological affinity are present in the Quaternary record of East Anglia and the southern North Sea basin, a conclusion consistent with independent new U-series data from other Hoxnian sites in East Anglia. An alternative model in which the amino-acid ratios are explained as a function of different post-depositional thermal histories, related to length of cover by ice and water, is discussed but considered unlikely. The conclusions have important implications for the timing and number of glacial events in and around the southern North Sea basin, and help to resolve discrepancies in relative sea-level histories and biogeography in temperate sequences hitherto accommodated within a single stage.

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