Late Pliocene-Pleistocene environments and glacial history of the northern North Sea

Reinardy, Benedict; Hjelstuen, Berit Oline; Sejrup, Hans Petter; Augedal, Hans; Jørstad, Arild

doi:10.1016/j.quascirev.2016.12.022

Cited by 32 publications

(38 citation statements)

References 79 publications

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“…Fluid flow in this area strongly depends on the local and regional stratigraphy and subsequent sediment properties. We have compiled a stratigraphic framework with seismic reflection data, industry well 15/25b‐1A (Figure a), British Geological Survey boreholes BH77/2, BH86/26, BH04/01 (Figure ), and information from literature (Graham et al, ; Holmes, ; Judd et al, ; Long et al, ; Sejrup et al, ; Reinardy et al, ). We are able to tie most seismostratigraphic units within our stratigraphic framework to previously published lithostratigraphic units (Figure ).…”

Section: Methodsmentioning

confidence: 99%

“…The 2-D and 3-D seismic data show bright spots within S2, which corresponds to glacigenic sediments deposited during Mid Pleistocene (190-130 ka till from MIS 6; Reinardy et al, 2017). This till unit shows lateral changes in thickness and truncation of reflections to unit S3 indicating an erosional surface (Figure 5b).…”

Section: Source Depthmentioning

confidence: 96%

“…The Witch Ground Basin was again a deposition center during the Quaternary (~600 m of sediment). The shallow sediments and especially the Early Pleistocene sediments of the Aberdeen Ground Formation show evidence for subglacial, glaciomarine, and marine conditions (Buckley, 2012(Buckley, , 2016Rea et al, 2018;Reinardy et al, 2017;Rose et al, 2016;Sejrup et al, 1987;Stoker & Bent, 1987). On seismic reflection sections, the Aberdeen Ground Formation is characterized by laterally continuous, high amplitude reflections (Ottesen et al, 2014).…”

Section: Stratigraphy Of the Witch Ground Basinmentioning

confidence: 99%

“…In the Witch Ground Basin, temperature conditions may have changed due to warm water inflow from the North Atlantic (e.g., Becker et al, 2018). Pressure conditions may have changed due to rapid sedimentation (Hustoft et al, 2009;Reinardy et al, 2017), disequilibrium compaction (Flemings et al, 2008;Talukder, 2012), tidal currents (Chen & Slater, 2016), large storms (Krämer et al, 2017), or earthquakes (Field & Jennings, 1987;Hasiotis et al, 1996), which may have ultimately led to episodic fluid escape from the shallow marine sediments in the Witch Ground Basin.…”

Section: Class 2 Pockmarks-timing and Controls Of Fluid Ventingmentioning

confidence: 99%

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Pockmarks in the Witch Ground Basin, Central North Sea

Böttner

Berndt

Reinardy

et al. 2019

Geochem Geophys Geosyst

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Marine sediments host large amounts of methane (CH4), which is a potent greenhouse gas. Quantitative estimates for methane release from marine sediments are scarce, and a poorly constrained temporal variability leads to large uncertainties in methane emission scenarios. Here, we use 2‐D and 3‐D seismic reflection, multibeam bathymetric, geochemical, and sedimentological data to (I) map and describe pockmarks in the Witch Ground Basin (central North Sea), (II) characterize associated sedimentological and fluid migration structures, and (III) analyze the related methane release. More than 1,500 pockmarks of two distinct morphological classes spread over an area of 225 km2. The two classes form independently from another and are corresponding to at least two different sources of fluids. Class 1 pockmarks are large in size (>6 m deep, >250 m long, and >75 m wide), show active venting, and are located above vertical fluid conduits that hydraulically connect the seafloor with deep methane sources. Class 2 pockmarks, which comprise 99.5% of all pockmarks, are smaller (0.9–3.1 m deep, 26–140 m long, and 14–57 m wide) and are limited to the soft, fine‐grained sediments of the Witch Ground Formation and possibly sourced by compaction‐related dewatering. Buried pockmarks within the Witch Ground Formation document distinct phases of pockmark formation, likely triggered by external forces related to environmental changes after deglaciation. Thus, greenhouse gas emissions from pockmark fields cannot be based on pockmark numbers and present‐day fluxes but require an analysis of the pockmark forming processes through geological time.

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Section: Methodsmentioning

confidence: 99%

Section: Source Depthmentioning

confidence: 96%

Section: Stratigraphy Of the Witch Ground Basinmentioning

confidence: 99%

Section: Class 2 Pockmarks-timing and Controls Of Fluid Ventingmentioning

confidence: 99%

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Pockmarks in the Witch Ground Basin, Central North Sea

Böttner

Berndt

Reinardy

et al. 2019

Geochem Geophys Geosyst

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“…In the west central North Sea, the Early Pleistocene Aberdeen Ground Formation is truncated by an extensive erosional unconformity, the Upper Regional Unconformity (URU), formed at ~ 1.2 Ma (Reinardy et al, 2017), that is widely regarded as predominantly of glacial origin (Larsen et al, 2000;Bradwell et al, 2008b;Graham et al, 2010;Graham et al, 2011). Increasing sediment influx from the west above the URU indicates the growing importance through the MPT of glaciers in Scotland as sediment conveyors to the North Sea.…”

Section: Pleistocene Tectonic and Climate Historymentioning

confidence: 99%

Early and Middle Pleistocene environments, landforms and sediments in Scotland

Hall

Merritt

Connell

et al. 2018

Earth and Environmental Science Transactions of the Royal Socie

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This paper reviews the changing environments, developing landforms and terrestrial stratigraphy during the Early and Middle Pleistocene stages in Scotland. Cold stages after 2.7 Ma brought mountain ice caps and lowland permafrost, but larger ice sheets were short-lived. The late Early and Middle Pleistocene sedimentary record found offshore indicates more than 10 advances of ice sheets from Scotland into the North Sea but only 4–5 advances have been identified from the terrestrial stratigraphy. Two primary modes of glaciation, mountain ice cap and full ice sheet modes, can be recognised. Different zones of glacial erosion in Scotland reflect this bimodal glaciation and the spatially and temporally variable dynamics at glacier beds. Depths of glacial erosion vary from almost zero in Buchan to hundreds of metres in glens in the western Highlands and in basins both onshore and offshore. The presence of tors and blockfields indicates repeated development of patches of cold-based, non-erosive glacier ice on summits and plateaux. In lowlands, chemical weathering continued to operate during interglacials, but gruss-type saprolites are mainly of Pliocene to Early Pleistocene age. The Middle Pleistocene terrestrial stratigraphic record in Scotland, whilst fragmentary and poorly dated, provides important and accessible evidence of changing glacial, periglacial and interglacial environments over at least three stadial–interstadial–interglacial cycles. The distributions of blockfields and tors and the erratic contents of glacial sediments indicate that the configuration, thermal regime and pattern of ice flow during MIS 6 were broadly comparable to those of the last ice sheet. Improved control over the ages of Early and Middle Pleistocene sediments, soils and saprolites and on long-term rates of weathering and erosion, combined with information on palaeoenvironments, ice extent and sea level, will in future allow development and testing of new models of Pleistocene tectonics, isostasy, sea-level change and ice sheet dynamics in Scotland.

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