Mid-Pleistocene thin-skinned glaciotectonic thrusting of the Aberdeen Ground Formation, Central Graben region, central North Sea
This paper presents the results of a high-resolution 2D seismic survey of mid-Pleistocene glaciogenic sediments in the Central Graben region of the central North Sea. Sediments have undergone major glaciotectonic thrusting and folding associated with the repeated southerly advance of a mid-Pleistoce...
Published in: | Journal of Quaternary Science |
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Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2017
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Subjects: | |
Online Access: | http://nora.nerc.ac.uk/id/eprint/513516/ https://nora.nerc.ac.uk/id/eprint/513516/1/DVH%20and%20phillips%20JQS%20North%20Sea%20paper.pdf https://doi.org/10.1002/jqs.2836 |
Summary: | This paper presents the results of a high-resolution 2D seismic survey of mid-Pleistocene glaciogenic sediments in the Central Graben region of the central North Sea. Sediments have undergone major glaciotectonic thrusting and folding associated with the repeated southerly advance of a mid-Pleistocene ice sheet. The total observed length of the thrust-stacked section is approximately 5–6 km, comprising a series of discrete thrust slices, which range in length from < 300 m to > 700 m. The basal detachment of the thrust complex occurs at a depth of ca. 220 m below the sea bed within the upper Aberdeen Ground Formation. A thin-skinned glaciotectonic model involving proglacial to ice-marginal glaciotectonic thrusting followed by post-tectonic deposition is proposed. Initial ice advance led to the over-pressurizing of groundwater within a laterally extensive sand sheet in the upper Aberdeen Ground Formation, promoting the formation of a major décollement surface at the base of the developing thrust-stack. Over-pressurization of the groundwater system is thought to have occurred in response to rapid ice advance, suggesting that the development of large-scale thrust complexes may be associated with surge-type behaviour. The proposed model evidences complex dynamics of mid-Pleistocene ice sheets within the central North Sea. |
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