TY - JOUR

T1 - Glaciotectonic deformations in the Jammerbugt and glaciodynamic development in the eastern North Sea

AU - Pedersen, Stig A. Schack

AU - Boldreel, Lars Ole

PY - 2017

Y1 - 2017

N2 - The Quaternary geology in the eastern part of the North Sea is characterized by large-scaleglaciotectonic complexes. The northernmost complex is the Jammerbugt Glaciotectonic Complex here addressed,which occupies an area of more than 300km2. It was recently recognized during an investigation of conventionalseismic profiles located about 10km offshore the west coast of northern Denmark. The deformed bedrock includesthe main part of the Cretaceous Chalk Group in the North Sea. In the northern part of the complex the detachmentsurface is situated in Lower Cretaceous greensand about 400m below sea level. In the central part of the complex,the thrusting ramps the strong reflectors at the base of the Chalk Group and the detachment surface continues inthe lower part of the Upper Cretaceous chalk. In the tectonic depression north of the complex, marine andglaciomarine deposits represent the Eemian–Early Weichselian Skærumhede Group, indicating a Saalian age of theglaciotectonic deformation. The balancing of the thrust fault structures shows that the thrust sheets in the tailingend of the complex had their source in the Skagerrak sea. The hole caused by displacement contributed toformation of the Skagerrak depression, i.e. early stage of the Norwegian Trench.

AB - The Quaternary geology in the eastern part of the North Sea is characterized by large-scaleglaciotectonic complexes. The northernmost complex is the Jammerbugt Glaciotectonic Complex here addressed,which occupies an area of more than 300km2. It was recently recognized during an investigation of conventionalseismic profiles located about 10km offshore the west coast of northern Denmark. The deformed bedrock includesthe main part of the Cretaceous Chalk Group in the North Sea. In the northern part of the complex the detachmentsurface is situated in Lower Cretaceous greensand about 400m below sea level. In the central part of the complex,the thrusting ramps the strong reflectors at the base of the Chalk Group and the detachment surface continues inthe lower part of the Upper Cretaceous chalk. In the tectonic depression north of the complex, marine andglaciomarine deposits represent the Eemian–Early Weichselian Skærumhede Group, indicating a Saalian age of theglaciotectonic deformation. The balancing of the thrust fault structures shows that the thrust sheets in the tailingend of the complex had their source in the Skagerrak sea. The hole caused by displacement contributed toformation of the Skagerrak depression, i.e. early stage of the Norwegian Trench.

U2 - 10.1002/jqs.2887

DO - 10.1002/jqs.2887

M3 - Journal article

VL - 32

SP - 183

EP - 195

JO - Journal of Quaternary Science

JF - Journal of Quaternary Science

SN - 0267-8179

IS - 2

ER -