Structural restoration of Cretaceous-Cenozoic (post-rift) palaeobathymetry in the northern North Sea

Kjennerud, T., Faleide, J.I., Gabrielsen, R.H., Gillmore, G.K., Kyrkjebo, R., Lippard, S.J. and Loseth, H. (2001) Structural restoration of Cretaceous-Cenozoic (post-rift) palaeobathymetry in the northern North Sea. In: Martinsen, O. and Dreyer, T., (eds.) Sedimentary Environments Offshore Norway - Palaeozoic to Recent. Amsterdam, Netherlands : Elsevier. pp. 347-364. (Norwegian Petroleum Society (NPF), Special Publication, (10)) ISBN 9780444502414

Abstract

Palaeobathymetric variations and palaeobasin shape are important for recognition of tectonic phases and distribution of sediment. We present an approach for restoring palaeobathymetry from interpreted, depth-converted seismic sections. The method involves section balancing / restoration techniques for extensional regimes and seismic sequence stratigraphy. The method is based on regional profiles that cover the entire basin using fixed water-depth points such as coal layers, shallow marine sand and subaerial unconformities, which are used to calibrate areas along the profile. Geometric information in the under- and overlying seismic sequences is used to shape the palaeobasin. The palaeowater-depths and basin gradients of the Cretaceous and Tertiary post-rift interval in the northern North Sea have been restored. The results show a highly segmented basin with high gradients and locally large water-depths in the earliest Cretaceous. A shallowing and a lowering of the basin gradients occurred in the early Cretaceous. A deepening and widening of the basin was initiated in the middle Cretaceous. During the late Cretaceous the water-depth and the basin gradients decreased. A deepening occurred in the Palaeogene resulting in high gradients on the flanks of the basin. The basin became shallower and the relief became smaller in the early Neogene. The basin deepened in the late Neogene and then became shallower to the present day. The palaeobathymetric trends correlate well with results obtained from micropalaeontological analysis of palaeowater-depth in the same area.

Actions (Repository Editors)

Item Control Page Item Control Page