Geodynamic generation of a Paleocene-Eocene landscape buried beneath North Bressay, North Sea

Histories of vertical lithospheric motions provide important clues about geodynamic processes. We present evidence of an ancient (similar to 58-55 Ma) landscape that likely uplifted and subsided rapidly during incipience of the Icelandic plume. Now buried beneath similar to 0.4-0.8 km of rock in the North Bressay region in the North Sea, this landscape is located within a sedimentary basin on the margin of the North Atlantic Ocean. We use high-resolution 3D seismic reflection data to map this ancient surface. Correlation of stratigraphy with a survey in the Bressay region constrains age and depositional environment. The landscape contains excellent evidence of meandering fluvial channels, some of which record avulsions, and terminate against a coastline to the east where deltaic landforms are identified. The landscape was depth-converted and decompacted to generate a digital elevation model from which river profiles were extracted. Their geometries indicate that the landscape was generated by three phases of uplift. This history of uplift and subsidence is analogous to similar-aged landscapes in the Judd area similar to 400 km to the west and Bressay similar to 30 km to the south, and appears to be another manifestation of lithospheric motions generated by the passage of warm thermal anomalies away from the Icelandic plume.

Automated summary

Histories of vertical lithospheric motions provide important clues about geodynamic processes. We present evidence of an ancient landscape that likely uplifted and subsided rapidly during the incipience of the Icelandic plume. This landscape contains meandering fluvial channels and exhibits three phases of uplift, similar to other landscapes in the nearby Judd and Bressay areas.