Rift kinematics preserved in deep-time erosional landscape below the northern North Sea |
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Authors: | Thilo Wrona Alexander C. Whittaker Rebecca E. Bell Robert L. Gawthorpe Haakon Fossen Christopher A.-L. Jackson Marit Stokke Bauck |
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Affiliation: | 1. Department of Earth Science, University of Bergen, Bergen, Norway;2. Department of Earth Science and Engineering, Imperial College, London, UK;3. Museum of Natural History, University of Bergen, Bergen, Norway;4. Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK;5. CGG, Oslo, Norway Department of Geosciences, University of Oslo, Oslo, Norway |
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Abstract: | Our understanding of continental rifting is, in large parts, derived from the stratigraphic record. This record is, however, incomplete as it does not often capture the geomorphic and erosional signal of rifting. New 3D seismic reflection data reveal a Late Permian-Early Triassic landscape incised into the pre-rift basement of the northern North Sea. This landscape, which covers at least 542 km2, preserves a drainage system bound by two major tectonic faults. A quantitative geomorphic analysis of the drainage system reveals 68 catchments, with channel steepness and knickpoint analysis of catchment-hosted palaeo-rivers showing that the landscape preserved a >2 Myr long period of transient tectonics. We interpret that this landscape records a punctuated uplift of the footwall of a major rift-related normal fault (Vette Fault) at the onset of rifting. The landscape was preserved by a combination of relatively rapid subsidence in the hangingwall of a younger fault (Øygarden Fault) and burial by post-incision sediments. As such, we show how and why erosional landscapes are preserved in the stratigraphic record, and how they can help us understand the tectono-stratigraphic evolution of ancient continental rifts. |
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Keywords: | drainage system fault growth geomorphology North Sea seismic reflection data transient tectonics |
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