Pre-existing structural controls on normal fault growth, tectonic geomorphology and sedimentation in multiphase rifts

The MultiRift research project aims to develop the next generation of structural and tectono-sedimentary models for rift basins addressing the role of pre-existing structure, and the coupling between tectonic deformation and erosional and depositional pro cesses operating at the Earth's surface. The project is led by the University of Bergen and involves academic partners at the University of Oslo, Imperial College London, University of Manchester and Uni Research (Bergen). Statoil is the industrial partne r in the project. The project is organized in three themes: 1) Subsurface analysis (seismic interpretation and analysis of borehole data) of the northern North Sea rift, focusing on a series of transects across the rift from the to the Horda Platfo rm in the east, to the Tampen Spur/East Shetland Basin in the west, together with a series of more detailed studies based on 3D seismic data from across the rift, 2) 2D and 3D numerical modelling of pre-existing structural control on rift and normal f ault evolution, and 3) Numerical modelling of interaction between fault growth, erosion, sediment transport and deposition. Our research will increase fundamental knowledge of the structural and stratigraphic evolution of multi-phase rift basins a nd will provide results with direct contribution toward increased exploration success (e.g. identification of new or modified syn-rift plays) and improved oil recovery (e.g. increased understanding of syn-rift reservoir location, geometry and heterogeneity).

It is widely accepted that normal fault zones evolve through growth and linkage of precursor fault segments, and that such fault zones play a major role in rift basin development. The underpinning structural models for normal fault evolution are based la rgely on homogeneous crust and homogeneous cover stratigraphy. However, a review of research on normal faults suggests that their structural style and evolution may be more complex than this, particularly in sedimentary basins that have undergone several phases of rifting (multiphase rift basins). Furthermore, erosion and sedimentation around evolving normal faults may significantly modify fault development. This proposed research project aims to develop the next generation of structural and tectono-se dimentary models for rift basins, addressing the effects of pre-existing structure, erosion and sedimentation on fault growth. The project will be organized around three interrelated themes: 1) subsurface analysis of a transect across the northern North S ea (from the Tampen Spur to the Horda Platform), 2) numerical modelling of pre-existing structural controls on normal fault evolution, and 3) numerical modelling of fault growth, erosion and sedimentation. This research will advance fundamental scientific knowledge about the factors that control normal fault and rift basin evolution. It will also contribute to improved understanding of hydrocarbon systems in rift basins, leading to increased exploration success (e.g. potential identification of new reser voirs) and improved hydrocarbon recovery.