Experimental Study of Submarine Fan Deposition in a Fault-Constrained Extensional Setting

Athmer, Wiebke¹, Marinus Eric Donselaar¹, Remco M. Groenenberg¹, Stefan M. Luthi¹, Dimitrios Sokoutis², Ernst Willingshofer² (1) Delft University of Technology, 2628RX Delft, Netherlands (2) Free University Amsterdam, 1081HV, Amsterdam, Netherlands

The conduits of turbidity currents down slope are controlled by slope topography. In recent deep-water exploration areas in the North Atlantic Ocean (e.g., Vøring Basin and West Greenland) syn-sedimentary extensional fault activity in the Late Cretaceous to Paleocene rifting phase played a major role in conditioning the flow path and depositional architecture of submarine fans with a high potential of hydrocarbons. Such fault-related bathymetric conditions are not taken into account in conventionally used depositional models, where submarine fan emplacement occurs on unconfined flat basin floors.

To better understand the influence of complex topography in extensional regimes on the conditioning of flow paths and the creation of slope accommodation a physical experimental study with a sandbox is performed. In this sandbox material is used that is able to flow and deform in the same way as in a natural setting. Thereby different sedimentary layers are represented by different colors of the material. During every time-step of the experiment the newly formed topography is scanned by a laser and visualized on a computer. Additionally, photographs of cross-sections are taken after the experiment to analyze internal structures. The sandbox allows to study and model different scenarios of faulted settings such as faults with variable shapes and orientations (e.g., normal and listric faulting) and soft-linked relay ramps between linked extensional faults.

The results of the physical experiment will be an important input for the development of predictive fan models in a fault-constrained setting, especially in consideration of the fact that deep-marine sediments become more and more of interest in petroleum exploration sites in deep-water frontier areas.