Source-to-Sink Analysis of Rift Basin Tectonics and Sedimentation
PhD Jonathan Smith
Supervisors: Professor R.L. Gawthorpe (UiB), Dr S.H. Brocklehurst and Dr E. Finch (UoM)
The stratigraphic record of a sedimentary basin is the combined record of tectonics, climate and base-level change. These factors combine to determine the nature of the erosional, transport and depositional systems, controlling the character of the basin fill both spatially and temporally. The source-to-sink (S2S) approach views erosion, transport and deposition of sediment as one dynamically linked system, and seeks to understand the controls, interactions, coupling and feedbacks between these sub-systems.
The study focuses upon regional scale, S2S systems in modern-day rift settings such as the Red Sea, Rio Grande, and Basin and Range. Rift basins are generally well studied and facies models well established, however, the majority of studies view individual sub-basins in isolation and rarely take into account the interaction between adjacent sub-basins. Although not ignoring simple footwall-hangingwall relationships, this study places an emphasis on regional drainage evolution, particularly between sub-basins of varying elevations, often adhering to different base-levels. By examining a number of rift settings in varying stages of maturity, evolution of regional S2S systems is assessed.
The project attempts to combine analysis of digital elevation models (DEM’s), satellite imagery, numerical modelling and field studies in order to;
- Quantify the spatial distribution of topography and drainage networks in areas of active extension to understand the first-order controls on the location and size of sedimentsources and evolution of sediment transport pathways.
- Understand how regional drainage patterns change through time in response to the structural evolution of rift basins
- Investigate the role of accommodation zones in along-strike segmentation of sub-basins and their effect upon sediment supply and distribution patterns
- Understand how migration of fault activity affects stream networks (diversion, reversal or entrenchment);
- Improve existing models of rift-scale drainage evolution and sediment supply