PhD: Evolution of Mesozoic alluvial habitats

The interaction between physical alluvial processes and vegetation plays a major role in sedimentation, geomorphology, channel patterns and ecosystem functioning in rivers. The awareness of this importance has been used to construct non-actualistic conceptual models of alluvial processes and habitats that operated in the Palaeozoic and Precambrian, yet the Mesozoic – the time of the first flowering plants, the first grasses, a huge variety of terrestrial ecosystems that provided the theatre for dinosaur, bird and mammal evolution – remains unstudied from this perspective.

The sedimentary and geomorphological importance of plants with advanced ecological adaptations in modern rivers is clear. Angiosperms and grasses, aquatic life-habits and C4 carbon fixation are critical aspects of vegetation in modern rivers and yet none appeared on Earth until the Mesozoic. This project will assess how the evolution of these traits affected physical sedimentation and enable us to more fully answer fundamental questions surrounding the co-evolution of life and physical environments, the

The primary task of the student on this project will be the construction (through literature survey) of a comprehensive global database of changing characters of alluvial facies throughout the Mesozoic Era. From this, field sites will be identified (e.g., the extensive alluvial basin fills of Wyoming) from which ground-truthing of observed trends and characteristics will be analysed in detail, primarily using a variety of sedimentary geology field techniques including logging and architectural analysis. Statistical analysis of the database and field observations will provide a robust assessment of the effects of evolving vegetation on sedimentary facies.