The Mechanics of Large River Deltas

River deltas are the sites of some of the largest sediment accumulations on Earth. They are important to our understanding of sediment progradation and dynamics and plate mechanics and flexure. River deltas are also sites of relative sea-level rise and, given thier proximity to large populations, are of immense societal interest. The aim of this project is to use sediment thickness data, together with gravity anomaly and seismic refraction data, to better understand the role of plate flexure at the Mississippi river delta. Particular attention will be given to the role of flexure, compared to that of other factors such as thermal subsidence and uplift, salt collapse, and sea-level changes in determining the stratigraphic "architecture" of the Cenozoic deltaic depositional system. The project will involve the compilation of 3-dimensional sediment thickness "grids", backstripping, gravity anomaly, and thermal and mechanical modelling, and comparative studies of other large river delta systems such as the Amazon where we plan, later this year, to carry out the first detailed seismic study of the deep crustal and upper mantle structure of a large river delta system.

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