ESR 1 - Mantle dynamics, very long wavelength deformations and large rivers source to sink systems: the case example of Africa (Congo, Nile)
- Researcher: Iwan Setiawan
- Host institution: Université de Rennes 1
- Supervisors: François Guillocheau, Cécile Robin
Most of the “source to sink” studies of large rivers are related to catchments upstream bounded by mountain belts (e.g. Ganga-Brahmaputra, Indus, Mississippi). Few attentions are paid to the ones located over anorogenic relief (large plateaus and domes) due to mantle dynamics (dynamic topography including plumes). The objective of this project is to study two large rivers – the Congo and the Nile – located over a continent – Africa - where mantle dynamics controlled most of the relief. Both rivers are characterized by intermediate zones of accumulation (Sudan Rifts for the Nile and Congo Basin for the Congo) prior to their end deposition along the margins. The goal is to measure - for each time slice of relief growth and in a known climatic (precipitation) setting – the erosion / sedimentation budget along the different segments of the rivers and to characterize the relative importance of mantle deformation and climate. These data will be integrated in coupled deformation/surface processes models to better predict the behaviour of these systems. The used tools are:
- geomorphological analysis (onshore)
- seismic stratigraphy (offshore)
- gravimetric inversion (offshore) and
- numerical modelling for (i) reconstructing the past onshore and offshore topographic evolution and therefore the different deformation wavelengths and (ii) the erosion/sedimentation budget and its prediction.
- quantified reconstruction of the rivers profiles and catchments from 140 Ma
- measurement of sediment volumes on the margin and onshore basins for critical time intervals
- measurement of the very long wavelength deformations from 145 Ma to today
- modelling of the surface processes.
- GFZ – Helmholtz Centre Potsdam (J. Braun, J. Sippel, M. Scheck-Wenderoth) Surface processes modelling - gravimetric inversion (7 months)
- Halliburton (G. Nicoll) Global palaeogeography (1 month)