Flora BAJOLET
Long wavelength deformation and paleogeography of the Guiana shield linked with the source-to-sink approach
Supervisors:
Delphine Rouby and Dominique Chardon GET/CNRS/IRD/UMR5563, Toulouse
Jean-Yves Roig – BRGM, Orléans, France
Major Results
This study highlight 4 major source-to-sink configurations: supercontinent intra-cratonic drainage at the end of Permian, erosion/by-pass-dominated paleogeography from Triassic to Lower Cretaceous, deposition in cratonic basins mainly sourced from cratons from Upper Cretaceous to Eocene, Andean-sourced sediments in transcontinental drainage configuration.
Abstract
A synthesis of geodynamic, tectonic, sedimentology, thermochronology and provenance data from bibliography was used to draw paleogeographic maps illustrating the tectonic and kinematic framework of continental areas under erosion (sources), by-pass and accumulation (sinks) over the Amazonian craton, its adjacent regions and along its Atlantic margins.
Since the Early Mesozoic, the source-to-sink system evolved under the interplay of five main processes: (i) volcanism and arc building along the proto-Andes, (ii) long-term dynamics of the Amazon intracratonic basin, (iii) rifting and relaxation of the Atlantic margins, (iv) building of the Andes, (v) convection and mantle plumes influence on surface topography.
Summarized interpretation of the sediment routing system of the Northern half of South America.