Andean Tectonics and Mantle Dynamics as a Pervasive Influence on Amazonian Ecosystem.

The Amazonian landscape evolution is the result of the combined effect of Andean tectonism, climate and the Earth's interior dynamics. To reconstruct the landscape evolution and its influence on paleoenvironmental variations within Amazonia since the Oligocene, we conducted numerical experiments that incorporate different surface and geodynamic processes, reproducing many paleogeographic features as inferred from the sedimentary record. We show that the evolution of the drainage pattern gradually reduced the area of sedimentation derived from the Guiana and Brazilian shields while expanded the Andean derived deposits during the Miocene, affecting the nutrient availability.