From breakup to continental collision: influence of rifted margins on the dynamics of colisional orogens through time

• Grant number: 23/08679-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: November 10, 2023
• End date: November 09, 2024
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal Investigator: Victor Sacek
• Grantee: João Pedro Macedo Silva
• Supervisor: Gianreto Manatschal
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Université de Strasbourg, France
• Associated to the scholarship: 21/06670-4 - From breakup to continental collision: Influence of rifted margins on the dynamics of collisional orogens through time, BP.DR

Abstract

The Earth's tectonic regime evolved over geological history culminating in the present Plate Tectonics. Due to secular cooling of the planet over billions of years, it is expected that in the past, its thermal and rheological structure were different, affecting the deformation pattern of crust and lithospheric mantle over geological time. Previous investigations based on thermomechanical numerical models showed that the oceanic and continental subduction patterns at convergent zones varied since Precambrian. However, for the transition from oceanic to continental subduction, these works considered that the continental margins used in convergence had a simplified geometry and did not consider structural inheritances of previous lithospheric stretching. So, this project aims to numerically simulate the formation of rifted margins considering a variable initial thermal structure and chemistry of the upper mantle, according to Earth's geological age, to evaluate how these parameters affect the architecture and magmatic budget of rifted margins throughout the Archean to the present. The outcome of these simulations will be further used to evaluate how different rifted margins affect continental subduction in the context of supercontinent formation, from Nuna to Pangea. The numerical scenarios will be simulated in the numerical model MANtle DYnamics simulatOr Code (MANDYOC) which allows the simulation of thermomechanical evolution of lithosphere and asthenospheric mantle incorporating nonlinear rheologies over geological time scale. 2D and 3D numerical scenarios will be explored during the project, using geological and geophysical constraints, to evaluate the viability of conceptual models presented previously in the scientific literature. (AU)