Kinematic evolution of the Equatorial Atlantic ocean

• Grant number: 22/08028-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: January 01, 2023
• End date: March 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal Investigator: Ricardo Ivan Ferreira da Trindade
• Grantee: Juliana Fernandes Bonifacio
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

A cornerstone of the continental drift theory and plate tectonics is the geometric similarity between east South American and west African margins. Over the last 60 years, several models have been proposed in order to improve the West Gondwana plate reconstruction. The proposal of lithospheric sub-blocks that may accommodate intraplate deformation in South America and Africa is a solution to reconstructions misfits. However, some problems still remain regarding the sub-blocks boundaries, precise ages of rifting phases and the kinematic modelling of the Equatorial Atlantic ocean opening combining strike-slip movements and block rotation. This project seeks a solution to these problems through the paleomagnetic study of Cretaceous mafic dyke swarms emplaced during the breakup in both South American and African platforms. Records of these dyke swarms in Brazil reveal a thought-provoking arcuate shape that may be linked to crustal deformation during the Equatorial Atlantic ocean opening. Paleomagnetism is an outstanding tool to quantify continental blocks movements and rotations and provides data for defining South American and African apparent polar wander curves. Therefore, these novel data will contribute to understanding the role of intraplate deformation related to crustal stress changes during the Atlantic opening and will assist the proposal of new kinematic and West Gondwana reconstruction models. (AU)