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Testing the Amazônia-West Africa connection and true polar wander in the Neoproterozoic

Grant number: 17/18840-6
Support type:Scholarships in Brazil - Post-Doctorate
Effective date (Start): May 01, 2018
Effective date (End): October 31, 2020
Field of knowledge:Physical Sciences and Mathematics - Geosciences
Principal Investigator:Ricardo Ivan Ferreira da Trindade
Grantee:Paul Yves Jean Antonio
Home Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Associated research grant:16/06114-6 - The Neoproterozoic Earth System and the rise of biological complexity, AP.TEM
Associated scholarship(s):18/23755-0 - Testing the Amazônia-West Africa connection: new paleomagnetic poles for West Africa, BE.EP.PD

Abstract

The Neoproterozoic is a period marked by extreme climatic variations with the possibility of events of snowball earth but also by the Ediacaran biotic revolution. This period (1000 - 541 Ma) corresponds to the transition between the supercontinent Rodinia and the amalgamation of Gondwana. Due to a poor paleomagnetic database for the different cratons, the paleogeography during this period is controversial. The large Amazonian craton stands as one of the units for which few Neoproterozoic key poles are available. On the basis of geological correlations and few paleomagnetic data, this craton is always associated to the West African craton since the Paleoproterozoic (~2000 Ma) in the paleogeographic reconstructions. The two cratons seem to have a related history but with scattered paleomagnetic data during the Neoproterozoic it is impossible to test this association. This relation is still enigmatic and suggested by Zhao et al. (2002): "Did South America and West Africa marry and divorce or was it a long-lasting relationship?". The aim of this project is to obtain new robust paleomagnetic data for the Amazonian and West African cratons during the Neoproterozoic. Three Neoproterozoic targets were selected in this project for sampling, the Tampok suite (~809 Ma, French Guiana), the Piranhas dike swarms (~535 Ma, Tapajós, Brazil) and the Manso dike swarms (~800 Ma) in West Africa. These new data will allow one to test whether a long-connection is paleomagnetically viable between the Amazonian and West African cratons. Furthermore, new paleomagnetic data for the West Africa craton suggest very rapid True Polar Wander (TPW) episodes in Neoproterozoic (Robert et al., 2017). With the Camaquã Basin sequence (Rio de la Plata craton), which is the only complete sequence of the Neoproterozoic, we will test the existence of TPW episodes. (AU)