Paleomagnetic analysis of the sediments of the Dom João stage in the Araripe Basin

• Grant number: 19/16051-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2019
• Effective date (End): December 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Giancarlo Scardia
• Grantee: Gabriela Cassamasso
• Host Institution: Instituto de Geociências e Ciências Exatas (IGCE). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

The Dom João stage is a local chronostratigraphic unit of the Brazilian Mesozoic defined in the Northeast of Brazil. It is considered to precede the rift that broke Gondwana by driving away the South American plate from the African plate. Biostratigraphic studies on ostracods and palynomorphs in several basins from the Brazilian Northeast referred the Dom João stage to the Late Jurassic, although there was no sufficiently precise foundation. Sedimentary rocks from Recôncavo and Sergipe-Alagoas basins, belonging to the Dom João stage, were recently submitted to Rb-Sr datings and were assigned to the Upper Triassic, coinciding with the age obtained with different geochronological methods on volcanic rocks in the nearby Lavras de Mangabeira Basin. All of those basins are traditionally linked to the opening of the South Atlantic Ocean.The purpose of this research proposal, developed within the framework of the FAPESP project 2019/02600-1 coordinated by Prof. Dr. Giancarlo Scardia, is to test through the application of paleomagnetism the upper Triassic age of the Dom João stage within other basins of the Northeast and, more specifically, in the Araripe Basin. The chronological definition of the Dom João stage is fundamental for the understanding of the tectonic evolution of the Brazilian Northeast, linked to the chronologic determination of the rupture that originated the South American and African plates.