The onset of tholeiitic magmatism in the Paraná Magmatic Province: age, duration and volcano-plutonic correlation through high-precision U-Pb geochronology

• Grant number: 25/14035-8
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: November 01, 2025
• End date: August 31, 2030
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Brenda Chung da Rocha
• Grantee: Mariane Zanetti Polito
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/22084-8 - The Paraná Magmatic Province: petrogenesis, chronology and environmental impact of Cretaceous tholeiitic, alkaline and silicic magmatism in the Brazilian Platform, AP.TEM

Abstract

Magmatism in large igneous provinces (LIPs) can be responsible for the abrupt emplacement of large volumes of magma over very short time intervals, and thus cause changes in the entire terrestrial biosphere, especially in the climate and in the chemical composition of the oceans. The interaction of subvolcanic rocks (sills and dyke swarms) with volatile-rich sedimentary host rocks during LIP emplacement can promote the large-scale release of volatile gases (CO2, CH4, F, Cl, S) during rapid magmatic input, potentially resulting in oceanic anoxic events. Obtaining reliable ages is essential to align magmatic episodes chronologically with the geological and environmental transformations of the planet. This project aims to determine the crystallization ages of low-Ti (Torres and Vale do Sol Formations of the Gramado type) and high-Ti-Sr (Urubici type) basaltic magmas in the Paraná Magmatic Province, using the high precision U-Pb CA-ID-TIMS (chemical abrasion isotope dilution thermal ionization mass spectrometry) technique, applied to zircon and/or baddeleyite. The acquisition of these isotopic data is essential to understand the duration of the predominant mafic magmatism in the Paraná Magmatic Province (PMP). In this way, it will be possible to determine the age and duration of the first magmatic pulses in the southern portion of the Paraná Magmatic Province and thus reassess the environmental and climatic effects of the magmatism, as well as establish more assertive correlations of the PMP units with the African counterpart (Etendeka), for a better understanding of the timescales involved and the geodynamics of the fragmentation of the supercontinent Pangea.