Volcanism of the Parana Magmatic Province in the State of Sao Paulo: stratigraphy based on geochemistry of samples from deep boreholes

• Grant number: 24/13156-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Valdecir de Assis Janasi
• Grantee: Thaís Ferreira Buscarioli
• 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

The stratigraphy of the succession of flows in the Paraná Magmatic Province, one of the most expressive occurrences of continental basalts on the planet, is still very incompletely known, especially in its northern portion (state of São Paulo and surrounding areas), where rock exposures are limited. Recent studies on a regional scale have allowed the individualization of flows from field observations and chemical analyses of whole rock samples from outcrops or, more rarely, from tubular wells, but the correlations are still insufficient to define a consistent stratigraphic framework. This project takes advantage of the availability of a large collection of rock chip samples from deep tubular wells drilled in recent years to capture groundwater in the region to contribute to the definition of the stratigraphy of volcanism in the northwestern portion of the state of São Paulo (region between Assis and Araraquara). The rock chips will be carefully prepared using specific methodology applied in previous studies for petrographic and geochemical analyses. Based on regional correlations with previous field information, the work seeks to identify flow successions with characteristic geochemical signatures and stratigraphic positions, which can be used as guide layers.