Unravelling the igneous processes and mantle source(s) of the Paraná Magmatic Province reservoirs

• Grant number: 24/04920-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: December 01, 2024
• End date: August 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Adriana Alves
• Grantee: Thais Mothé Maia
• 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 Paraná-Etendeka LIP is one of the biggest magmatic episodes recorded on the Earth, with a volume of at least 1.7 x 10^6 km^3 that spreads throughout areas of Brazil, Argentina, Uruguay, and Paraguay in South America (Paraná Magmatic Province - PMP), and Namibia and Angola in Africa (Etendeka Province). It is linked with the Gondwana breakup and comprises Lower Cretaceous rocks, which are prevalently tholeiitic basalts, with subordinates' silicic rocks. The PMP has been divided into two suites, low-Ti (LT; < 2 wt.%) and high-Ti (HT; > 2 wt.%), that have a large geochemical variability and are subdivided into magma types. Some authors interpreted the Paraná-Etendeka LIP as the earliest manifestation of the Tristan-Gough Plume, but there is no consensus in the literature. Other models propose a non-plume-related heat source for the Paraná-Etendeka LIP generation, e.g., the edge-driven convection (EDC) process. This study aims to construct a new in situ trace elements and Sr-Nd-Pb isotopic database using plagioclase, clinopyroxene, and apatite crystals signatures. The work aims to contribute to the discussion about the influence of a mantle plume versus other mantle processes in the Paraná-Etendeka magmatism genesis. With the novel data, we also expected to investigate the geochemical variability of the Paraná Province magma types, along with the magmatic evolutionary processes responsible for the geographic control of the chemical signatures.