Detailed petrographic analysis of melt inclusions contained within plagioclase and pyroxene crystals of the Paraná-Etendeka basalts

• Grant number: 18/16983-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2018
• End date: October 31, 2019
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Adriana Alves
• Grantee: Ana Maria Afonso Sena
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The Paraná-Etendeka Magmatic Province (PMP) formed during the opening of the Atlantic Ocean and holds up to 1 km3 of tholeiitic basalts and silicic rocks exposed over an area of 1 million km2. The early magmatism includes tholeiitic basalt flows, followed by a much less voluminous silicic magmatism, locally overlaid by a recurrence of the basaltic volcanism. This Large Igneous Province is believed to have formed in a short period and to have disturbed climate on a global scale. Despite the recent evidences that link the PMP magmatism to the Weissert Anoxic Event, information about the composition and volume of volatiles released during the magmatic events are still lacking. In order to bridge this gap, the present Scientific Initiation project aims the identification and petrographic description (via optical and electron microscopy) of melt inclusions trapped within pyroxene and plagioclase crystals taken from feeder dykes from the Ponta Grossa region. The goal is to identify the degree of crystallization of the melt inclusions and to determine petrographic relationships of the phases present. This information will subsidize the selection of samples to be targeted for high temperature homogenization procedures in the ambit of the larger project to which this project will be linked (Projeto Serrapilheira - G-1709-21397 - Placing quantitative constraints on the potential environmental impacts associated to the Paraná-Etendeka Magmatism).