Use of luminescence of quartz and feldspar to reconstitute discharge variations of the Amazonas River during the glacial-interglacial transitions

• Grant number: 25/11857-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: André Oliveira Sawakuchi
• Grantee: Daniel Nicodemo Belmonte
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Glacial to interglacial transitions exhibit significant climate changes in global and regional scale. This includes changes in rain patterns with the displacement of convective cells and atmospheric and ocean circulation systems, also related with sea level changes due to the melting of ice masses, that generates effects on the taxes of erosion in different regions and interfere in the provenance patterns of the continental sediments (increase or reduction of the contribution of certain areas over time). Thus, the analysis of marine sediments supplied by continental scale fluvial systems, such as the Amazon River and its tributaries, enable the identification of continental precipitation changes. In the case of the Amazon basin, the andean and cratonic areas supply sediments with distinct characteristics, as the Andes comprise younger rocks and high slope relief than the cratonic areas. In this context, the optically stimulated luminescence and thermoluminescence techniques of quartz and feldspar can be employed for the differentiation between andean and cratonic sediments. This project intends to apply these techniques for the reconstruction of relative variations of the Andean and cratonic sediment contribution for the Atlantic ocean during the last two transitions from glacial to interglacial periods (0-20 ka and 120-140 ka). This will enable the detection of relative rainfall variations. For this, it will be used marine sediments core (MD23-3652Q-53) recently collected by the research group in which this scientific initiation project will be developed. It can be highlighted that this project will enable the learning of laboratory methods applied to paleoclimatology in a multidisciplinary research group. (AU)