Geochemical proxies and paleoceanography: the role of metals as climate indicators in the South Atlantic

• Grant number: 25/07668-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2026
• End date: May 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Chemical Oceanography
• Principal Investigator: Rubens Cesar Lopes Figueira
• Grantee: Giovanna de Araujo Trindade Pedrão
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 20/14356-5 - The Santos Bifurcation: present and past, AP.PFPMCG.TEM

Abstract

Paleoclimatology and paleoceanography are sciences that are based on reconstructions of past environmental conditions in the atmosphere and oceans, enabling a better understanding of how the climate system and current ocean dynamics function. These studies are generally based on the analysis of geological records, especially marine sediments. Among the techniques used to perform these analyses is the use of proxies. Most of these proxies are used due to the geochemical composition of the sediment and are important for understanding the provenance of the sediment, weathering processes, redox conditions of the environment, dynamics of water masses, among others. Thus, the objective of this work is to study the role of metals, rare earth elements and mercury as geochemical proxies in the paleoceanographic and paleoclimatic reconstruction of the southwestern region of the South Atlantic over the last 120,000 years. To conduct this study, the concentrations of rare earth elements and mercury will be determined through total digestion and subsequent use of ICP-OES and ICP-MS techniques. In addition, organic matter and granulometry data will be integrated with the metal analysis, using multivariate statistics to aid in the interpretation of environmental responses to oceanographic processes. Also, time series will be created and applied to interpret these data and identify oceanographic and climatic processes related to variations over time. It is expected that this study will contribute to the understanding of paleoceanographic and paleoclimatic processes in the region, expanding the use of rare earth elements and mercury as geochemical indicators.