This study seeks to offer invaluable and novel insights into the nature and geochemical evolution of the upper mantle across various tectonic environments in Brazil. The proposed methodology involves determining mineral chemistry data, pressure and temperature estimates, isotopic geochemistry, and ages. The research focuses on three regions where mantle xenoliths, intrinsic fragments of the upper mantle, have been collected. These include the volcanic island of Fernando de Noronha in Pernambuco (representing oceanic lithosphere), the Carolina kimberlitic intrusion in Rondônia (representing continental cratonic lithosphere), and the Canastra-1 kimberlitic intrusion in Minas Gerais (representing continental lithosphere in a mobile belt). The goal is to ascertain whether these regions reflect the influence of thermal anomalies, potentially linked to the fragmentation of supercontinents and the opening of the South Atlantic Ocean. Additionally, the study aims to determine whether ancient subduction zones (areas where tectonic plates converge) have contributed to the lithological and chemical heterogeneity of the mantle in these regions.