Assessing the geochemical correlation between petroleum source rocks in the Brazilian Equatorial margin basins and global oceanic anoxic events

This research aims to investigate the correlation between the Cretaceous Oceanic Anoxic Events (OAEs) and the source rocks of the Brazilian Equatorial Margin (BEM) basins. These source rocks, particularly from the Cenomanian-Turonian interval, are known to contain high levels of Total Organic Carbon (TOC) and exhibit significant hydrocarbon potential. The principal focus is on how global anoxic events, such as OAE-1b, OAE-1d, and OAE-2, influenced the depositional environments and organic matter types across the BEM basins, which include Foz do Amazonas, Pará-Maranhão, Barreirinhas, Ceará, and Potiguar. Key results indicate a strong correlation between periods of anoxia and the accumulation of organic-rich sediments in these basins. The Foz do Amazonas Basin features predominantly terrestrial-derived kerogen (Type III), while the Ceará and Potiguar basins show marine-derived kerogen (Type I and II), aligning with global productivity patterns during anoxic events. These variations in kerogen type reflect differences in depositional environments influenced by sea-level changes and nutrient influx. The research concludes that the OAEs significantly impacted organic matter preservation and hydrocarbon generation in the BEM basins. The study's findings contribute to the broader understanding of how Cretaceous OAEs shaped the geochemical and sedimentary processes in equatorial Atlantic margins, highlighting the potential for further oil and gas exploration in these regions. • OAEs correlation with source rock deposition in Brazilian Equatorial Margin basins. • High TOC values indicated high hydrocarbon potential in deep and ultra-deep waters. • Sea-level changes influenced organic matter deposition during anoxic events. • OAEs shaped sedimentary processes in equatorial Atlantic margins.