Tectono-stratigraphic and geochronological evolution of the Bambuí Group, São Francisco Basin, Brazil

• Grant number: 25/20819-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: January 01, 2026
• End date: July 31, 2029
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Lucas Verissimo Warren
• Grantee: Deniro Felipe Goncalves Costa
• Host Institution: Instituto de Geociências e Ciências Exatas (IGCE). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

The Bambuí Group comprises a carbonate-siliciclastic sedimentary succession deposited in the São Francisco Craton, with ages mostly attributed to the Ediacaran Period, based on the presence of marine carbonate layers, fragments of the Cloudina index fossil, and U-Pb ages in detrital zircon from the Sete Lagoas Formation. However, inconsistencies between the depositional age and the age of deformation of the unit raise questions about the chronology of these events. Added to this scenario are doubts about the origin of the Bambuí Basin, with gaps in knowledge about the generating tectonics and the type of subsidence that conditioned the installation of this basin. Therefore, understanding the tectono-stratigraphic and geochronological evolution of the unit is essential, focusing on the intrinsic relationship between geodynamics, formative tectonics, subsidence, and filling patterns. Following this line of inquiry, this project proposes an integrated study using established geological techniques with current methods of dating and analysis of sedimentary basins, involving fieldwork for the collection of structural data and stratigraphic descriptions, U-Pb dating in carbonates and/or detrital zircon from base units (Fm. Sete Lagoas), intermediate units (Serra de Santa Helena and Lagoa do Jacaré formations) and top (Serra da Saudade and Três Marias formations), using LA-ICP-MS. These data will be supported by tectono-stratigraphic analysis performed using geophysical profiles, well data, and existing seismic sections. The expected results of new depositional and provenance ages will allow us to refine the evolutionary model of the basin and its relationship with the surrounding orogens, seeking, among other aspects, to identify similarities/differences between provenance patterns among the different units of the Bambuí Group. It is also expected to refine the geometric analysis of the basin in its entirety, identifying structural and stratigraphic parameters that allow the definition of initial subsidence patterns. Obtaining this data will allow, in light of an integrated view of basin evolution and geodynamics, the temporal ranking of the generation and deformation events of the Bambuí Group, a problem that remains challenging for Brazilian geology. (AU)