Inventory of geological samples collected from the Rio Grande Rise: Caeté Lithotheque (Minas Gerais State), Geological Survey of Brazil

The Rio Grande Rise Project (PROERG), developed by the Geological Survey of Brazil since 2009, has collected hundreds of cobalt-rich ferromanganese crusts, sediment samples, and biological material. After 14 years of storage, a systematic inventory was carried out between October 2024 and August 2025 at the Caeté Lithotheque, in the state of Minas Gerais. The work included classification, reorganization, and documentation of lithotypes, thin sections, and geochemical aliquots. A total of 132 stations were inventoried, corresponding to 13.6 t of samples, including 355 geochemical aliquots, 114 new aliquots, 57 thin sections, 4 piston cores (129 m), and 1659 photographs. The results highlight the scientific and strategic importance of the collection for cobalt- and phosphate-rich crusts, paleoceanographic reconstruction, and fossil occurrences. Recommendations include more detailed studies of ferromanganese crusts, thin section production, generation of geochemical data, research on stromatolites, and fossil specimens, including a probable Otodus megalodon. The revitalized PROERG collection represents a significant contribution to marine geology, sovereignty over marine resources, and the dissemination of geoscientific knowledge.