| Texto completo | |
| Autor(es): |
Del Rey, Giovanna Orletti
;
Souza-Neto, Pedro Walfir
;
Vieira, Lucieth Cruz
;
Del Rey, Antonio Cosme
;
Neto, Arthur Ayres
;
Lisniowski, Maria Aline
;
Santos, Roberto Ventura
Número total de Autores: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | MARINE GEOLOGY; v. 478, p. 11-pg., 2024-12-01. |
| Resumo | |
This study investigates the interplay between hydrodynamics, sediment dynamics, and topography in the Rio Grande Rise (RGR) area. It addresses bedforms found in five different regions, attributing their formation to the interaction between unconsolidated carbonatic substrate and bottom currents, particularly the M2 tidal flow, the primary lunar semidiurnal constituent. The bedforms are shaped by the interplay of the M2 tidal current and local topography, with the bottom mean flow also contributing to specific areas. Generally, bedforms are classified as subaqueous dunes/tidal banks. The environmental sectorization within the RGR, driven by variations in bottom velocities related to flow-topography interaction, delineates deposition and non-deposition areas. Bathymetric data reveal that bedforms are present in shallower, lower-flow energy zones, whereas Fe-Mn crusts are located in more profound, higher-flow energy areas. They indicate that carbonate sediments are either being transported away from the crust regions or remobilized, leading to accumulation in the areas with bedforms. The flow velocity in Fe-Mn crust areas is able to cause sediment bypassing, resulting in areas where deposition does not occur. Furthermore, these velocities exceed the optimal flow conditions for Fe-Mn crust precipitation and could be eroding the previously formed Fe-Mn crusts. These findings imply that Fe-Mn crusts lie beneath the subaqueous dunes to some extent. This study highlights the complexity of the interaction of oceanic flow with the RGR substrate and its morphology, emphasizing the importance of local hydrodynamics and topography when analyzing these features. (AU) | |
| Processo FAPESP: | 14/50820-7 - Marine ferromanganese deposits: a major resource of E-tech elements |
| Beneficiário: | Frederico Pereira Brandini |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |