Research paperSpatial and dimensional relationships of submarine slope architectural elements: A seismic-scale analysis from the Espírito Santo Basin (SE Brazil)

- Distinct stratigraphic architectures characterise Cenozoic units in SE Brazil.
- Identical scale relationships are observed for distinct architectural elements.
- The distribution and dimensions of architectural elements are controlled by salt diapirs.

High-quality 3D seismic data are used to interpret the styles and scale-relationships of architectural elements on the continental slope of Espírito Santo (SE Brazil). Sand-prone architectural elements identified in this work include: a) axial canyons incising a salt-withdrawal basin (Unit 1), b) turbidite lobes intercalated with heterogeneous mass-transport deposits (Unit 2), and c) channel complexes confined by salt-controlled topography (Unit 3). Analyses of width/height (W/H) ratios reveal two distinct dimensional groups: Mass-transport deposits and turbidite lobes with W/H ratios ≥ 100, and channels and blocks with W/H ratios between 1 and 30. Importantly, all buried submarine canyons and channels systems show average W/H ratios of 12-13 for different stratigraphic units. Length-width (L/W) ratios of structural and stratigraphic compartments vary between 1 and 10. A key result of this work is the confirmation that the distributions and dimensions of architectural elements are controlled by salt-related faults and topography, with higher dimensional variability and lower continuity of sand-prone elements occurring in the vicinity of salt ridges. Our data also shows a marked tendency for clustering and scale overlap between distinct architectural elements. The approach in this paper is relevant for hydrocarbon exploration as it uses quantitative data to predict slope compartmentalisation as a function of basin geometry.