Depositional mechanisms and architecture of a pre-early Cambrian mixed sand-mud deepwater ramp (Apiúna Unit, South Brazil)

The depositional mechanisms have a direct relationship to the architectural elements and the regions of the depositional system. Settling, very low-density turbidity currents and slumps formed the slope deposits. Channel deposits are formed by debris flows, hyperconcentrated density flows and concentrated density flows, in that vertical sequence order. Levee deposits were made of surge-like turbidity flows. Proximal sandstone sheet deposits were formed by concentrated density flows. Distal sandstone sheet deposits are formed by concentrated density flows and surge-like turbidity flows. Surge-like turbidity flows and quasi-steady (?) turbidity flows formed the interchannel deposits.