ALT Fig. 1. (a) Location map of the Campos Basin and the study area within the Marlim Unit (blue rectangle).

ALT Fig. 2. Graph showing longitudinal variations in thickness along and parallel to the channel thalweg (across the corridor, step and ramp) and the lobate features LB and LC (across the step).

ALT Fig. 3. Large-scale structural control on the Marlim Sul Channel (marked as blue lines).

ALT Fig. 4. (a) Thickness map (m) of the lobate features (LB and LC) and the Marlim Sul Channel fill with the main faults. Slope breaks shown as dotted pink lines (the slope break at the entrance of the step coincides with a fault). The channel geomorphology is marked by white dotted lines.