High Resolution Morpho-Sedimentary Characteristics of the Distal Orinoco Turbidite System
The distal Orinoco turbidite system (from 4,200 to 5,000 m water depth) has been surveyed with state-of-art, high-resolution acoustic techniques, such as the SIMRAD EM12 multibeam and the SIMRAD TOPAS ultra high-resolution parametric echo sounders. New results indicate that the distal part of this turbidite system shows at least two active systems of sediment transfer, towards the north and towards the east. Both sediment transfer systems depict a large sedimentary complex on which channels with variable sinuosity, degree of incision, and width/relief ratio, braided channels, and distal depositional lobes coexist even in short distances. Such complexity is the result of different patterns of sediment transport of the gravity flows within the turbidite system and of different styles of sedimentation. In addition, the complexity of the east-trending distributary system is accentuated by the probable activity of unchannelized turbidity currents whose interaction with the topography generates a sediment wave field on the right-hand inner margin of this system. The east-trending distributary system connects with the Vidal midocean channel, earlier through a channel that now is filled, and at the present time through a bypass zone of unchannelized debris flows.