AUTOGENIC PROCESSES IN SUBMARINE TRANSPORT SYSTEMS AND THEIR LINKAGE TO TERRESTRIAL BOUNDARY CONDITIONS (Invited Presentation)

Linked shelf-edge delta to submarine fan systems produce the largest sediment accumulations found on Earth. These deposits have the potential to store high fidelity environmental signals, including information pertaining to changing terrestrial conditions. Unfortunately, reconstructing paleo-environmental signals from marine continental margin stratigraphy is not trivial. For signals of changing terrestrial conditions to be stored in these settings they must exceed the temporal and spatial scales of terrestrial autogenics and be able to propagate across the shoreline in a manner that maintains temporal and spatial scales of the signals to a level that is in excess of the marine autogenic processes. Here we use simple scaling relationships, laboratory experiments, and analysis of field data to examine the time and space scales of autogenics in linked shelf-edge delta to submarine fans systems. First, we examine the terrestrial conditions necessary to construct self-channelized submarine fans. Specifically, we examine conditions that set the mobility of deltaic channels and their influence on submarine fan deposition. Second, we examine autogenic mechanisms for channel avulsion on submarine fans, specifically the relative importance of super-elevation and channel hydraulics in setting the time and space scale of avulsions. Finally, we examine controls on the completeness of the stratigraphic record of deltas and submarine fans and trade-offs between high stratigraphic completeness and the quality of information preserved.