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Integrating Observations From Recent Seafloor Surveys With the Deep-Water Stratigraphic Record: Implications for Securing Energy Resources, Geohazard Assessments, and Other Potential Applications

Abstract

Deep-water depositional systems are important conveyers of sediment, pollutants, and organic carbon from continents to deep-sea basins, and their deposits are of wide societal interest, hosting vast hydrocarbon resources and providing a long-term archive of events in Earth history (e.g., earthquakes). In the past, the ancient stratigraphic record served as a primary source of information about sediment routing due, in part, to the inaccessibility of the deep sea. Over the last decade, significant technological advances have enabled direct monitoring of turbidity currents, as well as the dynamic response of the seafloor, changing how we interpret fundamental sedimentary processes and the deposits they leave behind. For example, both upslope migrating bedforms and knickpoints are now regularly observed in submarine channel systems - they are evidently critical to the maintenance of active conduits on continental margins globally. With these new data answering long-running questions about deep-water sediment transfer, we contemplate ways that the stratigraphic record can continue to be leveraged for societal benefit, including established uses (e.g., managing energy resources) and more novel applications (e.g., geohazard assessments for seafloor infrastructure).

In this study, recent observations of submarine channel morphodynamics are used to reinterpret the stratigraphic record in classic deep-water outcrops, emphasizing the products of upstream migrating bedforms and knickpoints. We highlight that the deep-time stratigraphic record constitutes a unique source of important information about turbidity currents beyond the typical scale of historical records, and fills important gaps in our understanding of rare, outsized events. We demonstrate that more accurate, seafloor-inspired interpretation of the stratigraphic record is relevant for: (1) efficient management of energy and mineral resources on continental margins around the world; (2) honed forecasting of turbidity current frequency and magnitude; and (3) deducing the impact of environmental drivers (e.g., climate) on submarine fan activity, deep-ocean circulation, and carbon storage. These insights have implications for infrastructure development projects on the seafloor, including telecommunications cables and pipelines, and inform ongoing investigations of the transport, distribution and effects of pollutants (e.g., microplastics) on ocean ecosystems.