From Bureau of Economic Geology, The
University of Texas at Austin (www.beg.utexas.edu).
For more information, please contact the author.
Bureau Seminar, Sept 10, 2010
Stratigraphic Complexity of Shelf-to-Basin Depositional Systems
Dr. Vanessa Kertznus* and Ben Kneller
Department of Geology and Petroleum Geology, University of Aberdeen, United Kingdom
*Current address: New Ventures and Business Development, Shell International Exploration and Production, Inc. Houston, Texas
The architectural development of continental margins characterized by continental-scale clinoforms is the result of very complex interactions between external controls, local variables, and morphodynamic feedbacks of the depositional system itself, rather than a trajectory resulting from the interplay between accommodation and sediment supply.
Results from the study of the 3-D geometries and stratigraphical relationships that characterize the post-Messinian successions of the Nile Cone and the Ebro Continental Margin, in the western and eastern Mediterranean Sea, respectively, suggest that "well understood" mechanisms of margin development are heavily influenced by local variables such as physiographic template, oceanographic regime, faulting, halokinesis, and by the occurrence of large mass failure events. The interaction between these factors can have a profound effect on the mechanisms of margin growth, sedimentary dynamics, and sediment transfer processes. These can lead to inherent stratigraphic complexities that can potentially undermine our conceptual understanding of the timing and mechanisms for accommodation creation/destruction, the persistence of significant stratigraphic surfaces, and the distribution and delivery of sediment along and across the depositional profile. These observations are particularly important for the application of sequence stratigraphic concepts on third and higher order sequences, as well as for the prediction sand-prone units.