Middle Miocene - Holocene Stratigraphic Evolution of the Magdalena Submarine Fan - Implications for Deepwater Architecture

The Magdalena submarine fan is located in a compressive regime where the Caribbean plate and the South American plates converge. Lateral migrations of the fan have been documented by Romero (2009) and others and the submarine expression of this deposition generated the sequence now present the area. For this study a sequence stratigraphic framework for the area was developed using seismic stratigraphy concepts and the correlation of these sequences with the known structural evolution (previous works) of the area. Eight seismic stratigraphy sequences were identified for the Early Miocene to Pleistocene time frame. Measurement of key points such as changes in slope angle, trajectory of the depocenter and shelf edge were used to characterize the margin through time in a graded or out-of-grade setting (Pyles et al, 2010). It was established that (1) graded profiles will be present in areas only weakly affected by tectonism and resulting low slope angles and (2) out-of-grade margins due to deformation. This study provides a geological evolution of the fan in terms of grade and out-of-grade styles of deposition within a sequence stratigraphy framework where tectonism and eustatic changes combined to affect the distribution of the different architectural elements.