Architectural Variation in Confined Channels: Examples from Outcrop and 3D Seismic Data

Thompson, Philip¹, Benjamin Kneller¹, Mason Dykstra² (1) University of Aberdeen, Aberdeen, United Kingdom (2) University of California, Santa Barbara, CA

We present an integrated approach to the study of confined submarine channels using high-resolution 3D seismic data and outcrop data. Outcrop studies from the San Fernando Channel Levee System, Baja California have shown a systematic trend in submarine channel evolution which is observed at a range of scales from individual channel bodies (m's) through to channel body sequences (100's m). The range of channel architectures observed is related to the degree of confinement within the system. The lowest sections of individual channel bodies and channel body sequences are typically erosionally confined and are dominated by amalgamated channel deposits due to the repeated re-incision of the channel base. The upper parts typically show thinner, more laterally extensive, segregated channel deposits that are less erosive and only amalgamate locally. Seismic data from the Foz do Amazonas Basin and the Nile Cone has been used to study the variation in the cross sectional profile and morphology of confined channels as they evolve through time. A combination of 3D seismic interpretation, iso-proportional slicing, amplitude analysis and attribute analysis has been used to investigate the evolutionary variation of confined channels which have been observed in seismic data and include submarine channels which are entirely erosionally confined, levee confined, levee/slope confined and confined by deformed levees.