2012. "Slope Valleys", Application of the Principles of Seismic Geomorphology to Continental Slope and Base-of-Slope Systems: Case Studies from SeaFloor and Near-Sea Floor Analogues, Bradford E. Prather, Mark E. Deptuck, David Mohrig, Berend Van Hoorn, Russell B. Wynn
Download citation file:
Apron 1 in the Shallow Auger Fan System records the transition from ponded deposition in the lobe complex to bypass at the top of the channel complex. The lobe complex, at the base of Apron 1, exhibits characteristics typical of ponded apron deposits: it onlaps the basin margin, exhibits a concentric isopach pattern, has a lobe geometry in amplitude extraction, and is composed of continuous seismic reflections that have uniform thickness. The transition from ponded deposition to bypass is recorded with increasing gradients along the four channels in the channel complex. Healed-slope accommodation is filled as these channels aggrade at the sediment entry point. In the proximal reaches, the channels have thick levee deposits and minimal incision. Downdip, the levee deposit thickness decreases and incision increases. Each channel aggrades to a single gradient; once this gradient is achieved, the channel avulses to an area of greater accommodation. As healed-slope accommodation fills, channel gradients in the proximal reaches decrease and sinuosity increases. In the distal reaches of the channel, greater incision depths may compartmentalize the underlying ponded deposits.