Print this pageSeismic Geomorphology and Evolution of Upper Pleistocene Deep-Water Depositional Systems, Alaminos Canyon, Northwestern Deep Gulf of Mexico
The Alaminos Canyon area of northwestern deep Gulf of Mexico is located at the transition zone between the confined continental slope and unconfined deep basin. This setting offers a good opportunity to study the evolution of upper Pleistocene channelized deepwater depositional systems. High-resolution near seafloor 3D seismic data (upper 1000 msec) were interpreted to reveal the seismic geomorphology of two shallow sequences. The stratigraphic architecture was determined from combining seismic profiles, time slices, horizontal 
RMS
attribute and stratal slices, spectral decomposition.
3-D seismic imaging shows a chaotic reflection pattern near the base of the lower sequence, overlain by an areally widespread zone of high-amplitude seismic reflections. The stratigraphic architecture indicates that a mass-transport complex was deposited first, followed by the development of a channel complex that was amalgamated updip, and then spread out basinward. Younger distributary channels migrated eastward and evolved into two discrete channels. The upper sequence consists of a single aggradational channel flanked by low amplitude levee reflections; the channel increases in sinuosity throughout its evolution. Quantifying the dimensions of this younger channel shows that it evolved from wider, straight channel (higher energy) to relatively narrow sinuous (lower energy) channel with increasing sinuosity upward.
We suggest that the distribution and quantification of the architectural elements and their evolution in these two sequences can be used as an analog to exploration targets and reservoir models at greater depth in this and other deepwater basins.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009
