Brush, Eugene R.1, Joseph C. Fiduk1, Frank Love2,
Peter Gibbs3, Stiig Brink-Larsen4, George Farrow5
(1) CGG Americas, Houston, TX
(2) Shell International E & P,
(3) CGG Consultant, Kent, United Kingdom
(4) Long Island Exploration,
ABSTRACT: The Rio Doce Canyon System in the Northern Espirito Santo Basin, Offshore Brazil: A Model For Interpreting Ancient Deep-Water Sand Transportation Fairways
The Rio Doce is one of two modern deep-water canyon systems found in the Northern
Espiritos Santo Basin, Offshore Brazil. It has been mapped using 3D seismic data covering
approximately 10,600 sq km. The system is north-south trending and extends over 150 km
south of the shelf margin canyon incision through which a modern river feeds sediment into
the system. Seismic interpretation suggests that the Rio Doce system has been active
throughout the Tertiary and seismic amplitudes suggest that it is a sand-rich system. It
is possible that the Rio Doce system can be tracked back into the Cretaceous section and
linked to the ancient Regencia Canyon system.
The second canyon system trends northwest-southeast and does not have a river feeding sediments into the system. The canyon is growing toward the shelf by headward erosion. Retrogressive slumping of the canyon walls and occasional debris flows from the shelf margin are the primary sources of sediment for this system. An assessment of seismic amplitudes suggests that this system is mostly sand-poor.
Using the two modern canyon systems as analogs, it is possible to develop a model for deep-water sediment fairways in the Cretaceous and potentially to predict which are sand-rich and which are sand-poor. Ideally, the methodology would involve the combined use of sequence stratigraphy, seismic attribute analysis, and depth imaging.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.