Sand Body Distribution and Geometry in Small Delta- Fed Submarine Fans

M. E. Deptuck
Dalhousie University, Department of Earth Sciences, Halifax, Nova Scotia, Canada

Small, delta-fed submarine fans are common in shallow shelf-seas on both active and passive margins and have been recognized in both modern and ancient stratigraphic successions. In this study, conventional 3-D seismic data from the Upper Cretaceous and Paleogene shelf, slope, and basin floor in the Jeanne d’Arc Basin (offshore Newfoundland), in combination with HUNTEC high-resolution shallow penetrating seismic data (vertical resolution 0.4 m) from the Hueneme (offshore California) and East Corsica (Mediterranean) fans, are being used to characterize the sand body geometry in small, deltafed fans deposited in relatively shallow water settings (<1000 m).

Three-dimensional seismic data permit the broader-scale characterization of fan geometry and to some extent flow units, and reveal the detailed characteristics and evolution of the fans in the Jeanne d’Arc Basin. Canyons with curvilinear and sinuous thalweg channels, incised meander loops, submarine channels, braided, linear, and irregular channel termination lobes, scours and slumps are all well imaged, but lack detailed information about sub-loop seismic-scale architecture. High-resolution seismic data permit near outcrop-scale characterization of individual sand bodies on both the Hueneme and East Corsica fans, with detailed knowledge about fan location and shelf-slope-basin floor physiography (which even exceptional outcrop studies rarely can provide). Combined with the use of synthetic seismic models and well calibration, it is hoped that this study will provide a detailed understanding of the sand body architecture and distribution in small, delta-fed fan systems at both the loop and subloop seismic scales.

AAPG Search and Discovery Article #90902©2001 AAPG Foundation Grants-in-Aid