Integrated Seismic and Gravity Data Modeling: Basement Structure in the Gulf of Mexico

Dale E. Bird¹, Barbara J. Radovich², and Jerry Moon^3
1 Bird Geophysical, 16903 Clan Macintosh Dr., Houston, Texas 77084
² Silver Grass Enterprises, 101 N. Hall Dr., Sugar Land, Texas 77478
³ Global Energy Strategies LLC, 205 Millbrook St., Houston, Texas 77024

Three mega-regional north-south transects, extending 300 mi (500 km) to over 500 mi (800 km) through the onshore and offshore parts of the northern Gulf of Mexico Basin, have been modeled by integrating gravity, seismic refraction, and composite seismic reflection data. The composite lines consist of long-offset Pre-Stack Depth Migrated (PSDM) marine streamer, legacy onshore, and Ocean Bottom Cable (OBC) data processed by GX Technology. The models indicate that the basin increases in depth to over 50,000 ft (15 km) offshore beneath the continental shelf and that a prominent basement high in the Keathley Canyon concession area rises over 9800 ft (3 km) above the surrounding basement. Detailed interpretations of the reflection seismic lines show that the basin structure and stratigraphy are affected by this basement architecture and are presented in a companion study.

Our results contribute to the understanding of the Gulf of Mexico Basin framework, and they are consistent with a recently proposed evolutionary model that requires a mantle plume eruption prior to sea-floor spreading in the basin. This evolutionary model suggests that prominent gravity anomalies over the Sigsbee Salt Nappe and center of the Gulf of Mexico are produced by hotspot tracks that were created as the basin opened, by counterclockwise rotation of the Yucatan block away from the North American Plate, over the mantle plume.

AAPG Search and Discover Article #90069©2007 GCAGS 57th Annual Convention, Corpus Christi, Texas