Seeing the Salt in the Laurentian Basin Using Combined Gravity and Seismic Data

Integration of gravity anomaly data with seismic reflection profiles lowers exploration risk and enhances the geologic interpretation of the subsurface. This project focused on pinpointing the location of marine salt domes within Canada’s Laurentian Basin. Salt domes concentrate hydrocarbons in about 50% of the world’s basins, so studying salt behavior is critical in understanding the mechanisms of the Laurentian petroleum system. Combined seismic and gravity studies are effective for mapping salt bodies because of the large respective velocity and density variations of the subsurface that they provide. This study considers their application in the largely unexplored Laurentian Basin that holds deep-water Mesozoic salt domes related to the Triassic extension of the Atlantic Ocean. In particular, multiple possible salt bodies imaged on 29 lines of full stack 2D seismic reflection data with OpendTect-software processing were compared with gridded free-air gravity anomalies processed by Geosoft’s Oasis montaj software. The analysis suggested that the pattern of strongly negative gravity anomalies may reflect Triassic structures delineated along several seismic lines. Furthermore, the seismic data reveals a drop in bathymetry into the Laurentian Fan, which lies in the southeastern part of the gravity grid marked by strong positive anomalies. Accordingly, given its analogy with the divergent margins of the hydrocarbon-rich Brazilian and Angolan Basins, the Laurentian Basin will continue to be of exploration interest to the hydrocarbon industry.No embarg