THE SOUTH AMERICAN GRAVITY PROJECT

The South American Gravity Project (SAGP 1988-1991) is designed to bring together into a single database all available proprietary and public domain land and marine gravity data. The land and marine gravity data are reprocessed tD a common datum and resampled onto a S'xS' grid approximately 10km x 10km). This grid is used to construct colour contour maps at a range of scales. The five minute grid prevents gravity anomalies less than 20km in wavelength from being seen thus preserving the commercial value of proprietary data used in the project. The gravity maps do however provide sufficient detail to resolve the spatial configuration of sedimentary basins and delineate their tectonic control. The talk will focus on how the delineation of the regional gravity anomaly field associated with the Cretaceous rift basins of West and North Africa provides a key to the understanding of their mode of origin and their tectonic linkage with the opening of the South Atlantic Ocean.