A process-oriented approach to modeling the gravity signature of continental margins

The gravity anomaly at a continental margin can be regarded as the result of all the processes that have shaped it through time. These include rifting, sedimentation, and magmatic underplating. This article discusses a new “process-oriented” approach to gravity interpretation which uses seismic constraints on sediment thickness and the underplate at continental margins to estimate the gravity anomaly that is associated with rifting, sedimentation, and magmatic underplating. By comparing the calculations to the observed free-air gravity “edge-effect” anomaly, we have been able to determine the elastic thickness and crustal structure, and to provide an estimate of the location of the ocean-continent transition. Since crustal structure is a proxy for the amount of heating that occurred at the time of rifting, the approach has important implications for the deep-water hydrocarbons industry.