Inversion of gravity data with isostatic constraints

We have developed a simple iterative gravity-inversion approach to map the basement and Moho surfaces of a rift basin simultaneously. Gravity anomalies in rift basins commonly consist of interfering broad, positive crustal-thinning anomalies and narrow, negative sedimentary-basin anomalies. In our model, we assumed that the Moho and basement surfaces are in Airy isostatic equilibrium. An initial planelayered model was iterated to fit the gravity data.We applied the process to a model in which the inverted basement and Moho surfaces matched the model surfaces well and to a gravity profile across the Kosti Basin in Sudan.