The start depth in gravity anomaly inversion is discussed in this paper

and a new method called “test comparing method” is presented to determine the start depth when both boring data and seismic data are not available. Anticline and syncline density interface models are designed to test the method; the calculated result agreed well with the designed value

which proved that the new method can be used to determine the start depth in the gravity anomaly inversion when boring data and seismic data are not available.