A GENERALIZED CONCEPT OF RESULTANT GRADIENT TO INTERPRET POTENTIAL-FIELD MAPS

The existing concept of the gradient of the potential field anomaly ov er a 3D source has been generalized. An observed anomaly is modified t hrough a filter based on an assumed source geometry. The first-order d erivatives of this modified anomaly in three mutually orthogonal direc tions form the components of a vector termed the resultant gradient. T he gravity anomaly over a point mass, a vertical line mass and the gra vity/magnetic anomaly reduced-to-pole over a bottomless right rectangu lar prism have been suitably modified to yield a specific shape for th e amplitude of the resultant gradient in order to decipher the depth o f the source centroid/corner. The applicability of the proposed techni que is demonstrated by the analyses of a simulated example over a comp osite source and a real example from published literature with drill-h ole information.