A generalized concept of resultant gradient to interpret potential field maps

Abstract

The existing concept of the gradient of the potential field anomaly over a 3D source has been generalized. An observed anomaly is modified through a filter based on an assumed source geometry. The first‐order derivatives of this modified anomaly in three mutually orthogonal directions form the components of a vector termed the resultant gradient. The gravity anomaly over a point mass, a vertical line mass and the gravity/magnetic anomaly reduced‐to‐pole over a bottomless right rectangular prism have been suitably modified to yield a specific shape for the amplitude of the resultant gradient in order to decipher the depth of the source centroid/corner. The applicability of the proposed technique is demonstrated by the analyses of a simulated example over a composite source and a real example from published literature with drill‐hole information.