Euler deconvolution using differential similarity transformations of gravity or magnetic anomalies

Euler deconvolution of gravity and magnetic anomalies can be used to estimate the coordinates of a simple point source and the level of a constant background in the deconvolved field by testing a series of structural indices. By using differential similarity transformations (DSTs), joint estimations of the source coordinates, the structural index and the coefficients of a linear background trend become possible. DSTs, calculated from the derivatives of the interpreted field, depend on the position of a chosen central point of similarity with respect to the source position. On this basis, techniques for Euler deconvolution of anomalous fields are presented. The theoretical formulations of DST and the deduced sets of equations for Euler deconvolution are tested and verified on model and field examples of magnetic anomalies caused by one-point and two-point sources such as thin and thick dikes, semi-infinite and finite sills, contacts, steps, faulted beds, etc. The possibility of an optimum estimation of the structural index can be used to define a second acceptance criterion along with the criterion of relative standard deviations. The joint application of these two criteria ensures the selection of reliable results. The suggested DST techniques are suitable for initial rapid estimations of the source type, depth and plane location. They may be applied to either profile or gridded data acquired from one-component measurements, as well as from gradient or three-component measurements. Additional data on the density or magnetization of the sources are not necessary.