A new approach for the interpretation of magnetic data by a 2-D dipping dike

We have developed a new algorithm for the interpretation of magnetic data measured along a profile by a dipping dike like body. The algorithm is based on the second horizontal gradient (SHG) anomalies calculated from the observed magnetic data using filters of successive window lengths (s). The main merit of this new method is its capability to estimate (successively rather than simultaneously) all the model parameters of the buried anomalous body: depth to top (z), half-width (d), index parameter (α) and amplitude coefficient (K). This technique successively estimates the parameters z, α and K of the anomalous structure at an assumed half-width for various window lengths by solving a nonlinear equation for z and by direct substitution in two consequent formulas in order to infer α and K. The best fitting solution is that for which the root mean square error (RMS) between the observed and predicted data is minimal. The method has been applied to synthetic examples with and without random noise. Following this, it has been applied to three field examples from Canada, China and the United Kingdom which assesses the accuracy of the method. The results were compared against drilling information and published approaches, which highlight the usefulness of the developed approach.