INVERSION FOR MAGNETIC-ANOMALIES OF ARBITRARY 3-DIMENSIONAL BODIES

We have developed a fully 3-D inversion algorithm intended for routine application to large data sets. The algorithm, based on a Fourier transform expression for the magnetic field of homogeneous polyhedral bodies is a 3-D generalization of CompuDepth. Like CompuDepth, the new inversion algorithm employs the spatial equivalent of frequency-domain autoregression to determine a series of coefficients from which the depths and locations of polyhedral vertices are calculated by solving complex polynomials. These vertices are used to build a 3-D geologic model. Application to the Medicine Lake Volcano aeromagnetic anomaly resulted in a geologically reasonable model of the source. -from Authors