Gravity and Magnetic Modeling of Polyhedron and Iterative SVD Applied to Regional-Residual Gravity Data Separation

We have developed a method of forward modeling to determine the gravity and magnetic potential of a convex polyhedron and an iterative procedure of singular value decomposition (SVD) to filter and extract residual gravity anomalies in order to obtain useful information to improve geological mapping and the search of sulphide deposits. The forward modeling method is based on the fundamental work of Werner (1994) . It employs Green’s divergence theoremto change potential volume integrals into asumof surface integrals, with each face of the polyhedron divided into triangles. So, each surface integral consists of the contribution of a triangle calculated relative to its own coordinate system – z perpendicular to the face and x parallel to one of its sides – which is subsequently transformed into the global coordinate. The resulting potentials are derived to yield the analytical solutions of the gravity and magnetic anomalies.