The magnetic field of the earth may be altered by the presence of magnetic materials that are found near the surface of the crust, like magnetite, that is normally associated with the presence of iron or other deposits. This survey can be done from aerial orof magnetic materials that are found near the surface of the crust, like magnetite, that is normally associated with the presence of iron or other deposits. This survey can be done from aerial or terrestrial platforms. Nevertheless, this field is also affected by other factors like lunar and solar tides, solar storms and meteorological phenomena. For this reason, aside from field measurements it is also required a simultaneous measurement of the magnetic field in a fixed base station, that registers the variations of the terrestrial magnetism while surveying is performed. After these compensations are done, a magnetic map of the sector will be obtained, whose variations or anomalies will be associated with the zones of interest.
