Abstract: A method and system for geophysical surveying. A non-rigid airship having a self-supporting gas envelope and propulsion units coupled to the gas envelope, the propulsion units being configured to control the steering and altitude of the airship without the aid of a rudder or elevators, is provided with geophysical survey equipment, and geophysical data is collected while flying the airship. Also a method for geophysical surveying that includes providing a first airship with a first set of geophysical survey equipment, providing a second airship with a second set of geophysical survey equipment that is complimentary to the first set, and conducting an airborne geophysical survey by flying the first airship and the second airship along a designated flight path within a predetermined range of each other.

Abstract: A method for identifying a possible porphyry copper deposit which includes flying an airborne sensor over a survey area measuring natural electromagnetic fields in the survey area, and then determining, in dependence on the measured natural electromagnetic fields, if one or more sub-areas in the survey area have a resistivity pattern that corresponds to a predetermined resistivity signature for a porphyry copper deposit.