Geophysical Prospection

It is not believed to be important, in this part, to develop all the geophysical methods, but some general advice will be given in the application of the simplest methods of geophysical prospecting.

Analysis of a set of geophysical methods
Everyone is aware that geophysics allows us to obtain, through measures done above the surface, information of what exists under the surface. These measures of physical parameters can allow us to localize bodies or structures that present contrasts (in density, magnetism, conductivity, etc.) as far as how much is in the proximities. It is probably less notorious that each method usually only makes one physical parameter intervene, that the geometric factors have a great amount of importance and that it is not possible to determine anything by just using any type of method. If the geologist or the prospector is aware of what he is looking for and therefore knows physical properties of the mineral that he is trying to find and of the terrain that he is looking for to determine the structure, a table will allow him to establish which geophysical method will help him to resolve the problems or set backs. The most used methods in prospecting of deposits are then:

• Spontaneous polarization
• Magnetism
• Radiometric methods (scintillometry and spectrometry)

As far as the description of the elements, equipment, methods etc, geophysical mining will need to be kept in mind remembering the following recommendations:

• Be careful with the materials: the apparatuses are efficient and projected to work in bad conditions but this is not a reason to mistreat them, transport them without any precautions, cause damages, leave them sitting in the rain or sun or trust them to workers so they can do as they please with them. The person that is in charge of the apparatus needs to be responsible to keep an eye on it and make sure it is used and treated adequately.
• The geographic measures should be positioned: on the field, installed with the topographic references. On a map, and in the case where there is not access to a sufficiently precise map, localize the measure of stations in relation to the placed references.
• The geographical results should be interpreted in collaboration with a geophysicist whether because the interpretation is not easy or because the geologist and prospector would have to analyze the results that confirm their hypothesis and rule out the ones that do not affirm their ideas.