Geophysical methods have proofed to be very useful in mining projects. Geophysical surveys generally look for concentrations of anomalously high values of a given property being measured (electrical conductivity, density, seismic velocity, magnetic susceptibility). The results of the survey are used to identify a target of interest, or to correlate the spatial variation of values of the property with variations in the geology. Thus, the primary reasons to do geophysics are to get information on geology, and possibly to find targets of economic interest.
Geophysical methods are routinely used for the rapid data collection and the can cover large areas economically.
In many cases, more than one geophysical method can be used to help understand the geological context of the geophysical survey results. For example, an electromagnetic survey may have identified a conductor body. A small gravity survey can be carried out to see if the EM conductor is associated with higher density material. If there is no gravity anomaly, then the conductor is not likely to arise from metallic sulphides.
Some geophysical applications in mining are:
- Reservoir assessment
- Analysis of Tailing Ponds
- Leakage mapping
The most commonly used geophysical methods in mining applications are:
- Electric methods (ERT, IP and SP)
- Seismic methods (Refraction and Surface-wave methods)
- Ground Radar Penetrating (GPR3D, GPR2D)
- Electromagnetics (TDEM, FDEM)
The benefits flowing from application of geophysics may be direct, as immediate cost reductions, or indirect in the form of an enhanced ore recovery, optimised blasting pattern, or early warning of a safety hazard.