Gravimetrics
The structure of the underlying geology as well as the presence of voids create small localized variations in the Earth’s magnetic field, providing information about subsurface variations in density. The contrasts in density can be measured using specialist instruments which measure the gradient of the magnetic variations, thereby allowing the depth and location of the object underground to be estimated.
Geological structures (e.g. faults, fracture zones) and their properties (consolidation, absorption) as well as the presence of any voids – natural or anthropogenic – create differences in density. The variations observed depend on the size, shape and depth of the anomaly. Sensitive instruments measure the density contrasts. The method is often used for mineral prospection, as bedrock is naturally more denser than sedimentary deposits.
Bargheer Geophysics is able to conduct a range of surveys using our own or hired in equipment, as required.
Applications
- Mineral exploration.
- Fault localization.
- Risk assessment for surface deformations resulting from mining.
- Detection of stationary and dynamic natural and anthropogenic voids (caves, tunnels, underground rooms, undocumented mine workings.
- To supplement and augment other methods.