Applications
Magnetic surveys measure small, localised variations in the Earth's magnetic field. The magnetic properties of naturally occurring materials such as magnetic ore bodies and basic igneous rocks allow them to be identified and mapped by magnetic surveys. Strong local magnetic fields or anomalies are also produced by buried steel objects. A broad range of applications of ground magnetic surveys are:
- Accurately mapping archaeological features
- Mapping basic igneous intrusive rocks & faults
- Evaluating the size and shape of ore bodies
- Identify geologic bedrock features such as mafic dikes or geologic contacts
- Delineate areas of ferromagnetic
- Finding buried steel tanks and waste drums
- Detecting iron and steel obstructions
- Locating unmarked mineshafts
- Locate underground storage tanks (USTs)
- Locate buried drums
- Delineate landfill perimeter
- Identify locations of historic structures
Gravitysurveys measure the changes of rock density by looking at changes in gravity caused by geological structures. State-of-the-art gravity meters can sense differences in the acceleration (pull) of gravity to one part in one billion. Measurements taken at the Earth’s surface express the acceleration of gravity of the total mass of the Earth but because of their high sensitivity the instruments can detect mass variations in the crustal geology. The amplitude of the variation from the high to the low of the gravity gradient zone is a function of the displacement on the fault. In addition to providing insights to fault problems, gravity methodology applies to any geologic problem involving mass variations. The common applications of gravity survey are:
- Mineral Exploration - massive sulphides, porphyry's structure
- Diamond Exploration - Kimberlitic pipes
- Coal Exploration - basin structure, grabens, large faults
- Petroleum - frontier basin mapping, diapirs
- Locating void(s) in Karst Topography
- Engineering, tunneling, footings
Technologies
GROUND MAGNETIC SYSTEMS
- Overhauser magnetometer system
- Optically pumped Potassium magnetometer and gradiometer systems
- Proton magnetometer system
GROUND GRAVITY SYSTEMS
- LaCoste& Romberg Model G Aliod1000
- LaCoste& Romberg Model G Land meter