The Demand for Geophysical Surveys;
Greater global demand for minerals is leading to an increased demand for mineral exploration and in turn, airborne geophysical surveys. Airborne geophysical surveying, and specifically,, airborne magnetic surveys and airborne radiometrics surveys have become leading techniques to lubricate exploration. Both helicopters and fixed wing aircraft are used for efficient acquisition of large volume airborne geophysical data sets.
Raw airborne survey data can be transformed into a wide variety of detailed geophysical map products, which are used to identify and model geophysical anomalies for further exploration. Airborne geophysical surveying is the primary tool in the mineral exploration process as the data provides key insight into where to carry out further in-depth exploration.
Geophysical surveys can be conducted via the following methods:
- Airborne (typically large and remote areas)
- Ground (property sized claim areas, close to road access)
- Marine (offshore, regional grids)
- Borehole (any site with drill holes)
These methods require different equipment and applied technologies in order to produce accurate and repeatable results. Airborne surveys are key as they allow for the most economical and efficient mapping of large areas. Single engine aircraft can economically fly small to large exploratory surveys over land, while twin engine aircraft have proven to be invaluable in finding oil and gas deposits offshore, or in remote surveys with long ferry distances from suitable airports. Helicopters are used to achieve very low survey altitude or to explore in mountainous terrain requiring high gradient climb ability.
Airborne Geophysical Survey Technology
There are a wide variety of different geophysical technologies that can performed from an airborne platform. These technologies are all proven, repeatable acquisition methods and can be provided by Terraquest for its clients.
- Magnetics (Single Sensor and Horizontal Gradiometer)
- Electromagnetics
- Radiometrics
- Digital VLF-EM
- Gravity
Terraquest typically collects magnetic, radiometric and Matrix Digital VLF-EM survey data on any given flight, however other technologies such as gravity, seep finder and electromagnetics can be acquired, depending upon the target. Each technology requires unique instruments and requisite survey parameters to acquire precise data. Survey factors vary for each technology and include:
- type of terrain in the survey grid
- survey altitude
- aircraft speed
- distance between survey lines
- wind and diurnal are also factors which must be considered and monitored throughout each flight
Airborne geophysical survey aircraft are generally restricted by the weight of the instruments that can be carried safely onboard an aircraft. Further, the equipment must be complimentary to each other in that they must share similar acquisition parameters as listed above.
The Industries that Drive Geophysical Surveying
Due to the increased activity in the mining industry and a significant increase in the amount of funding made available for exploration, as well as ongoing activity in the oil sector, the airborne geophysical surveying industry is also growing steadily.
Oil companies are constantly on the lookout for the next big deposit of hydrocarbons to capitalize on skyrocketing consumer demand. Oil companies are among the most well funded exploration companies in the world and provide significant business to the geophysical surveying industry.
Airborne geophysical surveying is predominantly used by Junior exploration companies when developing mineral evaluations of projects with the intention of selling their property to major mining corporations. Intermediate and major miners may also undertake surveys as projects warrant.
Specialists in Airborne Geophysical Surveys
Terraquest was established in 1984 and since then, our dedicated team has flown over 1,500 airborne geophysical surveys using both fixed wing and helicopter platforms. Our professional crews provide significant experience having carried out airborne magnetic surveys, airborne gravity surveys, airborne radiometric surveys, and airborne electromagnetic surveys on five continents.
Our quality data sets have been utilized in the exploration for base and precious metals, kimberlite, hydrocarbons, uranium, rare earth minerals and water. The company has performed exemplary surveys for both small and large exploration groups as well as many government agencies, including the USGS. References can be provided upon request. Visit
www.terraquest.ca.
Ed. GMH