Direct and Indirect Exploration using Airborne Geophysical Surveys

Edited by Admin
geophysical prospectingMineral and hydrocarbon exploration is conducted in several stages and the prospecting stage is arguably one of the most important. Prospecting can be done in various different ways but typically airborne geophysical surveys are used for either regional or detailed investigations.
There are two methods of prospecting, including direct and indirect. Surveys conducted as a direct prospecting method are employed to gain a detailed perspective on the presence of magnetic ores such as magnetic iron ores, chrome and kimberlites. Airborne magnetic survey data can lead to direct targeting.
The other method is called indirect prospecting to examine the structural body, depth and geometry of a specific region or detail area. Indirect prospecting assists in the task of mapping out weak magnetic fields as well as successfully discriminating between conductors that are magnetic or non-magnetic.
Detailed airborne magnetic surveys provide data at a higher resolution using tighter traverse line spacing of under 250 meters. As such, these surveys are valuable mineral prospecting tools for magnetic iron ores and kimberlites. A detailed survey is capable of helping to assess the characteristics and depths of geological structures that will be explored, and can locate specific basement targets in hydrocarbon exploration.
Regional airborne magnetic surveys assess a large terrain of usually more than 5000 square kilometers, with  traverse line spacing of up to 500 meters. These surveys are employed to help search for commodities such as coal and petroleum. Mining companies can also use regional surveying as a means of prospecting for other valuable commodities in the subsurface.
While there are several different types of geophysical surveys for mineral exploration, airborne magnetic surveys are the most commonly used surveys for this purpose. Airborne magnetic surveys work by employing the use of a magnetometer, either attached to the aircraft or towed behind, and work by detecting ambient magnetic fields that are caused by minerals in the subsurface of the Earth.
Airborne magnetic surveys allow a vast area to be assessed in a short time. While the aircraft is in flight, the magnetometer measures inherent magnetic fields which relate directly to targets, or indirectly to structures.
While airborne magnetic surveys are extremely useful for exploration, other techniques such as radiometrics, electromagnetics and gravity may also be used for mineral or hydrocarbon exploration.
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.  References can be provided upon request. Visit


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