Geophysical exploration is a means of sourcing out high concentrations of various minerals and commodities under the Earth's surface by employing surveying methods, such as electromagnetic surveys and magnetic surveys. Geophysical exploration can be conducted on the ground or by air and can detect a variety of different magnetic mineable ores such as kimberlites and magnetic iron ores.
Geophysical exploration can also aid in uncovering underground reservoirs, hydrocarbon, base and precious metals and uranium. Petroleum and coal are also commonly sourced out using geophysical exploration. Airborne geophysical surveys are useful in acquiring data for geophysical mapping.
Airborne magnetic surveys are the most commonly used method of geophysical exploration. Depending on the altitude of the flight, airborne magnetic surveys are categorized as either regional or detailed. Regional surveys cover vast spaces of up to 5000 square kilometers and a traverse line spacing of over 250 meters. It is these surveys that are used to gather data for mapping, as well as for uncovering concentrations of petroleum and coal.
Airborne magnetic surveys work by detecting the ambient magnetic fields, indicating where there are high and low concentrations of mineable magnetic ores. Electromagnetic surveys are employed in areas that are covered with bedrock, groundwater or clay as these factors can disrupt magnetic fields.
Both airborne magnetic and airborne electromagnetic (AEM) surveys are used by mining companies as a means of mineral prospecting, leading to mineral exploration.
Using a fixed wing horizontal gradiometer, it is possible to survey the horizontal gradient of the Earth, detecting mineable magnetic ores that are close to its surface.
Detailed surveys will benefit from using a fixed wing horizontal gradiometer, as they are capable of identifying the following:
- Magnetic axis within magnetic units
- The location of small anomalies
- Can discriminate between cultural and geological sources
- Can identify the dip of magnetic units
By using an aircraft that has been specifically modified for the purpose of geological surveying, it is possible to achieve more efficient and accurate results.
A specially modified aircraft combined with the use of an advanced data acquisition system ensures that a geophysical exploration will be successful in its purpose. The more sophisticated the data acquisition system, the more reliable the data. Accuracy and precision in data are the most important factors in geophysical exploration as many instigate mining exploration programs such as drilling. If the information acquired during a survey is incorrect, it may commence a costly mineral exploration that will not render estimated quantities of mineable commodities.
Mining companies and governments are wise to source out professional geophysical consultants who will have access to the most advanced geophysical exploration tools. By employing the use of specialized aircrafts and up-to-date data acquisition systems, along with a capable and experienced consultant who will analyze important data accordingly, chances of a successful geophysical exploration are increased.
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
www.terraquest.ca.
Ed. GMH