What are Geophysical Services?

Geophysical services are services that pertain to the collection, interpretation, and mapping of the physical properties of the surface and subsurface (below-ground) of an area. Some of the properties measured include gravity, magnetics, seismic refraction/reflection, electric fields, and more. The measurements from these surveys help to identify the mineral, geological, and structural makeup of the earth.

While there are many applications of geophysical services, including environmental studies, forensic science, and agriculture, some of the most common uses for geophysical services are mining, geology, and engineering.

GEOPHYSICS IN MINING

Because mining operations can cover a large area, it’s difficult to project reserves and conditions based only on drilling. Geophysical services help with prospect identification, field development and optimization plans, and risk reduction.

GEOPHYSICS IN GEOLOGIC STUDIES

Bedrock studies and soil surveys through geophysics are useful in helping to map geologic features. This includes things like fractures, joints, faults, changes in topography, and more.

EXAMPLES OF GEOPHYSICAL SERVICES

Geophysical services typically contain a range of data collection, analysis, and reporting. The surveys used depend on the land and the project goals. Common surveys include:

• Resistivity and Induced Polarity (IP) – This measures the electrical properties of subsurface rock. This assists in mineral, geothermal, and groundwater exploration.
• Gravity – This survey measures changes in the earth’s gravitational field caused by variations in the density of the subsurface, including faults, voids, bedrock topography, and basin geometry.
• Magnetics (Mag) – Magnetic survey helps to identify anomalies in the earth’s magnetic field. This can help to identify mineral-bearing ore bodies and subsurface structure.
• Seismic – Seismic surveys can be conducted onshore (land) and offshore (marine). They generate images of the earth’s subsurface using seismic refraction or reflection, helping to assist in planning exploration and development.
• Ground Penetrating Radar (GPR) – GPR uses radar pulses to image the subsurface by detecting reflected signals from the subsurface structures. This can help with prospecting, borehole structure mapping, and more.
• Time Domain Electromagnetics (TDEM) – This helps to determine subsurface electrical properties. They are also sensitive to subsurface magnetic properties. This is a very common surface EM technique for mineral exploration in both onshore and offshore applications.
• Frequency Domain Electromagnetics (FDEM) – FDEM measures voltages induced when exposed to a varying magnetic field. It is used for identifying transitions in soil type, detecting geological features, mapping, and more.
• Very Low Frequency (VLF) – VLF survey methods use very-low-frequency radio communication signals to determine electrical properties of the shallow subsurface. This is a good tool for quickly and inexpensively identifying target areas for further investigation.
• Gamma Ray Spectrometer – Gamma-ray spectrometry surveys map the natural occurrence of Potassium, uranium, and thorium within rock. These produce heat through radioactive decay. This can be a helpful tool for geological mapping of rock alteration and concentration of radioactive elements.
• Controlled Source Audio-frequency Magnetotellurics (CSAMT) – This low-impact survey method transmits an eclectic signal into the ground from one location and measures the received electric and magnetic fields. This helps to provide information about geologic structure, locations for mineral investigations, and more.
• Natural Source Audio-frequency Magnetotellurics (AMT) – AMT surveying uses naturally occurring passive energy sources to map geologic structures. This survey is particularly helpful in investigating deep structures.

LEARN MORE

Are you interested in learning more about geophysical services or how they can help with your mining or geology project? Contact Rangefront today to talk with one of our geophysics experts.

ABOUT THE AUTHOR

BRIAN GOSS

President, Rangefront Mining Services

Brian Goss brings over 20 years of experience in gold and mineral exploration. He is the founder and President of Rangefront, a premier geological services and mining consulting company that caters to a large spectrum of clients in the mining and minerals exploration industries. Brian is also a director of Lithium Corp. (OTCQB: LTUM), an exploration stage company specializing in energy storage minerals and from 2014 to 2017, he fulfilled the role of President and Director of Graphite Corp. (OTCQB: GRPH), an exploration stage that specialized in the development of graphite properties. Prior to founding Rangefront, Brian worked as a staff geologist for Centerra Gold on the REN project, as well as various exploration and development projects in the Western United States and Michigan. Brian Goss holds a Bachelor of Science Degree with a major in Geology from Wayne State University in Michigan.

You may also be interested in...