Common geophysical methods used in mineral and resource exploration involve various techniques that measure the Earth’s subsurface physical properties to identify geological structures and locate mineral deposits(Methods of Exploration – Boliden, n.d.).
Gravity Surveys
Gravity measurements detect changes in the Earth’s gravitational field, aiding in locating dense mineral deposits like sulfides and chromite. They are useful for mapping large structural features and detecting dense geological formations.
Electromagnetic (EM) Surveys
Electromagnetic methods use alternating magnetic fields to induce electrical currents in the subsurface. They help identify conductive mineral deposits such as sulfides, graphite, and kimberlite pipes, used widely in mineral and diamond exploration.
Seismic Methods
Seismic techniques, including reflection and refraction surveys, image subsurface geological structures at greater depths, enabling the delineation of mineralized zones and structural features relevant for resource estimation.
Electrical and Resistivity Techniques
These methods measure the ground’s resistance to electrical current flow. Induced polarization (IP) and resistivity surveys are particularly effective in detecting disseminated sulfide minerals and alteration zones related to mineral deposits.
Additional techniques such as ground-penetrating radar, borehole geophysics, and remote sensing are applied based on the scale and goals of the exploration project. These methods may be used separately or together to build a detailed picture of the subsurface and inform subsequent exploration efforts.
Geophysics is all about reading the Earth using physics! What are some of the most common geophysical methods used to investigate the subsurface, and what unique information does each technique reveal? Share your insights!
