ARCHEAN routinely provides geophysical services and support to both major and junior mining companies, ranging in scale from terrane assessment to near-mine. The different geophysical methods have different advantages and possibilities but also limitations. By using the right geophysical method in the right surrounding big profits can be made. Geophysics is used in mineral exploration to measure variation in the physical properties of subsurface materials without the need for drilling or excavation to recover samples. Such variations can be due to the different chemical compositions of lithologies, the presence of magnetic or conductive minerals, or the degree of water saturation, porosity and faulting below surface.

We have long experience and knowledge in how to perform geophysical measurements with excellent quality.

ARCHEAN has long experience of planning, performance, quality control and interpretation of geophysical surveys.

Magnetic

In general magnetic data has often been acquired in areas where it would enhance the geological interpretation. Magnetic data can be used to identify and delimit lithological units, deformation zones and provide information about the amount and proportion of different magnetic minerals.

Its exploits small variations in magnetic mineralogy among rocks.

Application Magnetic survey include mapping of intrusive bodies/dykes, alteration associated with supplied mineralization, structural mapping and fracture density mapping, and depth to basement determinations

Resistivity

The purpose of electrical resistivity surveys is to determine the subsurface resistivity distribution by making measurements on the ground surface. From these measurements, the true resistivity of the subsurface can be estimated. The ground resistivity is related to various geological parameters such as the mineral and fluid content, porosity and degree of water saturation in the rock. Electrical resistivity surveying is widely used in mineral exploration, groundwater exploration, environmental and mining and geotechnical investigations.

Seismic Refraction

The Seismic Refraction method depends on the principal that seismic waves possess varying compression and shear wave velocities within differing types of soil and rock material. Acoustic energy waves are refracted when they cross over between soil and/or rocks of differing (and increasing) seismic velocities. The seismic refraction method utilizes the refraction of seismic waves on geologic layers and rock/soil units in order to characterize the subsurface geologic conditions and geologic structure. Seismic refraction surveys provide a measure of material strengths and can consequently be used as an aid in assessing rippability and rock quality.