Interpretations help clients understand the geophysical results in the context of their project to facilitate the achievement of the project objectives. Because exploration projects are often run by geologists, SJ Geophysics’ expertise adds valuable insight into geophysical data.
Our interpretations can:
Borehole surveys involve the acquisition of geophysical data from within a borehole. They can be separated into two types: those measuring the physical properties of rocks near the borehole and those measuring the properties of objects located further away from the borehole.
Key features and benefits of borehole
Services provided by SJ Geophysics
Unique to SJ Geophysics
We can survey below the drill bit. Utilizing our unique Volterra borehole acquisition system, all data is logged within the acquisition unit downhole eliminating the need for expensive cables. The borehole survey occurs as the drill rods are removed from the hole. This means drillholes at high risk of collapse can be surveyed reducing the risk of not collecting data.
Controlled source electromagnetic surveys use the principals of electromagnetic induction to measure the electrical properties of the ground. EM data is acquired by transmitting a time-varying signal that induces currents in the ground which are then detected by a receiver unit. The induced currents in the ground are generated by the transmitter using either a surface loop or a grounded wire dipole. The measured response provides information on the subsurface distribution of rocks and minerals whose electrical properties are known to span many orders of magnitude.
Key features and benefits of EM
Services provided by SJ Geophysics
Ground acquisition of electromagnetic data:
Magnetotelluric surveys are an unique electromagnetic technique that utilizes natural energy as its source. Measurement in the variation of these natural magnetic B(t) and electrical E(t) fields can be used to derive the electrical properties of the subsurface material.
Key features and benefits
Services provided by SJ Geophysics
Magnetic surveys are a passive potential field method that measures variations in the Earth’s magnetic field (due to induced secondary fields caused by magnetic/ferrous materials). These variations can be used for the direct detection of metallic ore bodies or the identification of structural trends and geological framework.
Key features and benefits of magnetic surveys
Services provided by SJ Geophysics
Ground acquisition of magnetic data:
Exploration programs invest a lot of resources in performing surveys on their property. By combining the results and displaying them in 2D and 3D visualization environments, we give our clients a coherent picture of their exploration target.
Our services include:
Data Analysis involves the process of reviewing and evaluating data sets. A key objective is to identify and account for issues that might affect the quality of the data interpretation. SJ Geophysics has experience working with geophysical data in many forms and from various types of surveys.
In terms of data analysis, our company provides:
Survey evaluation and design (SED) aims to create custom surveys based on a project’s individual objectives and property characteristics. It is a two stage process (evaluation and design) that SJ Geophysics offers to clients, aiming to provide the best guidance in terms of project expectations.
As part of our services SED involves:
Inverting and modelling geophysical data provides insights for prospecting and drill targeting. SJ Geophysics builds 3D models of the subsurface using the geophysical data collected.
In terms of modelling and inversion, our company provides:
SJ Geophysics uses their expertise and experience to manage successful geophysical projects. Project management often includes elements from many of the other consulting services offered by SJ Geophysics. On top of managing the geophysical surveys we perform ourselves, we also manage projects performed by other teams.
Our services include:
Gravity surveys are a passive potential field method that measures variations in the earth’s gravitational field. These variations are the result of changes in the subsurface density distribution of rocks and minerals. Gravity data requires careful data reduction procedures to remove influencing factors such as the earth’s ellipticity, lunar tidal forces and local geographic effects. After corrections have been made, subtle features can be identified in the data.
Key features and benefits of gravity surveys
Services provided by SJ Geophysics
Resistivity (DC) and Induced Polarization (IP) is an electrical survey method used for measuring the electrical properties of the subsurface. In a DCIP survey, a time-varying current is injected into the ground using two current electrodes and the resulting potential field voltage distribution is measured. The measured response is then used to calculate the apparent resistivity of the ground. When the current is removed, materials capable of holding a charge (i.e. polarizable), will have residual currents that decay over time. The resulting change in voltage over time represents the chargeability of a material.
Key features and benefits of IP
Services provided by SJ Geophysics
Ground acquisition of IP data:
why Radiometric?
What we do
