IP (Induced Polarization) / Resistivity
Purpose: The IP/Resistivity method is used extensively for mineral exploration and environmental studies. This technique is valuable for identifying subsurface features by detecting chargeability and resistivity, which are influenced by mineral content, grain size, and distribution.
Applications:
Surface Surveys: Ideal for detecting sulphide concentrations, grain size uniformity, and chargeability in mineral deposits. 2D in-line and 3D configurations allow for high-resolution mapping, with 3D surveys capable of identifying features as small as 20 meters.
Borehole Surveys: Cross-hole IP/Resistivity uses electrodes between boreholes to gather detailed subsurface data for geotechnical and mineral exploration. Cross-hole setups can vary in spacing, making them adaptable for both near-surface and deep exploration.
Technical Process: Data from IP/Resistivity surveys are processed using inversion modeling (such as UBC GIF 2D and 3D software), which generates depth maps and pseudosections. These maps help geologists and engineers visualize the spatial distribution of chargeability and resistivity, essential for resource estimation and site characterization.
Key Uses: Effective for mineral prospecting (especially gold and sulphide deposits), void detection, and mapping waterway crossings or potential contamination zones.
IP/Resistivity Survey methods can be carried out on SURFACE or though BOREHOLES.
Surface
- This geophysical method uses Spectral parameters MIP, Tau and ‘c’ to obtain information about quantity of sulphides, grain size, and uniformity of grain size. This helps to characterize and prioritize otherwise similar chargeability and resistivity anomalies
- 2D in-line modes or in 3D with remote receivers are options to consider.
- 3D surveys detect relatively small (e.g., 20m) lenses.
- See also:
Borehole
- Cross-hole Surveys use transmitter electrodes located at infinity across strike and potential electrode pairs located across two boreholes.
- The cross-hole pairs can range from a couple meters apart for geotechnical investigations to hundreds of metres apart for mineral exploratoin
- We inversion model and review the results at the end of each field day so that we can plan the following day’s cross-hole pairs.
- UBC GIF 2D and 3D inversion model software inversion models the IP and Resistivity data.
- 2D results present as stacked pseudosections of chargeability, apparent resistivity, Spectral and 2D inversion model depth sections. Magnetic profiles from available airborne or ground surveys plot as profiles on these presentations.
- 2D results collected on a regular grid also inversion model in 3D.
- 3D inversion model results present as plan maps for various model depths and depth sections for any pertinent orientation
- See also:
