Induced Polarization Survey Design for Porphyry Copper Targets

Induced polarization (IP) surveys remain one of the most powerful geophysical tools for detecting disseminated sulfide mineralization associated with porphyry copper-gold systems. However, effective survey design requires careful consideration of multiple parameters.

Electrode array selection is the first critical decision. Dipole-dipole arrays provide good lateral resolution and are standard for detailed IP surveys, while gradient arrays offer broader coverage at lower resolution. For porphyry systems typically hosted in large intrusive complexes, a combination of both is often optimal.

Dipole length selection depends on the expected depth and size of the target. For porphyry systems with mineralization potentially extending to 600m depth, dipole lengths of 100-200m with n-spacings of 1-8 are typical. Survey line orientation should cross the inferred structural trend of the mineralized zone at approximately 90 degrees.

Data quality assurance during acquisition is critical — resistivity and IP phase readings should be checked in real-time, and apparent resistivity sections should be reviewed daily to identify data artifacts or equipment issues before they contaminate large areas of the survey grid.