Comparison of induced polarisation measurements over the Elura orebody

Abstract

Resistivity and induced polarisation measurements have been performed at identical locations over the Elura orebody using 100 m dipole?dipole arrays by operators of three advanced IP systems. While the three resistivity data sets correlate extremely well, the three sets of induced polarisation measurements correlate poorly. The polarisation response of the Elura deposit is most clearly shown by chargeability values measured using a HUNTEC Mark IV receiver. Phase measurements at 0.125 Hz using a ZERO GDP-12 receiver support the character of the chargeability pattern. Low frequency phase measurements acquired using the Phoenix Multispectral IP system were adversely affected by telluric noise, for which (owing to survey time limitations) inadequate signal stacking was employed. By contrast, the accompanying high frequency phase data contain useful information concerning the geoelectrical section and the electromagnetic response of the orebody. This case history may assist users of advanced IP systems in making the appropriate compromise between survey production and data quality.