Improving modelling of AEM data affected by IP, two case studies

Abstract

Modelling IP parameters, including dispersive resistivity, from AEM data showing clear IP effects is possible. Using the spatially constrained inversion approach, with forward response that account for the full Cole and Cole model, we recover realistic chargeability and "IP corrected" resistivities sections from two VTEM datasets, from Canada and Australia. The "IP corrected" resistivity sections often show better agreement with known geological features, while improving dramatically the data fit, with respect to those obtained without IP modelling. While the majority of the IP effect originate from shallow chargeable layers, there seems to be some positive correlation between an isolated deep chargeable anomaly and known base metal deposit location.