The Gidyea Structure marks the subsurface contact between the Mount Isa terrane and the Numil terrane further to the east. It also coincides with a significant conductivity feature, the Carpentaria Conductivity Anomaly (CCA). The copper endowment within reach of the CCA and Gidyea Structure is significant, with iron oxide copper gold deposits clustered along the hanging wall of the structure. A network of intersecting deep crustal seismic lines crosses the Mount Isa Province, providing a means to image this large-scale structure. The seismic traverses have complimentary MT data collected along them, at scales ranging between 2 km station spacing and 10 km station spacing. The three profiles of greatest interest are the 14GA-CF3, 06GA-M6 and 07GA-IG1 deep crustal seismic lines and their corresponding MT data.
A combination of gravity modelling and seismic interpretation has been used to create an interpretation of the Gidyea Structure across the deep crustal seismic network. Using this interpretation as a backbone, we can investigate how the different resolution MT surveys image features along the same structure. We use a combination of new MT inversions and published models to investigate this relationship. The broad conductivity structure of the CCA resolves into several smaller features as MT data resolution increases. There is remarkable consistency in the resistivity structure along the Gidyea Structure for seismic lines 14GA-CF3 and 06GA-M6, despite them being separated by over 100 km. Further north, the conductivity structure along the Gidyea Structure on 07GA-IG1 is significantly stronger, hinting that different processes are occurring in this area.