3D geological and geophysical modelling was used in conjunction with mineral potential modelling

to assess unrealised Cu-Au potential in the Quamby area in the Eastern Succession of the Mount Isa

Inlier. This report documents the process used by the Geological Survey of Queensland, including 3D

modelling and geophysical inversion, to create a Common Earth Model (CEM) for 3D mineral potential

modelling over the Quamby Project area. The area is divided into three main geological domains, the

Mary Kathleen, Constantine and Soldiers Cap Domains (adapted from the North-West Queensland

Mineral and Energy Province Report (NWQMEPR), Geological Survey of Queensland, 2011b).

The Quamby Project area contains the major operating Ernest Henry Cu-Au mine as well as other

significant Cu-Au projects and is highly prospective for a range of mineralisation styles including

Cu±Au±Fe deposits and stratabound sediment-hosted Cu deposits. Mesozoic and Cenozoic sediments

cover more than 70% of the project area. Although interpreted cover depths are generally less than

150m, much of the area remains under-explored.

A 3D geological model was created using GOCAD and SKUA software incorporating new

interpretations from recent mapping by the Geological Survey of Queensland (Geological Survey of

Queensland, 2011b) as well as drillhole and seismic data. This 3D model was used as a starting model

to constrain potential field inversions yielding 3D physical property models (density and magnetic

susceptibility).