Executive summary: Active seismic sources such as explosives, air guns and vibroseis generate energetic P-waves well suited for reflection seismic studies. However, they can have negative environmental impacts and are expensive, both of which have motivated the development of passive seismic methods. Passive seismic methods utilise ambient noise from meteorological and anthropogenic activity. They have been successful for surface wave recovery but extracting body waves for reflection imaging is still a challenge. A key goal of the PACIFIC project is to develop methodologies for extracting body waves from passive seismic data, and for using these body waves for subsurface imaging. This report describes the development of synthetic velocity models that characterise the geological structure and seismic reflectivity at the Marathon Cu-PGE prospect Ontario, Canada. Synthetic seismic signals generated in these models will then be used to develop and test processing procedures for body wave recovery and body wave imaging. A first velocity model consists of two vertical sections obtained by interpolation of lithological contacts identified in drillholes. One section is perpendicular to the dip of the main gabbro intrusion, the other is parallel. A second model is obtained by blind 3D interpolation between drillholes and uses velocities measured on hand samples and drill core. Work in progress uses dedicated geological modelling software to generate a 3D block model that honors geological structures and cross-cutting relationships. A recently acquired downhole acoustic log avoids negative velocity biases from microfractures that can be introduced during depressurisation (e.g. of drill core). This will be used to calibrate a new velocity forward model.