Yeah - in these cases geophysics is all indirect evidence of...

Yeah - in these cases geophysics is all indirect evidence of whatever you are measuring, and IP and Seismic will give you the location and geometry of faults and particular rock types, but not so much telling them directly where the gold is. The other complicating factor is that doing ground geophysics is difficult with an open pit and a mill over the top of the zone of interest and also the surrounding waste dumps make the logistics of doing ground-based seismic or IP that much more difficult, compared to an un-mined exploration prospect out in a flat paddock. Building a detailed geological model is also worth considering but you need to have underground/open pit exposure and/or drill holes to get enough data to build a geological model.