Exploration for deep-seated mineral deposits in mature mining camps requires integration of large and heterogeneous spatial data-sets. Traditionally, geological, geochemical, and geophysical observations are acquired, processed and analysed independently within separate spatial contexts or more commonly, for geochemical data, in non-spatial feature space. Although methodological developments are still in progress, 3D GIS (geographic information system) technologies already provide powerful tools that can be used to integrate such heterogeneous data-sets to visualize, compare, and characterize geological relationships in a more supportive interpretive environment. Importantly, this technology provides better opportunities to embed all these properties in a more robust geometric framework in which structural history and palaeogeographic setting can be taken into account. We present 3D GIS applications that aid in interpreting relationship patterns amongst faults, folds and geochemical trends. Examples from the Noranda mining region, a classic VMS mining camp, demonstrate the applicability of 3D GIS to support the discovery of new mineral resources at depth.