Extract: Geoscientists with experience of field-based mapping are valuable assets in the mining and petroleum industries because their training enhances their spatial awareness and abilities to think in 3D. This is why fieldwork forms a core component of geoscience teaching at university, with undergraduates being encouraged to produce maps, sketches and 3D interpretative diagrams to describe the geology they see in the field. Traditionally, this is a paper-based process requiring a degree of abstraction and simplification. In recent years, petroleum geologists have taken this mapping and model building process a stage further, building highly detailed 3D models of sub-surface geological architectures for use in hydrocarbon exploration and production. The key difference here is that the geological surfaces used to construct these models are picked from prominent reflections imaged on seismic datasets which are geospatially referenced, i.e. there is little spatial abstraction every surface used to build the model is close to its correct relative location to all other surfaces. If onshore geologists are to accurately compare and contrast their observations with those made in offshore regions, then an onshore equivalent of 3D seismic is required, i.e. a means of capturing geospatially referenced images of surfaces in outcrops.