This book is the result of 3- and 4-D modelling as part of the EU FP7 Promine project, which for the first time in Europe addressed the issue of pan-European 3- and 4 D geological models as a basis for mineral exploration and extraction under cover. The models that have been established cover four major mineral belts in Europe: Skellefte-Vihanti-Pyhäsalmi in Fennoscandia, Forsudetic monocline in Poland-Germany, the Iberian Pyrite Belt and the Ozza Morena zone in Spain-Portugal and the Hellenic belt of northern Greece. The basic principle for the modelling is to combine geological information from the surface, drill cores/holes, underground exposures with geophysical data, both airborne, ground and drill hole measurements. In most cases all existing and acquired data were imported and visualized in the gOcad software package. For some belts also uncertainty models are presented. 4-Dmodelling added the time aspect to the 3-Dmodels and aimed at visualizing the geological evolution of the district. 3-D predictivity maps are also presented using some different principles for the predictive models. We show in this book that it is possible to build robust 3-D models of major mineral belts in Europe and by using different approaches it is also possible to carry out 4-D modelling to help exploration industry with better targeting. The 3-D predictive models for the mineral belts clearly show the potential of undiscovered resources in various parts of Europe. The results from the modelling in the Promine project is a proof of concept, and we hope that this book serves as an inspiration for future, more full scale, projects that could be developed to contribute to a sustainable supply of metals to the society.