Petrology 17 Sedimentary rocks 14 Igneous rocks 13 Metamorphic rocks 11 Sedimentology 11 Sedimentation and deposition 9 Sedimentary basins 7 Mineralogy 4 Carbonate rocks 3 Crystalline rocks 3 Geology 3 Geology, Stratigraphic 3 Rocks 3 Diagenesis 2 Earth sciences 2 Hydrogeology 2 Metamorphism (Geology) 2 Petroleum 2 Rare earth metals 2 Ultrabasic rocks 2 Water-rock interaction 2 Carbonate reservoirs 1 Carbonates 1 Contact metamorphism 1 Distribution of rocks 1 Erosion 1 Facies (Geology) 1 GEOMATERIALS UNDER THE MICROSCOPE-- A COLOUR GUIDE 1 Geochemistry 1 Geodynamics 1