Related by context. Frequent words. (Click for all words.) 73 Proterozoic 71 Paleozoic 69 sedimentary rocks 68 Cretaceous 67 Ordovician 67 Late Cretaceous 66 Eocene 65 Archean 65 Mesozoic 63 Triassic 63 Devonian 63 limestones 62 sedimentary 62 volcanics 61 sedimentary rock 61 volcanic rocks 61 metasediments 60 Pliocene 60 intrusive rocks 60 magmatic 59 gneiss 59 volcanism 58 geologically 58 massive sulfide 57 peridotite 57 epithermal 57 mafic 57 stratigraphy 57 glaciation 57 granites 57 Pleistocene 57 felsic 56 porphyry 56 andesite 56 gabbro 56 banded iron 56 hydrothermal 56 hydrothermal alteration 56 carbonatite 55 fossils 55 mineralization occurs 55 breccia 55 Miocene 55 skarn 55 sulphides 55 sediments 55 granodiorite 55 Jurassic 54 olivine 54 ultramafic 54 lithologies 54 unconformity 54 carbonate 54 sandstones 53 disseminated sulphides 53 mineralogy 53 sulfides 53 diorite 53 stratigraphic 53 geologic 53 massive sulphide 53 VMS deposits 52 crustal 52 basalt 52 massive sulphide mineralization 52 uranium mineralization 52 sulphide 52 mineralizing 52 metamorphic 52 caldera 52 breccias 51 stockwork 51 calcite 51 structurally controlled 51 underlain 51 greenstone belt 51 Tertiary 51 silicates 51 pegmatite 51 brecciated 51 paleo 50 pegmatites 50 sulphide mineralization 50 rhyolite 50 vertebrate 50 sulfide 50 massive sulphides 50 bearing quartz veins 50 footwall 50 sulfide mineralization 50 mineralization 50 pyrrhotite 50 alteration zones 50 plate tectonics 50 lithology 50 epithermal gold 50 megafauna 50 galena 50 silicified 50 schist 50 silicification