Related by context. Frequent words. (Click for all words.) 69 sedimentary rocks 67 basalt 67 peridotite 66 sediments 65 volcanic rock 65 sedimentary 65 limestones 62 silicates 62 calcite 61 Precambrian 61 rock formations 60 sandstone 60 geologically 60 volcanic rocks 60 Earth crust 60 olivine 60 gneiss 59 quartzite 59 Paleozoic 59 Geologically 59 granites 59 gabbro 59 earth crust 58 sandstones 58 volcanism 58 magmatic 58 carbonate 58 chert 58 limestone 57 geological formations 57 carbonaceous 57 ultramafic rocks 57 regolith 57 geologic 57 banded iron 57 Proterozoic 57 schist 57 dolomite 56 andesite 56 sediment 56 intrusive rocks 56 mafic 56 stratigraphy 56 crustal 56 volcanics 56 iron oxides 56 Late Cretaceous 55 shales 55 hydrothermal 55 fossils 55 alluvium 55 Ordovician 55 brecciated 55 geologic formations 55 Cretaceous 54 metasediments 54 feldspar 54 ejecta 54 volcanic 54 magma 54 rhyolite 54 molten rock 54 overlies 54 outcrop 54 hematite 53 lithologies 53 intrusives 53 silica 53 granitic 53 Mesozoic 53 lava flows 53 carbonatite 53 sedimentary basins 53 outcrops 52 breccia 52 plate tectonics 52 glaciation 52 apatite 52 calcium carbonate 52 Eocene 52 felsic 52 subduction 52 carbonates 52 stalagmite 52 hydrothermal alteration 52 Archean 52 iron oxide 52 petrified wood 52 caldera 52 diatoms 51 ultramafic 51 rocks 51 disseminated sulphides 51 lake sediments 51 landforms 51 lava 50 Iapetus 50 granodiorite 50 subduction zones 50 geologically active 50 permafrost