Related by context. Frequent words. (Click for all words.) 68 volcanic crater 66 caldera 64 lava tubes 64 sandstone formations 61 lava tube 61 Namib Desert 60 volcanic 60 stalactite 60 graben 60 escarpments 59 Geologically 59 quartz monzonite 58 cenote 58 limestone cave 58 Valles Marineris 58 volcanic peaks 58 tuffs 58 magma chamber 58 Olympus Mons 58 igneous rocks 57 extinct volcano 57 igneous rock 57 hydrothermal vent 57 basaltic 57 basalts 56 depositional 56 pyroclastic 56 basalt 56 geologic 56 geologically 56 breccia pipes 56 Paleocene 56 mud volcanoes 56 supervolcano 56 lava 55 hydrothermal activity 55 overlies 55 Archaean 55 breccia pipe 55 schists 55 hydrothermal breccia 55 massif 55 volcanic rock 55 lava flowing 55 limestone formations 55 Mineralization occurs 55 dormant volcano 55 Kilauea Volcano 55 calcareous 55 dacite 55 lava flows 54 volcanoes 54 syncline 54 hydrothermal 54 volcanic vents 54 diatreme 54 rock outcrop 54 mudstone 54 deep gorges 54 clasts 54 limestone caves 54 hydrothermally altered 54 landform 54 jasperoid 53 lavas 53 embayment 53 landforms 53 outcrops 53 magmatic 53 gneiss 53 NE trending 53 sandstone cliffs 53 sedimentary rock 53 grassy plains 53 limestones 53 granitic 53 carbonate rocks 53 Chugach Mountains 53 icecap 53 rock outcrops 53 andesite 53 volcanic islands 53 stalagmites 53 quartz stockwork 52 rocky outcrops 52 breccia zones 52 Mount Ruapehu 52 Amazonian rainforest 52 mafic volcanics 52 Volcanic 52 icy crust 52 Burgess Shale 52 rock formations 52 relict 52 mineralizing system 52 Teton Range 52 buttes 52 explosive eruptions 52 Lake Vostok 52 quartz carbonate 52 siltstones