Related by context. Frequent words. (Click for all words.) 54 stalagmites 52 lichen 52 glaciers 52 aspen trees 51 lichens 51 lava tubes 51 stalactites 50 volcanic peaks 50 glacial melting 50 striations 50 jagged peaks 50 igneous rock 49 rock outcrops 49 stalactite 49 termite mounds 48 cumulus clouds 48 mud volcanoes 48 glaciers melt 48 whorls 48 landforms 48 Tibetan Plateau 48 glacier 48 crags 48 sequoias 47 igneous rocks 47 glacial retreat 47 lava flows 47 Andes mountains 47 towering peaks 47 temperate forests 47 evergreen forests 46 megafauna 46 Andes Mountains 46 timberline 46 lithosphere 46 ridges 46 icecap 46 volcanoes 45 mesas 45 limestone caves 45 melanosomes 45 buttes 45 ponderosa pines 45 melting glacier 45 snowfield 45 stromatolites 45 trackways 45 fossilization 45 Chaco Canyon 45 salt crystals 45 highlands 45 ptarmigan 44 continental drift 44 whorl 44 glacial ice 44 volcanic crater 44 spherules 44 Peruvian Andes 44 Andean highlands 44 dust devils 44 tufts 44 cirrus clouds 44 hillocks 44 rock outcrop 44 tectonics 44 mammoths 44 massif 44 granite boulders 44 limestone formations 44 mountain glaciers 43 plate tectonics 43 thawing permafrost 43 aspens 43 glacial melt 43 precipices 43 mountains 43 marine sediments 43 Sierra Madres 43 glacial 43 mountainsides 43 Inca ruins 43 sandstone cliffs 43 deep gorges 43 seedpods 43 glaciers melting 43 tidal pools 43 pectoral fins 43 retreating glaciers 43 glacial lakes 43 limestone cave 43 polar caps 43 Meridiani 43 vortices 42 explosive eruptions 42 mountain ranges 42 greenish brown 42 supercontinent 42 Southern Appalachians 42 landmasses 42 Sonoran desert 42 glaciologists