Related by context. Frequent words. (Click for all words.) 49 sandstone formations 47 geologic formation 46 billowing cloud 46 basalt rock 45 geologic formations 44 Explosions rocked 43 previously undrilled 43 kiva 43 quartz carbonate veins 43 saline aquifers 43 flames billowed 43 grayish white 43 hummocks 42 clastic 42 limestone formations 42 greenish gray 41 grayish blue 41 sandstone 41 mosaic depicting 41 granite cliffs 41 surface geochemistry 41 sandstone reservoirs 41 brownish gray 41 Valles Marineris 41 pyroclastic 40 vertical shafts 40 rock formations 40 bluish green 40 plumes 40 Marcellus shale formation 39 mossy green 39 black 39 smoke billow 39 mottled brown 39 hornfels 39 cone shaped 39 wormlike 39 lava tubes 39 roughly hewn 39 Carina Nebula 39 greenish brown 39 geological formations 39 vuggy silica 39 salt domes 39 sandstone cliff 39 reddish colored 39 oval shaped 39 Eureka Trend 38 cypress swamp 38 hydrothermal vent 38 triangular shaped 38 interbedded 38 tubeworms 38 concretions 38 Thick clouds 38 escarpments 38 white 38 smoke billows 38 gulches 38 craggy mountains 38 polar craters 38 grayish brown 38 stockwork veining 38 carbonate alteration 38 lunar craters 38 billowing clouds 38 Lava flows 38 crater 38 silvery gray 37 Olympus Mons 37 nylon jacket 37 rocky ledges 37 bluish gray 37 depositional 37 fumaroles 37 stood sentry 37 Namib Desert 37 volcanic crater 37 volcanic cones 37 quartz stockwork 37 sublevel 37 orangish 37 caverns 37 Perched atop 36 felsic volcanics 36 irregularly shaped 36 coal seams 36 Charred bodies 36 Mineralization consists 36 volcanic vents 36 limestone cave 36 iridescent blue 36 brown hooded sweatshirt 36 cavern 36 saucer sized 36 granite boulders 36 marble monuments 36 Upper Jurassic 36 funnel shaped 36 volcanic peaks 36 barrens