Related by context. Frequent words. (Click for all words.) 55 sedimentary rock 54 lithosphere 54 clasts 54 marine sediments 53 calcareous 53 carbonaceous 52 basaltic 52 glacial till 52 peridotite 51 lavas 51 depositional 51 methane hydrate 51 polar vortex 51 Arctic permafrost 50 pyroclastic 50 steam vents 50 alluvium 50 oceanic crust 50 continental crust 50 calcite 49 Upper Cretaceous 49 talus 49 stalactite 49 igneous rocks 49 silts 49 magma chamber 49 siliceous 49 igneous rock 49 basalts 48 pyroxenite 48 Namib Desert 48 graphitic 48 graben 48 lava tubes 48 lunar soil 48 sandstone formations 48 isotope ratios 48 mudstone 48 basalt 48 volcanic vents 48 olivine 47 icecap 47 icy crust 47 hydrothermally altered 47 breccia pipes 47 lake sediments 47 embayment 47 Weddell Sea 47 landmasses 47 earth crust 47 lakebed 47 siltstones 47 silica 47 geologic formation 47 moraine 46 sedimentary 46 termite mounds 46 crustal 46 sediments 46 underwater volcanoes 46 seabeds 46 Earth crust 46 magmas 46 interbedded 46 hydrothermal vent 46 tussock 46 schists 46 snail shells 46 limestones 46 volcanic rock 46 magmatic 46 electron density 46 gneiss 46 andesite 46 muskeg 46 kerogen 45 alluvial deposits 45 waxy substance 45 outcrop 45 Ross Ice Shelf 45 retreating glaciers 45 temperature gradient 45 tuffs 45 Jurassic Period 45 solar nebula 45 carbonate rocks 45 Lake Vostok 45 Olympus Mons 45 glacier 45 Carboniferous 45 sulphide bearing 45 barrens 45 chert 45 sedimentary rocks 45 siltstone 45 silicates 45 porosities 45 salt crystals 45 chalky white 45 calcrete 45 Sediments