Related by context. Frequent words. (Click for all words.) 57 erosional 57 stalactite 56 wormlike 56 clasts 55 lunar craters 55 snail shells 55 graben 54 striations 54 basaltic 54 basalts 54 igneous rock 53 calcareous 53 lunar soil 53 membranous 53 kimberlitic 52 mudstones 52 lava tubes 52 spherules 52 clastic 52 scarps 52 pyroclastic 52 Valles Marineris 52 icy moons 52 alluvium 52 steam vents 52 scalloped edges 52 stratiform 52 ellipsoid 51 striated 51 sulphide bearing 51 threadlike 51 glacial till 51 whorls 51 sedimentary rock 51 tuffs 51 andesitic 51 meteor impacts 51 igneous rocks 51 siltstones 51 quartz veined 51 subparallel 51 depositional 51 interbedded 51 talus 51 Fig. 1A 51 hydrothermally altered 51 gneiss 51 calcite 50 graphitic 50 stromatolites 50 greywacke 50 olivine 50 chalky white 50 hydrothermal activity 50 icy crust 50 braincase 50 gneisses 50 gyres 50 moonlets 50 magmas 50 hardened lava 50 polar craters 50 breccia zones 50 plutons 50 jasperoid 50 calyx 50 morphologies 50 irregular shapes 49 hollow tubes 49 loess 49 granitic rocks 49 schists 49 greenish brown 49 torus 49 concentric rings 49 igneous 49 oblong 49 protuberances 49 limestones 49 hillocks 49 mafic volcanic 49 abiotic 49 salt crystals 49 vuggy silica 49 sulphide minerals 49 pottery fragments 49 mudstone 49 vertical shafts 49 basalt 49 papillae 49 siliceous 48 deep gorges 48 abstract shapes 48 pebbly 48 syncline 48 mud volcanoes 48 irregularly shaped 48 latticed 48 anomalism 48 trefoil 48 sandstone formations