Related by context. Frequent words. (Click for all words.) 58 basaltic 56 corundum 55 basalts 55 erosional 55 polar craters 55 filamentous 55 goethite 55 clasts 55 loess 54 stratiform 54 glacial till 54 lunar craters 54 Gusev crater 54 chalcedony 54 calcareous 54 stalactite 54 syncline 54 rock outcrop 54 olivine 53 montane 53 membranous 53 scalloped edges 53 nanorod 53 spherules 53 schists 53 copper oxides 53 spinel 53 iron oxides 52 lava tubes 52 siliceous 52 mudstone 52 ellipsoid 52 stippled 52 manganese oxide 52 Fig. 1A 52 tuffs 52 wormlike 52 igneous rocks 51 striated 51 rock outcrops 51 planktonic 51 iridescence 51 gneisses 51 sepals 51 lowermost 51 embayment 51 landform 51 lithosphere 51 calyx 51 granite cliffs 51 igneous rock 51 hydrothermally altered 51 panicles 51 inflorescence 51 pinkish red 51 escarpments 51 hydrothermal fluids 51 purplish red 51 andesitic 50 alluvium 50 boron nitride 50 Valles Marineris 50 nanosized 50 reddish 50 greenish brown 50 basalt 50 martian soil 50 granitic rocks 50 brownish gray 50 threadlike 50 oceanic crust 50 snail shell 50 granitic 50 metamorphic rocks 50 photosphere 50 whorls 50 Namib Desert 50 aragonite 50 iridescent blue 50 mudstones 50 corrugations 50 exosphere 50 northerly trending 50 papillae 50 tubular flowers 50 sedimentary rock 50 NW trending 50 icy crust 50 fruiting bodies 50 mafic volcanics 49 moraines 49 subglacial 49 NE trending 49 underlayer 49 continental crust 49 jarosite 49 cartilaginous 49 protuberances 49 Sediments 49 mafic volcanic 49 steam vents