Related by context. Frequent words. (Click for all words.) 61 calcareous 60 silty 59 calcite 58 mudstone 58 alluvium 57 limestone 57 clasts 57 limestones 57 siltstones 57 sediments 57 sediment 56 sedimentary rock 56 silts 56 lava tubes 55 marl 55 calcrete 55 silt 55 magma chamber 55 igneous rock 54 limestone formations 54 karst 54 tuffs 54 glacial till 54 escarpments 53 sedimentary 53 streambeds 53 dolomite 53 sandstone 53 interbedded 53 gravels 53 graben 53 decomposed granite 53 siltstone 53 quartzite 53 drainage basins 53 pyritic 52 basalt 52 sedimentation 52 oceanic crust 52 jasperoid 52 lava tube 52 rock outcrops 52 basins 52 coulees 52 lakebed 51 coarse sand 51 basalts 51 basaltic 51 talus 51 siliceous 51 streambed 51 cenotes 51 stalactite 51 volcanic rock 51 alluvial deposits 51 caliche 51 schists 51 landforms 51 peridotite 51 Upper Cretaceous 51 deep gorges 51 lowermost 51 pebbly 51 crushed limestone 51 limestone caves 51 granite boulders 51 gneiss 51 iron oxides 51 andesite 50 sandy soils 50 icy crust 50 overlies 50 weakly mineralized 50 olivine 50 lithosphere 50 brecciated 50 steam vents 50 intermittent streams 50 basin 50 salt crystals 50 carbonic acid 50 oxbow 50 Mineralization occurs 50 quartz carbonate 50 soils 50 sandy soil 50 revetment 49 sandstones 49 Sinkholes 49 Sediments 49 surficial 49 aquifers 49 limestone cave 49 granitic 49 sandy loam 49 geotextile 49 friable 49 hardpan 49 carbonate 49 mossy 49 mineral salts