The Geological Observer

accumulations acid action alumina amid animals appear ashes beach beds beneath blocks bottom breakers British Islands calcareous carbonate carbonic acid cavities cinders clay cliffs coal coast considerable considered coral reefs Cornwall crater crystals deposits depth detritus district dry land earthquake Edition effected elevated eruption estuary evidence exposed fathoms feet felspar fissures formed fragments geological glaciers granite ground hornblende igneous rocks inferred kind lakes lava lime limestone magnesia manner marine mass mechanical suspension Mendip Hills miles mineral matter mode of occurrence modifications molluscs molten mountain noticed observer occur ocean old red sandstone oolitic organic remains pebbles portions present produced Professor quartz red sandstone regards regions respect rise river sand sea-bottom section fig seen shells shores side silicates Silurian Sir James Ross sometimes species specific gravity streams substances sufficient surface temperature thrown tidal tide tion trachytic traversed various vegetable veins volcanic