Introductory Text-book of Geology

abundant accumulations agency appear argillaceous arrangement basalt beds bituminous boulders building-stone calcareous carboniferous chalk chemical chiefly clay clay-slate coal coal-measures colours compact composed composition conglomerates contain coral-reefs corals crust crustacea crystalline deposits districts drift earth earthquake encrinites England eocene epoch estuaries felspar fishes flagstones formation forms fossils frequent fresh-water geographical geologists geology globe gneiss granite gravel greenstone grits groups hornblende igneous rocks interstratified islands KEITH JOHNSTON lakes laminated lava layers lias lignite lime limestone lower magnesian marine marls masses metamorphic mica mineral mountain limestone numerous occur ocean old red sandstone oolite origin peat-mosses peculiar period Permian Physical Atlas plants and animals pleistocene POST-TERTIARY present quartz regions remains of plants reptiles rivers rocky sand seams sedimentary shales shells silt silurian slates slaty strata stratified rocks structure surface termed tertiary texture thick tion trachyte trap trappean Triassic trilobites upheavals upper varieties vegetable volcanic wealden zoophytes