Text-book of Geology, Part 1

abundant acid alteration andesites augite basalt beds calcareous calcite carbonate Carboniferous cavities chemical compact composed cone consist constituents containing crater crystalline rocks crystals density deposits diabase earth earth's crust earthquake eruptive rocks Etna explosions feet felsite felspar fissures formations Fouqué fragments geological glass globe gneiss grains granite granular ground-mass heat hornblende igneous inclosed iron Islands Journ land lava layers leucite lime limestone liquid magma magnetite mass materials metamorphic mica mica-schist Michel-Lévy microlites microscope miles minerals molten rock mountain Neues Jahrb observed occurs ocean olivine organic original orthoclase oxide Palæozoic plagioclase planet porphyritic postea present pyroxene Q. J. Geol quartz rhyolites rise round sand sandstone Santorin schistose schists serpentine shells silicates solid sometimes steam stone structure substance sulphur surface temperature terrestrial thick tion traced trachytes Trans tuffs vapors varieties veins vents Vesuvius vitreous volcanic action volcanic cone volcanic rocks