The Geology and Extinct Volcanos of Central France

Allier appears Ardèche augite Auvergne basaltic currents basaltic lava base basin bed of basalt beneath breccia calcareous calcareous peperino Cantal cellular Central France chain of puys channel character Clermont clinkstone colour columnar compact composed conglomerate considerable contains covered crater crystals of augite current of lava deposits distance district domite dyke east elevation eruption evidently excavation feet felspar fissures flowed formed fragments freshwater formation geologists Gergovia gneiss granitic platform Graveneire Haute Loire heights hill lacustrine lake lava lava-current Le Puy Limagne limestone marls masses matter Mezen miles Mont Dore Monts Dôme mountain neighbouring numerous observed occupied olivine Pariou peperino plain Plate plateau points Pomel prisms probably Puy de Dôme puzzolana Ramond recent remarkable ridge rise river sandstone scoriæ seen side similar Sioule slope strata stream of lava substance summit surface tertiary thick tion torrents trachyte tuff valley vast vent Vivarais volcanic cone