Igneous Rocks: Composition, Texture and Classification, Description and Occurrence, Volume 2

abundant ægirite ægirite-augite albite alkali-feldspar alkalic amphibole analyses andesites andose anhedral anorthite apatite aphanitic aplite augite auvergnose basalts biotite calcic cent chemical composition chiefly common contain Creek crystals dacites diabase dikes diorite district Division eruptions essexite euhedral extrusive facies feldspar felsites femic components gabbro glassy gneisses granite granodiorite groundmass H₂O Hillebrand Hillebrand hornblende hypersthene igneous rocks Incl instances intrusive Island K₂O labradorite lassenose lavas lenads leucite lime-soda-feldspar liparose mafic mafic minerals magma magnetite mass mica monzonite Mountains Na₂O nephelite nephelite-basalt nephelite-syenite norite normative quartz Norway notable amounts obsidian oligoclase olivine orthoclase P₂OS pegmatites peridotites petrographical phanerites phenocrysts phonolites Pisani plagioclase porphyries potash prismoids pyroxene pyroxene-andesite quartz quartz-diorite quartz-monzonite quartz-porphyry quartzose Range region rhyolite rocks occur schists shonkinite SiO2 small amounts soda-microcline sodalite sodic sodipotassic syenite TABLE Tertiary texture tinguaite TiO2 tonalose toscanose trachytes tuffs varieties volcanic Washington Yellowstone