Igneous Rocks: Composition, Texture and Classification, Description and Occurrence, Volume 1J. Wiley & sons, 1909 |
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Common terms and phrases
acid akermanite albite alkali-feldspars alkalic aluminium amphibole andesine anorthite apatite aphanitic augite basalt biotite calcic calcium character chemical composition chiefly classification components compounds cooling crystals differentiation dikes diopside division elements equant eruption eutectic fabric feldspar feldspathoids femic ferromagnesian minerals gabbro gases Geol glass granite pegmatite granular groundmass H₂O hornblende hypersthene igneous rocks intrusive iron Jour K₂O kinds lava less leucite lime-soda-feldspar liquid magma magma magnesium magnetite mass metasilicate Mg,Fe)O mica microscopic mixture molecular molecules molten Na2O nephelite nephelite-syenite notable amounts occur olivine orthoclase orthosilicate oxides pegmatite petrographers phanerocrystalline phenocrysts porphyritic portion potash-feldspar potassium pressure prismoid proportions pyrogenetic minerals pyroxene quartz rock magmas salic saturation separation siliceous silicon SiO2 small amounts sodalite sodic sodium solid solidified solution sometimes spheroidal spherulites Subrang substance supersaturation surface syenite tabular take place temperature texture tion trachyte U. S. Geological Survey varieties viscosity volcanic
Popular passages
Page 331 - When exploded fragments of molten magma, large or small, fall together in a still heated condition, as may readily happen within the crater of a volcano or in the mouth of a fissure, they may be plastic enough to weld together in a more or less compact, coherent mass.
Page 173 - At any given temperature the concentration of that component, by the addition of which the freezing point is depressed is greater in the liquid than in the solid phase ; or conversely, the concentration of that component by the addition of which the freezing point is raised is greater in the solid than in the liquid phase.
Page 257 - ... the same in all cases, or constant in any one instance. Hence the sequence of rocks will not be uniform for all regions, nor will it necessarily be simple in any case. The sequence discovered by von Richthofen,1 when expressed in general terms, is of very wide application, and is to the effect that the earliest eruptions are of rocks having an average or intermediate composition, and that subsequent eruptions bring to the surface magmas of more and more diverse composition ; the last eruptions...
Page 97 - The relative lowering of vapor pressure is proportional to the ratio of the number of molecules of the dissolved substance to the total number of molecules in the solution.
Page 282 - Evidences of absorption by the igneous magma of material from adjoining rocks are very slight, even in cases where these rocks have been profoundly affected by the intruded magma.
Page 98 - More exactly, if one molecule of any substance is dissolved in one hundred molecules of any liquid of a different nature, the lowering of the freezing point of this liquid is always nearly the same...
Page 255 - Bohemia, and was afterwards clearly expressed by him in denning petrographical provinces as districts "within which the rocks erupted during any particular geological period present certain well-marked peculiarities in mineralogical composition and microscopical structure, serving at once to distinguish them from the rocks belonging to the same general group, which were simultaneously erupted in other petrographical provinces.
Page 97 - 71 Turpentine 136 -71 Cyanic acid 43 -70 Benzaldehyde 106 -72 Aniline 43 -71 Antimony chloride 228-5. -67 (iv) When the ratio of the number of molecules of the dissolved substance to the number of molecules of the solvent is made the same, the lowering of vapour pressure is independent of the nature of the substance and of the solvent. (For table see p.
Page 91 - Bunsen,2 holds good for solutions from which the dissolved gas is wholly removed by lowering pressure or raising temperature : the quantity of a gas dissolved by a specified quantity of a liquid is proportional to the pressure of the gas.
Page 111 - ... believe that we have here a set of things which are fundamentally of the same kind, for each form can be made from any of the others. We have, therefore, invented the conception of a single thing, of which heat, light, electricity, and motion are forms, and to it we give the name energy: energy is work and every other thing which can arise from work and be converted into work.