Principles of Geology: Being an Inquiry how for the Former Changes of the Earth's Surface are Referrable to Causes Now in Operation, Volume 4John Murray, 1834 - Geology |
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Common terms and phrases
alluvium alternate ancient animals appear aqueous argillaceous ations Auvergne basalt beds belong calcaire grossier calcareous called Cantal Central France chalk clay coal colour composed cones conglomerate containing crag crater cretaceous crystalline denudation deposits diagram dikes district earth elevation England Eocene Eocene period eruptions escarpment Etym extinct felspar flints fossil freshwater formation Geol geological geologists gneiss granite gravel gypsum height hills horizontal hundred feet hypogene igneous rocks lacustrine lakes land lava layers lime limestone lower green-sand marine marl mass Miocene mountains newer occur older Pliocene oolite organic remains origin Paris basin pebbles plants Pliocene plutonic Pyrenees quadrupeds quartz red sandstone resembling ridge river sand schist scoriæ secondary rocks secondary strata sedimentary seen shale shells siliceous simple mineral sometimes South Downs species stone strata stratified Subapennine supposed surface tertiary strata testacea texture thickness trachytic tuff upper valleys Velay volcanic rocks Weald
Popular passages
Page 224 - It is not to be expected that we should be able to find tests for conditional convergence as simple and general as those of §§ 173 et seq.
Page 323 - DIP. When a stratum does not lie horizontally, but is inclined, the point of the compass towards which it sinks is called the dip of the stratum, and the angle it makes with the horizon is called the angle of dip or inclination.
Page 304 - ... which is revealed to us by the microscope. We are prepared, therefore, to find that in time also, the confines of the universe lie beyond the reach of mortal ken. But in whatever direction we pursue our researches, whether in time or space, we discover everywhere the clear proofs of a Creative Intelligence, and of His foresight, wisdom, and power.
Page 333 - A limestone, so named, because it is composed of rounded particles like the roe or eggs of fish. The name is also applied to a large group of strata characterized by peculiar fossils.
Page 281 - I think, the only satisfactory solution of this problem. According to that theory, the materials of gneiss were originally deposited from water in the usual form of aqueous strata; but these strata were subsequently altered by subterranean heat, so as to assume a new texture.
Page 339 - SILT. The more comminuted sand, clay, and earth, which is transported by running water. It is often accumulated by currents in banks. Thus the mouth of a river is silted up when it entrance into the sea is impeded by such accumulation of loose materials.
Page 322 - Delta. — When a great river, before it enters the sea, divides into separate streams, they often diverge and form two sides of a triangle, the sea being the base. The land included by the three lines, and which is invariably alluvial, was first called, in the case of the Nile, a delta, from its resemblance to the letter of the Greek alphabet which goes by that name.
Page 324 - Fault, in the language of miners, is the sudden interruption of the continuity of strata in the same plane, accompanied by a crack or fissure varying in width from a mere line to several feet, which is generally filled with broken stone, clay, &c.
Page 338 - An extensive series of the stratified rocks, which compose the crust of the globe, with certain characters in common, which distinguish them from another series below them, called primary, and another above them, called tertiary.
Page 219 - These phenomena clearly indicate that there was a constant supply in that region, for a long period, of a considerable body of fresh water, such as might be supposed to have drained a continent or a large island, containing within it a lofty chaia...