Principles of Geology: Being an Attempt to Explain the Former Changes of the Earth's Surface, by Reference to Causes Now in Operation, Volume 4J. 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 222 - 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 302 - ... 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 318 - Conglomerate or Puddingstone. Rounded water-worn fragments of rock or pebbles, cemented together by another mineral substance, which may be of a silicious, calcareous, or argillaceous nature.
Page 279 - 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 318 - Coal Measures. There are, however, " coal formations" in all the geological periods, wherever any of the varieties of coal form a principal constituent part of a group of strata. Conformable.
Page 337 - 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 336 - A rock usually containing much magnesian earth, for the most part unstratified, but sometimes appearing to be an altered or metamorphic stratified rock. Its name is derived from frequently presenting contrasts of colour, like the skin of some serpents. SHALE. A provincial term, adopted by geologists, to express an indurated slaty clay. Etym., German schalen, to peal, to split.
Page 320 - 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 322 - 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 336 - 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.