Sketches of Geology |
Other editions - View all
Common terms and phrases
abundant animals appear augite Azoic basalt Basin beds Belemnite belonging bones Bradford clay British Rocks calcareous called Carboniferous CARBONIFEROUS SYSTEM chalk Characteristic Fo chiefly clay coal measures colour composed conglomerates contain copper coral Cretaceous crystalline crystals deposits DEVONIAN SYSTEM earth England extinct species feet felspar fish flints formation formed fossiliferous fossils fragments genera genus geologists Geology globe Gneiss granite Grauwacké green or black hornblende igneous rock land lava Lias limestone Llandeilo Lower Silurian Lyell's MAGNESIAN marine marl mass metamorphic mica mineral mollusca mountains Murchison ocean Old Red Sandstone older Oolite organic remains origin PALEOZOIC PALEOZOIC PERIOD peculiar Plesiosaurus quartz reign Equivalents reptiles Russia sand Schist SECONDARY PERIOD secondary strata sedimentary shale shells siliceous siliceous mineral Silurian Silurian rocks Silurian strata Silurian System slate stone strata stratified rocks stratum structure surface tion Trap rocks unstratified upheaval Upper New Red vegetable volcanic rocks Wealden
Popular passages
Page xvi - The ruins of an older world,' said Hutton, 'are visible in the present structure of our planet, and the strata which now compose our continents have been once beneath the sea, and were formed out of the waste of pre-existing continents. The same forces are still destroying, by chemical decomposition or mechanical violence, even the hardest rocks, and transporting the materials to the sea, where they are spread out, and form strata analogous to those of more ancient date. Although loosely deposited...
Page xxxi - ... or the natural position of minerals in particular rocks, together with the grouping of those rocks, their geographical distribution, and various relations. The phenomena observed in the structure of the globe had hitherto served for little else than to furnish interesting topics for philosophical discussion : but when Werner pointed out their application to the practical purposes of mining, they were instantly regarded by a large class of men as an essential part of their professional education,...
Page 89 - ... matter upon the earth ; for when this matter is dissolved or suspended in water, in that state of comminution and decay which immediately precedes its final decomposition into the elementary gases, and its consequent return from the organic...
Page xxix - Protogeea" in 1680. He imagined this planet to have been originally a burning luminous mass, which ever since its creation has been undergoing refrigeration. When the outer crust had cooled down sufficiently to allow the vapours to be condensed, they fell, and formed a universal ocean, covering the loftiest mountains, and investing the whole globe.
Page 89 - ... particles, and turn them back into the ascending stream of animal life. Having converted the dead and decomposing particles into their own living tissues, they themselves become the food of larger Infusoria...
Page xix - It was a resurrection in miniature; but the immutable laws prescribed to living beings were my directors*. At the voice of comparative anatomy, each bone, each fragment regained its place. I have no expressions to describe the pleasure experienced, in perceiving that as I discovered one character, all the consequences more or less foreseen of this character, were successively developed. The feet were conformable to what the teeth had announced, and the teeth to the feet ; the bones of the legs and...
Page 89 - For when this matter is dissolved or suspended in water, in that state of comminution and decay which immediately precedes its final decomposition into the elementary gases, and its consequent return from the organic to the inorganic world, these wakeful members of nature's invisible police are everywhere ready to arrest the fugitive organised particles, and turn them back into the ascending stream of animal life.
Page 31 - Thus, on the Ohio, the proportion of hydrogen, oxygen, and other volatile matters, ranges from forty to fifty per cent. Eastward of this line, on the Monongahela, it still approaches forty per cent., where the strata begin to experience some gentle flexures. On entering the...