A Manual of Elementary Geology: Or, The Ancient Changes of the Earth and Its Inhabitants as Illustrated by Geological Monuments

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D. Appleton, 1853 - 512 páginas
 

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Página 2 - of which distinct races of living beings have flourished on the land and in the waters, the remains of these creatures still lying buried in the crust of the earth. By the " earth's crust," is meant that small portion of the exterior of our planet which is accessible to human observation, or on which we
Página 206 - It is found in the Carpathians, and in full force in the north of Africa, as, for example, in Algeria and Morocco. It has also been traced from Egypt into Asia Minor, and across Persia by Bagdad to the mouths of the Indus. It occurs not only in
Página 111 - cainos, recent, because the fossil shells of this period contain an extremely small proportion of living species, which may be looked upon as indicating the dawn of the existing state of the testaceous fauna, no recent species having been detected in the older or secondary rocks. The term Miocene (from
Página 142 - that of the Alps, and is now entirely destitute of glaciers, yet it presents almost everywhere similar moraines, and the same polished and grooved surfaces, and waterworn cavities. The erratics, moreover, which cover it, present a phenomenon which has astonished and perplexed the geologist for more than half a century. No conclusion can be more
Página 228 - appears that they have been worn by mastication ; whereas the existing herbivorous, reptiles clip and gnaw off the vegetable productions on which they feed, but do not chew them. Their teeth, when worn, present an appearance of having been chipped off, and never, like the fossil teeth of the Iguanodon, have a flat ground surface • (see fig.
Página 334 - is dried up, during an unusually hot season, and the wood set on fire, pits are burnt into the ground many feet deep, or as far down as the fire can descend without meeting with water, and it is then found that scarcely any residuum or earthy matter is left.* At the bottom of
Página 260 - Middle Oolite. Coral Rag. — One of the limestones of the Middle Oolite has been called the " Coral Rag," because it consists, in part, of continuous beds of petrified corals, for the most part retaining the position in which they grew at the bottom of the sea. They belong chiefly to the genera
Página 101 - rock has been in part derived from the degradation of the older. Thus, for example, we may find in one part of a country chalk with flints ; and, in another, a distinct formation, consisting of alternations of clay, sand, and pebbles. If some of these pebbles consist of similar flint
Página 387 - The basalt, there, is part of a small stream of lava, from 30 to 40 feet thick, which has proceeded from one of several volcanic craters, still extant, on the neighbouring heights. The position of the lava bordering the river in this valley might be represented by a section like that already given at fig.
Página 469 - In the annexed diagram the flat surfaces of rock A, B, C, represent exposed faces of joints, to which the walls of other joints, JJ, are parallel. SS are the lines of stratification ; DD are lines of slaty cleavage, which intersect the rock at a considerable angle to the planes of stratification.

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