Elements of Geology; Or, The Ancient Changes of the Earth and Its Inhabitants as Illustrated by Geological Monuments

J. Murray, 1865 - 794 Seiten

Was andere dazu sagen - Rezension schreiben

Es wurden keine Rezensionen gefunden.


Häufige Begriffe und Wortgruppen

Beliebte Passagen

Seite 738 - crystallization,—that is to say, if they have been heated to a point at which the particles can begin to move amongst themselves, or at least on their own axes, some general law must then determine the position in which these particles will rest on cooling. Probably, that position will have some relation to the direction in which the
Seite 21 - fig- 13.) is almost invariably wanting, though occasionally found in a perfect state of preservation in white chalk at some distance. In this case, we see clearly that the sea-urchin first lived from youth to age, then died and lost its spines, which were carried away. Then the young Crania adhered to the bared shell, grew and perished in its turn
Seite 139 - the world ; BO that they are now lodged on the hills and valleys of a chain composed of limestone and other formations, altogether distinct from those of the Alps. Their great size and angularity, after a journey of so many leagues, has justly excited wonder; for hundreds of them are as large as cottages; and one in
Seite 502 - point, on which doubts had been entertained both in Europe and the United States. The footmarks were first observed standing out in relief from the lower surface of slabs of sandstone, resting on thin layers of fine unctuous clay. I brought away one of these masses, which is represented in the accompany drawing (fig.
Seite 298 - There occur no less than 137 species of this genus in the Paris basin, and almost all of them in the calcaire grossier. Most of the living Cerithia inhabit the sea near the mouths of rivers, where the waters are brackish ; so that their abundance in the marine strata now under
Seite 360 - find that it produces a corresponding influence on the scenery of the country; for it runs out like a step beyond the foot of the chalkhills, and constitutes a lower terrace, varying in breadth from a quarter of a mile to three miles, and following the sinuosities of the chalk-escarpment, f Fig.
Seite 497 - as we travel south-eastward towards the more bent and distorted rocks. 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
Seite 398 - most of their stems short off near the point of attachment. The stumps still remain in their original position; but the numerous articulations, once composing the stem, arms, and body of the encrinite, were scattered at random through the argillaceous deposit in which some now lie prostrate. These appearances are represented in the section b, fig.
Seite 715 - north-west side of Dartmoor, the successive members of the culmmeasures abut against the granite, and become metamorphic as they approach. These strata are also penetrated by granite veins, and plutonic dikes, called " elvans." * The granite of Cornwall is probably of the same date, and, therefore, as modern as the Carboniferous strata, if not newer.
Seite 701 - It is not uncommon for one set of granite veins to intersect another ; and sometimes there are three sets, as in the environs of Heidelberg, where the granite on the banks of the river Necker is seen to consist of three varieties, differing in colour, grain, and various peculiarities of

Bibliografische Informationen