Penny Blood: Serial Sensation and Working-Class Entertainment — page 239: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

222 GEOLOGICAL MOVEMENTS fon. xvin. fined to these regions, it is obvious that it is in continental areas, and along their shores that these processes are the more energetic. It is therefore conceivable that the medial regions of the great oceans may have been comparatively free from disturbance at all times, Nevertheless the growth of coral, the deposits from icebergs, and the sinking of the exuvie of marine organisms, are causes which may contribute to the unequal deposition of sediment, over such areas as _ these, and we would not therefore relegate even them to perpetual repose. It is certain that most of the existing greater mountain: chains are comparatively modern ; for it is possible to assign dates, geologically not remote, to the movements to which they owe their exceptional altitude, At the same time their struc- ture usually betrays that the original effort which raised them was not the final one; for they have been subjected to repeated compression, This comparatively modern character of the greater chains leads us to believe that the gradual degradation and obliteration of a mountain range is a law of nature, in accordance with which the older chains have been levelled down and disappeared. The corrugated rocks which may have formed parts of them are still to be discovered as fundamental gneiss for instance, showing by their chemical and mechanical condi- tion that they have been subjected at some former time to a high temperature and to great compression, They are now frequently covered up by later deposits. The rising upwards of an elevated region by floatation con- currently with its degradation, explains some well known facts, among which are the following. When the original contours of the strata are restored, which must have gone to form a disturbed tract, the enormous amount of subsequent denudation appears at first sight incredible. This 1s extremely well shown in Prof. Ramsay’s restored con- tours along some sections in South Wales’, where the heights a4and distances are laid down upon the same scale, a method 1 “Memoirs of the Geological Survey of Great Britain,” Vol. 1. 1846, pl. rv. COMIC OOOKS.EO