CHAPTEE X. 



THE GENERAL FEATURES OF SCENERY IN THEIR RELATIONS 

 TO GEOLOGICAL PHENOMENA. 



Tablelands and Low Plains. When a submarine ridge is elevated so 

 rapidly as to emerge from the ocean as a small island, tidal waters at 



Fig. 43. Gibraltar. 



once begin to cut back the coasts and form cliffs ; but, as the land rises 

 higher and enlarges, other cliffs are cut below them; so as to present in 

 succession all the steep descending slopes of mountain scenery. Eut 

 when the upheaval is more slow, so that the sea can cut away the 

 rock as fast as it is raised, then it does not rise from the water, but 

 the surface is planed level beneath the water, and when it at last 

 emerges, after losing from the uppermost strata in some cases thou- 

 sands of feet, or it may be miles of thickness, presents itself as a 

 plain of marine denudation. Such a plain is usually an anticlinal 

 fold, or rather a series of folds of which one or more originally rose 

 higher than the rest. Much of the surfaces of England and of Ireland 

 were originally plains formed in this way. When such a plain, how- 

 ever, is uplifted high above the sea, it is termed a tableland, and what 

 was an island is often thus enlarged into a continent. Once above the 

 water, the sea erodes its shores into cliffs, and as these descend lower 

 and lower with the increased elevation of the land, it inevitably 



