ELEVATION OF MOUNTAIN-CHAINS.
Professor Ansted, in his Ancient World, thus characterises this phenomenon:
These movements, described in a few words, were doubtless going on for many thousands and tens of thousands of revolutions of our planet. They were accompanied also by vast but slow changes of other kinds. The expansive force employed in lifting up, by mighty movements, the northern portion of the continent of Asia, found partial vent; and from partial subaqueous fissures there were poured out the tabular masses of basalt occurring in Central India; while an extensive area of depression in the Indian Ocean, marked by the coral islands of the Laccadives, the Maldives, the great Chagos bank, and some others, were in the course of depression by a counteracting movement.
Hitherto the processes of denudation and of elevation have been so far balanced as to preserve a pretty steady proportion of sea and dry land during geological ages; but if the internal temperature should be so far reduced as to be no longer capable of generating forces of expansion sufficient for this elevatory action, while the denuding forces should continue to act with unabated energy, the inevitable result would be, that every mountain-top would be in time brought low. No earthly barrier could declare to the ocean that there its proud waves should be stayed. Nothing would stop its ravages till all dry land should be laid prostrate, to form the bed over which it would continue to roll an uninterrupted sea.