Earth Movements and the Major Landforms

The face of the earth is constantly being reshaped by the agents of denudation - running water, rain, frost, sun, wind, glaciers and waves, so that our present landforms are very varied and diverse. But these agents only modify the pattern of mountains, plateaux and pains which have been modelled by movements of the earth's crust.

Since the dawn of geological time, no less than nine orogenic or mountain building movements have taken place, folding and fracturing the earth's crust. Some of them occurred in Pre-Cambrian times 600-3500 million years ago. The three more recent orogenics are the Caledonian, Hercynian and

Uses of Rocks

Rocks are very important economically. The thin surface layer of the earth, formed by the break-down of the rocks in various ways and by various processes, is known as soil. The geographer is, among other things, interested in the soil as the medium in which plants grow, hence the scene of production of most of man's food and most of his raw materials.
Man's vital water supply is connected with the nature of the rocks. Part of our drinking water is got by sinking wells to tap the sub-surface water which is filtered naturally during its passage through the rocks. The amount of surface run-off in the form of rivers and springs affects the siting of