ABSTRACT
This chapter considers the Earth as a whole, its general structure, and its larger surface features – the oceans and continents, and its age and origin. Surface changes can be observed by engineers and geologists alike; among them erosion is a dominant process which in time destroys coastal cliffs, reduces the height of continents, and transports the material so removed either to the sea or to inland basins of deposition. Geological processes such as those which operate at the present day have, during the very large span of geological time, left their record in the rocks – sometimes clearly, sometimes partly obliterated by later events. The rocks therefore record events in the long history of the Earth, as illustrated by the remains or marks of living organisms, animals or plants, when preserved; all rocks make their contribution to the record. In one sense geology is Earth-history.
