PART III Amazing Earth

Textl THE CHANGING EARTH

The study of geology has firmly established the great fact that the face of the earth, and the life upon it, represent merely a single phase of a tremendously long history which has involved many profound and far-reaching changes. For untold millions of years rocks at and near the surface of the earth have been crumbling under the weather; streams have been sawing incessantly into the lands; the sea has been eating into continental masses; the winds have been sculpturing desert lands; and more locally and intermittently, glaciers have plowed through mountain valleys and even vast sheets of ice have spread over consid­erable portions of continents. The outer shell of the earth has shown marked instability throughout geologic time. Slow upward and down­ward movements of the lands relative to sea level have been very com­mon, in many cases amounting to thousands of feet. Various parts of the earth have been, and are being, affected by sudden movements along fractures in the outer crust. During the eons of geological time, vast quantities of molten materials have, at intervals, been forced not only into the earth's crust, but also often out upon the surface. Moun­tain ranges have been brought forth and cut down, and sometimes rejuvenated. Sea waters have spread over many parts of what are now continental areas. There have been repeated advances and retreats of the sea over many districts. Lakes have come and gone. Plants and animals have inhabited the earth for many millions of years. The length of time of known human history is very short as compared to that of known geologic time. The former is to be measured by thousands of years, and the latter by tens or possibly hundreds of millions of years.

■ Give the English for:

глубокие и далеко идущие изменения; представлять лишь одну фазу в...; демонстрировать заметное непостоянство на протяже­нии геологического времени; движение суши вверх и вниз отно­сительно уровня моря; во многих случаях; насчитывать до...; вне­запные движения; время от времени; повторяющиеся наступле­ния и отступления суши; населять территорию; формировать ре­льеф суши; обновлять

Ш Give the Russian for:

to saw into; to eat into; to plow through; to spread over; to force into; to force out; to bring forth; to cut down

Ш Focus on structures:

• The length of time of known history is very short as compared to that of known geologic time.

• The former is to be measured by thousands of years, the latter by hundreds of millions of years.