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Unit 6
CHANGES IN THE EARTH'S OUTER CRUST
The various changes are continually taking place on the surface
of the earth. Here is three main kinds of them: a) the wearing away
of the land which is called the denudation; b) the removal of mate-
rial from one part of the earth's outer crust to another, which is
called the transportation; c) the sediment of above-mentioned ma-
terial in new places, which is called deposition. The denudation is
taking place because of action of the sun, wind, rain, frost, running
water, moving ice, the sea, etc.
In the hot parts of earth the sun heats greatly the rocks and
debris on the earth's surface all day along, so they expand forming
cracks. During the night time the rocks get cold and contract. In a
such a way the cracks form. Gradually they become larger and larger
and gradually the rock breaks up into small pieces.
The wind affects in two ways. For one thing the gale or strong
wind blows loose particles of soil and dust them away. For another
the wind wears away the land. The gale rises billions of sharp pieces
of dust and blows them against a cliff or hard rock, so it gradually
demolishes the surface and destroys the hard rock.
As for the rain, it has a powerful action especially in hot coun-
tries. By forming the endless number of streams, rushs, floods, and
trickles it loosens and carries away a great amount of soil. On passing
through the air, it absorbs gaseous carbon dioxide, making a solu-
tion, which in its turn, dissolves certain kinds of rocks, such as
limestoned ones.
It's well known, that water under the temperature –4°C ex-
pands. So when the water, having sunk into the ground freezes, it
causes the cracks to widen. In a such a way, step by step it demolish-
es the rock.
Almost any rain makes streams or trickles, which in their
moving produce grooves or little valleys and gradually these valleys
become deep canyons. In fact, running water influences the earth's
surface greatly, because after rainstorms the powerful streams are
running along the valleys moving large masses of stones and sand. In
such a case the water stream is cutting its way through solid masses
of hard rock.
Unit 6
CHANGES IN THE EARTH'S OUTER CRUST
The various changes are continually taking place on the surface
of the earth. Here is three main kinds of them: a) the wearing away
of the land which is called the denudation; b) the removal of mate-
rial from one part of the earth's outer crust to another, which is
called the transportation; c) the sediment of above-mentioned ma-
terial in new places, which is called deposition. The denudation is
taking place because of action of the sun, wind, rain, frost, running
water, moving ice, the sea, etc.
In the hot parts of earth the sun heats greatly the rocks and
debris on the earth's surface all day along, so they expand forming
cracks. During the night time the rocks get cold and contract. In a
such a way the cracks form. Gradually they become larger and larger
and gradually the rock breaks up into small pieces.
The wind affects in two ways. For one thing the gale or strong
wind blows loose particles of soil and dust them away. For another
the wind wears away the land. The gale rises billions of sharp pieces
of dust and blows them against a cliff or hard rock, so it gradually
demolishes the surface and destroys the hard rock.
As for the rain, it has a powerful action especially in hot coun-
tries. By forming the endless number of streams, rushs, floods, and
trickles it loosens and carries away a great amount of soil. On passing
through the air, it absorbs gaseous carbon dioxide, making a solu-
tion, which in its turn, dissolves certain kinds of rocks, such as
limestoned ones.
It's well known, that water under the temperature –4°C ex-
pands. So when the water, having sunk into the ground freezes, it
causes the cracks to widen. In a such a way, step by step it demolish-
es the rock.
Almost any rain makes streams or trickles, which in their
moving produce grooves or little valleys and gradually these valleys
become deep canyons. In fact, running water influences the earth's
surface greatly, because after rainstorms the powerful streams are
running along the valleys moving large masses of stones and sand. In
such a case the water stream is cutting its way through solid masses
of hard rock.
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