:15:02
Had not the climates and weather
constantly changed
:15:04
with the drift of the continents
:15:06
newer, more adaptive life-forms
would not have evolved
:15:10
to displace older species.
:15:13
Mamal might never
have succeeded reptile.
:15:17
Man might never
have gained dominion
:15:19
over all the fish and fowl
:15:22
and over every living thing
that moveth upon the Earth.
:16:06
Man has been uniquely favored
:16:08
by the forces which move
and alter the Earth's crust
:16:12
yet through all his history
:16:14
he has remained a hostage
to their powers of destruction.
:16:24
As new earth's crust is created
:16:26
in the spreading rifts
and ridges of the earth
:16:29
older crust is destroyed
:16:31
in a second great tectonic
process called "subduction."
:16:35
When an ocean floor plate
:16:36
collides with a continental plate
:16:39
the havier seafloor plate
is subducted.
:16:42
lt fractures
:16:43
and plunges beneath the thicker,
more buoyant continental plate
:16:46
creating an ocean tranch.
:16:50
Ponderously
:16:51
moving inches in years,
the great slab descends
:16:56
generating deep earthquakes
when it moves.
:16:59
The heat of friction
and of the Earth's interior