The Earth's Shifting Crust by Charles Hapgood - wire of information

THE MOUNTAINS 91
ments and possibly through a number of successive displacements
of the crust, to the formation of folded mountain
ranges.
The systematic presentation of this theory requires us to
consider the two different phases of displacement equatorward
and poleward separately, for they have very different
results. We will begin with the consideration of the effects
of a displacement of a crustal sector toward the equator.
In a shift in that direction, a crustal sector is submitted
to tension (or stretching), and this tension is relieved by the
fracturing that takes place when the bursting stress exerted
on the crust has come to exceed the strength of the crust. (For
Mr. Campbell's calculations of the quantity of the bursting
stress, as compared with estimates of crustal strength, see
Chapter XI.) Until fractures appear and multiply,
the crust
caijnot move over the bulge. After the fracturing permits
the movement to begin, the crustal blocks tend to draw
slightly apart. The spaces between them are immediately
filled by molten material from below.
Let us form a clear picture of this crustal stretching, from
the quantitative standpoint. It is important to estimate the
stretch per mile, if we are to visualize the results. Taking the
globe as a whole, the difference between the polar and equatorial
diameters is about 26 miles. The circumferences,
therefore, differ by about 78 miles. If the crust were dis-
placed so far that a point at a pole was displaced
to the
equator, the polar circumference would have to stretch 78
miles to fit over the equator. This would amount to about
17 feet in the mile. Since the magnitude of displacements,
however (according to evidence to be presented later), seems
to have been of the order of no more than about 30 degrees,
or one third of the distance from pole to equator, the average
stretch per mile may have amounted to five or six feet, or
one foot in a thousand.
It would be a mistake to visualize this stretching of the
crust in the equatorward-moving areas as evenly distributed
around the whole circumference of the globe. Obviously, the