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

2O2 EARTH'S SHIFTING CRUST
have taken place in 380 years? It seems probable that the
Cochrane Advance was local and minor. The Mankato Maximum,
however, was not. The entire transformation of the
climate must then have taken place in about 2,000 years.
In this short interval a continental icecap disappeared. It
had been growing thinner for a long time, to be surefor
about 10,000 years, since the Tazewell Advance but its final
dissolution was sudden. Compared with the usual geological
time concepts, even the period of 10,000 years for the decline
of the ice sheet from the end of the Tazewell Advance is in-
credibly rapid. Horberg, as I have mentioned, has pointed
out that if the radiocarbon method is valid, the rate at which
the ice must have advanced and retreated indicates that geo-
logical processes (especially meteorological processes like
rainfall) must have been greatly accelerated during
the ice
age. Now it is easy to show that these processes inevitably
would have been accelerated by a movement of the crust;
we shall return to consider this matter in detail below.
As a matter of fact, it is not necessary to depend wholly
upon radiocarbon dating to establish the extraordinary ve-
locity of the geological events of the ice age. Professor Urry's
method of radioelement dating, used to date the cores ob-
tained by Hough from Antarctica and elsewhere, shows precisely
the same thing: the datings obtained by this method
indicate several rapid glaciations and deglaciations of Antarctica,
and correlated world-wide changes of climate. We
will consider these again in Chapter IX.
A third line of evidence tending to the same effect is presented
by Emiliani, who has applied a technique of deter-
mining ancient temperatures of sea water that was developed
by Harold C. Urey. Urey's method is based on an isotope
of oxygen. Emiliani has noted many important temperature
changes in a comparatively short period during the latter
part of the Pleistocene; he has reached the conclusion that
the four known Pleistocene glaciations all occurred in the
last 300,000 years. He agrees essentially with Horberg as to
the date of the beginning of the Wisconsin glaciation (132).