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

THE ICE AGES 41
or third region; but there may be little direct evidence on the correspondence
of the several series of regional stages, the identification of
which then remains speculative (257:650).
At the time that Kroeber remarked on the difficulty of
correlating climatic changes in different parts of the world,
we were not yet in possession of the data recently provided by
the new techniques of radiocarbon and ionium dating, which
will be discussed below. The effect of the new data has been
to shorten very greatly our estimate of the duration of the
last North American ice age. This estimate has been reduced,
in the last few years, from about 150,000 years to about
25,000 years, or by five sixths. Now, if we adopt the view that
ancient glaciations, of which we know little, may reasonably
be considered to have been the results of the same causes
that brought about the North American ice age, then we
must grant that they, too, were of short duration. But if this
is true, how is it possible to establish the fact that they were
contemporary in the two hemispheres? A geological period
has a duration of millions of years. An ice age in Europe and
one in Australia might both be, for example, of Eocene age,
but the Eocene Epoch is estimated to have lasted about 15,-
000,000 years. We can discriminate roughly between strata
dating from the early, middle, or late Eocene, but we have no
way of pinpointing the date of any event in the Eocene. Even
with the new techniques of radiodating now being applied
to the older rocks, it is possible to determine dates only to
within a margin of error of about a million years. How, then,
is it possible to determine that an ice sheet in one hemisphere
was really contemporary with an ice sheet or an ice age in
the other?
The attempt to maintain the assumption of the simultane-
ousness of glaciations for the older geological periods is mani-
festly absurd. I shall show in what follows that it is equally
absurd for the recent geological time. It is my impression
that the material evidence for the assumption was never im-
pressive, and that the assumption
was never derived em-
pirically from the evidence but was borrowed a priori from