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

THEICEAGES 45
years. To a geologist a period of 1,000,000 years has come
to mean almost nothing at all. He is actually used to thinking
that events that took place somewhere within the same 20,-
000,000-year period were roughly contemporaneous. As to
the ice ages, the older ones were simply thrown into one of
these long geological periods, but there was no way
to de-
termine their durations (except very roughly), their speeds
of development, or precisely when they happened. It was
convenient to assume that they had endured for hundreds of
thousands or for millions of years, though no real evidence
of this existed. A good instance is that of the Antarctic ice-
cap, of which we shall hear more below.
So far as the most recent division of geologic time, the
Pleistocene, was concerned, geologists, with much more evidence
to work from, saw that there had been at least four ice
ages in a period of about 1,000,000 years. They consequently
proposed the idea that the Pleistocene was not at all like
previous periods. It was exceptional, because it had so many
ice ages. They may have been misled by failure to take suffi-
cient account of the fact that glacial evidence is very easily
destroyed, and that, as we go further back into geological
history, the mathematical chances of finding evidences of
glaciation, never very good, decrease by geometrical progression.
Down to ten years ago and, indeed, until 1951 it was the
considered judgment of geologists that the last ice age in
North America, which they refer to as the Wisconsin glacia-
tion, began about 150,000 years ago, and ended about 30,000
years ago.
This opinion appeared to be based upon strong evidence.
The estimates of the date of the end of the ice age were supported
by the careful counting of clay varves (6) and by
numerous seemingly reliable estimates of the age of Niagara
Falls. As a consequence, experts were contemptuous of all
those who, for one reason or another, attempted to argue that
the ice age was more recent. One of these was Drayson, whose
theory called for a very recent ice age. His followers produced