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

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EARTH'S SHIFTING CRUST
this, that in successive geological periods he did have increas-
ing distances between the continents, as if the drift had been
continuous.
Subsequently, Professor Ma developed his theory
into a
complete system, which is most interesting, and yet to which,
I think, serious objections may be raised.
Corals are, according to Ma, excellent indicators of the
climate for the time in which they grew, but, by the nature
of the case, since corals grow only in shallow water, and grow
upwards only as far as the surface, the period of time represented
by a single fossil coral reef is of the order of a few
thousand years only, as compared with the millions of years
embraced by a geological period.
How short the continuous growth of a coral reef may be
is indicated by numerous studies of the coral reefs of the
Pacific. A. G. Mayor, for example, says:
. . . The modern reefs now constituting the atolls and barriers of
the Pacific could readily have grown upward to sea-level from the
floors of submerged platforms since the close of the last glacial epoch
At Pago Pago Harbor borings were made down to the
basalt underlying the reef, and after estimates of the growth
rate were arrived at, the age of the reef (Utelei) was estimated
at 5,000 years. When these spans are compared with
those of entire geological periods of the order of 20,000,000
or 30,000,000 years, it is clear how fragile must be any con-
clusions based on the assumption that a given coral reef in
Europe was contemporary with another one in North America.
It is quite impossible in the present state of our knowl-
edge to decide that they were in fact contemporary.
This means that Ma's corals for a period like the Devonian
may be indications of different equators that existed at different
times during that period of 40,000,000 years. Therefore
it is obvious that thousands of coral specimens would be re-
quired to give any certainty as to the actual climatic history
of an entire geological period.