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

THE MOUNTAINS 125
It follows that when lateral pressures develop during a
displacement of the crust, as the downward projections of
continents and mountains are brought to bear against the upward
extension of the viscous layer below the ocean base-
ments, large blobs of this soft rock of lesser density will be
detached from the undersides of the continents, or mountain
ranges, and will get shifted to other places. If, as a result of
this shifting around, the average densities of vertical columns
extending from the bottom to the top of the crust get
changed, then there will eventually be corresponding changes
of elevation at the surface. Some areas might, as a result, tend
to rise, and others to sink. This could account, naturally, for
changes of sea level, and for many topographical features
such as basins and plateaus.
To sum up the question of sea levels, it appears that the
assumption of displacements of the crust (especially if they
are considered to have been numerous) may help to explain
them. It seems able to explain why glaciated areas (which
we consider to have been areas displaced poleward) appear
to have stood higher relatively to sea level, and why periods
of warm climate in particular regions appear to have been
associated with reduced elevation of the land, and transgres-
sions of the sea. The theory seems to satisfy Umbgrove's
conclusion that sea-level changes have resulted from some
"world-embracing cause" (430:93). It accounts, too, for
Bucher's suggestion that regressions of the sea have resulted
from subcrustal expansion, and transgressions from sub-
crustal contraction, for this, obviously, is only another way
of looking at a displacement of the crust (58:479). (If an area
is displaced poleward, the effect of subcrustal contraction is
created; if it is displaced equatorward, the effect of subcrustal
expansion occurs.) At the same time it provides an explanation
for the rhythmic changes of sea levels through geological
history that so mystified Grabau:
This rhythmic succession and essential simultaneousness of the
transgressions as well as the regressions in all the continents, indicates