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

io6 EARTH'S SHIFTING CRUST
It is clear, I think, from what has already been said, that
Lapworth was in error in ascribing the folded mountains to
the effects of fracturing alone. However, it may well be that
formation of block mountains, such as the Sierra Nevadas,
can be accounted for in this way. Innumerable other features
of the crust have been formed or obviously much affected
by the fracture patterns. Hobbs, for example, has maps of
river systems in Connecticut and Ontario, showing how
closely the rivers and their tributaries follow the lines of the
fracture systems (216:226). Many river beds, many submarine
canyons, were never created by subaerial erosion; they were,
instead, the results of deep fractures in the crust, later occupied
by rivers or by the sea. On the land erosion no doubt
often, if not usually, completed the shaping of the valleys,
while turbidity currents may have created or deepened can-
in the unconsolidated materials of the ocean bottom
yons
037> 139* M )-
A succession of theories to account for the world-wide or
"planetary" fracture patterns has been developed and re-
jected. As soon as it became clear that these patterns could
not be explained as the result of local forces, the problem
was recognized as very formidable. Sonder, a Swiss geologist,
attempted to explain them as the result of a difference in the
compressibility (or elasticity) of the rocks of the continents
as compared with those under the oceans. But Umbgrove
pointed out that this would call for independent fracture
systems for each of the continents, whereas existing fracture
patterns extend to several continents (430:300-01).
The Dutch geologist Vening Meinesz suggested that the
fracture patterns could be explained mathematically by a
displacement of the crust of the earth. He postulated one
displacement about 300,000,000 years ago, through about 70
of latitude (194:204^. Umbgrove rejected this theory be-
cause he saw that there were many features of the earth's sur-
face that could not be explained by the particular displacement
suggested by Vening Meinesz. This is not at all
remarkable, since it is quite impossible to see how any one