486 
Van Else—Earth Movements. 
place rapidly. Consequently at first land would emerge from 
the water in the equatorial region, and land would be submerged 
in the polar regions; and later a reverse effect would occur. 
Moreover, he finds as a result of the precession of the equinoxes 
and changing eccentricity of the earth’s orbit, that the lessened 
rotation has not occurred uniformly, but irregularly, and this 
affords a cause for the recurrence of lagging and readjust¬ 
ment of the earth, the sea each time, however, adjusting itself 
promptly to the changing period of rotation. Uniting these 
factors, he thinks he finds an adequate cause for important 
shifting of the beach lines, first in one direction and then in the 
other, but at any given time in opposite directions in the polar 
and equatorial areas. Suess 1 and Blytt, 2 find evidence that in 
late geological time there have been actual shiftings of the 
beach lines, such as demanded by Blytt’s theory. If these 
movements have the potency advocated by Blytt, it would fol¬ 
low that in the equatorial regions and in the polar regions there 
are two sets of more or less extensive intercontinental uncon¬ 
formities. However, they would be in an opposite sense. When, 
as a result of the ready adjustment of the sea and the lagging 
behind of the land, due to the changing speed of rotation, the low- 
lying polar land areas were submerged and therefore areas of 
deposition, the low-lying equatorial areas would stand above 
the sea and therefore be subjected to erosion. When the 
stresses had sufficiently accumulated, the equatorial land areas 
sank, and the polar land areas rose. As a result the low- 
lying districts formerly eroded in the equatorial regions 
would .become areas of deposition, and the formerly low-lying 
areas of deposition in the polar areas would be above the water, 
and be areas of erosion. However, it is not supposed that these 
alternating intercontinental unconformities are of the same order 
of magnitude as those mentioned upon page 485, for which an¬ 
other cause is assigned. 
It is to be noted that the change of the form of the sphe¬ 
roid as a result of lessening rate of rotation causes the polar 
areas to rise absolutely. This, however, is no exception to the 
1 Antlitz der Erde, by E. Suess: Vol. II, 1888, pp. 697. 
2 Loc. cit., pp. 87-92. 
