DIASTROPHISM AS BASIS OF CORRELATION 687 
or fraction of a continent may, in this case, be contemporaneous with 
the emergent phase of another continent or fraction of a continent, 
and the progress of events on one continent is as likely to be contrasted 
with those of another continent as to fall in with them co-ordinately. 
According to the other view, deformations are inheritances, one 
of which follows another in due dynamical kinship. ‘The succession 
is therefore homogeneous and the results co-ordinate. If, for example, 
the first depression of the abysmal basins was due to the superior 
specific gravity of the basin-hottoms, this specific gravity remained 
and participated in the next deformation. If the continental masses, 
at the outset of continental formation, were relatively low in specific 
gravity, this low specific gravity was handed down to later periods 
and helped to renew deformation of the same phases in the same 
regions. Under this view, ocean basins and continental elevations 
tended toward self-perpetuation. It is not assumed that this prevented 
shell crumplings, provincial warpings, or block movements of diverse 
phases within the continental or the abysmal areas, for these might 
obviously be necessary effects of the general deformative movements, 
‘or at least inevitable incidents connected with the dynamics lying 
back of them. 
A choice between these two conceptions is imperative to this 
discussion, as they lie at the parting of the ways in the interpretation 
of the larger events of geologic history. I accept the second view 
with much confidence. It should be more fully qualified respecting 
the incidental accompaniments just mentioned, but time does not 
permit. 
According to this view, each great diastrophic movement tended 
toward the rejuvenation of the continents and toward the firmer 
establishment of the great basins. The distinction between con- 
tinent and basin must not, however, be interpreted on the super- 
ficial ground of the water-line, for the water-line merely shows that 
the basin is over-full, just full, or under-full, as the case may be. 
The average water-line undoubtedly helps to give a definite terrace 
border to the abysmal basin, but the water-line freely abandons this 
and often is far from coinciding with it. 
The base-leveling processes have shown that they are able to 
lower the continents approximately to the sea-level in a fraction of 
