; 
B 
q THE GEOLOGICAL HISTORY OF NEW YORK STATE 59 
lating sediments caused this sinking. Finally, toward the close of 
the Paleozoic era, sinking of the marginal sea bottom and deposition 
“of sediments ceased, and “eventually the trough began to yield to 
‘lateral compression and its contained strata were thrown into folds 
or fractured by great overthrusts. Thus in place of a sinking sea 
bottom along the shore of the great interior sea, arose the Appala- 
chian mountains, which in their youth may have been a very lofty 
“range rivalling the Alps in height. This range extends from the 
“mouth of the St Lawrence river to Alabama.’? As a result of this 
great physical revolution practically all of eastern North America 
was raised well above sea level, though the more moderately ele- 
vated Mississippi valley region was unaccompanied by folding or 
faulting of the strata. 
The. effect of the Appalachian revolution upon New York State 
is of fundamental importance because the whole State, except 
probably a small area near the mouth of the present Hudson river, 
was raised well above the sea, and true marime conditions never 
again prevailed over any part of its area except the extreme south- 
eastern portion.” Judging by the vast amount of erosion which 
took place during the succeeding Mesozoic era, we are safe in our 
belief that the general elevation of the State at the close of the 
Paleozoic was at least several thousand feet above sea level. It is 
also important to note that this great uplift in New York was 
accomplished without any folding of the strata except along the 
Hudson valley. The gentle southward to southwestward tilt (dip) 
of the Paleozoic strata, however, is thought to have been produced 
at this time due to somewhat greater uplift on the north. 
Along the western side of the Hudson valley, folds produced at 
the time of the Appalachian revolution are plainly visible, though 
the folding of the rocks here was much less violent than in the 
Appalachians proper. As a matter of fact these folds are but 
continuations of those of eastern Pennsylvania, but the compres- 
sive force in southeastern New York was too weak to cause much 
disturbance. Professor Davis has aptly styled these, “ Little 
mountains east of the Catskills.’ By far the most conspicuous 
physiographic feature of this folded region is the Shawangunk 
mountain (ridge) which stands out very prominently and whose 
*Scott’s Introduction to Geology, second edition, p. 647. 
* The influx of tide waters along the eastern and northern borders of the 
State in the Quaternary period presents no exception to this statement 
because the conditions then were esturaine rather than marine. 
