XXXVII. The Chautauqua Region with refer- 

 ence to the Physiographic regions of New 

 York State 



1. Most of the physiographic provinces of New York are merely 

 portions of larger areas which extend into it from the neighboring 

 States. The provinces are: 



a. Long Island. 



b. Gneissic Highland. 



c. Taconic. 



d. Catskill. 



e. New York-Pennsylvania Plateau (Chautauqua). 



f. Lake Shore Plains. 



g. Mohawk Valley. 

 h. Adirondack. 



The Chautauqua region is the most westerly New York portion of the 

 New York-Pennsylvania Plateau. This great plateau region occupies 

 fully one-third of the State, and is deeply dissected by numerous broad 

 river valleys. 



2. It is made entirely of Devonian rocks, mostly upper Devonian 

 shales and sandstones, in which, however, there are some strata of lime- 

 stone. The strata of this province are in a nearly horizontal position, 

 which determines the extensive plateau character of the province, a 

 feature which extends southward across the Pennsylvania line, along 

 the western base of the Appalachians. 



3. Throughout the New York section of the plateau the hilltops 

 frequently rise to elevations of 1,500 to 2,000 feet, and their average 

 elevation above sea-level cannot be less than 1,000 to 1,200 feet. From 

 the valleys the region does not resemble a plateau, but rather a moun- 

 tainous country; for the hills often rise to heights of 1,000 to 1,200 

 feet above the low valleys. But from the tops of the hills one is able 

 to see that it is really a plateau region very much cut by stream action 

 and carved by denundation into a maze of hills, many of which are 

 capped by the harder layers of the nearly horizontal strata. 



4. Considered as one great dissected plateau, its surface undulates 

 somewhat. Where the branches of the Susquehanna head against the 

 headwaters of the Finger Lake streams, the plateau level is somewhat 

 depressed. It sags in the middle, being higher near the western base 

 of the Catskills and lower in the Finger Lake region ; then rising again, 



"3 



