246 Report ok tiik State Geologist. 



vale that has a very slight descent. < mehalf mile Bouth of Marcellus a wide, 

 deep opening has been cut through tlie east side of the Nine Mile creek \alh-\ 

 down to the top of the limestone. This is the head of the Cedarvale valley, 

 which extends in a southeasterly direction and joins the Onondaga valle) 

 near Smith ( >n<>ndaga. 



The Skaneateles lake valley, near the western border of the county, has 

 a general direction from the southeast to the northwest. Skaneateles lake, 

 which is sixteen and one-half miles long and has an average width of about 

 one mile, occupies the southern part of the valley. About the head of the 

 lake the sides are precipitous and rocky to the height of 100 to 400 feet, then 

 they slope gently upward to the height of 700 to 1,100 feet, above the level of 

 the lake, which has an elevation of 860 feet A. T. Toward the north end of 

 the lake the width of the valley is greater, the hills are much lower, and the 

 geutle slope of the sides is continued ipiite to the shores. The passage 

 through the limestone escarpment is about on&half mile w ide and three mile- 

 long. The rocks are abundantly exposed, but there are no high cliffs nor 

 deep lock cuts. North of the New York Central railroad the vallej winds 

 among low hills of drift or shall- in a northerly direction across the town of 

 Elbridge to the Seneca liver. 



The Geologic Succession. 

 The rocks exposed on the surface in this county are all of sedimentary 

 origin, with the exception of a. small amount of eruptive matter in a single 

 locality. The geological formations to which the\ belong, named in order 

 from the low est, are : 



, T . . , i Clinton Group. 



Niagara renou ' . r 



' Niagara Group. 



Salina Period j Recl Shales - 



' Gypseous Shales. 



Lower Helderberg Period Hydraulic Limestone. 



Oriskany Period Oriskany Sandstone. 



Upper Helderberg Period Corniferous Limestone. 



Marcellus Shales. 



Hamilton Period J Hamilton Shales. 



Tully Limestone. 



Chemung Period I Genesee Slate. 



I Portage Group. 

 Quaternary System J Glacial Drift. 



' < 'hamplain Deposits. 



