JEFFERSON {OUNTY. iOO 



shales. They open gradually, or become gradually enclosed by walls continually increasing 

 in height as they are penetrated towards their head or origin. For example, the gulf in Rod- 

 man terminates near Sodom. Passing up the gulf, we find the foundation rock is the trenton 

 limestone, and it is worn to the depth of twelve feet by the gulf sln-am. In Wn rods, the 

 black or utica slate makes its appearance, resting on the limestone : it is about ten feet thick 

 at its commencement. Ascending seventy or eighty rods farther, the slate has become thirty 

 feet thick, and the limestone which is exjiosed, much less. In a mile or a mile and a half, 

 the walls upon each side have attained a height of two hundred feet ; the trenton rock has 

 disappeared, and the utica slate forms the floor of the gulf, the sides of which are composed 

 of the loraine shales. The greatest height of the walls which I had an opportunity to mea- 

 sure, is three hundred feet. In tracing them upward after the gulf is fully entered, thev vary 

 in height from one hundred to three hundrcil feet. This height is slowly but gradually in- 

 creasing by the continually wearing of the utica slate in the bottom of the gulf, which, when 

 entirely cut through, will increase the height of the walls to three hundred and seventy-five 

 feet. The width or distance from side to side is about sixteen rods, but it depends much 

 upon the windings of the stream. 



The gulfs in all cases commence with the origin of the streams, beginning to be worn im- 

 mediately from the very poiiit where the springs issue from the ground. The length, there- 

 fore of the gulfs, comprises mostly the entire length of the sandy creeks. According to some 

 estimates, and from inquiry made upon the spot, their length, including some of the windings, 

 exceeds twelve miles. These long passages in the rocks afford the finest opportunities for 

 exploring the deeper seated beds. The trenton, being the first rock, is partially exposed ; the 

 utica slate is entirely cut through, and so is the mass composing the shales. 



These gulfs, besides being objects of geological interest, are well worthy of a visit from the 

 traveller who seeks recreation and amusement ; for few objects in our country possess a greater 

 share of the marvellous than these. Hitherto they have received no attention, which is rather 

 remarkable, as they are quite accessible, being near one of the common travelled routes from 

 Rome to Watertown. 



The number of gulfs I am unable to state. I found that every stream of much size flowed 

 tlurough one. The longest and most important are upon the main branches of the South- 

 Sandy creek. 



Geol. 2d DisT. 52 



