JEFFERSON COUNTY. 
409 
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 stream. In ten 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 exposed, 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, they vary 
in height from one hundred to three hundred 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 point 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 
through one. The longest and most important are upon the main branches of the South- 
Sandy creek. 
Geol. 2d Hist. 
52 
