388 GEOLOGY OF THE SECOND DISTRICT. 



The thickness of the trcnton limestone at Watertown, including the whole mass which 

 extends south, and which is embraced in the section, is about three hundred feet. 



The natural joints as exposed on the northern outcrop, arc N. 45^ E. and S. 75^ E. The 

 former corresponds to the principal valleys of the count}-. 



Having given those details in relation to the position and general character of this rock 

 which seemed necessary, I shall now proceed and describe its boundaries. I shall commence 

 at Champion, near which place I suppose this rock to come up from Denmark in the county 

 of Lewis. From Champion, the trenton forms a curve sweeping round to the northwest in 

 the form of a high commanding bluff, till it reaches the Black river about four miles east of 

 Watertown. It forms, for the most of this distance, the steep rocky banks on the south side 

 of the river. At Watertown, a small broken bluff appears upon the north side, but extends 

 scarcely more than half a mile. From the south side of the river, the broken edge of the 

 trenton may be traced southwest twelve miles, to or near the lake shore, and about six miles 

 north of Henderson. It forms a part of the rocks near the shore at Henderson. From this 

 place it runs directly south to Ellisburgh, in which direction it continues till it passes into the 

 county of Oswego. 



The southern boundary, or the line of junction between this rock and the utica slate or lo- 

 raine shales, passes nearly northeast from Mannsville, in the direction of Adams, Whitesville 

 and Tylerville. Between Adams and Tylervilie, the utica slate crops out beneath the loraine 

 shales, and forms a narrow curved belt, scarcely more than two miles in width. 



The geographical position of the trcnton, then, is south of the Black river, between Cham- 

 pion on the east and Hounsfield on the west, and Watertown on the north and Adams and 

 Whitesville on the south. This forms the great body of the rock in Jefferson county. There 

 are, however, several smaller patches which it is important to notice. Thus, after leaving 

 the eminence upon which Watertown is built, and proceeding towards the west, we imme- 

 diatel)^ pass from the trcnton to the birdscye. This is, however, but a narrow belt, not over 

 half a mile wide. After leaving the birdseve, we pass from it again to the trenton, about one 

 mile below Watertown. The trcnton at this point is merely a low narrow ridge, but it 

 increases in width and height as it stretches away south ; and where the road to Brownville 

 crosses it, it is equal in height to the hill upon which Watertown stands. From this ridge of 

 trenton limestone we pass again to the birdseye, when about one mile east of Brownville, 

 whence the latter rock continues to Dexter on Black river bay. The range of trenton, then, 

 lying between Watertown and Brownville, stretches away to Sacket's-Harbor, where it forms 

 the shore of the lake. 



This mass of the trenton is therefore entirely insulated, or cut off from the great mass on 

 the south side of the vein, and the cause of this separation has been detailed at some length. 

 A mass just west of Watertown has been entirely cut out as far southwest as the lake, for the 

 distance of ten miles, leaving on the west the ridge just described, which lies with its long 

 axis to the northeast, coming to an apex about half a mile west of Watertown. 



