76 



AX AMEKICAN GEOLOGICAL RAILWAY GUIDE. (N.Y.) 



GO. This railroad cuts through Trenton, Calciferous and Potsdam within less than 10 miles of 

 Saratoga. Fine sections of ripple marked Potsdam in railroad cut in Greenfield. The Ausable 

 chasm is repeated at the High Falls of the Hudson at Luzerne or Hadley station on the Adirondack 

 Railroad, in Warren County, where the river flows for a mile through a gorge at the junction of the 

 Potsdam sandstone and the gneiss. The walls rise in some places to a height of one hundred 

 feet. 



61. Potsdam. This is the locality which gave the name to the Potsdam sandstone. See the 

 description of that formation in another part of this volume. 



62. Trenton Falls. For about three miles between Trenton Falls station and Prospect Nation 

 and a mile or two east of the railroad, the East Canada Creek has cut a passage through the 

 Trenton limestone, the sides of the excavation rising vertically with an average height of over 100 

 feet. In this passage are the Trenton Falls or Cascades which have given so much celebrity to the 

 place, justly meriting by their number, beauty and position, the admiration they receive. Including 

 the one at Prospect Village there are six falls, five of which are placed at intervals somewhat 

 regular and occupy the middle part of the excavation. The rock is in thin layers of from 6 to 10 

 inches in thickness, separated by thin layers of shale, and contains trilobites in prodigious numbers. 

 The formation derives its name from this place. It is 500 feet thick and about seven miles in 

 breadth. Going east or south it grows thinner and is about 30 feet thick in the Mohawk Valley. 

 The stone quarried at Prospect and used at Utica, is the upper part of the Trenton, which is here of 

 a gray color and of a more solid and crystalline structure and appearance. Going on north by this 

 railroad you travel for many miles on a terrace of the limestones of this group, forming the banks 

 of Black River, which has its rocky channel in this formation all the way to Watertown, with three 

 important falls at Lyons, Carthage and Watertown and many cascades. Very picturesque scenery 

 and interesting geology, with an abundance of fossils. 



63. Boonville. The first range or cliff of limestone on Black River, extending by the side 

 of the river from opposite Boonville to Watertown, is the Birdseye limestone. It is of a light dove 

 color which by long exposure to the weather becomes of a light ash gray or white. It is in thick, 

 straight layers, with straight, vertical joints, giving the rock when quarried the appearance of a wall, 

 and it has a compact grain and smooth fracture. 



64. At Lyons Falls, Black river falls 63J feet over gneiss or 1 a. Laurentian rock. Thence to 

 Carthage it falls but 9 feet and there is another fall over gneiss rock. 



65. The high hills west of Martinsburg are of the Hudson River group. 



