REPORT OF THE STATE PALEONTOLOGIST 1901 535 



and is exposed at intervals for 1 mile down stream to the 

 Lozier dam, 127-B5. The rock at TreadwelFs mill is a gray dolo- 

 mite with an included 4 foot bed of fine grained black are- 

 naceous shale, but at Fredenburg Falls, 127-B4, and at the 

 Lozier dam, 127, 127-B5, it is a heavy, dark blue-brown dolomite, 

 slightly arenaceous, with numerous geodes of yellow and pink 

 calcite. No traces of fossils were found in any part of it. The 

 shale at TreadwelFs mill was carefully searched for Graptolites 



without finding any. 



Salmon river section 



The elevated land to the west of Peru and Lapham Mills, 

 and to the southeast of Peaseleeville is due to the resistant 

 character of the heavy beds of the lower portion of the Potsdam 

 sandstone which covers the eastern slope of the gneissoid hill 

 known as Terry mountain. The sandstone has a very thin 

 covering of soil and drift and is exposed along the roads that 

 traverse this region, which is locally known as " The Patent ". 

 These outcrops of the lower Potsdam, 129-Aol, consist of ledges 

 of coarse grained quartz sandstone with a considerable admix- 

 ture of fresh, nonkaolinized feldspar. In color the rock varies 

 from white to gray, yellow, and red. Ripple-marks and cross- 

 bedding are common. No traces of fossils were found. Owing 

 to the irregularity of the ground it was impossible to measure 

 a section across this region. The general strike is northwest, 

 with a dip of 5° or less to the northeast. 



This portion of the sandstone belongs apparently at a much 

 lower horizon in the formation than does that at Ellis dam on 

 Saranac river. 



Higher layers of the Potsdam are exposed at the mill dam 

 and at the site of the old forge on the Salmon river at Norris- 

 ville, 1J miles northeast of the exposures of 129-Aol on " The 

 Patent ". 



At Norrisville, white sandstone, 129-Ao, 30 feet thick, is seen 

 in the small gorge of Salmon river. The rock is heavily bedded 

 in layers 2-3 feet thick, with much ripple-marking and cross- 

 bedding, but with neither pebbles nor fossils, and has a diminish- 

 ing amount of feldspar. 



