LOWER SILURIAN SYSTEM OF EASTERN MONTGOMERY CO. 453 
of glacial origin. In its lower course the creek flows between high 
banks of boulder clay. 
The above section shows conclusively that the Hudson river ter- 
rane has its base below the present level of the Trenton formation 
which outcrops a short distance to the west. There ,is certainly 
a displacement in the strata at this point represented by the thick- 
ness of the Utica stage and probably in addition by a portion of 
the lower part of the Hudson river stage. The writer is also of 
the opinion that the graptolitic shales exposed on the Sandseakill 
are very near to if not coincident with this fault line. For the 
layers of this exposure are not only disturbed as indicated by the 
reversal of the dip, but they are apparently 300 feet lower than cor- 
responding layers in the less disturbed strata west of this locality. 
Furthermore they are almost immediately succeeded by thin sand- 
stones belonging to the upper or middle Hudson river stage, ex- 
posed in the northern slope of Princetown hill. 
A short distance west of the Sandseakill one half mile south- 
west of Pattersonville the Trenton limestones outcrop and are ex- 
tensively quarried.t A section was measured at this locality begin- 
ning with the Calciferous in the bottom of the canal at the long 
cut on the West Shore railroad west of Pattersonville station. 
2B Pattersonville section 
B! At the level of the bottom of the canal, com- 
pact, thick bedded layers of steel-gray, arenaceous 
limestone, weathering yellowish and containing 
abundance of flint. 30 feet in canal cut and 18 feet 
in railroad cut. Dip at western end of railroad cut 
4° N, 55° W and at eastern end 4° in the opposite 
direction. Calciferous. AG AS” 
1In Smock’s report these quarries are described as follows: ‘‘ There are two quarries 
in the town of Rotterdam, Schenectady co. near Pattersonville station which are 
worked at intervals. They are opened in limestone on the hill 200 feet above the 
Mohawk river and half a mile south of Pattersonyille station (West Shore railroad) and 
the Erie canal. That of James Walker was opened a few years ago when the New 
York, West Shore and Buffalo railroad was built. The face has a south 55° east course 
and a length of 150 yards, and has been worked back 75 feet from north to south. 
- - .The beds which are quarried range from 4 to d8 inches in thickness and the 
total thickness of the quarry beds is from 10 to 15 feet. At the west end there are two 
beds each 2 feet thick, of gray, semi-crystalline limestone. The dip is to the south- 
southeast at a small angle. . . Mrs Moore’s quarry adjoins that of Walker’s on the 
east, and with it makes really one continuous opening. . . It is 10 to 15 feet deep. 
The dip is 3° south-southeast. . . Here also the top strata are thin and the thick 
beds are at the bottom. . .Both these quarries are in the Trenton limestone.’’—N. Y. 
state museum nat. hist. bul. 3, Mar. 1888, p. 105, 106 
