16 NEW YORK STATE MUSEUM 



the Palisades near Piermont, there is a great thickness of coarse 

 sandstones, with some shales and some conglomerates. In general 

 the shales and finer grained sandstones are more abundant in the 

 eastern part of the area, i. e. lower in the series, and the con- 

 glomeratic beds increase in number and thickness in the western 

 part. This change in lithologic constitution is reflected in the 

 topography, for the coarser sandstones and conglomerates are 

 more resistent than the shales and therefore form a higher belt 

 of country. There is no sharp line of demarcation between the 

 beds referred to the Stockton group and those considered the 

 equivalents of the Brunswick shales. 



The characteristics of these beds and the succession of layers 

 will be better understood by a somewhat detailed statement of 

 the outcrops as found in various parts of the area. 



Local details. Arkose sandstones and red shales outcrop along 

 the Hudson river at many points from the state line, northward to 

 Haverstraw. With the exception of a few localities of limited 

 extent, where the trap rock of the Palisades descends to the 

 water's edge, the sandstone and shale everywhere underlie the 

 trap and form the lower part of the steep escarpment which is so 

 conspicuous a feature on the west bank of the Hudson river from 

 Hoboken (N. J.) to Haverstraw (N. Y.) 



At Piermont there are a number of good exposures of a coarse, 

 gray arkose sandstone, which is pebble-bearing in some layers. 

 Just below the* railroad station the trap and sandstone are ex- 

 posed on opposite sides of the road, and the latter can be seen 

 to be somewhat indurated near the trap. A mile north of here 

 there is a small exposure of hard, straw-colored sandstone and 

 indurated, black shale in a stream bed about 10 feet below the 

 base of the trap. 



Midway between Nyack and Piermont, a line of old quarries 

 along Piermont avenue gives good exposures of heavy bedded, red 

 shale and fine grained, red and brownish sandstone. None of the 

 beds were observed to be conglomeratic. These beds are slightly 

 above those exposed at Piermont. The latter resembles the New 

 Jersey beds which I have called Stockton and are apparently very 



