18 NEW YORK STATE MUSEUM 



So far as can be determined, the beds for two or three miles 

 west of the Palisades, that is those along the valley of the Hacken- 

 sack river, are chiefly fine-grained sandstone and shale. Some 

 conglomeratic layers occur, but they are few and of no great thick- 

 ness. Numerous exposures can be found along the road on the 

 west side of the Hackensack from Orangeville north to New City 

 and Short clove. Near Orangeville there are ledges, typical of 

 the conglomeratic phase of the sandstone. The finer sandstone 

 and shale phase is well shown near the old mill, north of Clarks- 

 ville, and along a tributary stream toward Bardonia. 



Ascending higher in the series, the beds become more con- 

 glomeratic. Pebbles often several inches in diameter are scat- 

 tered through the sandstone beds. Lenses of conglomerate sev- 

 eral inches to a few feet in thickness occur. Sometimes these are 

 sharply differentiated from the sandstone beds, but more fre- 

 quently they grade into each other just as the sand and gravel 

 layers do along many streams or on the seashore. The pebbles 

 are usually of sandstone, quartzite, quartz, slate and feldspar. 

 The absence of gneiss, granite or schist pebbles is conspicuous 

 and remarkable, inasmuch as the higher one ascends in the series, 

 the nearer one approaches the borders of the crystalline area,, 

 from whence such pebbles might have been derived. Good ex- 

 amples of such sandstones and conglomerates are found 1) in 

 Monsey glen, 2) on the southeast side of Union Hill, Suffern, 3) 

 two miles east of Suffern, 4) just east of Spring Valley, 5) one 

 and one half mile east of Pomona station, near G. W. Johnson's, 

 6) a mile north of the preceding locality and 7) at numerous points 

 along the road which skirts the south side of the high trap ridge 

 east of Mt Ivy station. Many other small exposures are found 

 at various points along the roads or stream beds, but it is ob- 

 viously impossible to mention them all. 



Calcareous conglomerates 



As one approaches within three of four miles of the north- 

 western border of the formations, limestone pebbles, cobbles and 

 even boulders several feet in diameter appear in greater or less 



