20 NEW YORK STATE MUSEUM 



the crystalline hills, is significant. It is impossible to suppose 

 that the conglomerates were derived from the older rocks which 

 now immediately adjoin them. The waves of the sea in which 

 the Newark beds were deposited did not beat against the rocks 

 which apparently now border this area. These conclusions are 

 fully substantiated by the facts as shown in New Jersey, where 

 the evidence is more decisive. 1 



The facts furthermore demonstrate that these border conglomer- 

 ates do not mark any definite horizon. Traced away from the 

 border along the strike, they are found to grade into sandstones 

 and shales. This relationship again is more clearly seen in the 

 case of the border conglomerates of New Jersey. 



Local details. On the southeastern flank of Union hill, Suffern, 

 coarse sandstone and conglomerate beds are exposed in a series of 

 ledges, 10 to 25 feet high. The conglomerate is composed of 

 quartzite, sandstone, limestone and quartz pebbles. One lime- 

 stone boulder three feet in diameter is shown. The limestone con- 

 stituent forms from 25$ to 30$ of the whole. 



Two and one half miles northeast of Suffern is exposed, in the 

 Crum quarry, a most remarkable conglomerate, made up of huge 

 limestone boulders, some of which were reported to be 12 feet 

 in diameter. The quarry is partially filled with water, so the 

 report could not be fully verified, but boulders four and five feet 

 in diameter were seen. The limestone is a dark bluish black rock, 

 somewhat: saccharoidal in appearance. Chert nodules occur in 

 some boulders. The smaller fragments are sharply angular, but 

 the larger boulders are fairly well rounded. Careful examination 

 was made of the surface of two of the largest which were access- 

 ible, to see whether they bore traces of glacial action. None were 

 found. A red, micaceous mud matrix cements the whole to- 

 gether. Owing to the heavy drift deposits, it is impossible to say 

 how far beyond the limits of the quarry the conglomerate ex-* 

 tends. 



About three fourths of a mile northeast of the quarry, several 

 small exposures of a somewhat similar rock were noted near 

 Blauvelt's plow works. 



lAnnual report of the state geologist of New Jersey for 1897. p. 52-56. 



