no NEW YORK STATE MUSEUM 



limestone and the rate of dip (since the surface is about level) is 

 therefore a trifle less than 25 feet in the mile. 



The crinoidal limestone is the most prominent stratum on the edge 

 of the escarpment. From its base springs of cold and clear water 

 issue at numerous places along the outcrops, both on the edge of 

 the escarpment and in the gorge. The most prominent of these is 

 at the head of " Milk cave " or St Patrick's falls, and here as almost 

 everywhere at the base of the crinoidal limestone, shallow caverns 

 abound. One of these caverns near the head of the falls, has a depth 

 of 35 or 40 feet and is high enough to permit one to walk upright. 

 No stalactites are found in these caverns, but the walls are much 

 disintegrated and in places covered with a fine residual sand. 



In the fields above this cavern are several sink holes of moderate 

 depth, which serve as catchment basins for the waters of the sur- 

 rounding country, which issue from these caverns during the wet 

 seasons. 



The cavern known as the Devil's hole belongs to this category. 

 As in the other caverns, the roof is formed by the crystalline crin- 

 oidal limestone (stratum 3), the cavern itself being hollowed out in 

 the hydraulic cement rock. This cavern is deeper than most others, 

 and at the end a spring of deliciously cool water issues from between 

 the two beds, the upper '' spring line " of this region. There is no 

 evidence that the cavern extended any deeper than it does at present, 

 nevertheless the spot is worth visiting, as it is the only accessible 

 one of the numerous springs and caverns. The fall of the Bloody 

 run at this place is over a thickness of almost 60 feet of limestone, 

 and the chasm which this stream has worn is interesting both from 

 its historic and scenic points of view.^ 



West of the Niagara river on Queenston bights several quarries 

 have been opened in these limestones, some distance south of the 

 edge of the escarpment. The rock quarried is the crinoidal lime- 

 stone and overlying beds. The total depth of rock in the quarry is 

 27 feet, of which the lower 14 or 15 feet are bluish gray and the 

 upper of a lighter gray color. The limestone is here much more 

 uniform, crystalline throughout and more fossiliferous. This may 



"^Sce brief mention of Bloody run massacre in Introduction. 



