NIAGARA FALLS AND VICINITY 89 



The succeeding beds of the Medina as well as the Clinton, Roches- 

 ter and Lockport beds, are best exposed along the railroad cut of 

 the Lewistori branch of the New York Central and Hudson River 

 railroad. This cut is reached from the Lewiston end through a 

 short tunnel cut in the Medina sandstone (plate 12). As the beds 

 dip southward, and the roadbed rises in the same direction, we pass 

 rapidly across all the formations from the lowest to the highest 

 exposed. 



Upper shales and sandstones. The contact between the quartzose 

 sandstone and the overlying Medina shales is not generally well ex- 

 posed, except in one place. This is in Evan's gully, the first of the 

 small excavations in the roadbed, made by the streams of water 

 which in the spring time cascade from the banks. The quartzose 

 sandstone forms the bed of the gully below the bridge on which the 

 railroad crosses it, and it also forms the capping rock over which the 

 stream cascades to a lower level. 



1 The lowest beds of this division of the Medina are gray shales, 

 25 feet in thickness and readily splitting into thin layers and gen- 

 erally smooth to the touch, indicating the absence of sand. There 

 are however beds of a more sandy character, even to fair sandstones, 

 interbedded with the shales, and this is particularly the case near the 

 middle of this shale mass. These sandstone beds are similar in 

 character to the quartzose sandstone below the shales, but they occur 

 in thin layers, separated by shaly masses. These same beds are ex- 

 posed in the cutting which leads to the tunnel on the north, where 

 they are shown near the base of the section. They vary in thick- 

 ness up to 8 inches, and in some cases contain a few fossils, notably 

 the shells of Ling u la cuneata (fig. 81). The shales below 

 the sandstone layers are mostly below the level of the roadbed, the 

 greatest thickness exposed above that, being about 6 feet. 



The upper 13 or 14 feet of this shaly series are well shown in the 

 cutting north of the tunnel, where they may be seen above the sand- 

 stones just alluded to. These rocks present in places an almost per- 

 pendicular wall, where the overlying sandstones have not been re- 

 moved, while from the rapid weathering of the shale, the capping 

 stone generally projects beyond the face of the shale cliff. The un- 



