NIAGARA FALLS AND VICINITY 95 



it. The quartzose capping rock consists at the base of a white 

 bed, from i| to 2 feet thick and showing cross-bedding structure, 

 followed by shale i to i^ feet thick and of a reddish color in places, 

 and finally by a solid bed of white quartzose sandstone 5 feet in 

 thickness, and like the lower bed, showing cross-bedding structure 

 on the weathered sections. A few thin layers of sandstone overlie 

 this bed, having a total thickness of less than half a foot. On these 

 follow the shales of the Clinton formation. 



The upper Medina sandstones and shales may be traced in both 

 walls of the gorge nearly to the falls. From the southward dip, the 

 beds progressively pass below the water level, till near the falls 

 only a small portion of the upper beds remains. These may be seen 

 at the river margin in the bottom of the gorge, between the Alaid 

 of the Mist landing and the carriage bridge on both sides of the river. 

 On the New York side only a few feet of the red sandstones are ex- 

 posed, the remainder being covered by talus. During high stages 

 of the river these exposed beds are covered by the water. On the 

 Canadian side an extensive ledge of the red Medina sandstone is 

 exposed opposite the inclined railway on the New York side. In 

 the banks behind this ledge the white quartzose sandstone which 

 forms the top of the Medina occurs, its top being at least 25 feet 

 above the water level. It here forms a projecting shelf on which 

 rest huge blocks of limestone broken from the cliff above. From 

 this we may judge that at the foot of the Horseshoe falls the upper 

 layers of the Medina may still be above the water level. 



Clinton beds 



The Clinton beds at Niagara aggregate about 32 feet in thick- 

 ness and consist of a stratum of shale at the base and two distinct 

 strata of limestone above this. (See Plate 14) 



Clinton shale. Resting immediately on the quartzose layers 

 which terminate the Medina formation, is a bed of olive green to 

 grayish or sometimes purplish gray shale, which readily splits into 

 very thin layers v/ith smooth surfaces, and is quite soft enough to 

 be easily crumbled between the fingers. Fossils are rare in it, but 

 occasionally layers are found which have their surfaces covered with 



