BULL. GEOL. SOC. AM. 



VOL. 25, 1913, PL. 13 



Figure 1. — Contact of the Cataract (Whirlpool) Sandstone on the Brick Red Qdeenston 



Shales 



Exposure along the Grand Gorge Railway, Niagara Falls, New York 



Figure 2. — Contact of the Cataract (Wiiun.rooL) Sandstone on Queenston Shale 



Stony Creek, Ontario, Canada 



CONTACTS BETWEEN SILURIC AND ORDOVICIC (CINCINNATIC) SYSTEMS 



