190 THE CANADIAN NATURALIST. [Vol. viil 



No fact has been more clearly brought to light during the 

 Geological Surveys of New York and Ohio than that the present 

 rivers are not flowing, in all cases, where they flowed during the 

 Tertiary age. When the ice advanced southward it obliterated 

 the rivers then existing, and on retiring left their channels filled 

 with stones and clay. These beds of drift, as they are called, 

 remained after the ice had disappeared, and when the rivers 

 began again to flow, they failed, in many cases, to find their 

 ancient beds. These ancient channels remained filled with clay 

 stones and sand, and have only been discovered by borings and 

 cuttings made generally for economical purposes. A good in- 

 stance of this will be found in the volume of tha Geological Sur- 

 vey of Ohio for 1873. Prof. Orton writes in his account of 

 Clarke County — p. 460 : 



"An old valley of Mad River is disclosed in the heavy cut of 

 the Atlantic and Great Western Railway, a few miles west of 

 Springfield. The tongue of land that occupies a bend in the 

 river has an elevation of 100 to 125 feet above the level of the 

 stream, and gives no hint in its contour of any break in the 

 rocky floor underlying it. The Sandusky railroad, which was 

 first in construction, cuts across the tongue. A considerable 

 portion of this cut is wrought in solid rock, the maximum depth 

 of the stone cutting being 18 feet. With these facts before 

 them, the Atlantic and Great Western Company, whose line 

 crosses the river half a mile higher and on a grade of ten feet 

 below the first road, expected also to find rock, and made ar- 

 rangements for tunnelling the hill. The road that they selected 

 however, chanced to be a buried channel of the river, which 

 allowed an open cut of 65 feet through clay and sand. Sound- 

 ings that have since been made from the track to the level of 

 the river, show drift material throughout the whole extent." 



In the north of the State, near Cleveland, where the Cuyahoga 

 River enters the lake, is another of these buried channels. 

 Borings have revealed the fact that the Cuyahoga now flows 

 over a bed of clay and sand, 220 feet in depth, filling an older 

 channel in the same or nearly the same place, whose rocky bot- 

 tom lies 210 feet below the level of the lake. Ten miles west 

 of Cleveland the Rocky River also enters the lake by a deep 

 channel with precipitous walls. But two miles to the west is 

 found its ancient channel filled like that of the Cuyahoga with 

 clay, the Erie clay — " which here as at Cleveland extends far 

 below the lake level." 1873, p. 172. 





