"74 THE PREGLACIAL DRAINAGE OF OHIO. 



an intermittent action. Even if there was more than one glacial 

 period, the sequence of events would not be greatly dififerent 

 from the series here described. The work was begun by the 

 one which first blocked the Kanawha, and was completed by 

 the one which extended farthest south. 



When the ice retreated, the drift which it left behind shut 

 the rivers and creeks ofif from their former ways, and they were 

 left as we now find them. The channel of old Limestone has 

 been partially taken possession of by the Little Aliami and its 

 East Fork ; the part between these streams and its former mouth 

 at (G) is deserted. Licking turns west at Covington, and its 

 ancient valley from Cincinnati to Hamilton has been pre- 

 empted by the insignificant Mill creek. The Whitewater, a 

 post-glacial stream, and the mouth of the Great Miami use a 

 fragment of the old Kentucky river valley in Ohio, but the part 

 between (I) and (H) is abandoned. The Miami utilizes that 

 portion of its channel between Hamilton and the point (I), where 

 Taylor's creek formerly emptied ; but the immense gravel de- 

 posits which were left here deflected the new river toward the 

 east. It followed a small ra\'ine for a short distance, then broke 

 over a low place in the divide between this ravine and Taylor's 

 creek, filled the latter to the col (F), tore this out, and at Cleves 

 fell into the creek which came through the hill at North Bend; 

 it went with that creek to the drift filled valley of the old Ken- 

 tucky near Valley Junction, through which it has eroded its 

 devious way to the Ohio. 



A large creek entered the old Kentucky at the town of 

 Harrison ; the Whitewater crossed this to reach the ancient 

 valley, leaving an island of Silurian rock between the former and 

 recent beds, just as the Great Miami did at the gravel deposits 

 at (I). 



The old streams herein described flowed through valleys 

 which were eroded to a considerable depth below the waters 

 which now go through them. While the new channels were 

 forming the old ones were being filled with sediments of mud- 

 laden torrents and debris from masses of floating ice. The 

 streams of today have not had time to clear out these 

 deposits, so they remain as the bottom lands on either side of 



