181 



row except for a few miles near Louisville where it has developed a 

 valley several juiles wide mi the Devonian shales and attain widens in 

 the southwestern part of the State, in the art-a of the cnal measures. 

 There are a few places between IMttshuru and Louisville where the width 

 of the valley exceeds two miles, and usually it is less than a nule wide. 

 The narrows above Louisville range in depth from 301 > to -i'tii feet, below 

 Louisville the average is about 300 and in (he wider jiarts the depth is 

 from KM) to 150 feet. The lower Ohio appears to be a very old drainage 

 line. 



The course of the lower Ohio is almost parallel with the dip of the 

 formations. 



There has been almost a total disregard of topographic features ; the 

 part of the river as boundary which has bec-n directly affected by the 

 slaciation is between Louisville and the Indiana-Ohio line. The early 

 liistory of the stream has been largely obliterated by glacial deposits. 

 The entire part of the Ohio which has been intluenced by the result of 

 glaciation extends from Louisville to Maysville, Ky., a distance of 190 

 miles, and including the abandoned channel near Cincinnati the glacial 

 extent is about 225 miles. The drift deposits are found to extend down 

 to the rock floor at a lower le^el than the present bed of the river, and as 

 the material is unmodified the full excavation of the valley precedes the 

 stage of glaciation. This work was done during the Illinoian period. 



White Water. — White Water River in the eastern part of the State 

 drains an area of about 1.500 square miles, partly from Ohio. The source 

 of the stream is in a moraine in southern Randolph County. The east 

 and west forks unite near Brookville. 



"The head water portion for 15-20 miles are flowing in channels cut 

 in drift. The east fork, then, near Richmond enters the rock and has 

 carved its course partly in rocks from that point to Brookville. The west 

 fork encounters rock at only a few points. Below Connersville it is in a 

 partially filled preglacial valley, with broad bottom and elevated uplands 

 on either side. 



"The west fork, with its head waters, constituted an important line of 

 drainage for the waters from the ice sheet at the time the moraine above 

 referred to was forming and probably also at earlier stages in the glacial 

 epoch. It is in consecpience a gravel-filled valley, and the work of the 

 present stream has been merely a removal of a small portion of these 



