116 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



In the 100 miles between the outcrop of the resistant conglomerate 

 Coal Measures near Cannelton, Ind., and the pouit where the Ohio opens 

 into the broad valley of the Lower Mississippi near Paducah, Ky., the rock 

 formations are so friable that the bluffs are in large part broken down to a 

 lower level than the gradation plains would be expected to occupy. It is 

 scarcely possible, therefore, to carry a definite tracing of the gradation 

 plains across this interval and connect them with the equivalent deposits on 

 the Lower Mississippi. It is possible, however, that discriminative studies 

 will make clear the equivalents on the Lower Mississippi both of the grada- 

 tion plains and the Tertiary deposits of the Lower Ohio system. 



DRAINAGE CHANGES NEAR CINCINNATI. 



Reference has already been made to the old northward line of dis- 

 charge of the Licking and part of the Ohio from Cincinnati, through the 

 valley of Mill Creek, to the Great Miami near Hamilton, Ohio. The course 

 of the Licking was through the western part of Cincinnati along the lower 

 course of Mill Creek reversed, while that of the Ohio was around the east 

 and north borders of the Walnut Hills upland to the junction with the old 

 Licking in the north part of the city (see PI. V). James, some years ago, 

 made the interpretation that the course of drainage just outlined was 

 continued from the Grreat Miami near Hamilton westward, through an 

 abandoned valley, to the Whitewater River near Harrison, Ohio, and thence 

 down the Whitewater Valley to its junction with the Great Miami Valley 

 iiear the point where the latter joins the Ohio at Lawrenceburg, Ind.^ 

 The Ohio is thus given a detour of about 20 miles to the north of its 

 present course. This interpretation has recently been in part called in 

 question by Gerard Fowke,^ who has suggested that the Ohio continued 

 northward from Hamilton along the Great Miami Valley and that it received 

 a tributary from the direction of Lawrencebiu-g instead of taking a course 

 past that city. 



While the course of di-ainage suggested by Fowke may have been 

 operative at some remote period, as already indicated, it seems quite certain 

 that the course suggested by James was in operation in the period of deep 

 valley excavation that preceded the deposition of thp oldest drift of that 



^ An ancient channel of the Ohio River at Cincinnati, by Joseph F. James: Jour. Cincinnati 

 Soc. Nat. Hist., Vol. XI, 1888, pp. 96-104. 



2 Bull. Denison Univ., Vol. XI, 1898, pp. 1-10. Also Ohio Acad. Sci., Special Papers No. .3, 

 1900, pp. 68-75. 



