LOWER OHIO DRAINAGE SYSTEM. 115 



mouth of Big Bone Creek, in the reverse direction of the present flow of the 

 Ohio. This would bring support to a view recently advanced b}^ Fowke,^ 

 that the Licking and the neighboring part of the Ohio continued from 

 Cincinnati northward, past Hamilton, through the Great Miami Basin, and 

 received this and other small tributaries along the line leading- to Hamilton 

 from the southwest, past Lawrenceburg, Ind. But upon further reflec- 

 tion and a reexamination of the locality doubt has arisen concerning the 

 validity of this interpretation. A strong element of uncertainty is found in 

 the fact that the part of the Ohio near the points where this small abandoned 

 channel makes its connections has the exceptional width of IJ to 2 miles, 

 and carries worn and receding bluffs that seem to be as old as the 

 abandoned channel at its side. There is also some uncertainty as to the 

 interpretation that this abandoned channel was opened by Eagle Creek. 

 Its size is more in harmony with that of Big Bone Creek, and markedly 

 less than the portion of Eagle Creek Valley with which it connects. At 

 present it is uncertain whether by the abandonment of this valley the Eagle 

 has been deflected from the Ohio to the Kentucky, or whether the Big Bone 

 has been deflected from the Eagle-Kentucky drainage to the Ohio. This 

 question is, however, of less importance to the subject under discussion 

 than that of the existence of a gradation plain which corresponds quite 

 closely with the remnants of gradation plains found on the lower course of 

 the Licking and Kentucky. 



LTpon passing below Louisville to the portion of the Ohio outside the 

 limits of glaciation, remnants of a gradation plain have been found on 

 tributaries which enter through the resistant sandstone formation They 

 are especially well defined on Big Blue and Little Blue rivers, one of which 

 enters above and the other below the abrupt bend made by the Ohio 

 River at Leavenworth, Ind. Like the gradation plains of the Licking and 

 Kentucky, they stand about 175 to 200 feet above the stream, but their 

 altitude above tide is only about 560 feet, or fully 50 feet lower than the 

 gradation plains near the mouth of the Kentucky. This is to be expected 

 on the supposition that the drainage was along the present course. These 

 gradation plains in the vicinity of Leavenworth stand about 150 feet below 

 the level of the Tertiary deposits which, as above described, cap the bluffs 

 of that portion of the Ohio Valley. 



iBull. Denison Univ., Vol. XI, 1898, pp. 1-10. * 



