Drift. 73 



terraces or banks of sand and gravel, evidently of riparian origin, 

 and that these deposits were made when water was very abundant. 

 We know the boulder clay and valley drift as the great water- 

 bearing material of the country. But we find little of the clay 

 drift, except in the form of river silt below the level of the gravel 

 terraces. 



Sections of the alluvial deposits in the valleys of this vicinity 

 show two features worthy of careful study, as they appear with per- 

 sistent uniformity in all the deeper valleys upon one or both sides 

 of the stream. First, bed-rock lies from thirty to fifty feet lower 

 than the present channel of the water-course, showing that the 

 valleys have silted up to that extent. Second, a well-defined soil, 

 with driftwood and frequently standing stumps of trees, at near 

 the level — generally five to ten feet above — of low water of the 

 principal water-course. This ancient soil is again underlaid by the 

 sand bars and gravel beaches of the water-course as it existed before 

 the silting up of the valley. 



Let us now turn to figure 3, a sketch map of the vicinity of 

 Cincinnati, and imagine what might have occurred during the 

 Glacial Epoch. We will imagine a water-course occupying the 

 valley, but not necessarily in all cases the present channel of 

 the Ohio River, with its bed at the level at which we now find 

 bed-rock, and its flood-plain, or river bottoms, at the level of 

 the ancient soil. We will suppose it to be joined by a tributary 

 at or near where the Little Miami now joins it; this tributary 

 recieves a branch rising on the plateau near the present position of 

 Norwood ; the high land then extending in an unbroken line from 

 the river bluff (Walnut Hills) to Pleasant Ridge and beyond, but 

 deeply gashed by this precipitous stream on the east, and a like 

 branch on the west, falling near Chester Park into the river that, 

 flowing nearly south through the valley now occupied by Mill Creek, 

 joined the main water-course at this point. The great ice field 

 approaches from the North, and, by its increasing thickness, 

 attains an angle that, when the brief summers come and the 

 surging waters of the southern tributaries of the Ohio are poured 

 into the valley and melt their way through the channel, cutting 

 away the toe of the ice field, causes it to move steadily down, and 

 adds to the floods that are hurrying to the sea. The glacier moves 

 steadily on, pushing the current against the Kentucky hills, which 

 will not yield. The river is obstructed, the waters rise higher, 

 the channel from Price Hill to the adjacent Kentucky cliffs is 



