322 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



Creek Valley should be referred to the Wisconsin stage of glaciation. It 

 seems probable, however, that it should be onlj^ a small part. It inay 

 include only the fresh-looking surface till, such as is exposed in the railway 

 cutting, and may extend but little below the level of the flat part of the 

 valley. 



Along the Grreat Miami River there is a gravel-filled valley three- 

 fourths to 1|^ miles in width, of which the upjjer 60 feet of filling, aS noted 

 above, seems referable to the Wisconsin outwash. West of this valley the 

 uplands in Hamilton and Butler counties, Oliio, carry a thin sheet of drift, 

 but the lowlands and larger valleys carry a very thick deposit. The low- 

 land tract connecting the Great Miami with Whitewater River, in northwest- 

 ern Hamilton County, though utilized probably as a preglacial and possibly 

 an interglacial drainage line, seems not to have been thus used since the 

 Wisconsin ice invasion Like the valley of Mill Creek, it has been filled 

 chiefly with till. A well in this lowland, at Mr. Gruest's, about a mile east 

 of Preston post-office, passed thi'ough 90 feet of till and, at bottom, 10 feet 

 of sand before obtaining water. The well surface is about 70 feet above 

 the bed of Dry Fork at Preston. Ordinarily wells in this till tract find 

 water at 40 feet or less, there being deposits of water-bearing sand inter- 

 bedded with the till. The till tract presents a variable surface structure, 

 such as is displayed in the majority of moraines whose main component is 

 till, there being many places where sand and gravel immediatelj^ underlie 

 the soil, but these are apparently in local and isolated tracts. 



North and northwest from this lowland till tract are uplands standing 

 200 to 300 feet above it. On these uplands the prominent ridges and hills 

 have a very thin coating of drift, but the lower parts of the uplands are 

 covered with a sheet of till of moderate thickness. The valleys have con- 

 siderable gravel either flanking their slopes or aggregated in low knolls in 

 their bottoms, but the main bulk of the drift in the valleys is till, the 

 gravel seeming to be mostlj^ superficial. These hills are not silt covered in 

 Butler County, Ohio, but in Franklin County, Ind., there is a narrow belt 

 along the north side of the Whitewater which resembles the tract south 

 of that stream in having a silt 3 to 4 feet or more in thickness covering an 

 old drift, the Wisconsin drift being absent. With the exception of this nar- 

 row belt, which seldom reaches back 5 miles from the Whitewater Valley, 

 the surface portion of the drift of northeastern Franklin County is a fresh, 



