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Ohio Biological Survey 
toriinn pnrpurcni), and white snakeroot (Eiipatorium ^irticacfoliiim), are 
abundant. 
The sand and silt terraces differ from those of gravel, in that they 
lack the usual xerophytic margin of the latter. The trees of the flood 
plain are followed immediately by the mesophytes of the terrace, even 
where there is considerable difference in the altitude of the flood plain 
and terraces. 
Clearings on these terraces have nothing characteristic about them. 
The associations are not extremely xerophytic, as are those of gravel ter¬ 
races, and the characteristic herbs of the latter are not found on these 
sand and silt terraces. 
C. FILLED VALLEYS 
The pre-glacial valley of the Ohio, which is partially filled with deep 
glacial deposits, is divisible into three parts, differing somewhat in soil 
features and plant associations. One of these commonly known as the 
Norwood trough, extends from the Little Miami in the vicinity of Plain- 
ville and Red Bank to Alill creek. This part of the valley is filled with 
deposits of Illinoian age, covered with a thick mantle of loess. 
A second portion of this valley, includes the upper part of Mill creek 
valley from about Hartwell northward to Hamilton, and the belt of low 
hills on the west side of the valley. The hills are of Wisconsin till, the 
valley filled with undifferentiated glacial deposits. 
A part of the former valley of the Ohio, which is not included in the 
present discussion, is now occupied by the Miami river, from Hamilton 
almost to New Baltimore. Nothing but recent alluvium is exposed in 
this valley, and its associations belong almost entirely to the flood plain 
series. The remainder of the valley, extending from the Miami in the 
vicinity of New Baltimore westward to the Whitewater river at Harrison 
is filled with till of Illinoian and Wisconsin age. 
Other valleys of the region were filled in the same way. Much of 
the glacial filling has since been removed from those now occupied by 
large streams, but in many places along these valleys, small areas of deep 
drift deposits remain. The vegetation of these areas is considered under 
clay bluff's. 
In general features, the vegetation of all filled valleys is similar. 
1. The Norwood trough 
The plant associations of the Norwood trough are most closely re¬ 
lated to those of the uplands covered with Illinoian till. Undissected 
