98 FLORIDA GEOLOGICAL SURVEY ELEVENTH ANNUAL REPORT. 
The structure in this area is further demonstrated by its influ- 
ence on the location and characteristics of the principal streams. 
The two large rivers of this part of the State pass at either side of 
this area, approximately paralleling the structural axis. Moreover, 
each stream receives its principal tributaries in Florida from this 
area. The stream at the east side, the Apalachicola River, is im- 
pinging strongly on its left or east bank and is gradually migrating 
down the dip. The Choctawhatchee. at the west side in a less con- 
spicuous manner is through the greater part of its course in Florida 
impinging on its right or west bank. The Apalachicola, however, 
is more distinctly at the side of the anticline than is the Choctaw- 
hatchee. 
On the west side of the Apalachicola and on the east side of the 
Choctawhatchee is a belt of low lands, while on the opposite bank 
are high lands. These topographic features are due to the struc- 
tural conditions and are evidence of them. Because of these struc- 
tural and drainage features, the originally higher land of the north 
is now of lower elevation than that farther south.* However, 
structure in this belt is not pronounced, and it is not to be hastily 
concluded that these mild large structures are sufficient to lead to 
the expectation of deposits of oil and gas. Smaller sharp struc- 
tural features such as would in the nature of the case afford more 
promising prospecting for these deposits, have not been detected in 
this area. 
* The possible relation of topographic development to structure in the area 
easl: of the Ocklocknee river is discussed in the 9th Ann. Report, pp. 130-132. 
