SECOND ANNUAL REPORT—EUEEERS EARTH. 
279' 
seven feet or more per mile. At Aspalaga fully sixty feet of the Chat¬ 
tahoochee limestone stands above the river, while at Rock Bluff, five 
and one-half miles south of southwest, not more than seven or eight 
feet stands above water at the same stage of the river. This indicates 
a dip of at least ten feet per mile. Alum Bluff lies six and one-half to 
seven miles in a direct line from Rock Bluff. Upon the estimate of 
a dip of twenty-three feet per mile made by Harris the entire Rock 
Bluff section of 100 feet, would pass under the river before reaching 
Alum Bluff. Upon the estimated dip of seven to ten feet per mile 
the greater part of the‘ Rock Bluff section would pass under the river 
before reaching Alum Bluff. The latter is probably approximately the 
rate of dip, as the slightly phosphatic sandstone with lime cement lying 
near the water in the Alum Bluff section seems to represent the similar 
rock found in Rock Bluff, forty-six to seventy-six feet above the river. 
Langdon (1. c. p. 324) expressed the view that the bluffs along the 
Apalachicola River represented “the western terminations of ridges 
that extend eastward parallel to each other like gigantic ribs.” Dali 
also assumed that the river at these sections cuts into anticlinal ridges. 1 
The writers having followed the river bluff from the Florida line to 
Alum Bluff find no evidence of large anticlinal ridges of this character. 
On the contrary, as previously stated, the limestone dips to the south 
or southwest gradually through a succession of small folds. 
THE OCKLOCKNEE RIVER SECTION. 
The Ocklocknee River lies between Gadsden and Leon Counties, 
forming the eastern and southeastern boundaries of Gadsden County. 
From the Florida line to the crossing of the Seaboard Air Line Rail¬ 
road, a distance of sixteen miles, this river flows north-northeast to 
south-southwest. Beyond this crossing the river flows to the southwest 
to the entrance of Telogia Creek, from which point it flows southeast 
to the Gulf. Ocklocknee thus closely parallels the course of the Apa¬ 
lachicola. The approach to the Ocklocknee River from the west in 
Gadsden County is by a gradual slope and with one exception no bluffs 
occur on the west side of the river. In this respect also a parallel be¬ 
tween the two rivers is found, the gradual slope to the Apalachicola 
from the west having been previously mentioned. On the east side of 
the Ocklocknee, in Leon County, bluffs occur which, although much 
lower in altitude, may be compared to the bluffs found on the east side 
of the Apalachicola. A small bluff in Sec. 26, T. 1 N, R. 3. W., on 
the east bank of the river gave the following approximate section: 
1 Cenozoic Geology Along the Apalachicola River, William H. Dali and 
Joseph Stanley-Brown. Bull. Geol. Soc. Am., vol. v. 1894. 
