82 
FLORIDA STATE GEOLOGICAL SURVEY. 
the lower end of the bluff; the measurements were by hand level and steel tape; 
the uppermost exposure was a ledge and the thickness as has already been stated 
was 59 feet 6 inches, or roughly, 60 feet. 
Near the upper end of the bluff an aneroid section was made and 55 feet 
was the thickness by that measurement, practically the same as the preceding. 
Coming down the road to Aspalaga Landing is an exposure just before 
passing to the river bottom. To the right of the road is a small branch that 
empties into the Apalachicola at Aspalaga Landing. The Chattahoochee forma¬ 
tion forms an escarpment a few feet high along the northern side of the branch. 
An aneroid measurement from the water’s edge to the highest exposure on the 
road gave a thickness of 35 feet, that is, only a portion of the limestone is there 
exposed. 
At the crossing of the River Junction-Bristol Road, over (Flat Creek?) 
is an exposure of limestone of small extent, probably the Chattahoochee. 
Tests with acid of specimens from Aspalaga Bluff. 
Stratum 4. 
Stratum 3. 
Stratum 2. 
Stratum 1. 
Specimens from highest exposure effervesces. 
Specimen from chalk ledge in face of bluff effervesces. 
Clay, just beneath base of No. 4, considerable effervescence. Very 
calcareous, stiff blue clay effervesces strongly. 
A friable limestone, containing considerable clay. 
Is an argillaceous limestone, chalk. 
Section western end of trestle east of River Junction , Mile-post 206. 
T hickness . 
Feet. Inches 
(7.) 4. Soil and humus . 1 6 
(6.) 3. Gray sands . 3 
(5.) 2. Stiff, mottled sandy clay . 3 
(4.) 1 . Stiff, non-calcareous blue clay . 3 2 
Total . 10 8 
(Section measured with steel tape.) 
Immediately below (4) 1, of the preceding section and nearer the Creek. 
Thickness: 
Feet. Inches. 
3. Sandy, ferruginous clays containing black, - apparently carbon¬ 
aceous particles. Stratum mottled yellowish or brown, 
and bluish white with black spots. 3 
2. Stiff blue clay with lumps or seams of white clay. 1 
1. White, sandy, non-calcareous clay oxidizing yellowish or brown 
on surface . 3 6 
The barometer readings correlate these clays in altitude with those im¬ 
mediately back of the station house at River Junction and as they are similiar 
in character this correlation is apparently trustworthy. 
One telegraph pole west of milepost 205 is an exposure of the argillaceous 
chalk of the Chattahoochee 2.7 feet in thickness. It is overlain by the dump 
from the railroad excavation. The material was tested with acid and found to 
be calcareous. It has the appearance of the usual limestone of the Chattahoochee 
