48 FLORIDA GEOLOGICAL SURVEY TENTH ANNUAL REPORT. 
6. White water-worn, elongated siliceous pebbles imbedded in yellow 
sandy clays and lying witji long axis parallel with the lines of 
stratification 1 foot 
5. Yellow clayey sand t 7 feet 
4. Greenish, sticky, sandy clay 9 feet 
3. Covered and sloping (about) 44 feet 
2. Alum Bluff formation, including intensely blue sands and calcareous 
and phosphatic sands 20 feet 
1. Covered in this section from the Apalachicola River, including the 
upper part of the Chattahoochee formation and the lower part 
of the Alum Bluff formation (about) 80 feet 
The Choctawhatchee formation is not recognized in this sec- 
tion, and is not present, unless possibly in a somewhat modified 
form. The contact between the Alum Bluff formation and the 
later materials is possibly within the covered interval, No. 3 of 
the section. 
In the section at Aspalaga Bluff, the covered interval of 60 
feet at the top may, in part, include this formation. I11 the sec- 
tion at Chattahoochee Landing, it would seem admissible to refer 
Nos. 11 and 12, including 37 feet of pinkish clay and red sands 
to this formation. The contact at the Chattahoochee Landing be- 
tween the Alum Bluff formation and the overlying formation is 
presumably found within the covered interval of 42 feet, No. 10 
in the section. If this interpretation is correct, the formation in 
question is traceable to the Georgia-Florida State line. 
To the east from the Apalachicola river, many exposures are 
found in the streams and public road and railroad cuts showing 
cross-bedded red sands which may be of this formation. In passing 
from River Junction to the plateau level in Gadsden county, both 
the Apalachicola Northern and the Seaboard Air Line railways, 
which utilize the valley of Mosquito creek, afford exposures of 
these red sands. The following section was obtained by follow- 
ing the course of the Apalachicola Northern railroad from Mos- 
quito creek to the plateau level near Hardaway. The base of this 
section, as determined from the profile of the Apalachicola Nor- 
thern railway, is 120 feet above sea, and the top is 303 feet above 
sea. The top of the Alum Bluff formation presumably is found 
in the covered interval, No. 3 of this section, hence at an elevation 
above sea of 184 feet or more. 
