SECOND ANNUAL REPORT—PULLERS EARTH. 
265 
The intense cross bedding found in these deposits together with 
their variable character, indicates deposition in shallow water in pres¬ 
ence of conflicting currents. Unconformities in this part of the sec¬ 
tion are numerous, but apparently of local extent. The stratification 
or bedding, except where affected by cross bedding or local clay lenses 
is horizontal. The succession beneath this coarse sand is lacking in 
uniformity. Very frequently, as in the section two miles northeast of 
Aspalaga, a reddish sandy clay with white clay partings lies beneath 
the coarse sand. Material of this character occurs widely distributed 
not only in Gadsden but in Leon and Jefferson Counties. This in turn 
is underlaid by finely laminated clays and by greenish alum tasting 
clay such as that found in the section near Rock Bluff Landing 
(p. 274). Beneath the greenish clay is found the fullers earth series. 
The total thickness of the formations lying above the fullers earth 
when not reduced by erosion is about 100 feet. 
In the Rock Bluff section (p. 273) the fullers earth is underlain by 
approximately 100 feet of yellow gray and blue more or less calcareous 
sands which represent the Alum Bluff formation. Beneath these sands 
is found the Chattahoochee limestone. The Alum Bluff sands and the 
Chattahoochee limestone will be described in connection with the 
Apalachicola River section on the following pages. Beneath the Chat¬ 
tahoochee limestone the Vicksburg or Lower Oligocene may be ex¬ 
pected. The Vicksburg, however, is not exposed at the surface in 
Gadsden County. 
THE APALACHICOLA RIVER SECTION. 
The Apalachicola River section is classic in the study of Florida 
geology. Since the discovery by Langdon in 1887 of the excellent 
exposures along the river this section has been repeatedly visited and 
studied by geologists, and a relatively rich literature has developed. 
The following papers, listed in the Bibliography of Florida Geology, 
First Annual Report, pp. 73-108, 1908, relate to the Apalachicola River 
section. 
1889—Langdon, Daniel W., Jr. Some Florida Miocene. Am. Journ. Sci. (3) 
XXXVIII, 322-324, 1889. Republished with some additions in Geology of the 
Coastal Plains of Alabama, Geol. Surv. Ala., pp. 373-376, 1894. 
1891—Johnson, Lawrence C. The Chattahoochee Embayment. Geol. Soc. 
Am. Bull III, 128-132 1891. 
1891— McGee, W. J. The Lafayette Formation. U. S. Geol. Surv. 12th 
Ann. Rept. pt. i, pp. 347-521, 1891. 
1892— Dali, W. H. and Harris, G. D. Correlation Papers: Neocene of North 
America. U. S. Geol. Siirv. Bull. 84, 1892. 
1893— Foerste, Aug. F. Studies on the Chipola Miocene of Bainbridge, 
Georgia/and of Alum Bluff, Florida. Am. Jour. Sci. (3) XLVI, 244-254, 1893. 
