4 2 FLORIDA GEOLOGICAL SURVEY TENTH ANNUAL REPORT. 
Fig. 4. Contours on the fullers earth horizon of the Alum Bluff formation. Elevations marked by the “plus-minus” sign 
are inferred levels. AA' indicates the line of approximately uni form levels on the Choctawhatchee formation, which apparently 
does not conform in structure to the Alum Bluff and Chattahoochee formations. 
