GEOLOGY BETWEEN THE CHOCTAWHATCHEE AND 
APALACHICOLA RIVERS IN FLORIDA. 
E. H. SELLARDS AND H. GUNTER.* 
LOCATION, AREA AND MINERAL INDUSTRIES. 
H. GUNTER. 
The area to which this report relates lies in western Florida 
between the Apalachicola and Choctawhatchee rivers. It extends 
from the State line at the north to the Gulf of Mexico, and in- 
cludes Jackson, Calhoun, Holmes, Washington and Bay counties. 
The total area is 3,890 square miles, or 2,489,600 acres. 
CLIMATE. 
Records on temperature and rainfall are available at the Mari- 
anna Station from the United States Weather Bureau. This sta- 
tion probably may be accepted as fairly representative of the area 
covered by this report. The average for rainfall and temperature 
at Marianna is based on records from 1912 to- 1916^* 
The annual mean temperature at Marianna, in Jackson County, 
is 67.4 degrees Fahrenheit. The mean for the four seasons of the 
year is as follows: Winter, 56.6; Spring, 77.3: Summer, 76.3; Fall. 
57.7 ; the maximum summer heat recorded at this station during this 
five, year period is 106 degrees Fahrenheit. The minimum winter 
temperature recorded is 22 degrees Fahrenheit. 
The annual mean rainfall at Marianna is 56.3 inches. This is 
distributed throughout the year as follows: January, 3.4 inches; 
February, 6.3 inches; March, 5.2 inches; April, 3.5 inches; May, 
3.1 inches; June, 4.4 inches; July, 8.9 inches; August, 5.5 inches; 
September, 5.8 inches; October, 3.3 inches; November, 2.4 inches; 
December, 4.0 inches. 
! * The field work on this report has been done jointly by the authors. The 
manuscript has been prepared as indicated. 
tClimatological Data, Florida Section, Annual Summary for years 1912- 
1916, by A. J. Mitchell, U. S. Dept. Agri.., Weather Bureau Office, Jackson- 
ville, Florida. 
