248 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT. 
also an area bordering Silver Springs Run and connecting with the 
Dead River Swamp, on the northeast boundary of the area. 
The Swamp is the lowest-lying land in the area. The elevation 
lies between 40 and 50 feet above sea level. The Swamp owes its 
occurrence to the sinking of the land resulting from the solution of 
limestone. 
Drainage over most of the type would be very difficult and ex¬ 
pensive, if not impossible. When the streams are at the high-water 
stage the swamps are covered by water, but during dry seasons the 
immediate surface may be entirely dry. 
The soil of the Swamp varies considerably, as might be expected. 
As a general rule, however, the surface is mucky to some depth. In 
places the underlying clays are found near the surface. They are 
of drab or bluish to dark color and often mottled, ranging from stiff 
plastic clay to heavy sandy clay. In places a compact white or drab 
sand is encountered beneath the mucky surface material. 
Swamp, marl subsoil phase .—A part of the Swamp is underlain 
by marl. Around Lake Panasoffkee the profile consists of muck 
underlain by shell marl, and some of the Swamp along Silver 
Springs Run is of the same character, though no attempt was made 
to differentiate such areas in the latter section. Low hammocks of 
marly character in the Swamp along Withlacoochee River support 
a growth of cedar and are.known as cedar hammocks. 
The mineral soil material of the Swamp, particularly the clay, 
is in part residual from limestone, marl, and shell beds. Deposits 
from the stream flood waters have been added. The mucky sur¬ 
face is from the partial decay of the heavy vegetation growing in the 
swamps. 
The cypress trees constitute the main value of the Swamp, but 
during the dry season the land affords good range for hogs. It 
has no present agricultural value. 
SUMMARY. 
The Ocala area is situated in the north-central part of the Florida 
peninsula*and comprises an area of 1,002 square miles, or 641,280 
acres. It includes parts of the counties of Marion, Sumter, Citrus, 
and Levy. It forms an elevated portion of the peninsula and is 
underlain by limestone. 
The topography is varied, ranging from low and flat areas in the 
swamps and flatwoods to rolling in the sandy hills and high ham- 
