y6 FLORIDA GEOLOGICAL SURVEY-TWELFTH ANNUAL REPORT 
STRUCTURAL CONDITIONS. 
The formation in southern Florida west of the Everglades 
deviate somewhat from their original position by slight folding 
of the strata and by tilting of the land area. The minor folds of 
the Caloosahatchee formation have long been observed and fre¬ 
quently described. The folds in this formation are small and 
numerous. Their general direction is north to south or northwest 
to southeast. The Fort Thompson formation also presents minor 
folds, although less numerous, perhaps, than the Caloosahatchee 
formation. This is well seen in the banks of the canal crossing 
Lake Flirt. The limestone which stands as much as 5 feet above 
water level at the rapids passes below water level one or two miles 
above the rapids. This limestone, however, comes to the surface 
again at Coffee Mill Hammock about 8 miles east of Fort Thomp¬ 
son. 
THE COFFEE MILL HAMMOCK ANTICLINE. 
The ridge of rock cut through by the canal at Coffee Mill 
Hammock represents a small anticline which has a general north- 
south direction, and may be traced by the outcropping of rock at 
the surface for some miles. Lake Flirt occupies the shallow 
trough between this anticline and the Fort Thompson rock ex¬ 
posure which probably also represents a small anticline. 
In the Everglades southeast of Lake Okeechobee along the 
North New River canal no evidence of folds are found, the rock 
lying horizontal or nearly so for a north-south distance of forty 
miles. Approaching the east border of the Everglades, however, 
particularly in that part of the canal which has a due east coarse, 
evidence of dip of the formations to the east is apparent. A 
general east dip is further indicated by the fact that flowing ar¬ 
tesian wells are obtained at a comparatively shallow depth at Fort 
Lauderdale and at Miami on the Atlantic coast. 
