126 
FLORIDA STATL GEOLOGICAL SURVEY. 
they probably do not exceed fifteen feet in height. Elsewhere, no 
folding has been observed; but it is probable that the disturbance 
which produced the low arches on the Caloosahatchee was general 
and consequently the other Pliocene beds may exhibit the same struct¬ 
ural features. 
Local Details: — There are numerous exposures of the Caloosa¬ 
hatchee marl between Labelle and Caloosa, on the Caloosahatchee 
River. Of this Pliocene rock Dali 1 says: 
On the Caloosahatchee, the strata may be divided into oyster-reef marl beds, 
conchiferous or Turritella marl, and layers of sand; which intergrade without 
distinction and have no invariable succession, but always grade into the shallow 
water fauna at the top, which is overlain by the Planorbis rock, and this in turn 
by post-Pliocene deposits which are seldom of great thickness. 
At Labelle the Pliocene beds have a thickness of four feet beneath 
three feet of fossiliferous Pleistocene marl covered by three feet of 
sandy loam. At this locality the Caloosahatchee marl consists of 
calcareous sand containing a large number of Pliocene shells. One 
mile below Labelle the following section was observed: 
Recent: 
Surficial soil and muck .... 3 feet. 
Pleistocene or Recent: 
Banded marl varying from nearly black to yellow. 1 foot. 
Caloosahatchee marl: 
Gray clayey marl containing some nodules, very fossiliferous. 4 feet. 
Well stratified greenish gray clayey marl containing some fossils... 2 feet 
Total .... 10 feet. 
One-half mile below the last locality the Caloosahatchee marl 
has a thickness of about seven feet and is abundantly fossiliferous, 
containing many large Pectens, ostreas and gastropods. About one 
mile farther down stream, a conspicuous oyster bed about one foot 
thick rises above the level of the river. Five miles below Labelle, the 
following section was examined: 
Concretionary calcareous marl very fossiliferous... 3 feet. 
Oyster bed characterized by a large Ostrea sculpturata and Pecten 
eboreus .. 2 feet. 
Soft white clayey marl... 4 feet. 
Total ... 9 feet. 
The oyster bed is exposed at intervals for several miles. 
1 Dali Wm. H., Neocene of North America, U. S. Geol. Survey, Bull. No. 84, 
p. 147, 1892. 
