FLORIDA GEOLOGICAL SURVEY


characterized by a distinct color change from tan to brown
limestone and by abundant cone-shaped foraminifers. The formation
is a brown, dolomitic, porous limestone. Selenite (gypsum) near
the base of the formation probably forms the bottom of the
Floridan aquifer. The Avon Park Limestone is highly permeable
and is the main source of water for most of the high-capacity wells
in the area. Figure 9 shows the configuration of the top of the
Avon Park Limestone. The map shows the northwest-southwest
trend of the faulted anticline.


 STRUCTURE

 The Peninsular arch (Applin, 1951), a buried anticlinal structure
of Paleozoic sediments, trends generally north-northwestward and
its main axis is located east of the Green Swamp area. A flexure,
developed on the western flank of the Peninsular arch in the
Tertiary limestones, is called the Ocala Uplift. The Green Swamp
area is located at the southern end of the Ocala Uplift (figs. 8
and 9).
 Vernon (1951) dated the Ocala Uplift as post-Oligocene in age.
 Faults in the Green Swamp area complicate the definition of the
 geology and the hydrology. The main area of faulting occurs
 along the Lake Wales Ridge. Faulting in this area was described
 by Vernon (1951, p. 56) and named The Kissimmee Faulted Flexure.
 The cross sections in figure 8 show vertical displacement along
 fault zones.
 The faults are probably post-Oligocene. Subsequent movement
 along fault zones may have occurred over a long period of time,
 the later movements being associated primarily with subsidence
 and sinkhole collapse along the solution-widened zones.
 Figure 9 shows a structural map based on the top of the Avon
 Park Limestone. The contour lines generally define the shape of
 the anticline with associated faults. The linearity of ridges on the
 anticline suggests that other faults exist in the area.
 Faulting probably could affect the hydrology of the Green
 Swamp in the following ways:
 (1) Joints or faults within the Floridan aquifer, widened by
 solution, could cause zones of high permeability, or could cause
 zones of low permeability when filled with plastic materials.
 (2) Displacement along the faults could position formations
 of different lithology (hence permeability) one against the other,