FLORIDA GEOLOGICAL SURVEY


Florida, a small area of the Madison Hills in northwestern Hamilton County is separated from the
main body of this zone by the Withlacoochee River Valley (Figure 3 on OFMS 99-03). The
elevation of the hills is generally lower than in the Tallahassee Hills with hill tops often below 200
feet (61.0 meters) above MSL. In the study area, elevations range from 50 feet (15.2 meters) to
slightly more than 200 feet (61.0 meters) above MSL. The valleys are broad and poorly drained.
The Miccosukee Formation forms the higher areas while the Hawthorn Group sediments underlie
the lower portions of the landscape. Karst features occur most commonly in the eastern part of the
district. The Lower Oligocene Suwannee Limestone underlies the Hawthorn Group in the Madison
Hills.

 Tallahassee Hills

 The Tallahassee Hills extend from the Apalachicola Bluffs and Ravines in Gadsden and
Liberty Counties on the west to eastern Jefferson County (Figure 3; OFMS 99-03). The lowest
elevations are approximately 50 feet (15.2 meters) above MSL along the Cody Scarp, the
boundary between the Tallahassee Hills and the Woodville Karst Plain, while elevations of hill
tops range to more than 300 feet (91.4 meters) above MSL. Well drained valleys have local relief
often exceeding 150 feet (45.7 meters) above MSL. In general, the hill top elevations decrease from
west to east and north to south. A number of large lakes exist in this area, including Lake Jackson
and Lake Miccosukee. This area is generally well drained with swampy conditions existing in the
lower elevations. In the study area, the Tallahassee Hills are developed on the Hawthorn Group and
Miccosukee Formation siliciclastic sediments. Karst features are present within this zone where the
carbonates of the St. Marks Formation and Suwannee Limestone occur near the surface.

Cody Scarp

 The Cody Scarp has been described as "...the most persistent topographic break in the
State" (Puri and Vernon, 1964). White (1970) interpreted the scarp as being a combination of fluvial
and karst erosion and shoreline development. The scarp is a multiphasic scarp in that it may have
initially been a sea-level scarp but subsequently was highly modified, at least in part, by
karstification and surficial erosion. It is named for the community of Cody in Jefferson County
which is just west of the map area. Upchurch (2007) describes the Cody Scarp as "a classic
example of a karst escarpment with numerous poljes, uvalas, sinkholes, sinking streams, siphons,
springs, and other karst features along its length." The difference between a karst escarpment and
any other topographic scarp is that the toe of the scarp is characterized by limestone or dolostone
that is dissolved by the surface water and groundwater as the scarp retreats (Upchurch, 2007).
 The scarp is very well developed near Wacissa (Photo 1; OFMS 99-03), where it appears to
be primarily a sea-level scarp, and separates the Tallahassee Hills from the Woodville Karst Plain.
Further east, where the scarp forms the boundary between the Madison Hills and the subdivisions of
the Ocala Karst District, it becomes less distinct as more karstification and surficial erosion have
altered it. Where the Cody Scarp occurs between the Tallahassee Hills and the Woodville Karst
Plain, the toe of the scarp is at approximately 50 feet (15 meters) and the crest is at 125 feet (38
meters) above MSL. In the eastern portion of the map area, the scarp is less distinct with the toe at
approximately 75 feet (23 meters) and the crest at more than 125 feet (38 meters) above MSL.