Big Cypress National Preserve 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2008/021 

National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center 
THIS PAGE: THIS PAGE: 

West Mud Lake Cypress Dome, Big Cypress N Pres

ON THE COVER: ON THE COVER: 

Dwarf Cypress Prairie, Big Cypress N Pres

Photos by: Paul C. Murphy Photos by: Paul C. Murphy 
Big Cypress National Preserve 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2008/021 

Geologic Resources Division 

Natural Resource Program Center 

P.O. Box 25287 

Denver, Colorado 80225 

February 2008 

U.S. Department of the Interior 

Washington, D.C.
The Natural Resource Publication series addresses natural resource topics that are of interest 

and applicability to a broad readership in the National Park Service and to others in the 

management of natural resources, including the scientific community, the public, and the NPS 

conservation and environmental constituencies. Manuscripts are peer- reviewed to ensure that 

the information is scientifically credible, technically accurate, appropriately written for the 

intended audience, and is designed and published in a professional manner. 

Natural Resource Reports are the designated medium for disseminating high priority, current 

natural resource management information with managerial application. The series targets a 

general, diverse audience, and may contain NPS policy considerations or address sensitive 

issues of management applicability. Examples of the diverse array of reports published in this 

series include vital signs monitoring plans; "how to" resource management papers; 

proceedings of resource management workshops or conferences; annual reports of resource 

programs or divisions of the Natural Resource Program Center; resource action plans; fact 

sheets; and regularly- published newsletters. 

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not constitute endorsement or recommendation for use by the National Park Service. 

Printed copies of reports in these series may be produced in a limited quantity and they are 

only available as long as the supply lasts. This report is also available from the Geologic 

Resource Evaluation Program website (http://www2.nature.nps.gov/geology/inventory/

gre_publications) on the internet, or by sending a request to the address on the back cover. 

Please cite this publication as: 

Thornberry- Ehrlich, T. 2008. Big Cypress National Preserve Geologic Resource Evaluation 

Report. Natural Resource Report NPS/NRPC/GRD/NRR—2008/021. National Park Service, 

Denver, Colorado. 

NPS D- 176, February 2008 
 BICY Geologic Resource Evaluation Report iii

Table of Contents 

List of Figures .............................................................................................................. iv

Executive Summary ...................................................................................................... 1

Introduction ................................................................................................................... 2

Purpose of the Geologic Resource Evaluation Program ............................................................................................2

History and Overview of the Preserve ........................................................................................................................2

Geologic Setting .........................................................................................................................................................2

Geologic Issues............................................................................................................. 6

Hydrogeologic System at Big Cypress National Preserve ..........................................................................................6

Oil and Gas Issues .....................................................................................................................................................7

ORV Management......................................................................................................................................................8

Geologic and Topographic Mapping...........................................................................................................................9

Disturbed Lands .........................................................................................................................................................9

Geologic Features and Processes............................................................................. 15

Freshwater Sloughs and Strands .............................................................................................................................15

South Florida Basin and the Sunniland Trend ..........................................................................................................15

Sinkholes and Karst..................................................................................................................................................16

Hydrogeology ...........................................................................................................................................................16

Hardwood Hammocks ..............................................................................................................................................17

Stratigraphic Record.................................................................................................................................................18

Map Unit Properties .................................................................................................... 25

Map Unit Properties Table........................................................................................................................................26

Geologic History.......................................................................................................... 27

Late Paleozoic Era ...................................................................................................................................................27

Early Mesozoic Era...................................................................................................................................................27

Middle Mesozoic Era ................................................................................................................................................27

Late Mesozoic Era....................................................................................................................................................27

Cenozoic Era............................................................................................................................................................28

Glossary....................................................................................................................... 33

References................................................................................................................... 36

Appendix A: Geologic Map Graphic .......................................................................... 39

Appendix B: Scoping Summary................................................................................. 41

Attachment 1: Geologic Resource Evaluation Products CD 
 NPS Geologic Resources Division iv 

List of Figures 

Figure 1. Location and ecosystem map for Big Cypress National Preserve...................................................................4

Figure 2. Map of physiographic subsections in South Florida. .......................................................................................5

Figure 3. Deep Lake.....................................................................................................................................................10

Figure 4. Remains of oil and gas extraction operations at an oil pad...........................................................................11

Figure 5. Abandoned oil pad ........................................................................................................................................11

Figure 6. Rusting culvert along an access road to an oil pad.......................................................................................12

Figure 7. Intact culverts along an access road.............................................................................................................13

Figure 8. Rutted ORV trail through the forest...............................................................................................................14

Figure 9. Slow-flowing slough ......................................................................................................................................19

Figure 10: Map of Florida showing location of Big Cypress National Preserve ............................................................20

Figure 11. A simplified cross section showing Late Jurassic and Cretaceous rocks....................................................21

Figure 12. Stratigraphic section for South Florida basin...............................................................................................22

Figure 13. Development of a karst landscape..............................................................................................................23

Figure 14. Diagram showing rough cross sectional view of the aquifers beneath Big Cypress National Preserve ......24

Figure 15. Geologic time scale.....................................................................................................................................30

Figure 16. Evolution of the landscape in the Florida Platform area..............................................................................31

Figure 17. Open prairie area largely underlain by freshwater marly limestone ............................................................32

0
 BICY Geologic Resource Evaluation Report 1

Executive Summary 

This report accompanies the digital geologic map for Big Cypress National Preserve in 

Florida, which the Geologic Resources Division produced in collaboration with its partners. 

It contains information relevant to resource management and scientific research. 

Located in the part of South Florida that also includes 

the Everglades, Big Cypress National Preserve is part of a 

unique area on Earth. Habitats at Big Cypress National 

Preserve include estuarine areas, slow- flowing 

freshwater sloughs, saline marshes, freshwater marshes, 

cypress swamps, prairies, domes, strands, mangrove 

zones, buttonwood ridges, coastal prairies, freshwater 

marl prairies, hardwood hammocks, and pinelands. The 

geology of the area has shaped these environments. 

Geology influences surface water flow, thus contributing 

to climate, weather, hydrology, and topography in 

Florida. Geologic units and structures are the basis for 

the extensive aquifers and the presence of oil and gas 

beneath Big Cypress National Preserve. 

The Big Cypress area is one of the lowest, youngest, and 

most geologically stable platforms of North America. 

This overall stability belies dynamic geologic processes at 

work on the landscape of South Florida. With its lowlying landmass, South Florida has been repeatedly 

submerged and exposed with variations in sea level over 

the past 50,000 years. Beneath the surface at Big Cypress 

are thousands of feet of roughly horizontal geologic 

layers that are rich in carbonate minerals. These minerals 

dissolve in rainwater and groundwater made acidic by 

decaying organic materials. Dissolution of 

interconnected spaces in the subsurface of South Florida 

ultimately results in a karst landscape defined by solution 

holes, sinkholes, disappearing streams, and springs. Such 

a landscape can store a great deal of water. 

From the late 1800s, human population has steadily 

increased in South Florida. Canals, ditches, dams, and 

levees drained swamps for agriculture, oil and gas 

exploration, and urban development. Thus people have 

forever altered the once- steady, slow flow of fresh water 

from Lake Okeechobee south to Florida Bay along the 

“River of Grass”—the Everglades. This ecosystem is 

rapidly changing and is threatened with destruction. 

A comprehensive, multiagency cooperative research 

effort is underway to restore water flow and preserve 

what remains of the once vast wetlands of South Florida. 

An increased understanding of geologic resources is 

important to these efforts at Big Cypress National 

Preserve. 

The subsurface rock units at Big Cypress produce oil and 

gas, the development of which has been and continues to 

be one of the key resource management issues that face 

park management. Roads leading to active production 

pads provide access to the remote heart of the preserve. 

These roads may also provide access for recreational 

vehicles. However, most access roads that lead to active 

oil and gas wells are not currently used by recreational 

vehicles except for crossing at designated locations. The 

Bear Island Grade in South Bear Island also allows 

street- legal vehicles on designated roads. The remote 

areas of the preserve are difficult to patrol, and 

widespread recreational use is destroying fragile habitat 

at the preserve. Abandoned oil and gas production pads 

require careful reclamation, and future exploration and 

drilling is always a possibility at the preserve. 

The following selected issues, features, and processes 

have geological importance and a high level of 

significance for resource management within the 

preserve: 

• The hydrogeologic system. 

The Big Cypress Swamp is a western extension of the 

Everglades hydrologic system. The Big Cypress basin 

provides approximately 42% of the water flowing into 

Everglades National Park and is a vast hydrologic 

network—among the least altered remaining in South 

Florida. Water flows on the surface in marshes and 

sloughs and below ground through porous substrate in 

aquifers. Big Cypress Swamp is a significant aquifer 

recharge area. In the wet season, approximately 90% 

of the preserve is inundated. Conditions in the dry 

season reduce this inundated area to approximately 

10% of the preserve. Understanding the hydrogeologic 

system at the preserve to is crucial to managing 

restoration efforts and predicting future conditions. 

• Oil and gas issues.

Oil and gas development has been ongoing at Big 

Cypress for over 50 years. These efforts pose a number 

of resource management issues, including increased 

access to the heart of the preserve, alterations and 

interruptions to the natural overland water flow, 

potential contamination of natural resources, and the 

presence of abandoned oil well pads and roads that 

require remediation. 

• Off-road-vehicle (ORV) management.

ORV use has been a recreational pastime at Big 

Cypress National Preserve for generations. Resource 

managers at the preserve are attempting to limit ORV 

use to designated areas. However, many sections of the 

preserve are remote and difficult to patrol. Areas 

affected by ORV trails are vast and require restoration. 

An understanding of the long- term effects of surface 

disturbance by ORVs would help in restoration efforts. 

• Disturbed Lands.

Disturbed lands include areas directly affected by oil 

and gas operations (e.g. well pads and access roads), 

borrow pits excavated for the construction of oil and 

gas pads, and roads built to access remote sites. 
 NPS Geologic Resources Division 2 

Introduction 

The following section briefly describes the National Park Service Geologic Resource 

Evaluation program and the regional geologic setting of Big Cypress National Preserve. 

Purpose of the Geologic Resource Evaluation Program 

The Geologic Resource Evaluation (GRE) Program is 

one of 12 inventories funded under the NPS Natural 

Resource Challenge designed to enhance baseline 

information available to park managers. The program 

carries out the geologic component of the inventory 

effort from the development of digital geologic maps to 

providing park staff with a geologic report tailored to 

their specific geologic resource issues. The Geologic 

Resources Division of the Natural Resource Program 

Center administers this program. The GRE team relies 

heavily on partnerships with the U.S. Geological Survey, 

Colorado State University, state surveys, and others in 

developing GRE products. 

The goal of the GRE Program is to increase 

understanding of the geologic processes at work in parks 

and provide sound geologic information for use in park 

decision making. Sound park stewardship relies on 

understanding natural resources and their role in the 

ecosystem. Geology is the foundation of park 

ecosystems. The compilation and use of natural resource 

information by park managers is called for in section 204 

of the National Parks Omnibus Management Act of 1998 

and in NPS- 75, Natural Resources Inventory and 

Monitoring Guideline. 

To realize this goal, the GRE team is systematically 

working towards providing each of the identified 270 

natural area parks with a geologic scoping meeting, a 

digital geologic map, and a geologic report. These 

products support the stewardship of park resources and 

are designed for non- geoscientists. During scoping the 

GRE team brings together park staff and geologic experts 

to review available geologic maps and discuss specific 

geologic issues, features, and processes. Scoping 

meetings are usually held for individual parks and on 

occasion for an entire Vital Signs Monitoring Network. 

The GRE mapping team converts the geologic maps 

identified for park use at the scoping meeting into digital 

geologic data in accordance with their innovative GIS 

Data Model. These digital data sets bring an exciting 

interactive dimension to traditional paper maps by 

providing geologic data for use in park Geographic 

Information Systems and facilitating the incorporation of 

geologic considerations into a wide range of resource 

management applications. The newest maps come 

complete with interactive help files. As a companion to 

the digital geologic maps, the GRE team prepares a parkspecific geologic report that aids in use of the maps and 

provides park managers with an overview of park 

geology and geologic resource management issues. 

For additional information regarding the content of this 

report and up to date GRE contact information please 

refer to the Geologic Resource Evaluation Web site 

(http://www2.nature.nps.gov/geology/inventory/). 

History and Overview of the Preserve 

Established on October 11, 1974, during Gerald Ford’s 

presidency, Big Cypress was the first national preserve 

incorporated into the National Park Service 

(16 U.S.C. § 689f et seq.). The preserve covers 720,567 

acres of a water- dependent ecosystem in southwestern 

Florida; it includes much of the western Everglades. 

Big Cypress National Preserve spans the area northwest 

of Everglades National Park (fig. 1). It stretches as far east 

as Shark River Slough and the Florida State Miccosukee 

Indian Reservation. The northern boundary is the Big 

Cypress Seminole Indian Reservation (north of Interstate 

Highway 75). The western boundary consists of Florida 

State Highway 29, the Fakahatchee Strand State Preserve, 

and the Florida Panther National Wildlife Refuge. The 

northerwestern boundary of Everglades National Park 

defines the southern edge. Together, these two National 

Park Service units cover the southern tip of the Florida 

peninsula and most of Florida Bay between the peninsula 

and the Florida Keys. 

Great biodiversity is characteristic of Big Cypress. 

Environments include sawgrass prairies, estuaries, 

mangrove forests, pinelands, cypress swamps (strands 

and domes), hardwood tree islands and hammocks, 

slow- flowing freshwater sloughs, and coastal marshes. 

As much as 90% of the preserve is inundated from May 

to October. 

The preserve is heavily used for recreation. It also 

contains two active oil and gas fields. 

Geologic Setting 

South Florida lies within the Atlantic Coastal Plain 

physiographic province. In the area of Big Cypress 

National Preserve, this province is divided into several 

subprovinces: Big Cypress Swamp, Everglades, Southern 

Atlantic Coastal Strip, Ten Thousand Islands, Florida 

Keys, and Southwestern Flatwoods (fig. 2) (Brooks 1981). 

The Big Cypress Swamp subprovince defines the western 

boundary of the Everglades subprovince. The rocks 

underlying this area are among the oldest in South 

Florida and are composed of silt, sand, and carbonate 

minerals. This area is slightly higher in elevation than the 

Everglades basin because it is underlain primarily by the 

coral- rich limestone of the Pliocene Tamiami Formation 

(3- 4 Ma), which is exposed in large areas of Big Cypress 
 BICY Geologic Resource Evaluation Report 3

National Preserve. Elevation in the Big Cypress Swamp 

ranges from 3.6 to 12 m (12 to 39 ft) above mean sea level 

in the northern reaches to just slightly above sea level in 

mangrove zones in the south. Drainage in the province is 

primarily to the south and southwest. 

The Everglades subprovince forms a south- dipping, 

spoon- shaped, low- lying area between the Southern 

Atlantic Coastal Strip to the east, and the Big Cypress 

Swamp to the west. The basin has very low relief. The 

elevation change is only 3.6−4.3 m (12−14 ft) from the 

maximum near Lake Okeechobee to sea level. Prior to 

the digging of canals and ditches and building of dams, 

flow in this drainage system was slow and steady from 

north to south. 

The Southern Atlantic Coastal Strip subprovince 

comprises Pleistocene marine limestone covered by thin 

sheets of quartz sand. The marine limestone is composed 

of tiny ooids of carbonate that longshore currents 

pushed into a linear ridge during the Pleistocene ice age. 

The subprovince ranges in elevation from 1.5 to 6 m (5 to 

20 ft) in the southernmost parts. The width of the linear 

ridge ranges from 16 km (10 mi) in southern Miami−Dade 

County to 5−8 km (3−5 miles) farther north. 

The southern parts of the ridge are breached in places by 

sloughs (transverse marshes) oriented perpendicular to 

the trend of the ridge. The subprovince wraps around 

the southern end of Florida containing vast tracts of 

coastal marshes and mangrove swamps. These 

environments cover an area from the northeastern part 

of Florida Bay, around the southern Florida peninsula, 

and west into the Gulf of Mexico as far as the Ten 

Thousand Island region near Everglades City. Strips of 

swamps and brackish marshes that are just above sea 

level characterize this area. Freshwater runoff and tidal 

fluxes cause the salinity to vary dramatically. The 

mangrove, capable of enduring such salinity changes, 

thrives in this area. 

The Ten Thousand Islands subprovince is along the 

southwestern edge of Big Cypress Swamp. Cast areas of 

mangrove forest, tidal sloughs, and open lagoons 

characterize this area. Seaward of the forest is a sand 

ridge which has built up above sea level. Miocene and 

Pliocene sedimentary rocks and sediments underlie the 

Southwestern Flatwoods subprovince to the north of Big 

Cypress Swamp. Recent deposits are thin or nonexistent. 

Landforms of this area include flatwoods, cypress 

swamps, rocklands, and marl plains. The Florida Keys 

contain long, narrow islands of limestone or carbonate 

sand and mud that stretch in an arcuate pattern from the 

southeastern tip of Florida to the Dry Tortugas. Coral 

rock underlies the northern keys. Between these 

limestone keys and the bioclastic, carbonate sand and 

mud of the Dry Tortugas are islands composed of oolitic 

limestone. 

 BICY Geologic Resource Evaluation Report 5

Figure 2: Map of physiographic subsections in South Florida as defined by Brooks (1981). Geographic data provided by St. Johns 

River Water Management District (http://www.sjrwmd.com; accessed February 21, 2006). Graphic is by Trista L. Thornberry-Ehrlich

(Colorado State University). 
 NPS Geologic Resources Division 6 

Geologic Issues 

A Geologic Resource Evaluation scoping session for Big Cypress National Preserve was 

held on January 27−28, 2005, to discuss geologic resources, to address the status of 

geologic mapping, and to assess resource management issues and needs. The following 

section synthesizes the scoping results, in particular those issues that may require 

attention from resource managers. 

Issues in this section are identified in relative order of 

resource management significance with the most critical 

listed first. Potential research projects and topics of 

scientific interest are presented at the end of this section. 

Hydrogeologic System at Big Cypress National 

Preserve 

The Big Cypress Swamp is a western extension of the 

Everglades hydrologic system. The Big Cypress basin 

provides approximately 42% of the water flowing into 

Everglades National Park (Dorney and Mott 1983). As 

part of the freshwater wetland, Big Cypress Swamp is a 

vast resource (Spiker et al. 1995). It is among the least 

altered hydrologic systems remaining in South Florida 

(Miller and McPherson 2001). Water flows on the surface 

in marshes and sloughs and below ground through 

porous substrate in aquifers. In the wet season, 

approximately 90% of the preserve is inundated, with 

water depths ranging from several centimeters to more 

than 0.9 m ( a few inches to 3 ft). Conditions in the dry 

season reduce this inundated area to approximately 10% 

of the preserve (Miller and McPherson 2001). 

As water level declines during the dry months, physical, 

chemical, and biological processes increase the rate of 

decomposition of organic matter. Similarly, the 

concentrations of organic waste, nutrients, and 

contaminants increase in the remaining surface waters 

(Miller et al. 2004). The environment at the preserve is 

dependent on the seasonal flow of non- polluted water 

across the landscape. Managing this flow is complicated. 

The present topographic and hydrogeologic information 

is too coarse and/or inadequate for resource 

management. More scientific study and modeling is 

necessary to understand the true water budget of the 

preserve. 

Water quality is an important management issue at Big 

Cypress National Preserve. The wetland soils and 

sediments, in addition to being a reservoir of water and 

nutrients, also contain a record of information about the 

system, including changing vegetation, biogeochemistry, 

predevelopment conditions, and increased human 

influences (Spiker et al. 1995). In sediment samples 

collected from the Barron River Canal and Turner River, 

lead, copper, zinc, normalized aluminum, phthalate 

esters, arsenic, cadmium, and zinc were higher than 

background levels. 

Pesticides, mercury, polynuclear aromatic hydrocarbons, 

and p- cresol were also detected in sediments within the 

preserve (Spiker et al. 1995; Miller and McPherson 2001). 

These contaminants are likely anthropogenic in origin, 

stemming from roads, vehicular traffic, encroaching 

development, an old creosote wood- treatment facility, 

and agriculture. Chloride concentrations in nearby 

Taylor and Shark River Sloughs doubled from 1960 to 

1990 and the pesticide Atrazine is present in the waters at 

Big Cypress (Miller et al. 2004). It is unknown what 

collective effect these contaminants have on the 

ecosystem at Big Cypress. 

The construction of roads, trails, oil pads, canals, and 

levees has altered the flow of water through the preserve. 

State and local water extraction policies control a vast 

proportion of water input to Big Cypress Swamp. 

Pumping can control basin groundwater dynamics. A 

major goal of the preserve is the restoration of the 

original flowways as closely as possible (Scoping 

participants 2005). A focus area is in- channel 

construction near U.S. Highway 41 in the Turner River 

basin (9−12 m [30−39 ft] wide). Restoration efforts 

include reconnecting flows through canals and under 

roads (building causeways). The Bear Island area is 

another area to focus restoration efforts. Cooperation is 

necessary between resource managers and local agencies 

that control water volume to coordinate and organize the 

timing of gates and pumps. 

Hydrostratigraphic studies of cores within the preserve 

(including time domain electromagnetic [TDEM] and 

direct- current [DC] resistivity) suggest the geologic 

framework and aquifer system beneath Big Cypress 

Swamp is complex (Shoemaker 1998). Due to karstic 

dissolution, most of Florida acts as a limestone sponge, 

storing and moving groundwater through underground 

conduits. Big Cypress Swamp is a recharge area for the 

aquifers (Dorney and Mott 1983). The interaction 

between groundwater flow and the overall ecological 

quality of freshwater must be quantitatively determined 

at Big Cypress National Preserve. The karst aquifer 

system of South Florida is open to recharge of water 

from precipitation, surface flow, and man- made 

diversions (such as canals, ditches, ponds). The 

underlying Tamiami Formation forms part of the near 

surface aquifer beneath Big Cypress National Preserve. 
 BICY Geologic Resource Evaluation Report 7

Understanding the nature of the hydrologic exchange 

between surface and ground waters is critical to 

understanding the movement of water and dissolved 

nutrients, wastes, metals, and other substances in the Big 

Cypress ecosystem (Bruno et al. 2003). 

Various hydrogeologic models of regional water flow 

have been used to characterize Big Cypress National 

Preserve. These models have varied in their success. The 

South Florida Water Management Model (SFWMM) 

ignores roads and uses an outdated climatic scheme. The 

Natural Systems Model (NSM) uses vegetation patterns 

to predict an improved pseudotopography. The Across 

Trophic- Level System Simulation (ATLSS) correlates 

species with hydrology, hydroperiod, and vegetation. 

The Everglades Landscape Model (ELM) covers the 

hydrology of bounded systems of canals and structural 

control with rain- driven triggers. The Interim Structural 

and Operational Model (ISOP), which was slated for 

implementation in 2007- 8, is probably the closest to 

successfully modeling the water budget needed to 

manage the preserve, but it still uses core data from the 

SFWMM model. Cell size (minimum mappable unit) and 

vertical precision vary on these models from 3.2 km (2 

mi) to 30 m (100 ft) and from 15 to 3 cm (6 to 1 in.), 

respectively. Lidar surveys would vastly improve the 

vertical precision (Scoping participants 2005). 

Inventory, Monitoring, and Research Needs for the 

Hydrogeologic System 

• Study the spatial distribution of rainfall and its effects 

on the hydrologic system. 

• Use flow studies and depth- to- bedrock 

measurements to determine quantifiable relationships 

between the water budget and substrate thickness. 

• Compare hydraulic changes in the surface and 

groundwater flow at Big Cypress National Preserve 

caused by natural processes with those caused by 

anthropogenic alterations. 

• Monitor hydrologic response to storm events. 

• Continue to support sediment sampling to determine 

baseline conditions and monitor changes in 

contaminant levels (Miller and McPherson 2001). 

• Cooperate with regional lidar mapping efforts to 

obtain surveys of sloughs at Big Cypress National 

Preserve for small- scale topographic changes. 

• Increase hydrologic sampling and install hydrologic 

monitoring stations in key locations. 

• Determine more stage- level measurement points; 

determine baseline conditions and continuously 

monitor stage levels, especially related to spatial and 

seasonal variations. 

• Seek further support from the Comprehensive 

Everglades Restoration Program (CERP) efforts. 

• Cooperate with federal, state, and local agencies to 

monitor and clean up ground and surface water; 

examples of pollution include creosote (from 

Copeland sawmill in the 1960s) and agricultural runoff 

(including pesticides from tomato farms). 

• Map and study karst landscapes and features in and 

surrounding Big Cypress National Preserve to 

determine the nature of Deep Lake (27 m, or 89 ft, 

deep), the southernmost sinkhole in Florida (fig. 3). 

• Focus geologic studies on geomorphologic processes 

and biologic influences rather than just on surficial 

features. 

• Categorize, describe, and model the near- surface, 

mid- and deep aquifers below Big Cypress National 

Preserve. 

Oil and Gas Issues 

When Big Cypress National Preserve was created in 1974 

and additional lands were added to the preserve in 1988, 

surface ownership within both areas was acquired by the 

U.S. government. Private entities or the State of Florida 

retained the subsurface mineral rights on these lands, 

with private entities retaining most (approximately 99%) 

of these rights. The federal government does not own 

any of the subsurface oil and gas rights in the preserve, 

yet the NPS is required by its laws, policies, and 

regulations to protect the preserve from any actions, 

including oil and gas operations, that may adversely 

impact or impair park resources and values. 

Management of oil and gas activities within the original 

preserve are guided by a Minerals Management Plan 

(MMP) prepared in 1991. The MMP does not apply to 

the addition lands. Preserve staff are currently preparing 

an Oil and Gas Management Plan to address oil and gas 

exploration and development throughout the entire 

preserve, as well address new technologies, regulations, 

NPS policies and orders, and scientific information that 

have come about since development of the 1991 MMP. 

Oil and gas exploration began in south Florida in 1923. 

The first oil discovery in south Florida occurred 

northwest of the preserve in 1943 with the discovery of 

the Sunniland field. The most active drilling period was 

in the mid 1970s. The main petroleum- producing 

geologic unit is the Sunniland Formation. Over 200 wells 

have been drilled along the northwest- southeast 

oriented Sunniland trend. 

Today oil and gas exploration in the preserve is rapidly 

declining. As of August 2007, there were 14 wells 

producing from 8 fields along the trend. Eight of these 

producing wells are located within the preserve at the 

Raccoon Point and Bear Island fields. Through 

November 2007, cumulative production from these two 

fields totaled 30.5 million barrels of oil and 3.2 billion 

cubic feet of natural gas (http://www.dep.state.fl. 

us/geology/programs/oil_gas/prod_report/nov_2007_fla

_mon_prod.xls accessed February 2008). 

Oil and gas wells in the preserve are directionally drilled 

from four common pads. In addition to the two oil fields, 

located entirely or partly within the preserve boundaries, 

there are two small, inactive fields—Pepper Hammock 

and Baxter Island. As of 2007, with the exception of one 

inactive disposal well, south Bear Island wells have been 

plugged and abandoned (Don Hargrove, written 
 NPS Geologic Resources Division 8 

communication 2007). Other significant fields, such as 

the Sunniland, Seminole, and Forty Mile Bend fields, are 

located within the greater Big Cypress Swamp drainage 

and therefore have relevance to park resource 

management (Pollastro et al. 2000). 

The oil and gas reservoir rocks have 10−30% porosity. 

They are composed of carbonate grainstone (oyster 

shoals) and dolomite sealed by evaporites and/or 

nonporous carbonate minerals. The overall success rate 

of drilling based on two- dimensional seismic surveys 

and on gravity and magnetic data has been about 3%. 

(Norby 2005). 

Drilling and production activities in Big Cypress 

National Preserve have created a large environmental 

footprint in the form of roads, well pads, and production 

facilities. The pads and roads left behind when a well is 

plugged and abandoned leave a large scar on the 

landscape and affect the hydrologic system at Big 

Cypress (figs. 4 and 5). Roads built of borrow pit material 

are elevated above the surrounding drainage. Culverts 

are irregularly spaced, and many are in disrepair (fig. 6). 

These roads also provide access for off- road vehicles 

and impact a larger area of the preserve. However, most 

access roads that lead to active oil wells do not allow 

recreational vehicle use except for crossing at designated 

locations. The Bear Island Grade in South Bear Island 

allows street- legal vehicles on designated roads (Don 

Hargrove, written communication 2007). The 

responsibility for monitoring, compliance with 

regulations, restoration, and remediation is often 

unclear, and pipes, wells, and structures remain at 

abandoned pads. 

Reclamation of access roads and oil well pads, and 

removal of flow lines, drilling pads, and equipment 

infrastructure are the responsibility of the operator (36 

CFR § 9.38). The NPS Nonfederal Oil and Gas Rights 

regulations cover nonfederal oil and gas operations in 

NPS units. Operations that are not covered by an 

approved plan of operations must meet reclamation 

requirements as described in 62C – 25- 30 (Florida 

Administrative Code) and are subject to federal 

regulatory authority (Don Hargrove, written 

communication 2007). 

Inventory, Monitoring, and Research Needs for Oil and Gas 

Issues 

• Continue work with the Geologic Resources Division 

to develop a new oil and gas management plan. 

• Work with Geologic Resources Division on current 

and proposed oil and gas exploration and 

development activities to avoid and mitigate adverse 

impacts. 

• Collect depth- to- bedrock measurements to provide 

stratigraphic information available to preserve 

resource managers. Such data may be available 

through cooperative efforts with drilling and seismic 

survey teams. 

• Obtain seismic information to incorporate into GIS. 

Private mineral owners are not required to share their 

propietary seismic information with the NPS so it may 

be difficult to obtain this data. 

• To aid reclamation efforts and reduce the use of 

quarried rocks, use road and pad fill from abandoned 

oil wells to construct new trails and develop areas for 

visitor use 

ORV Management 

In 2005, more than 400,000 visitors came to the preserve 

for recreational purposes. Recreational activities include 

camping, kayaking, hiking, bird watching, canoeing, 

hunting, off- road- vehicle (ORV) use, and airboat access. 

A significant issue for resource management at the 

preserve has been public access to remote areas (Dorney 

and Mott 1983). ORV and airboat use have been popular 

recreational activities in the preserve for many years, the 

type of vehicle evolving with increased access to wild 

areas of the preserve. The preserve is attempting to 

concentrate visitor access and reduce environmental 

impacts from visitation. 

An ORV management plan, completed in 2001, requires 

all ORV users to obtain a permit (quota is 2,000), 

specifies time restrictions, controls ORV types, and 

mandates a restriction to 644 km (400 mi) of trails in the 

preserve. It is estimated that at least 35,000 km (22,000 

mi) of trails currently exist throughout the preserve. 

ORVs must depart from designated access points. 

Sensitive areas such as marl prairies, Cape Sable, the 

Loop and Deep Lake Units, and areas south of lower and 

upper Wagonwheel Road are closed. Seasonal closures 

(of about 60 days) are planned for rest and restoration of 

resources (NPS 2006). Management and enforcement of 

established trails and ORV activity is difficult for rangers 

on duty at Big Cypress National Preserve: The preserve is 

the size of Rhode Island, and many areas are too remote 

to patrol regularly. 

ORV use at Big Cypress has caused and continues to 

cause major damage to the hydrology, water quality, and 

soils. Extensive areas of marl prairies within the preserve 

are being irreparably rutted (Rice et al. 2003). By 

churning and burying the substrate, buggies and other 

ORVs destroy living algae (terraphytes) populations in 

the soils. The entire ecosystem is based on these 

microorganisms, which lie dormant in dry conditions. 

When they are churned up and buried by passing ORVs, 

the landscape loses its capacity to support native 

vegetation. Soil characteristics, chemistry, depth, 

structure, and resiliency at the preserve are not well 

understood and merit further study. 

Most of the access roads in the preserve are elevated, 

constructed with gravel, and pebbles with intermittent 

drainage culverts (fig. 7). Raised roadbeds across South 

Florida have impeded the natural, low- relief, slowmoving sheet- flow from Lake Okeechobee to Florida 

Bay. 
 BICY Geologic Resource Evaluation Report 9

In addition, access to the heart of the Big Cypress 

National Preserve has increased due to seismic 

exploration and production activities. Roads leading into 

pristine areas of the preserve, such as Raccoon Point, to 

access oil production pads, now allow ORV users to 

access wild areas of the preserve more than ever before 

(fig. 8). ORV users have largely thwarted attempts to gate, 

block, and/or patrol these access roads (Dorney and 

Mott 1983). Active oil and gas access roads are prohibited 

for ORV use. At present, gates, regulations, and law 

enforcement attempt to mitigate potential impacts from 

use of unauthorized ORVs on these roads. Today there 

are few documented violations of use of access roads to 

active wells. Only the oilfield operator and contractors, 

state and federal administrative officials, researchers, and 

fire fighters have authorized access to these roads (Don 

Hargrove, written communication 2007). 

In addition to overuse by traditional buggies and ORVs, 

unauthorized airboat use is also a resource management 

issue affecting water quality, plant and animal 

populations, noise levels, and marshy soils. The ORV 

management plan contains specific regulations regarding 

airboat access and vessel requirements (NPS 2006). 

Inventory, Monitoring, and Research Needs for ORV 

Management 

• Using land- use patterns mapped in a GIS, determine 

the best sites for a designated trails system. 

• Study cores of sediments containing a pollen record 

within ORV- affected areas to determine local 

vegetation differences (distribution and abundance) 

that result from anthropogenic activity (Willard et al. 

1996). 

Geologic and Topographic Mapping 

Water flowing through the natural Everglades slowly 

trickles down to the sea from central Florida. This water 

exits the south shore of Lake Okeechobee, travels 160 km 

(100 mi) and drops only 6 m (20 ft) to the southern 

terminus at Florida Bay (Dorney and Mott 1983). The 

gradient at Big Cypress National Preserve is 

approximately 6 cm/km (2 in/mile), or 4.6 m over 145 km 

(15 ft over 90 mi). This low relief allows for the 

development of plentiful sloughs, swamps, and marshes 

at Big Cypress. 

Geologic units and structures in the subsurface and 

surficial variations in rock unit composition, bedding 

structures, and sediment thickness control the minor 

changes in relief at Big Cypress National Preserve. 

Interdisciplinary, large- scale geologic mapping would 

help determine the effect of these parameters on the 

water budget at Big Cypress. 

Combining spatial geologic information with current 

vegetation patterns, anthropogenic landscape alterations, 

and high- resolution topographic mapping data would 

provide resource managers with a powerful tool for 

analyzing interrelationships between these systems. 

Incorporated into a GIS, this information may aid 

resource managers in targeting areas for restoration, 

preservation, and visitor use. 

Inventory, Monitoring, and Research Needs for Geologic 

and Topographic Mapping 

• Study the correlation of small topographic differences 

with the locations of hardwood hammocks and 

pinelands at the preserve. 

• Map exposures of Tamiami Limestone, including 

compositional variations and bedding structures. 

• Focus on key areas for topographic mapping and 

construction of cross sections (coordinate with the 

original flow- way restoration efforts). 

• Incorporate mapping of karstic dissolution features 

into surveys of canals and locations of rock pits. 

• Cooperate with the slough- mapping project through 

the Audubon Society. 

• Describe in greater detail the type section for the 

Tamiami Formation, which is located within the 

preserve. Further, define unit composition, structures, 

bioturbation, and sedimentary features. 

• Using current maps of strands and paleochannels, 

determine through analysis in a GIS if these features at 

Big Cypress are related. 

• Using new geologic and topographic mapping, attempt 

to determine why the boundary between Big Cypress 

and The Everglades is distinctive. Also, use this 

information to determine the nature of the boundaries 

between strands. 

• Support studies to create Digital Elevation Models 

(DEMs) which could help determine original flow 

ways. 

• Promote more interagency (e.g., U.S. Geological 

Survey, Bureau of Land Management, Natural 

Resources Conservation Service, South Florida Water 

Management District, Florida Department of 

Transportation) cooperative geologic mapping 

projects. 

Disturbed Lands 

Human activities have led to the deterioration of the 

stability, biodiversity, extent, and productivity of the 

freshwater wetland ecosystem of South Florida (Spiker et 

al. 1995). Agricultural activities and flood control, 

including the diversion of water through canals, ditches, 

and levees, have altered the hydrology of the region and 

limited freshwater flushing of Florida Bay, south of Big 

Cypress National Preserve. Many of these anthropogenic 

structures and activities are outside the preserve but have 

a lasting effect on the ecosystem within it. 

The preserve itself contains hundreds of sites where fill 

was either excavated or brought in to elevate the area. As 

the preserve boundaries continue to change, additional 

disturbed areas will undoubtedly need to be inventoried 

and remediated. Some sites have been mapped and 

incorporated into a GIS to measure type of fill (debris 

such as trash, stones, building material), depth of fill, 
 NPS Geologic Resources Division 10 

volume of fill, and other site characterization (NPS 

2006). 

Disturbed lands include areas directly affected by oil and 

gas operations (pads and fields), borrow pits excavated 

for the construction of oil and gas pads, and roads built 

to access remote sites. Access roads may pose the largest 

lasting threat to the hydrologic system at Big Cypress 

National Preserve because they interrupt water flow, 

introduce contaminants associated with motorized 

vehicles, and permit access to the heart of the preserve. 

Inventory, Monitoring, and Research Needs for Disturbed 

Lands 

• Quantitatively identify disturbed sites and explore 

remediation possibilities to restore natural water flow. 

• Remove and remediate the access roads to the Bear 

Island oil field and other remote, unused areas. 

• Remediate borrow pits. Use recycled paving materials 

for building future visitor facilities. 

• Focus on roads perpendicular to the overall direction 

of water flow, research ways to build bridges and 

culverts along established (permanent?) roads to 

restore natural flow conditions. 

Figure 3. Deep Lake, Big Cypress National Preserve, the southernmost large sinkhole in Florida. Photograph is by Trista L. ThornberryEhrlich (Colorado State University). 
 BICY Geologic Resource Evaluation Report 11

Figure 4. Remains of oil and gas extraction operations at an oil pad in Big Cypress National Preserve. Photograph was taken in 2005. 

This pump station at South Bear Island has since been removed by Enron, but other still exist within the preserve (Don Hargrove, 

written communication 2007). Photograph is by Trista L. Thornberry-Ehrlich (Colorado State University). 

Figure 5. Abandoned oil pad at Big Cypress National Preserve. Photograph was taken in 2005. This operation at South Bear Island has 

since been removed by Enron, but other still exist within the preserve (Don Hargrove, written communication 2007). Photograph by 

Trista L. Thornberry-Ehrlich (Colorado State University). 
 NPS Geologic Resources Division 12 

Figure 6. Rusting culvert along an access road to an oil pad at Big Cypress National Preserve. Photograph by Trista L. ThornberryEhrlich (Colorado State University). 
 BICY Geologic Resource Evaluation Report 13

Figure 7. Intact culverts along an access road within Big Cypress National Preserve. Photo is taken from the road. Note the height of 

the road above the water level and the degree of ponding behind the roadway. Photograph by Trista L. Thornberry-Ehrlich (Colorado 

State University). 
 NPS Geologic Resources Division 14 

Figure 8. Rutted ORV trail through the forest near the western boundary of Big Cypress National Preserve. Photograph by Trista L. 

Thornberry-Ehrlich (Colorado State University). 
 BICY Geologic Resource Evaluation Report 15

Geologic Features and Processes 

This section describes the most prominent and distinctive geologic features and processes 

in Big Cypress National Preserve. 

Freshwater Sloughs and Strands 

Water is the predominant resource at Big Cypress 

National Preserve. Water at the preserve does not flow in 

well- defined streams and rivers (NPS 2006). Instead, 

water flows around elongated bands of cypress trees 

called “strands,” cypress domes, and through extensive, 

meandering marshy areas referred to as “sloughs” that 

characterize the Big Cypress Swamp (Miller et al. 2004). 

Cypress swamps are present in areas that are 

continuously inundated for 240 to 290 days annually 

(National Audubon Society 2006). Nearly 150 cm (59 in.) 

of rainfall each year floods the cypress strands and 

prairies before slowly flowing over the surface and 

through sloughs towards Everglades National Park (NPS 

2006). This rainfall supplies the watershed, and the slow 

flow rates allow recharge to the surficial aquifer within 

the preserve. 

In the southeastern United States, a slough refers to a 

type of swamp or shallow lake system that is similar to a 

bayou with trees (Neuendorf et al. 2005). At Big Cypress 

National Preserve, a slough forms where the surface of 

the ground coincides with the shallow water table (fig. 9). 

Sloughs are a critical source of fresh water for wildlife, 

especially during seasonal droughts. Sloughs also 

accumulate nutrients for soils and vegetation (Taylor 

Schoettle 2006). 

Shark River Slough separates Big Cypress National 

Preserve from the northwestern corner of Everglades 

National Park. Other large sloughs in the preserve 

include Dixons, Lostmans, Dayhoff, Gum, Bamboo, 

Mullet, Okaloacoochee, and California. These broad, 

slow- moving waterways separate higher, treesupporting strands such as Sig Walker, Cow Bell, 

Kissimmee Billy, Sweetwater, Roberts Lakes, Gator 

Hook, Gannet, Monroe, New River, Georges, Skillet, 

East Crossing, and Deep Lake. The strands and sloughs 

at Big Cypress are all parallel and trend more or less 

northeast to southwest. 

Cypress trees cover approximately one- third of the 

preserve, in many places lining the sloughs in strands 

(NPS 2006). Strands form where high water level and 

sufficient flow result in a channel along a depression 

(USDA Forest Service 2006). Most of these trees are 

dwarf pond cypress (Taxodium distichum), with a few 

areas of giant, bald cypress trees, some of which are 

600−700 years old. 

The cypress may also be present in cypress domes, mixed 

hardwood and cypress swamps, and “hatrack” cypress (a 

dwarf species) communities. Cypress domes are 

relatively small, discrete areas of freshwater swamp 

dominated by bald cypress trees. 

The term “dome” refers to the characteristic 

configuration of larger trees growing in the center of the 

area with progressively shorter trees growing towards 

the edges. These domes and forests tend to coincide with 

solution collapse (karst processes) of near- surface 

limestone caprock. The depression collects nutrients and 

allows deeper root penetration for larger tree species 

(NPS 2006; USDA Forest Service 2006). 

South Florida Basin and the Sunniland Trend 

Big Cypress National Preserve lies within the 

northeastern part of the South Florida basin (200,000 

km2

, or 80,000 mi2), the thickest part of which is 

northwest of the Florida Keys, beneath Florida Bay. 

Deposition of mixed carbonate, evaporite, and clastic 

sediments in the subsiding basin has been more or less 

continuous since the Late Jurassic. Several large, positive 

structural features surround the basin: the Florida 

escarpment to the west (a major barrier reef complex 

that separates the Florida Shelf from the deep Gulf of 

Mexico basin), the Peninsular arch to the east, the Pine 

Key arch to the southeast, and the Tampa- Sarasota arch 

to the northwest (fig. 10). The most prominent of these—

the Peninsular arch—is a crystalline basement feature of 

Paleozoic age that plunges south- southeast along the 

length of the Florida Peninsula. This arch controlled the 

deposition patterns of Jurassic and Cretaceous 

sediments. Beneath South Florida, units of these ages 

onlap, wedge, or pinch out against the arch (Pollastro et 

al. 2000). 

The Sunniland Formation is among the Cretaceous units 

that pinch out along the Peninsular arch (fig. 11). The 

sediments that became the Sunniland Formation were 

deposited in tidal shoals and carbonate reef 

environments; the lower beds of the formation contain 

fractured carbonate rubble (Norby 2005). The Sunniland 

is sealed below and above by the salt and evaporite 

deposits of the Punta Gorda Anhydrite and the Lake 

Trafford Formation, respectively (fig. 12) (Pollastro et al. 

2000) and have been found to trap hydrocarbons along 

the Sunniland Trend in south Florida 

The Sunniland and Dollar Bay Total Petroleum System is 

32 km (20 mi) wide and 240 km (150 mi) long; it trends 

northwest to southeast through Lee, Hendry, Collier, 

and Dade Counties and passes through the north and 

east boundaries of Big Cypress National Preserve. The 

petroleum is located at depths of between 3,350 and 

3,660 m (11,000 and 12,000 ft) below the surface. The 
 NPS Geologic Resources Division 16 

porous reservoir developed on a subtle structural high 

within the Sunniland Formation. 

More than 200 wells in 14 fields (8 of which are still 

active) have been drilled along the Sunniland trend. It is 

estimated that Big Cypress National Preserve covers 6% 

of the trend. Other exploration continues in a second 

defined petroleum system, the Pre Punta Gorda Total 

Petroleum System (4,570−4,880 m [15,000−16,000 ft] 

deep). This second system is part of the Wood River 

Formation, which contains lower Cretaceous dolomite 

and clastic rocks. The Wood River pinches out against a 

structural high, creating a natural trap for petroleum 

storage. Big Cypress National Preserve covers 8% of the 

area of this system (Norby 2005). 

Sinkholes and Karst 

“Karst” is a term for a characteristic terrain produced by 

the chemical erosion of carbonate rocks such as 

limestone or dolomite. Acidic water reacts with 

carbonate rock to dissolve it along cracks and fractures. 

Most meteoric water (precipitation), so- called acid rain, 

is of relatively neutral pH and becomes more acidic as it 

flows through decaying plant debris and soils (Florida 

Geological Survey 2005). 

Most of the limestone and dolomite in South Florida are 

inherently porous. Over hundreds of thousands of years, 

dissolution within intergranular pores and along 

fractures has created increasingly larger voids (fig. 13). 

The system of underground voids in South Florida is 

extensive. Collapse of overlying rock and soil into a void 

produces a sinkhole such as Deep Lake at Big Cypress 

National Preserve. If the sinkhole develops in a 

streambed, it may capture the water flow and thus create 

a disappearing stream. 

When groundwater, under hydraulic pressure, 

discharges from an underground drainage system, a 

spring is formed (Florida Geological Survey 2005). In 

areas of dense karst terrain, solution holes generally 

provide preferential pathways for water and 

contaminants to reach the underlying aquifers (Arthur et 

al. 2005) 

At Big Cypress National Preserve, the predominant 

geologic units exposed at the surface are the Miami 

Limestone and the Tamiami Formation. The Pleistocene 

Miami Limestone is ≈125 – 130 ka and contains two facies, 

the oolitic facies and the bryozoan facies (Cunningham 

2005). The Pliocene Tamiami Formation is ≈4.1 – 2.1 Ma 

and composed of mixed carbonate and siliciclastic rocks. 

This unit is very complex and contains several aquifers as 

described below (Scott 2001). The carbonate- rich layers 

in these units are highly susceptible to dissolution from 

acidic rain and groundwater. 

The extensive carbonate rocks of Florida have been 

exposed to terrestrial weathering processes since the last 

significant interglacial period led to the flooding of the 

Florida platform some 130,000 years ago. Since that time, 

much of the original rock has been altered and/or 

dissolved by acidic rainwater and groundwater 

undersaturated with respect to calcium carbonate. 

Large solution holes formed in the Miami Limestone 

when sea level and the water table were lower than 

present levels. 

As sea level has risen during the Holocene (a trend that 

continues in South Florida), many of the solution holes 

at lower elevations have filled with organic material and 

marl. As organic material continues to decay, lowering 

the pH of the groundwater with addition of carbonic 

acid, dissolution of the near- surface limestone will also 

continue at Big Cypress National Preserve. Deep Lake is 

the southernmost identified sinkhole in Florida, but 

others are likely to form when overburden collapses in 

areas throughout the preserve. Continued research is 

necessary to determine the degree of active dissolution 

and the connectivity between subsurface conduits. 

Hydrogeology 

Possibly the most distinctive features of the South 

Florida wetland ecosystem are the gently sloping 

landscape and its large capacity for long- term water 

storage. Prior to anthropogenic alterations and water 

management practices, water flowed very slowly through 

the system, buffering the ecosystem from extreme 

changes caused by droughts and floods. Understanding 

this system means understanding the relationship 

between geology and water flow at Big Cypress National 

Preserve (Florida Department of Environmental 

Protection 2005). 

“Hydrogeology” refers to the study of groundwater 

movement with specific emphasis on its relation to the 

surrounding geology, modes of movement, and water 

chemistry (Florida Geological Survey 2005). This study 

combines hydrology, geology, chemistry, physics, 

biology, mathematics (modeling), and engineering to 

understand the characteristics of groundwater 

movement in the complex and enigmatic subsurface. 

Groundwater is the most available source of potable 

water in South Florida. Water- bearing rocks at Big 

Cypress National Preserve include carbonate limestone, 

sandstone, and dolostone (a rock rich in dolomite, a 

carbonate mineral). As described above in connection 

with karst, the carbonate rocks in the subsurface are 

extensively dissolved and highly permeable, meaning 

that water is able to flow freely through the rock (Florida 

Geological Survey 2005). 

A zone in the subsurface in which groundwater collects 

is referred to as an aquifer. A viable aquifer typically 

yields water in sufficient quantities to support agriculture 

and domestic use, for example. Aquifers are classified as 

unconfined, confined, or semi- confined on the basis of 

the physical parameters that define the aquifer. 

Unconfined aquifers have the general water table as an 

upper boundary. Unconfined aquifers are open to 

meteoric water filtering through the soil and subsurface 

and are thus susceptible to pollution from agricultural 
 BICY Geologic Resource Evaluation Report 17

and domestic use. A confined aquifer is any waterbearing layer that is sandwiched between two aquitards, 

layers of rock that are so impermeable they cannot 

transmit useful amounts of groundwater (Idaho 

Geological Survey 2006). Semi- confined aquifers have 

characteristics of both confined and unconfined aquifers 

in different places. 

The Florida aquifer system contains all three types of 

aquifers described above. This system underlies all of 

Florida and is the main source of water for most human 

use (Florida Geological Survey 2005). This system is 

located at different stratigraphic levels in the subsurface. 

The unconfined surficial aquifer (often referred to as the 

Biscayne aquifer in South Florida) comprises karstic 

platform carbonate rocks of the Pleistocene Miami 

Limestone and other Holocene to Pleistocene sandstone 

units (Cunningham 2004a, 2004b). The high porosity and 

permeability of these units allows considerable exchange 

between surface and ground waters (Bruno et al. 2003). 

In some parts of South Florida, a cap rock cover on the 

porous limestone controls the surface flow of water and 

its subsequent infiltration of the groundwater. Cap rock, 

bedrock structures (pinnacles), and dissolution features 

such as solution cavities, buried sinkholes, and conduit 

networks complicate hydrogeologic modeling at the 

preserve (Kruse et al. 2000). 

At various stratigraphic levels below the surficial aquifer, 

other aquifers and aquitards create a complex system of 

layered water- bearing units. Terminology for these units 

varies depending on specific location. There are at least 

three aquifers (including the surficial aquifer) divided by 

three aquitards in the upper geologic units below Big 

Cypress National Preserve (fig. 14; model from Wexler 

2004). 

A significant aquifer lies within the Tamiami Formation. 

This aquifer, referred to as the Gray Limestone Aquifer, 

is being studied as a possible potable water resource for 

South Florida. The upper and lower confining units are 

predominantly clastic mud, sand, and clay (Shoemaker 

1998). This aquifer is less permeable than the surficial 

aquifer and located at depths that vary over short 

distances. The depth to the base of this aquifer decreases 

from 45 m (150 ft) in eastern Collier County to 15 m (50 ft) 

in western Collier County. This variability requires 

careful and thorough study to understand the nature of 

the aquifer (Shoemaker 1998). 

With the recent funding of the Comprehensive 

Everglades Restoration Plan (CERP), innovative and vital 

studies are underway to understand the changes in the 

natural habitats of The Everglades and, by extension, Big 

Cypress National Preserve, as a result of human 

activities. The CERP includes restoration of natural 

patterns of water flow. Data related to the hydrogeologic 

system at Big Cypress National Preserve, as a major 

contributor to the water budget of The Everglades, is 

critical to this goal. 

The CERP is a cooperative effort of the National Park 

Service, National Oceanic and Atmospheric Association, 

U.S. Geological Survey, Florida Department of 

Environmental Protection, South Florida Water 

Management District, U.S. Army Corps of Engineers, 

Florida Geological Survey, South Florida Natural 

Resources Center, and Florida International University, 

among others (Loftus et al. 2001; South Florida Water 

Management District 2002). 

Hardwood Hammocks 

Hardwood hammocks are areas of closed canopy forests 

of dense vegetation dominated by evergreen and semideciduous tree and shrub species (U.S. Fish and Wildlife 

Service 2007). Hammocks in the Big Cypress National 

Preserve include the Tamarind, Hess, Dr. Tiger, and 

Coconut Hammocks. At the preserve, as well as in 

neighboring Everglades National Park, the hammocks 

contain some of the rarest and most unusual plant and 

animal species in South Florida. In the northern 

hammocks more than 100 species of trees and shrubs, 

ranging from red maple and laurel oak trees in the lower 

hammock areas to live oak and cabbage palm in the 

higher parts, can be found. To the south, tropical species 

such as strangler fig, wild tamarind, pigeon plumb, 

gumbo limbo, poisonwood, coco plum, redbay, and 

other broad- leaved tropical trees and shrubs dominate 

the hammocks (McPherson et al. 1976). Major hammock 

types include 1) rockland hammock “islands” on 

limestone substrate in or on the edges of pine rockland 

or marl prairies, 2) Keys rockland hammock on 

limestone substrate (Florida Keys), 3) coastal berm 

hammock on storm- deposited berms, 4) tree island 

hammock in Everglades marsh and marl prairies, 5) shell 

mound hammock on aboriginal sites (U.S. Fish and 

Wildlife Service 2007). 

The existence of the hammocks is dependent upon the 

underlying geology and hydrogeologic processes. 

Hammocks develop on land that is slightly higher than 

that of the surrounding marshes and prairies. In South 

Florida, this elevation difference is generally less than 3 ft 

(1 m). Hammocks develop slowly because organic 

material must build up over many years to create a 

topographic high (McPherson et al. 1976). Soils of 

hammocks are typically moist, but rarely inundated (U.S. 

Fish and Wildlife Service 2007). Of interest to cultural 

resource studies, this higher land supported ancient 

human occupations such as the Calusa Indians, as 

evidenced by pottery fragments, metal containers, shell 

mounds, burial sites, and planted exotic species 

(McPherson et al. 1976). Aboriginal garbage mounds and 

mollusk shell mounds in turn provided a foundation for 

hardwood, closed canoy forest development (U.S. Fish 

and Wildlife Service 2007). 

Bay heads, precursors to hammocks, are tree islands 

dominated by broad- leaved, evergreen, and swamp 

hardwood species. These areas occupy high peat benches 

above the surrounding marsh. Bay heads often develop at 

solution holes or depressions in the solid bedrock. Peat 

and other organic materials accumulate in the 
 NPS Geologic Resources Division 18 

depressions and nurture the development of larger trees 

and forests. Peat continues to accumulate until a 

topographic high is created (see fig. 13). If the peat is not 

lost to fires, hardwood hammocks ultimately develop. 

Hammock forests are a climax community of plants 

developed in the long- standing absence of fire. Deeper 

water and/or high humidity produce dense vegetation 

that shelters the hammocks from fire. Any hammocks on 

limestone substrates, such as those in Big Cypress Swamp 

are dependent on the underlying water table to keep 

humidity levels high (U.S. Fish and Wildlife Serviece 

2007). However, temperature and salinity can limit the 

development of hardwood hammocks (McPherson et al. 

1976). Many hammocks require the presence of fresh 

water or low salinity lenses in their soils and substrates 

(U.S. Fish and Wildlife Service 2007). If salt water 

incursion or increased evaporation leads to higher 

salinities, the health of the hammock may suffer. 

Similarly, hammocks flourish at near constant 

temperatures. The dense canopy minimizes temperature 

fluctuations by reducing soil warming during the daytime 

and preventing excess heat loss at night (U.S. Fish and 

Wildlife Service 2007). 

Stratigraphic Record 

Cores drilled during oil and gas exploration reveal a 

thick and time- extensive stratigraphic sequence 

underlying the preserve. In the oil and gas producing 

areas of Big Cypress, the sedimentary sequence is 

4,572−5,182 m (15,000−17,000 ft) thick (Pollastro et al. 

2000). This sequence overlies Jurassic volcanic rocks 

(rhyolite and basalt) and consists of some of the oldest 

rocks in Florida. The sedimentary rocks of Big Cypress 

fill the South Florida basin, described above. 

The earliest sediments, part of the Wood River 

Formation, are continental clastic rocks overlain by salt, 

limestone, anhydrite, and brown dolomite. Between the 

Wood River and the oil- producing Sunniland Formation 

lie the predominantly carbonate- evaporite Bone Island 

and Pumpkin Bay Formations, and the Glades Group of 

shale, dolomite, and anhydrite (Faulkner and Applegate 

1986). The Lower Cretaceous Sunniland Formation is 

composed of anhydrite, a thin limestone layer, and 

dolomite. The Sunniland; the anhydrite and limestone of 

the Lake Trafford Formation; and the dolomite, 

limestone, and anhydrite of the Rattlesnake Hammock 

Formation make up the Ocean Reef Group (Pollastro et 

al. 2000). 

The Big Cypress Group and Naples Bay Group overlie 

the Ocean Reef Group. These are largely dolomite and 

anhydrite beneath Big Cypress National Preserve. The 

Upper Cretaceous Pine Key Formation is composed of 

chalky limestone and dolomite. It is approximately 914 m 

(3,000 ft) thick. The Paleocene to present- day 

sedimentary layers overlie the Pine Key Formation at Big 

Cypress (Faulkner and Applegate 1986). Relatively 

uninterrupted Tertiary deposition amassed the grand 

carbonate platform of South Florida. These sediments 

reach great thicknesses, approximately 1,676 m (5,500 ft). 

Cores drilled in nearby Everglades National Park help 

determine the stratigraphy of younger units at Big 

Cypress National Preserve. Eocene to late Oligocene 

deposition resulted in the marine carbonates of the Avon 

Park Formation, the Suwannee Limestone, the Ocala 

Group, and the Arcadia Formation of ramp- setting 

carbonates with scant quartz content increasing 

northward (Cunningham 2005). 

A major disconformity marks the boundary between the 

Arcadia Formation and the overlying Peace River 

Formation. In other areas of Florida, the Hawthorn 

Group (Miocene) is between the Arcadia and Peace 

River Formations. The Peace River Formation contains 

two distinct units: a lower diatomaceous mudstone, and 

an upper muddy, fine- grained quartz sandstone 

(Cunningham et al. 1998). Deposited atop the Peace River 

Formation is the Tertiary age Tamiami Formation. This 

unit comprises much of the surface outcrop at Big 

Cypress. 
 BICY Geologic Resource Evaluation Report 19

Figure 9: Slow-flowing slough at Big Cypress National Preserve. During the dry season the slough is an essential water source for 

local wildlife and vegetation. Photograph (January 2005) is by Trista L. Thornberry-Ehrlich (Colorado State University). 
 NPS Geologic Resources Division 20 

Figure 10. Map of Florida showing location of Big Cypress National Preserve relative to major positive structural elements of the South 

Florida basin. Graphic is by Trista L. Thornberry-Ehrlich (Colorado State University) based on information from Pollastro et al. (2000). 
 BICY Geologic Resource Evaluation Report 21

Figure 11. A simplified cross section showing Late Jurassic and Cretaceous rocks from the central part of the Peninsular arch across 

South Florida basin and south to the Florida Keys. The cross section shows stratigraphic patterns controlled by the location of the 

structural high. Note: Diagram is not to scale. To show the various units clearly, the section is exaggerated in the vertical dimension; 

thus, units appear thicker than they really are. Stratigraphic nomenclature is after the Florida Geological Survey. Graphic is by Trista L. 

Thornberry-Ehrlich (Colorado State University), adapted from figure 2 in Pollastro et al. (2000). 
 NPS Geologic Resources Division 22 

Figure 12: Stratigraphic section for South Florida basin along the Sunniland trend. showing units from the late Mesozoic Era. Diagram 

is not to scale. Graphic is by Trista L. Thornberry-Ehrlich (Colorado State University), after figure 3 in Pollastro et al. (2000). 
 BICY Geologic Resource Evaluation Report 23

Figure 13: Development of a karst landscape from initial dissolution of bedrock to the ultimate formation of a hardwood hammock at 

Big Cypress National Preserve. Graphic is by Trista L. Thornberry-Ehrlich (Colorado State University). 
 NPS Geologic Resources Division 24 

Figure 14: Conceptual diagram showing cross section of the aquifers beneath Big Cypress National Preserve. Diagram is not to scale. 

Graphic is by Trista L. Thornberry-Ehrlich (Colorado State University), using information from Wexler (2004). 
 BICY Geologic Resource Evaluation Report 25

Map Unit Properties 

This section identifies characteristics of map units that appear on the Geologic Resource 

Evaluation digital geologic map of Big Cypress National Preserve. The accompanying 

table is highly generalized and is provided for background purposes only. Grounddisturbing activities should not be permitted or denied on the basis of information in this 

table. More detailed map unit descriptions can be found in the help files that accompany 

the digital geologic map or by contacting the National Park Service Geologic Resources 

Division. 

Map units exposed at the surface at Big Cypress National 

Preserve are limited to the Tamiami Formation, shellbearing sediments, the Miami Limestone, 

undifferentiated Holocene and Pleistocene deposits, and 

Holocene sediments (Scott 2001). 

The complex Tamiami Formation may be roughly 

subdivided into lower clastic rocks, the Gray Limestone, 

and the upper clastic rocks. The lowermost part 

comprises quartz sandstone, mud, clay, and limestone 

cobbles. The Gray Limestone is lightly cemented, 

fossiliferous, sandy limestone. The uppermost clastic 

layer comprises sandstone interbedded with mud, clay, 

and limestone cobbles (Shoemaker 1998). 

Tertiary through Quaternary shell- bearing sediments 

underlie the Miami Limestone, which is exposed at the 

surface. Two facies exist in the Miami Limestone. The 

western part of the unit is predominantly the bryozoan 

facies; the unit then becomes more oolitic eastward 

towards Everglades National Park (Hoffmeister et al.

1974; Cunningham 2005). The Miami Limestone is 

extensively dissolved to form karst topography in the Big 

Cypress area. 

Overlying the Miami Limestone are relatively 

undifferentiated Pleistocene and Holocene 

unconsolidated surficial units of sand, mud, freshwater 

peat and organic muck, freshwater marl, and 

cyanobacteria mats in the swampy marsh, strands, and 

pinelands at Big Cypress (Scott 2001; Cunningham 2005). 

The peat and muck typically occur in low- lying sloughs 

and solution holes and are dark and fine- grained. 

During the standing- water phase of the wet season, 

extracellular precipitation of calcium carbonate by 

cyanobacteria forms fresh limestone marls (Cunningham 

2005). 

Map features for Big Cypress National Preserve also 

include karst- related topographic depressions, such as 

sinkholes for south Florida as captured on Florida 

Department of Environmental Protection (FDEP) Digital 

Elevation Model map (DEMs) at a resolution of 30−15 m 

(enhanced) and U.S. Geological survey 1:24,000 

topographic maps (Arthur et al. 2005). 

The following pages present a tabular view of the 

stratigraphic column and an itemized list of features for 

each map unit. This sheet includes several properties 

specific to each unit present in the stratigraphic column, 

including map symbol, name, description, resistance to 

erosion, suitability for development, hazards, potential 

paleontologic resources, cultural and mineral resources, 

habitat, potential for recreational use, and global 

significance. 

 BICY Geologic Resource Evaluation Report 27

Geologic History 

This section describes the rocks and unconsolidated deposits that appear on the digital 

geologic map of Big Cypress National Preserve, the environment in which those units 

were deposited, and the timing of geologic events that created the present landscape. 

The Florida platform is among the younger additions to 

the North American continent. Thousands of meters of 

interlayered carbonate and siliciclastic rocks represent a 

generally stable deposition environment punctuated by 

erosional and high- energy events. The rocks deep below 

Florida give clues to its origin and geologic history (fig. 

15). 

Late Paleozoic Era 

During the Mississippian, the landmass that underlies the 

grand carbonate platform of Florida today was not part 

of the North American craton. It is speculated that it was 

attached to the northwestern part of the African 

continent (Condie and Sloan 1998). Marine carbonate 

sediments were being deposited over much of the area 

atop a Paleozoic crystalline basement high, the 

Peninsular arch (Pollastro et al. 2000). 

In the Pennsylvanian, a collision event known as the 

Ouachita orogeny sutured the Florida landmass to the 

continent as Gondwanaland and North America 

collided, eventually forming the supercontinent Pangaea. 

Many north- to northeast- trending strike- slip and 

thrust faults were active as a result of multi- directional 

tectonic stresses at this time (Amsbury and Haenggi 

1993). The land was still submerged, and South Florida 

was located at the junction of the North American, South 

American, and African plates (fig. 16). Through the 

Permian, Pangaea remained intact (Condie and Sloan 

1998). Highlands to the north of the Florida landmass 

eroded quickly when compressional tectonic forces 

subsided during the Permian. 

Early Mesozoic Era 

At the beginning of the Triassic Period, Pangaea began to 

break up (≈220−245 Ma). During the late Triassic–

Jurassic periods, South and Central America and Africa 

began to rift away from North America. This established 

the long- standing passive margin along the eastern 

seaboard that persists today. The Florida and Cuba 

blocks detached from northwestern Africa, and the Gulf 

of Mexico opened (Condie and Sloan 1998). This created 

large basins for deposition of sediments shed from the 

rapidly eroding Ouachitan highlands. In the early stages, 

a series of discontinuous rift basins developed parallel to 

the edge of the opening ocean basin. These basins 

extended from Mexico to Nova Scotia (Hentz 2001). 

Accompanying the rifting of Pangaea was the widespread 

extrusion of volcanic rocks consistent with mantle plume 

upwelling due to crustal tension (Heatherington and 

Mueller 1991). This continental rifting also opened the 

Atlantic Ocean basin. 

Middle Mesozoic Era 

Underlying the South Florida basin are igneous 

rhyolitic- basaltic rocks (Thomas et al. 1989). These rocks 

were sampled in a core from 5.7 km (3.5 mi) deep in 

Collier County. Geochemical composition of these rocks 

indicates they formed within a mantle plume in a 

continental rifting environment consistent with the 

breakup of Pangaea. Geologists surmise a hotspot 

initiated local rifting off the southern tip of the Florida 

platform (Heatherington and Mueller 1991; Cunningham 

2005). 

These igneous rocks were exposed on the surface and 

eroded during the late Triassic to middle Jurassic. 

Deposits of sand and silt covered local areas, which upon 

exposure formed redbeds. Accompanying the opening of 

the proto- Atlantic Ocean, the Caribbean basin, and the 

ancestral Gulf of Mexico were major lateral 

displacements along transform faults such as the North 

Bahamas fracture zone (Condie and Sloan 1998). 

As the Atlantic Ocean and Caribbean basin continued to 

develop, deltaic and shallow marine sediments were 

deposited over the Florida platform in the late Jurassic. 

Restriction of marine circulation at this time resulted in 

periodic accumulations of evaporite and marine 

carbonate sediments (Cunningham 2005). Deposition of 

Jurassic and Cretaceous sediments was controlled by the 

south- southeast- plunging axis of the Peninsular arch. 

Basal sediments onlap and pinch out against the arch 

(Pollastro et al. 2000). 

Late Mesozoic Era 

As marine transgression (rise in sea level) proceeded 

during the early Cretaceous, the Florida platform was the 

site of more widespread deposition of marine carbonate 

sediments and building of reefs. Reefs clustered along 

the margin of the ancestral Gulf of Mexico and the edges 

of the Florida platform (Cunningham 2005). From the 

middle Cretaceous to the late Paleogene, the Suwannee 

Strait (often called the “Gulf Trough”) separated the 

carbonate Florida platform from a clastic shelf and slope 

that was developing along the southeastern margin of 

North America. These clastic sediments eroded from the 

Appalachian Mountains. 

Currents running through the strait prevented the clastic 

sediments from interrupting the continuous 

accumulation of carbonate sediments on the Florida 

platform. As currents changed and the seaway was 

infilled, by the late Eocene, some of the siliciclastic 

sediments mixed with the deep carbonate sediments 

(Cunningham et al. 2003). 
 NPS Geologic Resources Division 28 

Further transgression and global warming during the 

Late Cretaceous established an open marine 

accumulation of carbonate sediments over the entire 

Florida Peninsula. Accompanying this widespread 

accumulation was the development of deposition of 

rudistid bivalves in reefs around the southern margin of 

the Florida area. 

By the Late Cretaceous, the Gulf of Mexico was 

completely open. The new crust formed by igneous 

extrusion during extension was now the ProtoCaribbean tectonic plate. This oceanic crust separates 

the Gulf of Mexico and the Yucatan from South 

America. At this time, the Antilles arc (parts of which 

now belong to Hispaniola and Puerto Rico) moved 

eastward and was subducting beneath the Cuba block 

(Condie and Sloan 1998). 

Cenozoic Era 

Cenozoic development of the Florida platform included 

additional deposition of marine carbonate sediments and 

deposition of siliciclastic sediments (grains of silicate 

minerals such as quartz) from northwestern highland 

sources and longshore oceanic currents. Tertiary faulting 

occurred south of Florida as the Cuban block continued 

to collide with the Antilles arc and carbonate 

accumulation continued in Florida (Condie and Sloan 

1998). In southern Florida, the open marine depositional 

setting continued during the Paleocene as more 

restricted flow to the north resulted in deposits of mixed 

carbonate sediments and intermittent evaporites (during 

restricted marine conditions). Eocene and Oligocene 

deposition is marked by shallow- water carbonate rocks. 

Sedimentary deposits were intermittently exposed 

during this time, forming erosional surfaces and scant 

redbeds associated with local oceanic regressions. 

Deposition in South Florida during the Miocene 

changed with the introduction of more widespread 

siliciclastic sediments from a fluvio- deltaic system that 

developed from north to south on the peninsula. These 

deposits were derived from the rapidly eroding southern 

Appalachian Mountains as the Atlantic coastal plain 

continued to grow eastward. Phosphates and the 

carbonate ramp of the Arcadia Formation were 

deposited during the Miocene in southeastern Florida 

(Cunningham 2005). Siliciclastic deposits of the Peace 

River Formation then buried this carbonate ramp during 

the Miocene. Marine upwelling at this time is responsible 

for the diatomaceous mudstone and plentiful organic 

matter represented by the lower beds of the Peace River 

Formation (Cunningham et al. 1998). 

Some of the Miocene siliciclastic deposits of the Peace 

River Formation were eroded and reworked during a 

marine regression. This Pliocene lowstand caused a 

disconformity between the Peace River and the overlying 

Long Key Formation. South of Big Cypress National 

Preserve, the Peace River Formation is absent—either it 

was never deposited or was eroded away completely. 

During the Pliocene, a thick wedge of sand eroded from 

the Miocene deposits was deposited in the Everglades 

area, east of Big Cypress. This sand was being 

transported south to eventually form the Long Key 

Formation (Guertin et al. 1999; Cunningham 2005). It 

covered the area that is now Everglades National Park 

and extended as far south as the Florida Keys. The sand 

was deposited in fluctuating outer and inner shelf 

conditions with depths ranging from 150−180 m 

(≈500−600 ft) to 10−50 m (≈30−160 ft), respectively 

(Guertin et al. 1999). 

In addition to Pliocene siliciclastic deposition, carbonate 

sediments also accumulated in South Florida. In the 

western reaches of the peninsula was a mid- Pliocene 

reef environment. Near the lower Florida Keys and the 

southwest Florida shelf, the carbonate sediments of the 

Stock Island Formation were deposited at the same time 

that the reef was built. These sediments were perhaps 

associated with currents originating in the Gulf of 

Mexico, flowing eastward through the Straits of Florida 

(Cunningham et al. 1998; Cunningham 2005). 

The Pleistocene Epoch experienced numerous and 

extensive glacial events called ice ages. Although glacial 

ice never extended as far south as Florida, the 

accompanying global- scale climatic and sea level shifts 

played a major role in the formation of the geologic units 

and the overall landscape exposed today at Big Cypress 

National Preserve. During the Pleistocene, deposition 

shifted from siliciclastic sediments mixed with carbonate 

accumulation to more widespread carbonate 

sedimentation with occasional, localized siliciclastic 

contributions (Cunningham 2005). Global sea- level 

changes during the intermittent ice ages of the 

Pleistocene controlled the rate and distribution of 

carbonate sediments. 

At 120 ka, the last major fall in sea level occurred as the 

mixed carbonate- siliciclastic, shell- rich sediments 

formed the units underlying the Miami Limestone. 

Deposition was in a restricted lagoonal environment 

(rich in marine fossil remains) during successive sealevel highstands (Cunningham 2005). The western area 

of the Miami Limestone, including the Big Cypress 

National Preserve, contains the lower energy, more 

restricted bryozoan facies of the unit, indicative of 

lagoonal depositional conditions. 

At about 15−16 ka, sea level began to rise rapidly and 

southern Florida was extensively flooded around 7 or 6 

ka (Shinn et al. 1997). Sea level has continued to rise, but 

estimates vary as to the actual rate and continuity. 

The sediments at Big Cypress National Preserve indicate 

several episodes of marine inundation. However, most 

marine regressions and transgressions lead to erosion 

and subsequent reworking of sediments, which obscures 

all but the largest events. Around 5 ka, the rate of rise in 

sea level slowed and shoreline deposits became thin and 

narrow (Mitchell- Tapping et al. 1996). Sea level then 

rose steadily and flooded coastal lagoons, estuaries, and 

mangrove swamps and marshes. Florida Bay was 
 BICY Geologic Resource Evaluation Report 29

completely flooded at this time. At about 3 ka, a sharp 

transgression and regression is evident from core 

samples from Big Cypress National Preserve. This event 

lasted approximately 200−400 years and was 0.5−2 m 

(1.6−6.6 ft) in amplitude. During this time, marine 

sediments were reworked and redeposited in stable areas 

such as Estero Bay (Mitchell- Tapping et al. 1996). 

Holocene geologic activity in the Big Cypress area 

consists of the pervasive dissolution of carbonate 

bedrock units, the surficial accumulation of carbonate 

mud, marine and freshwater marl, marine sand terraces 

(including the Talbot and Pamlico terraces), and swamp 

deposits (Mitchell- Tapping et al. 1996; Cunningham 

2005). The underlying geology, sea level, climate, and 

vegetation patterns control Holocene sediment 

distribution (Cunningham 2005). 

Sea level rise slowed further after about 3 ka, with 

nearshore marine environments becoming more shallow 

and stable coastlines developing. Between 2,900 and 

2,500 years before present, a regression lowered relative 

sea level and promoted stabilizing vegetation growth 

across the area. 

Today mangrove peat and storm levees create a natural 

barrier between the landward freshwater environments 

and Florida Bay (Mitchell- Tapping et al. 1996). In lower 

sloughs and solution holes, deposition of organic muck 

and peat soils predominates (Craighead 1971). Freshwater 

marl and cyanobacteria mats characterize the open 

prairies and deeper sloughs, where calcium carbonate 

precipitates in situ to cover the ground and vegetation 

(fig. 17). Marine marls are common in the coastal areas of 

Florida Bay. Floods are responsible for the formation of 

these natural levees composed of aragonitic mud and 

shell fragments (Cunningham 2005). 
 NPS Geologic Resources Division 30 

Figure 15. Geologic time scale; adapted from the U.S. Geological Survey. Red lines indicate major unconformities between eras. Included 

are major events in the history of life on Earth and tectonic events occurring on the North American continent. Absolute ages shown are in 

millions of years (Ma. or mega-annum). 
 BICY Geologic Resource Evaluation Report 31

Figure 16: Evolution of the landscape in the Florida Platform area from the Mississippian-Pennsylvanian Ouachita orogeny through the 

Triassic-Jurassic extensional event opening the Gulf of Mexico, the Caribbean Sea, and the Atlantic Ocean. The Florida landmass sutured to 

the North American continent at this time. Diagram is not to scale. Graphic is by Trista L. Thornberry-Ehrlich (Colorado State University). 
 NPS Geologic Resources Division 32 

Figure 17. Open prairie area largely underlain by freshwater marly limestone at Big Cypress National Preserve. Photograph is by Trista L. 

Thornberry-Ehrlich (Colorado State University). 
 BICY Geologic Resource Evaluation Report 33

Glossary 

This glossary contains brief definitions of technical geologic terms used in this report. Not all 

geologic terms used are referenced. For more detailed definitions or to find terms not listed 

here please visit http://wrgis.wr.usgs.gov/docs/parks/misc/glossarya.html. 

active margin. A continental margin where significant 

volcanic and earthquake activity occurs; commonly a 

convergent plate margin. 

alluvium. Stream- deposited sediment that is generally 

rounded, sorted, and stratified. 

aquifer. Rock or sediment that is sufficiently porous, 

permeable, and saturated to be useful as a source of 

water. 

asthenosphere. Weak layer in the upper mantle below 

the lithosphere where seismic waves are attenuated. 

baseflow. Stream flow supported by groundwater flow 

from adjacent rock, sediment, or soil. 

baselevel. The lowest level to which a stream can erode 

its channel. The ultimate base level for the land surface 

is sea level, but temporary base levels may exist locally. 

basement. The undifferentiated rocks, commonly 

igneous and metamorphic, that underlie the rocks of 

interest. 

basin (structural). A doubly plunging syncline in which 

rocks dip inward from all sides (also see “dome”). 

basin (sedimentary). Any depression, from continental 

to local scales, into which sediments are deposited. 

beach. A gently sloping shoreline covered with sediment, 

often formed by action of waves and tides. 

bed. The smallest sedimentary strata unit, commonly 

ranging in thickness from one centimeter to a meter or 

two and distinguishable from beds above. 

bedding. Depositional layering or stratification of 

sediments. 

bedrock geology. The geology of underlying solid rock 

as it would appear with the sediment, soil, and 

vegetative cover stripped away. 

calcareous. A rock or sediment containing calcium 

carbonate. 

carbonaceous. A rock or sediment with considerable 

carbon, esp. organics, hydrocarbons, or coal. 

cementation. Chemical precipitation of material into 

pores between grains that bind the grains into rock. 

chemical sediment. A sediment precipitated directly 

from solution (also called “nonclastic”). 

chemical weathering. The dissolution or chemical 

breakdown of minerals at Earth’s surface via reaction 

with water, air, or dissolved substances. 

clastic. Rock or sediment made of fragments or preexisting rocks. 

clay. Clay minerals or sedimentary fragments the size of 

clay minerals (>1/256 mm). 

continental crust. The type of crustal rocks underlying 

the continents and continental shelves; having a 

thickness of 25- 60 km (16- 37 mi) and a density of 

approximately 2.7 grams per cubic centimeter. 

continental drift. The concept that continents have 

shifted in position over Earth (see and use ”plate 

tectonics”). 

continental rise. Gently sloping region from the foot of 

the continental slope to the abyssal plain. 

continental shelf. The shallowly submerged part of a 

continental margin extending from the shoreline to the 

continental slope with water depths of less than 200 m 

(656 ft). 

continental shield. A continental block of Earth’s crust 

that has remained relatively stable over a long period 

of time and has undergone only gentle warping 

compared to the intense deformation of bordering 

crust 

continental slope. The relatively steep slope from the 

outer edge of the continental shelf down to the more 

gently sloping ocean depths of the continental rise or 

abyssal plain. 

convergent boundary. A plate boundary where two 

tectonic plates are moving together (i.e., a zone of 

subduction or obduction). 

craton. The relatively old and geologically stable interior 

of a continent (also see “continental shield”). 

cross section. A graphical interpretation of geology, 

structure, and/or stratigraphy in the third (vertical) 

dimension based on mapped and measured geological 

extents and attitudes depicted in an oriented vertical 

plane. 

crust. The outermost compositional shell of Earth, 10−40 

km (6−25 mi) thick, consisting predominantly of 

relatively low density silicate minerals (also see 

“oceanic crust” and “continental crust”). 

crystalline. Describes the structure of a regular, orderly, 

repeating geometric arrangement of atoms. 

dip. The angle between a structural surface and a 

horizontal reference plane measured normal to their 

line of intersection. 

disconformity. An unconformity at which the bedding of 

the strata above and below are parallel. 

drainage basin. The total area from which a stream 

system receives or drains precipitation runoff. 

estuary. The seaward end or tidal mouth of a river where 

fresh and sea water mix. Many estuaries are drowned 

river valleys caused by sea level rise (transgression) or 

coastal subsidence. 

eustatic. Relates to simultaneous worldwide rise or fall 

of sea level in Earth’s oceans. 

evaporite. Chemically precipitated mineral(s) formed by 

the evaporation of solute- rich water under restricted 

conditions. 

extrusive. Of or pertaining to the eruption of igneous 

material onto the surface of Earth. 
 NPS Geologic Resources Division 34 

facies (sedimentary). The depositional or environmental 

conditions reflected in the sedimentary structures, 

textures, mineralogy, fossils, etc. of a sedimentary 

rock. 

fault. A subplanar break in rock along which relative 

movement occurs between the two sides. 

formation. Fundamental rock- stratigraphic unit that is 

mappable and lithologically distinct from adjoining 

strata and has definable upper and lower contacts. 

fracture. Irregular breakage of a mineral; also any break 

in a rock (e.g., crack, joint, fault) 

geology. The study of Earth, including its origin, history, 

physical processes, components, and morphology. 

hammock. A term applied to an area rising slightly above 

a plain or swamp, often supporting an island of dense 

tropical undergrowth. 

igneous. Refers to a rock or mineral that originated from 

molten material that is one of the three main classes or 

rocks—igneous, metamorphic, and sedimentary. 

intrusion. A body of igneous rock that invades older 

rock. The invading rock may be a plastic solid or 

magma that pushes its way into the older rock. 

island arc. A line or arc of volcanic islands formed over 

and parallel to a subduction zone. 

ka. Kiloannum, a period of one thousand years. 

karst topography. Topography characterized by 

abundant sinkholes and caverns formed by the 

dissolution of calcareous rocks. 

lithology. The description of a rock or rock unit, 

especially the texture, composition, and structure of 

sedimentary rocks. 

lithosphere. The relatively rigid outmost shell of Earth’s 

structure, 50−100 km (31−62 mi) thick, that 

encompasses the crust and uppermost mantle. 

longshore current. A current parallel to a coastline 

caused by waves approaching the shore at an oblique 

angle. 

Ma. Megaannum, a period of one million years. 

magma. Molten rock generated within Earth that is the 

parent of igneous rocks. 

mantle. The zone of the Earth’s interior between crust 

and core. 

marl. Unconsolidated earthy deposits consisting chiefly 

of an intimate mixture of clay and calcium carbonate 

formed under marine and freshwater conditions. 

matrix. The fine- grained interstitial material between 

coarse grains in porphyritic igneous rocks and poorly 

sorted clastic sediments or rocks. 

meanders. Sinuous lateral curves or bends in a stream 

channel. 

mechanical weathering. The physical breakup of rocks 

without change in composition (syn: physical 

weathering). 

member. A lithostratigraphic unit with definable contacts 

that subdivides a formation. 

ivergent tectonic margin)s) in the world’s oceans. 

mineral. A naturally occurring, inorganic crystalline solid 

with a definite chemical composition or compositional 

range. 

nonconformity. An erosional surface preserved in strata 

in which crystalline igneous or metamorphic rocks 

underlie sedimentary rocks. 

normal fault. A dip- slip fault in which the hanging wall 

moves down relative to the footwall. 

obduction. The process by which the crust is thickened 

by thrust faulting at a convergent margin. 

oceanic crust. Earth’s crust formed at spreading ridges 

that underlies the ocean basins. Oceanic crust is 6−7 

km (3−4 mi) thick and generally of basaltic 

composition. 

ooid. Small (< 2 mm), spheroidal, layered grains, often 

composed of calcium carbonate, that usually form on 

the sea floor in shallow environments. 

oolitic. Reference to a rock type containing characteristic 

abundant ooids as the primary constituent. 

orogeny. A mountain- building event, particularly a wellrecognized event in the geological past (e.g., the 

Laramide orogeny). 

outcrop. Any part of a rock mass or formation that is 

exposed or “crops out” at Earth’s surface. 

overthrust. A nondescript and not recommended term 

for a large- scale, low- angle thrust fault. 

Pangaea. A theoretical single supercontinent that existed 

during the Permian and Triassic Periods (also see 

“Laurasia” and “Gondwana”). 

passive margin. A tectonically quiet continental margin 

indicated by little volcanic or seismic activity. 

pebble. Generally small, rounded rock particles from 4 to 

64 mm in diameter. 

permeability. A measure of the ease or rate that fluids 

move through rocks or sediments. 

plateau. A broad, flat- topped topographic high of great 

extent and elevation above the surrounding plains, 

canyons, or valleys (both land and marine landforms). 

plate tectonics. The theory that the lithosphere is broken 

up into a series of rigid plates that move over Earth’s 

surface above a more fluid asthenosphere. 

plunge. The inclination of a fold axis or other linear 

feature measured in the vertical plane. 

porosity. The proportion of void space (cracks, 

interstices) in a volume of a rock or sediment. 

recharge. Infiltration processes that replenish 

groundwater. 

red beds. Sedimentary strata composed largely of 

sandstone, siltstone, and shale that are predominantly 

red due to the presence of ferric oxide (hematite) 

coating individual grains. 

regression. A long- term seaward retreat of the shoreline 

or relative fall of sea level. 

reverse fault. A contractional, high- angle (>45o), dip- slip 

fault in which the hanging wall moves up relative to the 

footwall (also see “thrust fault”). 

rock. A solid, cohesive aggregate of one or more minerals 

or mineraloids. 

sandstone. Clastic sedimentary rock of predominantly 

sand- sized grains. 

sediment. An eroded and deposited, unconsolidated 

accumulation of lithic and mineral fragments. 

sedimentary rock. A consolidated and lithified rock 

consisting of detrital and/or chemical sediment(s). 

sequence. A major informal rock- stratigraphic unit that 

is traceable over large areas and defined by a major sea 

level transgression- regression sediment package. 
 BICY Geologic Resource Evaluation Report 35

shale. A clastic sedimentary rock made of clay- sized 

particles that exhibit parallel splitting properties. 

siliciclastic. Pertaining to clastic noncarbonate rocks 

that are almost exclusively silicon- bearing, either as 

forms of quartz or as silicates. 

silt. Clastic sedimentary material intermediate in size 

between fine- grained sand and coarse clay (1/256−1/16 

mm). 

siltstone. A variably lithified sedimentary rock with siltsized grains. 

slough. A sluggish body of water in a bottomland area 

often with marshy, waterlogged ground. 

soil. Surface accumulation of weathered rock and 

organic matter capable of supporting plant growth and 

often overlying the parent rock from which it formed. 

spring. A site where water flows out at the surface due to 

the water table intersecting the ground surface. 

strand. The land bordering any large body of water. 

strata. Tabular or sheetlike masses or distinct layers (e.g., 

of rock). 

stratigraphy. The geologic study of the origin, 

occurrence, distribution, classification, correlation, 

age, etc. of rock layers, especially sedimentary rocks. 

stream. Any body of water moving under gravity flow 

and confined within a channel. 

strike. The compass direction of the line of intersection 

that an inclined surface makes with a horizontal plane. 

strike-slip fault. A fault with measurable offset where the 

relative movement is parallel to the strike of the fault. 

subduction zone. A convergent plate boundary where 

oceanic lithosphere descends beneath a continental or 

oceanic plate and is carried down into the mantle. 

suture. The linear zone where two continental 

landmasses become joined due to obduction. 

tectonic. Relating to large- scale movement and 

deformation of Earth’s crust. 

terraces (stream). Step- like benches surrounding the 

present floodplain of a stream due to dissection of 

previous flood plain(s), stream bed(s), and/or valley 

floor(s). 

thrust fault. A contractional, dip- slip fault with a 

shallowly dipping fault surface (<45o

) where the 

hanging wall moves up and over relative to the 

footwall. 

topography. The general morphology of Earth’s surface 

including relief and location of natural and 

anthropogenic features. 

total petroleum system. All genetically related petroleum 

that occurs in shows and accumulations generated by a 

pod or by closely related pods of mature source rock 

existing within a limited mappable geologic volume. 

transgression. Landward migration of the sea due to a 

relative rise in sea level. 

trend. The direction or azimuth of elongation or a linear 

geological feature. 

type locality. The geographic location where a 

stratigraphic unit is well displayed, is formally defined 

as a typical section, and derives its name. 

unconformity. A surface within sedimentary strata that 

marks a prolonged period of nondeposition or 

erosion. 

volcanic. Related to volcanoes; describes igneous rock 

crystallized at or near Earth’s surface (e.g., lava). 

water table. The upper surface of the saturated (phreatic) 

zone. 

weathering. The set of physical, chemical, and biological 

processes by which rock is broken down in place. 
 NPS Geologic Resources Division 36 

References 

This section lists references cited in this report as well as a general bibliography that may 

be of use to resource managers. A more complete geologic bibliography is available from 

the National Park Service Geologic Resources Division. 

Amsbury, D. L.; W. T. Haenggi. 1993. Middle 

Pennsylvanian strike- slip faulting in the Llano Uplift, 

central Texas. Bulletin of the South Texas Geological 

Society 34 (1): 9−16. 

Arthur, J. D., A. E. Baker, J. R. Cichon, A. R. Wood, and 

A. Rudin. 2005. Florida Aquifer Vulnerability 

Assessment (FAVA): Contamination potential of 

Florida's principal aquifer systems. Scale 1:24000. 

Florida Geological Survey Bulletin [in review]. 

Brooks, H. K. 1981. Physiographic divisions map of Florida. 

Scale 1: 500,000. University of Florida Institute of Food 

and Agricultural Sciences, Center for Environmental 

and Natural Resources. 

Bruno, M. C., K. J. Cunningham, and S.A. Perry. 2003. 

Copepod communities from surface and ground 

waters in the Everglades, South Florida. Southeastern 

Naturalist 2 (4): 523−546. 

Buursink, M. L. 1995. Shallow geologic features identified 

in southwest Florida ground penetrating radar surveys. 

Abstracts with Programs, 39−40, vol. 27, no. 2. Boulder, 

CO: Geological Society of America. 

Condie, K. C., and R. E. Sloan. 1998. Origin and evolution 

of the Earth: Principles of historical geology. Upper 

Saddle River, NJ: Prentice- Hall, Inc. 

Craighead, F. C., Sr. 1971. The trees of South Florida. Vol. 1,

The natural environment and their succession. Coral 

Gables, FL: University of Miami Press. 

Cunningham, K. J. 2004a. Application of groundpenetrating radar, digital optical borehole images, and 

cores for characterization of porosity hydraulic 

conductivity and paleokarst in the Biscayne aquifer, 

southeastern Florida, USA. Journal of Applied 

Geophysics 55: 61- 76. 

Cunningham, K. J. 2004b. New method for 

quantification of vuggy porosity from digital optical 

borehole images as applied to the karstic Pleistocene 

limestone of the Biscayne aquifer, southeastern 

Florida. Journal of Applied Geophysics 55:77−90. 

Cunningham, K. J. 2005. Hydrogeologic fieldtrip 

Everglades National Park, southeastern Florida.

Unpublished paper. 

Cunningham, K. J., S. D. Locker, A. C. Hine, D. Burky, J. 

A. Barron, and L. A. Guertin. 2003. Interplay of late 

Cenozoic siliciclastic supply and carbonate response 

on the southeast Florida platform. Journal of 

Sedimentary Research 73 (1): 31−46. 

Cunningham, K. J., D. F. McNeill, L. A.Guertin, P. F. 

Ciesielski, T. M. Scott, and L. de Verteuil. 1998. New 

Tertiary stratigraphy for the Florida Keys and 

southern peninsula of Florida. Geological Society of 

America Bulletin 110:231−258. 

Dorney, R. R., and P. R. Mott. 1983. Big Cypress: A 

partnership with nature. Interstate Oil Compact 

Commission Committee Bulletin 25 (2): 19−23. 

Duever, M. J., John Carlson, John Meeder, Linda 

Duever, Lance Gunderson, Lawrence Riopelle, Taylor 

Alexander, Ronald Myers, and Daniel Spangler. 1986. 

The Big Cypress National Preserve. Research Report 

of the National Audubon Society, 8. New York: 

National Audubon Society. 

Faulkner, B. M., and A. V. Applegate. 1986. Hydrocarbon 

exploration evaluation of the Pulley Ridge area, 

offshore South Florida Basin. Transactions—Gulf 

Coast Association of Geological Societies 36: 3−95. 

Florida Department of Environmental Protection. 2005. 

About the Everglades. 

http://www.dep.state.fl.us/secretary/everglades/about.

htm (accessed February 28 2006). 

Florida Department of Environmental Protection.. 2008 

November 2007 cumulative oil and gas production. 

http://www.dep.state.fl.us/geology/programs/oil_gas/p

rod_report/nov_2007_fla_mon_prod.xls (accessed 

February 5, 2008) 

Florida Geological Survey. 2005. Sinkholes. Florida 

Department of Environmental Protection. 

http://www.dep.state.fl.us/geology/geologictopics/sink

hole.htm (accessed February 24 2006). 

Guertin, L. A., D. F. McNeill, B. H. Lidz, and K. J. 

Cunningham. 1999. Chronology and 

transgressive/regressive signatures in the late Neogene 

siliciclastic foundation (Long Key Formation) of the 

Florida Keys. Journal of Sedimentary Research

69:653−666. 

Heatherington, A. L., and P. A. Mueller. 1991. 

Geochemical evidence for Triassic rifting in 

southwestern Florida. Tectonophysics 188:291−302. 
 BICY Geologic Resource Evaluation Report 37

Hentz, T. F. 2001. Geology. In The handbook of Texas. 

University of Texas at Austin, 

http://www.tsha.utexas.edu/handbook/online/articles/

GG/swgqz.html (accessed February 28 2006). 

Hoffmeister, J. E., K. W. Stockman, and H. G. Multer. 

1967. Miami Limestone of Florida and its recent 

Bahamian counterpart. Geological Society of America 

Bulletin 78:175−190. 

Hoffmeister, J.E. 1974. Land from the sea, the geologic 

story of south Florida. Coral Gables, FL: University of 

Miami Press. 

Idaho Geological Survey. 2006. Aquifer definitions: Some 

useful definitions for talking intelligently about aquifers. 

http://www.idahogeology.org/ (accessed February 24 

2006). 

Kruse, S. E., J. C. Schneider, D. J. Campagna, J. A. Inman, 

and T. D. Hickey. 2000. Ground penetrating radar 

image of cap rock, caliche and carbonate strata. 

Journal of Applied Geophysics 43:239−249. 

Loftus, W.F., M. C. Bruno, K. J. Cunningham, S. A. Perry, 

and J. C. Trexler. 2001. The ecological role of the karst 

wetlands of southern Florida in relation to system 

restoration. Water Resources Investigations WRI 01-

4011. U.S. Geological Survey. 

McCartan, Lucy, M. Buursink, L. Ward, S. Van 

Valkenburg, D. Mason, B. Szabo, and R. Thackeray. 

1995. Evolution of sinkholes in the South Florida 

carbonate platform south of Lake Trafford. In Vol. 1, 

Linked Earth systems: Congress program and abstracts.

Preface by Albert Hine and Robert Halley. Tulsa, OK: 

Society of Economic Paleontologists and 

Mineralogists. 

McPherson, B.F., C. Y. Hendrix, H. Klein, and H. M. 

Tyus. 1976. The environment of South Florida: A 

summary Report. Professional Paper 1011. U.S. 

Geological Survey. 

Miller, R. L., and Benjamin McPherson. 2001. 

Occurrence and distribution of contaminants in 

bottom sediment and water of the Barron River Canal, 

Big Cypress National Preserve, Florida, October 1998. 

Florida Scientist 64 (1): 1−19. 

Miller, R. L., Benjamin McPherson, Robert Sobczak, and 

Christine Clark. 2004. Water quality in Big Cypress 

National Preserve and Everglades National Park; trends 

and spatial characteristics of selected constituents. Water 

Resources Investigations WRI 03- 4249. U.S. 

Geological Survey. 

Mitchell- Tapping, H. J., Thomas Lee, and Aleta 

Mitchell- Tapping. 1996. Core evidence for a major 

marine transgression during the Holocene of 

southwestern Florida. Transactions—Gulf Coast 

Association of Geological Societies 46:307−311. 

National Audubon Society. 2006. Cypress Swamp 

(Palustrine Forested). 

http://www.audubon.org/states/fl/fl/main/wetlands/ch

p3.htm (accessed April 14 2006). 

National Park Service. 2006. Big Cypress National 

Preserve – Environmental Factors. 

http://www.nps.gov/bicy/naturescience/environmenta

lfactors.htm (accessed February 26, 2006). 

Neuendorf, K. K. E., James P. Mehl, Jr., and Julia A. 

Jackson. 2005. Glossary of Geology. Alexandria, 

Virginia: American Geological Institute. 

Norby, L. 2005. Oil and gas development South Florida 

and Big Cypress National Preserve. Unpublished 

_____. National Park Service. 

Paillet, F. L., and Ronald Reese. 2000. Integrating 

borehole logs and aquifer tests in aquifer 

characterization. Ground Water 38 (5): 713−725. 

Pollastro, R. M., C. J. Schenk, and R. R. Charpenter. 

2000. Undiscovered oil and gas in the Big Cypress 

National Preserve: A total petroleum system assessment 

of the South Florida basin, Florida. Open- File Report 

00- 317. U.S. Geological Survey. 

Rice, K. G., J. H. Waddle, and Frank Mazzotti. 2003. 

Impacts of off- road vehicle use on wildlife in the prairie 

ecosystem of Big Cypress National Preserve. Open- File 

Report OF 03- 0054. U.S. Geological Survey. 

Scott, T.M. 2001. Geologic formations of Florida. Digital 

file, scale 1:126,720. Florida Geological Survey. 

http://www.dep.state.fl.us/geology/gisdatamaps/state_

geo_map.htm (accessed February 26 2006). 

South Florida Water Management District. 2002. The 

Living Everglades. 

http://glades.sfwmd.gov/empact/home/index.shtml 

(accessed March 3 2006). 

Shinn, E. A., B. H. Lidz, and R. B. Halley, 1997.: A Field 

Guide: Reefs of Florida and the Dry Tortugas. In 

Geological Environments of Florida Bay and the Florida 

Keys Reef Tract, comp. A. Tihansky, E. Prager, and G. 

Shinn. Field Guide T176. Washington, D.C: 

International Geological Congress – American 

Geophysical Union. 

Shoemaker, W. B. 1998. Geophysical delineation of 

hydrostratigraphy within the Big Cypress National 

Preserve. Master’s thesis, University of South Florida. 

Spiker, E. C., A. Bates, L. Gough, J. Herring, C. Holmes, 

R. Kotra, H. Lerch, W. Orem, and V. Weintraub. 1995. 

South Florida ecosystems studies: Geochemical history 

of ecosystem conditions and variability In Application 

of geosciences to decision- making, ed. L.M. Carter, 

82−84. Circular 1108. U.S. Geological Survey. 
 NPS Geologic Resources Division 38 

Taylor Schoettle, H.E. 2006. Sloughs. In Natural History 

of the Georgia Coast. Marine Education Center and 

Aquarium. 

http://www.uga.edu/aquarium/nature/slough.html 

(accessed April 14 2006). 

Thomas, W.A., Chowns, T.M., Daniels, D.L., Neatherly, 

T,L., Glover, L., and Gleason, R.J. 1989. The subsurface 

Appalachians beneath the Atlantic and Gulf coastal 

plains. In The Geology of North America F- 2, 

Geological Society of America. 

USDA Forest Service. 2006. Kulcher Type: Cypress 

savanna. U.S. Department of Agriculture. 

http://www.audubon.org/states/fl/fl/main/wetlands/ch

p3.htm (accessed April 14 2006). 

U.S. Fish and Wildlife Service. 2007. Tropical Hardwood 

Hammock. 

http://www.fws.gov/southeast/vbpdfs/commun/thh.p

df (accessed September 27 2007). 

Wexler, E. J. 2004. Hydrostratigraphy review report for 

south west Florida feasibility study. Unpublished 

consultant’s report to South Florida Water 

Management District. Scale 1:100,000. 

Wikipedia. 2006. Slough (wetland). 

http://www.wikipedia.com (accessed April 14 2006). 

Willard, D. A., Lisa Weimer, and Charles Holmes. 1996. 

Vegetational changes over the last few millennia in 

South Florida; Evidence from the pollen record. 

Abstracts with Programs, 95, vol. 28, no. 7. Boulder, 

CO: Geological Society of America. 
 BICY Geologic Resource Evaluation Report 39

Appendix A: Geologic Map Graphic 

The following page is a preview or snapshot of the geologic map for Big Cypress National 

Preserve. For a poster- size PDF of this map or for digital geologic map data, please see 

the included CD or visit the Geologic Resource Evaluation publications Web page 

(http://www2.nature.nps.gov/geology/inventory/gre_publications). 

 BICY Geologic Resource Evaluation Report 41

Appendix B: Scoping Summary 

The following excerpts are from the GRE scoping summary for Big Cypress National 

Preserve. The scoping meeting occurred on January 27−28, 2005; therefore, the contact 

information and Web addresses referred to herein may be outdated. Please contact the 

Geologic Resources Division for current information. 

Executive Summary 

Followed by a field trip on January 28, 2005, a Geologic 

Resource Evaluation scoping meeting took place at the 

preserve headquarters on January 27, 2005. The scoping 

meeting participants identified the following list of 

geologic resource management issues. 

1. The hydrogeologic system at Big Cypress is a western 

extension of the Everglades. Surface water flows over 

the low relief landscape through sloughs and marshes. 

Roads, canals, and levees at the preserve have altered 

this flow. 

2. Geologic and topographic mapping when combined 

with flow patterns would help resource management 

determine which areas to focus on for restoration. 

3. Soils and bedrock depth surveys and measurements 

are needed at the preserve. This in addition to soil 

recovery research would help resource management 

deal with ORV damage remediation. 

4. Disturbed lands at the preserve include borrow pits 

and canals dug during the construction of roads and 

pads for oil and gas drilling. These features disrupt the 

flow of water and need to be remediated. 

5. ORV management is an ongoing process at the park. 

Implementation of the 2001 ORV Plan is a major 

management goal. The preserve is trying to designate 

644 km (400 miles) of trails to lessen ORV 

environmental impact. 

6. Oil and gas issues include regulating the eight 

producing wells located within the preserve. Land and 

mineral ownership rights differ between the surface 

and subsurface and responsibility for clean up and 

remediation is often mislaid. Impacts resulting from oil 

and gas exploration are the responsibility of the 

operator to clean- up. 

Introduction 

The National Park Service held a Geologic Resource 

Evaluation scoping meeting for Big Cypress National 

Preserve at the park headquarters near Everglades City, 

Florida on Thursday, January 27, 2005. Following this 

meeting was a field trip on January 28, 2005. The purpose 

of the meeting was to discuss the status of geologic 

mapping in the preserve, the associated bibliography, 

and the geologic issues in the preserve. The products to 

be derived from the scoping meeting are: (1) Digitized 

geologic maps covering the preserve; (2) An updated and 

verified bibliography; (3) Scoping summary (this report); 

and (4) A Geologic Resource Evaluation Report which 

brings together all of these products. 

Big Cypress National Preserve was established during 

Gerald Ford’s administration on October 11, 1974. Big 

Cypress covers 720,567 acres of the southwestern corner 

of Florida. Big Cypress National Preserve was the first 

national preserve incorporated into the National Park 

Service at the same time as Big Thicket National Preserve 

in Texas. This preserve features incredible biodiversity. 

The environments protected at the preserve range from 

sawgrass prairies, mangrove forests, cypress stands and 

domes, hardwood tree islands, to slow flowing sloughs 

and marshes. The area covers a large portion of the 

“western Everglades.” The preserve is heavily recreated 

and contains some of the most productive oil and gas 

fields in south Florida. 

Big Cypress National Preserve identified 37 quadrangles 

of interest. However, additional coverage of 30 more 

quadrangles (to the north and west) would add 

considerably to resource management’s understanding 

of the landscape and watershed at the preserve. The 

Florida Geological Survey (FGS) has digitized a geologic 

map covering the state from individual county maps at a 

small scale (≈ 1:126,720 or larger). This map only displays 

5 separate geologic units (Holocene sediments, 

Pleistocene−Holocene undifferentiated, Miami 

Limestone, Shell- bearing sediments, Tamiami 

Formation) for inside the boundaries of the park. 

Other geologic maps covering portions of the 

quadrangles of interest include the FGS MS6/19, MS 

6/20, MS 6/21, MS 6/22, MS 6/24, and MS 6/25 (1:24,000, 

2000), Geological Society of America (GSA) Memoir 147 

(1:79,000, 1977), the FGS OFMS 67 (1:26,720, Dade 

County), 66/01 (1:126,720, Monroe County), 62 (1:126,720 , 

Hendry County), 63 and Series 120 (1:126,720, Collier 

County), 64 (1:126,720, Broward County), 65 (1:126,720, 

Palm Beach County), USGS 84- 4068 and 86- 4126 

(1:134,000 and 1:136,000, 1985 and 1986, respectively). 

BEM Systems produced a hydrostratigraphy study for 

Big Cypress National Preserve and a small portion of the 

Everglades National Park that shows interpolated depth 

to the tops and bottoms of aquifer and aquitard layers. 

Additional mapping at a smaller scale will be more 

helpful for preserve management. 

Physiography 

South Florida lies within the Atlantic Coastal Plain 

physiographic province. In the area of Big Cypress 

National Preserve, it is divided into five physiographic 

subprovinces. The Big Cypress Swamp subprovince 

defines the western boundary of the Everglades. This 

area is slightly higher in elevation than the Everglades 
 NPS Geologic Resources Division 42 

basin because it is underlain primarily by the coral- rich 

limestones of the Pliocene Tamiami Formation (3−4 Ma). 

This formation is exposed in large areas of Big Cypress. 

Drainage in the province is primarily to the south and 

southwest. 

The Everglades subprovince forms a south dipping, 

spoon- shaped low- lying area between the Atlantic 

Coastal Ridge to the east, the Big Cypress Swamp to the 

west, and the Sandy Flatlands area to the north. The 

basin has very low relief. The elevation change is only 

3.6−4.3 m (12−14 ft) from the maximum near Lake 

Okeechobee to sea level. Prior to anthropogenic 

alteration, this drainage system flowed slowly from north 

to south. 

Bounding the Everglades subprovince on the east is the 

Atlantic Coastal Ridge. It is comprised of Pleistocene 

marine limestones covered by thin quartz sand sheets. 

The subprovince ranges in elevation from 1.5 to 6 m (5 to 

20 ft) in the southernmost portions. The width of the 

ridge ranges from 16 km (10 miles) in southern MiamiDade County and narrows to 5−8 km (3−5 miles) further 

north. Periodically breaching the southern portions of 

the ridge are sloughs (transverse marshes) oriented 

perpendicular to the trend of the ridge. 

The southern reaches of the Everglades and Big Cypress 

Swamp subprovinces transition into the Coastal Marshes 

and Mangrove Swamp physiographic subprovince. The 

subprovince covers an area from the northeastern part of 

Florida Bay, around the southern Florida peninsula, and 

west, into the Gulf of Mexico up to the Ten Thousand 

Island region never Everglades City. Bands of swamps 

and brackish marshes sitting just above sea level 

characterize this subprovince. Freshwater runoff and 

tidal fluxes cause the salinity to change dramatically. This 

is why the mangrove, capable of enduring such salinity 

changes, thrives in this area. 

Geologic History of South Florida 

Sediment cores indicate that South Florida has been 

predominantly an area of carbonate accumulation since 

the Mesozoic. 

Late Paleozoic Era—During the Mississippian, the 

landmass that would underlie the grand carbonate 

platform of Florida today was not attached to the North 

American Craton. It is speculated that it was attached to 

the northwest portion of the African continent (Condie 

and Sloan 1998). However, marine carbonates were being 

deposited over large portions of the area atop a Paleozoic 

age crystalline basement high, the Peninsular Arch 

(Pollastro et al. 2000). In the Pennsylvanian, a collision 

event, known as the Ouachita orogeny sutured the 

Florida landmass to the continent as Gondwanaland and 

North America collided eventually forming the 

supercontinent Pangaea. The land was still submerged 

and south Florida was located at the junction of the 

North American, South American, and African plates. 

Through the Permian, Pangaea remained intact (Condie 

and Sloan 1998). 

Early Mesozoic Era—At the beginning of the Triassic 

Period, Pangaea began to break up. During the late 

Triassic, South and Central America and Africa began to 

rift away from North America. This established the longstanding passive margin of the eastern seaboard that 

persists today. The Florida and Cuba blocks detached 

from northwest Africa and the Gulf of Mexico opened 

(Condie and Sloan 1998). 

Accompanying the rifting of Pangaea was the widespread 

extrusion of volcanic rocks consistent with mantle plume 

upwelling due to crustal tension (Heatherington and 

Mueller 1991). This continental rifting also opened the 

Atlantic Ocean basin. 

Middle Mesozoic Era—Underlying the south Florida 

basin are igneous rhyolitic - basaltic rocks (Thomas et al.

1989). These rocks were subaerially exposed and eroded 

during the late Triassic to middle Jurassic. This caused 

the formation of redbeds locally. As the Atlantic Ocean 

continued to develop, deltaic and shallow marine 

sediments were deposited in the late Jurassic. Restriction 

of marine circulation at this time resulted in periodic 

accumulations of evaporites and marine carbonates 

(Cunningham 2005). Deposition of Jurassic and 

Cretaceous sediments was controlled by the southsoutheast plunging axis of the Peninsular Arch. Basal 

sediments onlap and pinch out against the arch 

(Pollastro et al. 2000). 

Late Mesozoic Era—As marine transgression proceeded 

during the early Cretaceous, the Florida Platform was the 

site of more widespread deposition of marine limestones 

and reefs. Further transgression and global warming 

during the Late Cretaceous established an open marine 

accumulation of carbonates over the entire Florida 

Peninsula. 

Cenozoic Era—Cenozoic development of the Florida 

Platform included additional deposition of marine 

carbonates and deposition of siliciclastics (grains of 

silicate minerals such as quartz in lieu of carbonates) 

from northwestern highlands sources and long shore 

oceanic currents. Tertiary faulting occurred south of 

Florida as the Cuban block collided with the Antilles arc 

and carbonate accumulation continued in Florida 

(Condie and Sloan 1998). In southern Florida, the open 

marine setting continued during the Paleocene as more 

restricted flow to the north resulted in deposits of mixed 

carbonates and evaporites. Eocene and Oligocene 

deposition is marked by shallow water carbonates. 

Intermittent with this deposition were subaerial 

exposures associated with local oceanic regressions. 

Deposition in south Florida during the Miocene changed 

with the introduction of more widespread siliciclastics 

from a fluvio- deltaic system prograding down the 

peninsula. Phosphates and the carbonate ramp of the 

Arcadia Formation were deposited during the Miocene 

in south Florida. A Pliocene lowstand caused many of the 

previous deposits to be reworked and/or eroded. The 

Tamiami Formation is a Pliocene marine unit comprising 
 BICY Geologic Resource Evaluation Report 43

a wide range of rock types. These are predominantly 

fossiliferous sands and clays with limestone. 

The Pleistocene era resulted in the conversion from 

siliciclastic deposition mixed with carbonate 

accumulation to more widespread carbonate 

sedimentation (Cunningham 2005). Global sea- level 

changes during the intermittent ice ages of the 

Pleistocene controlled the rate and distribution of 

carbonate units. At 120 ka, the last major sea level fall 

occurred as the mixed carbonate- siliciclastic sediments 

formed the Fort Thompson Formation. This unit 

interfingers with the surficial geologic units, the Miami 

and Key Largo Limestones, and the Anastasia Formation 

(≈130 ka) (Cunningham 2005). 

At 15−16 ka sea level began to rise rapidly and flood 

southern Florida around 7 or 6 ka (Shinn et al. 1997). Sea 

level has continued to rise. Holocene geologic activity in 

the Big Cypress area consists of the dissolution of 

carbonate units, the accumulation of carbonate muds, 

freshwater marls, sand and swamp (organic peat and 

muck) deposits. 

Stratigraphy 

Cores drilled in the oil and gas exploration operations 

help define the stratigraphy underlying the preserve. In 

the oil producing area of Big Cypress, the sedimentary 

section is 4,572−5,182 m (15,000 – 17,000 ft) thick. The first 

2,134−2,743 m (7,000−9,000 ft) are Late Jurassic through 

Early Cretaceous rocks, the next 914 m (3,000 ft) are Late 

Cretaceous age rocks, and the remaining 1,676 m (5,500 

ft) are of Tertiary age to the present (Pollastro et al.

2000). These rocks fill the South Florida Basin, the center 

of which is located northwest of the Florida Keys. The 

basin is bounded on the east by the Paleozoic Peninsular 

Arch (trending northwest−southeast), the Florida 

escarpment to the west, the Tampa- Sarasota Arch 

(trending northeast−southwest) to the north, and the 

Pine Key arch to the south. 

Jurassic age basaltic- rhyolitic rocks underlie all of south 

Florida. Since the Jurassic, sedimentation has kept pace 

with overall basin subsidence. Deposition has included 

carbonates, clastics and evaporites (Pollastro et al. 2000). 

The earliest sediments, of the Wood River Formation are 

continental clastics overlain by salt, limestone, anhydrite 

and brown dolomite. Between the Wood River and the 

oil producing Sunniland Formation lie the 

predominantly carbonate- evaporite Bone Island and 

Pumpkin Bay Formations, and the Glades Group of 

shales, dolomites, and anhydrites (Faulkner and 

Applegate 1986). The Sunniland Formation of Lower 

Cretaceous age is comprised of anhydrites, thin 

limestone layers, and dolomites. The Sunniland, along 

with the anhydrite and limestone of the Lake Trafford 

Formation and the dolomite, limestone and anhydrite of 

the Rattlesnake Hammock Formation, comprise the 

Ocean Reef Group. 

The Big Cypress Group and Naples Bay Group overlie 

the Ocean Reef Group. These are largely dolomites and 

anhydrites beneath Big Cypress. The Upper Cretaceous 

Pine Key Formation is composed of chalky limestone 

and dolomite. It is approximately 914 m (3,000 ft) thick. 

The Paleocene to present day sedimentary layers lie atop 

the Pine Key Formation at Big Cypress (Faulkner and 

Applegate 1986). Relatively uninterrupted Tertiary 

deposition amassed the grand carbonate platform of 

South Florida. These sediments reach great thicknesses 

of approximately 1,676 m (5,500 ft). 

Cores drilled in nearby Everglades National Park help 

determine the upper stratigraphy at Big Cypress. Eocene 

to late Oligocene deposition consists of marine 

carbonates of the Avon Park Formation, the Suwannee 

Limestone and the Ocala Group, and the Arcadia 

Formation of ramp setting carbonates with scant quartz 

contents increasing northward (Cunningham 2005). A 

major disconformity marks the boundary between the 

Arcadia Formation and the overlying Peace River 

Formation. In other areas of Florida, the Hawthorn 

Group (Miocene) is between the Arcadia and Peace 

River Formations. The Peace River Formation contains 

two distinct units: a lower diatomaceous mudstone, and 

an upper fine- grained quartz muddy sandstone 

(Cunningham et al. 1998). Deposited atop the Peace River 

Formation is the Tertiary age Tamiami Formation. This 

unit comprises much of the surface outcrop at Big 

Cypress. 

Shallow water limestone of the Fort Thompson 

Formation underlies the surficial Miami Limestone. This 

limestone is probably combined with the capping unit of 

the Miami Limestone. The Fort Thompson is mostly 

lagoonal facies carbonate with abundant bivalve fossils 

and some quartz sand. The Miami Limestone is ≈125−130 

ka and represented deposition during an interglacial 

period. Two facies exist for the Miami Limestone. The 

western portion of the unit contains predominantly the 

bryozoan facies, the unit then becomes more oolitic 

eastward (Hoffmeister et al. 1974; Cunningham 2005). 

Overlying the Miami Limestone bedrock are surficial 

units of freshwater peat and organic muck, freshwater 

marls, and cyanobacteria mats in the swampy marsh at 

Big Cypress. The peat and muck typically occurs in lowlying sloughs and solution holes and are dark and finegrained. During the standing water phase of the wet 

season, extracellular precipitation of calcium carbonate 

by cyanobacteria forms fresh limestone marls 

(Cunningham 2005). 

Significant Geologic Resource Management Issues at 

Big Cypress National Preserve 

Hydrogeologic system at Big Cypress 

The Big Cypress is really a western extension on the 

Everglades system. Water is flowing on the surface in 

marshes and sloughs and below ground in slow flowing 
 NPS Geologic Resources Division 44 

aquifers through porous substrate. The present 

topographic and hydrogeologic information is too coarse 

and/or inadequate for resource management. More 

modeling is necessary to understand the true water 

budget of the preserve. 

The flow of water through the preserve has been 

drastically altered and diverted by the construction of 

roads, trails, pads, canals, and levees. The state and local 

pumping policies control a vast portion of water input to 

Big Cypress. Pumping can control basin dynamics. A 

major goal of the preserve is the restoration of the 

original flow ways as best as possible. A focus area is the 

9 to 12 m (30 to 40 ft) wide Turner River basin inchannel construction near U.S. Highway 41. Restoration 

efforts include reconnection flows through canals and 

roads (building causeways). The Bear Island area is 

another area to focus restoration efforts. Cooperation is 

necessary between resource management and local water 

volume management agencies to coordinate and 

organize the timing responses of gates and pumps. 

Regional models achieve varying degrees of success at 

Big Cypress. The South Florida Water Management 

Model (SFWMM) ignores roads and uses an outdated 

climatic scheme. The Natural Systems Model (NSM) 

uses vegetation patterns to predict an improved 

pseudotopography. The Across Trophic- Level System 

Simulation (ATLSS) correlates species with hydrology, 

hydroperiod, and vegetation. The Everglades Landscape 

Model (ELM) covers the hydrology of bounded systems 

of canals and structural control with rain- driven triggers. 

The Interim Structural and Operational Model (ISOP), 

which is 2−3 years from implementation, is probably the 

closest to the concerted water budget management the 

preserve needs, but still uses core data from the SFWMM 

model. Cell size and vertical precision vary on these 

models from 3.2 km (2 miles) to 30 m (100 ft) and 15 to 3 

cm (6 to 1 inches), respectively. Lidar would improve the 

vertical precision. 

Research and monitoring questions and suggestions 

include: 

• Study how rainfall controls the hydrologic system. 

• Does the depth to bedrock measurement have a 

significant control on the system? 

• Compare natural and anthropogenic caused hydraulic 

changes. 

• Monitor hydrologic response to storm events. 

• Try to get lidar mapping of sloughs for fine- scale 

topographic changes. 

• Obtain more hydrologic sampling and install 

hydrologic monitoring stations in key locations. 

• Determine more stage level measurement points. 

• Monitor stage level. 

• Attempt to align with the Comprehensive Everglades 

Restoration Program (CERP) efforts (Big Cypress is 

largely overlooked in favor of Everglades restoration). 

• Cooperate with federal, state, and local agencies to 

monitor and clean up ground and surface water; 

examples of pollution include creosote (from 

Copeland sawmill in the 1960s), agricultural runoff 

(including pesticides from tomato farms). 

• Deep Lake (27 m, or 90 ft, deep) is the southernmost 

sinkhole in Florida, why? 

• Focus geologic studies on processes rather than just 

features. 

• Categorize, describe, and model the near surface, midand deep aquifers below Big Cypress National 

Preserve. 

Geologic and topographic mapping 

The relief at Big Cypress is approximately 6 cm/km (2 

inches/mile) or 4.6 m over 145 km (15 ft over 90 miles). 

This incredibly low relief is the reason the sloughs, 

swamps, and marshes thrive at Big Cypress. Water slowly 

trickles down to the sea from central Florida. Highresolution topographic mapping, when combined with 

flow patterns would help resource management 

determine which areas to focus on for restoration. 

Research and monitoring questions and suggestions 

include: 

• Relate small- scale topographic differences with the 

locations of hammocks and pinelands at the preserve. 

• Map the locations where the Tamiami Limestone is 

exposed. 

• Focus topography and cross section production on 

key areas (coordinate with the original flow way 

restoration efforts). 

• Map karst features in addition to canals and rock pits 

on maps. 

• Cooperate with slough mapping project through the 

Audubon Society. 

• Expand upon the Tamiami type section located within 

the preserve. 

• Are strands and paleochannels related? 

• Why is the boundary between Big Cypress and the 

Everglades so dramatic? 

• What is the nature of the boundaries between strands? 

• Map rock outcrops at different scales and determine if 

they have a controlling influence on the location of 

Cypress stands. 

• Greg Desmond with the USGS is conducting a HighAccuracy Elevation Project with an Airborne Height 

Finger (AHF), which creates Digital Elevation Models 

(DEMs); support him to obtain better data. 

• Determine original flow ways with DEMs. 

• Suggest more USGS/BLM/NRCS/SFWMD/FLDOT 

cooperative geologic/mapping projects. 
 BICY Geologic Resource Evaluation Report 45

Disturbed lands 

Disturbed lands besides areas affected by oil and gas 

operations, include borrow pits excavated for the 

construction of the oil and gas pads and roads built to 

access remote sites. 

Research and monitoring questions and suggestions 

include: 

• Quantitatively identify disturbed sites and explore 

remediation to restore natural water flow. 

• Remove Bear Islands closed oilfield roads. 

• Work on finding ways to build bridges and reculvert 

established road areas to improve flow focusing on 

roads directly perpendicular to flow first. 

ORV management 

More than 425,145 visitors came to the preserve in 2004. 

These visitors enjoyed the incredible recreational 

opportunities at Big Cypress. Activities include camping, 

kayaking, hiking, bird watching, canoeing, hunting, ORV 

use, and airboat access. The preserve is attempting to 

concentrate visitor access to reduce environmental 

impact. 

Raised roadbeds across south Florida have dammed the 

natural, low relief, slow moving sheet- flow from Lake 

Okeechobee to Florida Bay. ORV use at Big Cypress has 

caused major damage to the hydrology and soils. Soil 

resiliency at the preserve is not well understood. Buggies 

and other ORVs destroy algae (terraphytes) populations 

in the soils. The entire ecosystem is based on these 

microorganisms that lie dormant in dry conditions. 

When they are churned up and buried, the landscape 

resembles a soil desert. An ORV management plan, 

completed in 2001, calls for a designation of 644 km (400 

miles) of trails in the preserve. It is estimated that at least 

22,000 miles of trails currently exist. For a park the size 

of the state of Rhode Island, the ranger on duty has 

difficulty patrolling the ORV activity. Unauthorized 

airboat use is also a resource management issue affecting 

water quality, noise levels, and soils. 

Research and monitoring questions and suggestions 

include: 

• Determine the best sites for a designated trails system. 

• Perform a preserve- wide soils survey to establish 

baseline conditions for trail planning. 

Oil and gas issues 

Oil and gas exploration began in the Big Cypress area in 

1923. Most of the active drilling was in the mid 1970s. The 

main producing geologic unit is the Sunniland 

Formation. Approximately 450 wells have been drilled 

along the northwest−southeast oriented Sunniland 

Trend. Oil and gas activity in the preserve is rapidly 

declining. As of September 2004, there are 18 wells 

producing from only eight fields. Eight of these 

producing wells are located within the preserve. The oil 

and gas reservoir rocks are porous (10- 30% porosity). 

They are composed of carbonate grainstones and 

dolomites sealed by evaporites and/or nonporous 

carbonates. Based on 2D seismic surveys, gravity and 

magnetics data, the overall drilling success rate has been 

about 3% (Norby 2005). 

Most of the oil and gas rights under the preserve are of 

private ownership, established prior to the designation of 

the preserve. Ninety- nine percent of the land at the 

preserve is “split estate” meaning the surface and 

subsurface ownership is different. The pads and roads 

left behind when a well is closed leave a large scar on the 

landscape and affect the hydrologic system at Big 

Cypress. Roads are built of borrow pit material 1.2 m (4 

ft) higher than the surrounding drainage. Culverts are 

thinly spaced and many are falling into rusty disrepair. 

The responsibility for monitoring, compliance with 

regulations, restoration and remediation is often unclear 

and pipes, wells, and structures are still at abandoned 

pads. 

Research and monitoring questions and suggestions 

include: 

• Explore making a depth to bedrock measurement 

mandatory per shot hole for oil and gas (seismic) 

exploration surveys conducted in the Preserve. 

• Obtain seismic information per township on a grid 

pattern. 

• Use road and pad fill for trail construction and other 

remediation work. 

• Work with corers to obtain more stratigraphic data. 

• Attempt to update the Minerals Management Plan to 

have stronger surficial protection regulations. 

•
 NPS Geologic Resources Division 46 

References 

Condie, K.C., Sloan, R.E., 1998, Origin and Evolution of 

the Earth, Principles of Historical Geology. PrenticeHall, Inc., 498 p. 

Cunningham, K.J., 2005, Hydrogeologic Fieldtrip 

Everglades National Park, Southeastern Florida, 

unpublished. 

Cunningham, K.J., McNeill, D.F., Guertin, L.A., 

Ciesielski, P.F., Scott, T.M., de Verteuil, L., 1998, New 

Tertiary Stratigraphy for the Florida Keys and 

Southern Peninsula of Florida. Geological Society of 

America Bulletin, vol. 110, pp. 231- 258. 

Faulkner, B.M., Applegate, A.V., 1986, Hydrocarbon 

exploration evaluation of the Pulley Ridge area, 

offshore South Florida Basin. Transactions – Gulf 

Coast Association of Geological Societies, vol. 36, pp. 

83- 95. 

Guertin, L.A., McNeill, D.F., Lidz, B.H., Cunningham, 

K.J., 1999, Chronology and Transgressive/Regressive 

Signatures in the Late Neogene Siliciclastic 

Foundation (Long Key Formation) of the Florida 

Keys. Journal of Sedimentary Research, vol. 69, pp. 

653- 666. 

Heatherington, A.L., Mueller, P.A., 1991, Geochemical 

evidence for Triassic rifting in southwestern Florida. 

Tectonophysics, vol. 188, pp. 291- 302. 

Hoffmeister, J.E., Stockman, K.W., Multer, H.G., 1967, 

Miami Limestone of Florida and its recent Bahamian 

counterpart. Geological Society of America Bulletin, 

vol. 78, pp. 175- 190. 

McNeill, D.F., Cunningham, K.J., Guertin, L.A., Melim, 

L.A., Warzeski, E.R., Anselmetti, F.S., Ginsburg, R.N., 

Eberli, G.P., Swart, P.K., 1996, Data Report: TertiaryQuaternary cores from the Florida Keys and 

Everglades. Miami Geological Society, South Miami, 

Florida, 98 p. 

Norby, L., 2005, Oil and Gas Development South Florida 

and Big Cypress National Preserve. National Park 

Service, unpublished, 3 p. 

Pollastro, R.M., Schenk, C.J., Charpenter, R.R., 2000, 

Undiscovered Oil and Gas in the Big Cypress National 

Preserve—A Total Petroleum System Assessment of 

the South Florida Basin, Florida. U.S. Geological 

Survey, Open File Report 00- 317. 

Shinn, E.A., Lidz, B.H., Halley, R.B., 1997, IGC Field 

Guide T176: A Field Guide: Reefs of Florida and the 

Dry Tortugas. In: Geological Environments of Florida 

Bay and the Florida Keys Reef Tract. Compiled by: 

Tihansky, A., Prager, E., Shinn, G. 

Thomas, W.A., Chowns, T.M., Daniels, D.L., Neatherly, 

T,L., Glover, L., Gleason, R.J., 1989, The subsurface 

Appalachians beneath the Atlantic and Gulf coastal 

plains. The Geology of North America, vol. F- 2, 

Geological Society of America. 

Warzeski, E.R., Cunningham, K.J., Ginsburg, R.N., 

Anderson, J.B., Ding, Z.D., 1996, Neogene Mixed 

Siliciclastic and Carbonate Foundation for the 

Quaternary Carbonate Shelf, Florida Keys. Journal of 

Sedimentary Research, vol. 66, pp. 788- 800. 

Scoping meeting participants 

NAME AFFILIATION PHONE EMAIL 

Ron Clark NPS, BICY 239- 695- 1106 

Sid Covington 

NPS, Geologic Resources 

Division (303) 969- 2154 sid_covington@nps.gov 

Don Hargrove NPS, BICY 239- 695- 1150 

Melanie Harris USGS, CCWS 

727- 803- 8747 

x3023 mharris@usgs.gov 

Carrie Karl NPS, BICY 239- 695- 1201 

Lisa Norby NPS- GRD 303- 969- 2318 

Frank Partridge NPS, BICY 239- 695- 1162 

Matt Patterson NPS, SFCN 305- 224- 4211 

Anne Poole 

NPS, Geologic Resources 

Division 303- 987- 6954 anne_poole@nps.gov 

Pedro Ramos NPS, BICY 239- 695- 1103 

Bob Sobczak NPS, BICY 239- 695- 1150 

Trista ThornberryEhrlich Colorado State University 757- 222- 7639 tthorn@cnr.colostate.edu 
The Department of the Interior protects and manages the nation’s natural resources and cultural heritage; provides scientific and other 

information about those resources; and honors its special responsibilities to American Indians, Alaska Natives, and affiliated Island 

Communities. 

Big Cypress National Preserve 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2008/021 

NPS D-176, February 2008 

National Park Service 

Director • Mary A. Bomar 

Natural Resource Stewardship and Science 

Acting Associate Director • Mary Foley, Chief Scientist of the Northeast Region 

Natural Resource Program Center 

The Natural Resource Program Center (NRPC) is the core of the NPS Natural Resource Stewardship and 

Science Directorate. The Center Director is located in Fort Collins, with staff located principally in 

Lakewood and Fort Collins, Colorado and in Washington, D.C. The NRPC has five divisions: Air 

Resources Division, Biological Resource Management Division, Environmental Quality Division, Geologic 

Resources Division, and Water Resources Division. NRPC also includes three offices: The Office of 

Education and Outreach, the Office of Inventory, Monitoring and Evaluation, and the Office of Natural 

Resource Information Systems. In addition, Natural Resource Web Management and Partnership 

Coordination are cross- cutting disciplines under the Center Director. The multidisciplinary staff of NRPC 

is dedicated to resolving park resource management challenges originating in and outside units of the 

national park system. 

Geologic Resources Division 

Acting Chief • John Vimont 

Planning Evaluation and Permits Branch Chief • Carol McCoy 

Credits 

Author • Trista Thornberry- Ehrlich

Review • Don Hargrove 

Editing • Diane Lane, Sid Covington, and Melanie Ransmeier 

Digital Map Production • Anne Poole 

Map Layout Design • Andrea Croskrey
Geologic Resources Division 

Natural Resource Program Center 

P.O. Box 25287 

Denver, CO 80225 

http://www.nature.nps.gov/geology/inventory/ 

(303) 969-2090 

EXPERIENCE YOUR AMERICATM 

National Park Service 

U.S. Department of the Interior