Everglades National Park. South Florida Research Center. P.O. Box 279. Homestead, Florida 33030 
Geologic Structure of the Surficial Aquifer System 

Underlying Everglades National Park 

and the Big Cypress National Preserve 

Report SFRC-85/02 

Martha Jarosewich and Joel Wagner 

National Park Service 

South Florida Research Center 

Everglades National Park 

Homestead, Florida 33030 

# 

2 ,. March 1985 
Technical review provided by: 

Howard Klein - U. S. Geological Survey 

and 

Garald Parker - Parker and Associates 

Jarosewich, Martha, and Joel Wagner. 1985. Geologic Structure of the Surficial 

Aquifer System Underlying Everglades National Park and the Big Cypress 

National Preserve. South Florida Research Center Report SFRC-85/02. 43 p. 
TABLE OF CONTENTS 

LIST OF TABLES ............................ ii 

. . LIST OF APPENDICES .......................... 11 

... LIST OF FIGURES ........................... 111 

ABSTRACT .............................. 1 

INTRODUCTION ............................ 2 

GEOLOGYOFSOUTHFLORIDA ..................... 5 

Late Cenozoic Geology ...................... 5 

The Biscayne and Chokoloskee Aquifers ............... 9 

STUDY METHODS ........................... 11 

Datacompilation ......................... 11 

Methods of Interpretation ..................... 13 

RESULTS AND DISCUSSION ....................... 15 

GeologicCrossSections ...................... 15 

Contour Map of the Base of the Surficial Aquifer System ....... -21 

SUMMARY AND CONCLUSIONS .................... -21 

ACKNOWLEDGEMENTS ......................... 23 

LITERATURE CITED .......................... 24 
Tables 

LIST OF TABLES 

Page 

1. Summary of late Cenozoic Formations of south Florida 

(modified from Schroeder et al. 1958). ............... 6 

LIST OF APPENDICES 

Appendix Page 

A. Index of wells investigated.. .................. .26 

Be Example of lithologic well log description. ............ .42 
LIST OF FIGURES 

Figure Page 

1. Generalized watersheds of pre-drainage south Florida. ........ 3 

2. Some major features of south Florida's Water Management System. .. 4 

3. Geologiccross-sectionalongaNaples-Miamitransect.. ....... 7 

4. Surficial geology of south Florida (modified from Parker et al. (1 955) ....................... andMcCoy(1962)). 8 

5. Surface extent of the Biscayne and Chokoloskee Aquifers. ...... 10 

6. Locations of wells with descriptive logs available in Dade, Collier, 

and northern Monroe Counties, Florida. .............. 12 

7. Example of a descriptive well log with corresponding electric 

resistivitylog. ........................ -14 

8. Transects of geologic cross-sec tions through Everglades National Park 

and the Big Cypress National Preserve. .............. 16 

9. Nort h-south geologic section ( A-A') along western Big Cypress 

NationalPreserve. ...................... -17 

10. East-west geologic cross section (B-B') along U. S. 41 through 

CollierCounty.. ....................... '18 

1 1. North-south geologic cross section (C-C') through the Big Cypress 

NationalPreserve. ...................... .19 

12. Northwest-southwest geologic cross section (D-Dl) through Everglades 

Nationalpark. ........................ .20 

13. Contour map of the base of the Surficial Aquifer System in Dade, 

Collier, and northern Monroe Counties, Florida. ........... -22 

iii P 

xq 
ABSTRACT 

Well logs from 67 existing deep wells in southern Florida were used to determine 

the stratigraphy, depth, and extent of the Surficial Aquifer System underlying 

Everglades National Park and the Big Cypress National Preserve, Florida. Four 

geologic cross sections were prepared along well transects within the park and 

preserve to profile the aquifer system. The profiles reveal considerable heterogeneity in the lithologies but suggest two distinct zones: an upper zone of permeable 

limestones and clastics and a more heterogeneous lower zone of relatively 

impermeable fine-grained sands and sandy silts interbedded with permeable sands, 

limestones, and shelly marls. 

The permeable upper zone and the more permeable beds of the lower zone were 

considered to be hydrologically connected; thus, the two zones were treated as 

comprising a Surficial Aquifer System. Presence of a regionally continuous "green 

clay bed" of the lower Tamiami Formation was verified, and it was considered the 

base of the aquifer system. Depth to this bed was determined for the 67 wells, and 

a contour map of depth to the base of the Surficial Aquifer System was constructed 

for Dade, Collier, and northern Monroe counties. Surficial Aquifer System depths 

in the study area range from 90 feet (27.4 m) to 300 feet (91.5 m) below mean sea 

level. 

Key words: Everglades National Park, Big Cypress National Preserve, hydrology, 

hydrogeology, geology, well logs, aquifer. 
INTRODUCTION 

Properties of the Surficial Aquifer System underlying southern Florida's Everglades 

and Big Cypress basins (Fig. 1) create a unique relationship between the area's 

surface and ground water hydrology. Gleason (1984) describes the aquifer system 

as a series of interstratified highly permeable and relatively impermeable layers 

extending from the surface down to a regionally continuous basal zone. Fluctuating hydraulic gradients, and the permeabilities of the sands, limestones, 

sandstones, marls, and silts that compose the aquifer system control regional 

groundwater movement. Left undisturbed, this movement is generally slow 

freshwater seepage toward coastal areas, with some inland migration of seawater 

occurring during extended drought periods. Overall high permeability of the 

lithologies, together with low land elevations, lack of surf ace relief, and seasonally 

plentiful rainfall also allows the water table in the aquifer to rise above the land 

surface over large areas. These surface waters may then follow seaward gradients 

as "sheetflowl' to tide, but also serve as a source of recharge for the Surficial 

Aquifer System. Thus, surface and groundwater are closely related, and disturbance of either must ultimately be viewed as having consequences for both. 

The historic surface and groundwater hydrology of southern Florida, including the 

areas within what is now Everglades National Park and the Big Cypress National 

Preserve (Fig. Z), clearly have been perturbed by water management practices. 

For example, prior to drainage efforts spanning the last 100 years, Shark Rivef 

Slough in Fverglades National Park was the downstream end of the 9000 mi 

(23,3 00 km ) Kissimmee-Lake Okeechobee-Everglades basin (Fig. 1 ). This formerly 

integrated hydrologic system is now subdivided by hundreds of miles of canals and 

levees (Fig. 2) installed for purposes of drainage, flood control, and water supply. 

Leach et al., (1 972) and various other authors have documented some effects of 

south Florida water management upon Everglades hydrology. Surface waters may 

now be retained by levees and released to downstream areas according to 

schedules. Groundwater may be intercepted by canals and diverted to other basins 

or to the ocean. Watersheds in the eastern part of the park have been similarly 

affected by water management external to park borders (Rose, Flora, and 

Rosendahl 1981), and most of the Big Cypress basin no longer retains its natural 

hydrologic character (Klein et al. 1970). Management of the park and preserve's 

water resources is, therefore, aimed at minimizing any deleterious effects of 

upstream or local water management practices and restoring historic surface and 

groundwater processes where practicable. 

Physical-mathematical models capable of integrating regional surface and groundwater hydrology show promise as tools for evaluating park restoration proposals. 

Accuracy in such modelling is usually dependent upon the availability of extensive 

regionally distributed hydrologic and geologic data. However, insufficient data, 

theoretical constraints, or other limitations often require simplification of some 

model components. Such is often the case with subsurface flow, where twodimensional representations of groundwater processes are widely employed despite 

the heterogeneous lithologies that may in fact be present (Dunne 1982). This 

report analyzes the available geologic data with the intent of defining the 

heterogeneous structure of the Surficial Aquifer System underlying the park and 
GULF OF MEXICO 

Watershed Boundory 

Atlontic Coostol Ridge 

FLORIDA BAY fl 

Figure 1. Generalizear watersheds of pre-drainage south Florida. 

YC 
GULF OF MEXICO 

LEGEND 

Figure 2. Some major features of south Florida's Water Management System. 
preserve. However, emphasis is also placed on defining the extent of the aquifer 

from a simplified homogeneous perspective for application to most physicallybased regional hydrologic modelling efforts. 

GEOLOGY OF SOUTH FLORIDA 

Late Cenozoic Geology 

The Surficial Aquifer System consists of layered late Cenozoic era formations 

(Table 1) sloping from the central part of south Florida toward the coasts. The 

Naples to Miami cross-section shown in Figure 3 illustrates most of these formations. Stratigraphic unconformities in the formations resulted from distinct 

changes in sedimentary environments, followed by periods of erosion. During the 

early Pliocene when southern and eastern Florida were submerged, shelly marl 

beds, sandy limestones, and calcareous clays of the Caloosahatchee Marl and 

Tamiami Formations were being deposited. In the late Pliocene, a period of crustal 

instability caused the Floridan Plateau to emerge and differentially erode. Alternating freshwater and marine sediments in the late Pleistocene and Recent epochs 

were subsequently deposited, corresponding to sea level fluctuations during different glacial episodes (Parker et al. 1955; Parker and Cooke 1944). 

The Tamiami Formation (Fig. 3) is the oldest member within the Surficial Aquifer 

System. It consists of two principle units; a lower unit of heterogeneous detrital 

sediments of variable permeability and an upper unit of generally highly permeable 

limestones and sandstones. The lower unit of the Tamiami Formation consists of 

shelly fine sands and greenish sandy, clayey silt beds. Throughout southern Florida 

these lower strata vary in thickness and extent, conforming with the surface of the 

underlying Hawthorn Formation (Schroeder et al. 1958). The lowest silt bed, a low 

permeability green clay, is identified by its argillaceous property rather than by 

mineral content (Peacock 1983). This bed and similar low permeability beds near 

the interface of the Tamiami and Hawthorn Formations form the major confining 

unit separating the Surficial Aquifer System from the underlying Floridan Aquifer 

(Gleason 1 984). 

The permeable upper unit of the Tamiami Formation extends as the surface 

bedrock over a large area of southwestern Florida (Fig. 4), including much of the 

Big Cypress basin. Dissolution and reprecipitation of dissolved minerals in the 

exposed limestone have formed a dense authigenic caprock throughout most of the 

preserve (Center for Wetlands 1979). The clast ic members underlying the 

limestone in this area are generally argillaceous, shelly marls which, in part, have 

been indurated to a permeable limestone. Toward the east, the clastic and 

limestone beds increase in sand and silt content. Toward the west, the upper beds 

of the formation are interstratified with some green silty shell beds of the 

Caloosahatchee Marl which thicken toward the coast. 

Pleistocene Age formations overlying the Tamiami Formation are primarily composed of marine and freshwater sediments. The Fort Thompson Formation (Fig. 3, 

Table 1) best reflects these alternating depositional environments. It consists of 

very permeable, fossiliferous, sandy marine limestones and calcareous sandstones 

interstratified with thin 1ayer.s of dense freshwater limestone. In Dade County the r 
Table 1. Summary of late Cenozoic Formations of south Florida (modified from Schroeder 

et al. 1958). 

Period Epoch For mat ion Characteristics 

T Pliocene 

Miocene 

Pamlico Sand Permeable quartz sand, white to black, 

very fine to coarse. Covers large areas 

underlain by Miami Oolite and the 

Anastasia Format ion. 

Miami Limestone 

Anastasia 

For mat ion 

Key Largo 

Limestone 

Fort Thompson 

Formation 

Limestone, oolitic with a lower Bryozoan 

layer. Permeable. 

Coquina, sand, calcareous sandstone, 

sandy limestone, and shell marl. Probably 

composed of deposits equivalent in age to 

marine members of Fort Thompson Format ion. Permeable. 

Cavernous coralline reef rock. 

Very permeable. 

Alternating marine and freshwater 

limestone and sandstone. Very permeable. 

Caloosahatchee Marl Sandy and marly clay, silt, and shell beds. 

Generally low permeability. 

Tamiami Formation White and greenish-gray clayey marl, silty 

shelly sand, and shell marl locally hardened to limestone. Upper unit is highly 

permeable, lower unit is of low permeability. 

Hawthorn 

For mation 

Sandy, silty with "green clay" or marl. 

Generally impermeable, however, interstratified with sand and sandy pebble 

lenses. 

.............. 

............. 

............... ..................... 

...................... 

..................... ..................... 

.................... 

................... ................. 

................... 

------A 

I--- TI- = z- -=I 

-1- 

- - - - - - - - - - - - - - - 

-- 

-- - - - - - - - - - 
formation unconformably overlies the Tamiami Formation, forming a wedge which 

thickens toward the east coast (Fig. 3). The Fort Thompson Formation also 

overlies the Tamiami Formation toward Florida's west coast, forming the surface 

bedrock in portions of eastern and northern Collier County (Fig. 4). The Anastasia 

Formation (Fig. 4), a permeable limestone of marine origin, is approximately 

equivalent in age to the Fort Thompson Formation. It forms much of the surface 

bedrock in western Monroe County (Fig. 4) and thickens to the north. The Key 

Largo Limestone, a permeable coralline limestone, extends along the coastal area 

of southern Dade County and in the upper Florida Keys (Fig. 4). It yields large 

volumes of water due to its cavernous property but, like other permeable coastal 

formations including the Miami Limestone and Fort Thompson Formation, also 

permits salt water intrusion. 

Younger Pleistocene formations were deposited over the Fort Thompson and 

Anastasia Formations in southeastern Florida. The Miami Limestone unconformably overlies these formations and forms the surface bedrock throughout most of 

Dade County. It consists of an upper, prominent oolitic facies and a lower 

bryozoan facies. The formation has high vertical permeablity but its horizontal 

permeability is lower (Parker et al. 1955). The Pamlico Sand Formation of late 

Pleistocene unconformably and intermittently overlies the Miami Limestone in 

Dade County. It is a permeable, generally unconsolidated clean quartz sand 

deposited during interglacial periods. 

In southwestern Florida, younger Pleistocene marine sediments overlying the 

Tamiami Limestone are wedge-shaped (Fig. 3) and thicken toward the northwest. 

The limestones and sandstones are generally mapped as the Anastasia Formation 

but may be facies from a diagenetically altered Fort Thompson Formation and an 

unnamed member of the Tamiami Formation (Gleason 1984). The Pamlico Sand 

Formation unconformably overlies these limestone and sandstone beds and is a 

prominent surface feature along the gulf coast (Fig. 4). 

The Biscayne and Chokoloskee Aquifers 

Aquifer studies in south Florida have largely concentrated on two permeable water 

yielding zones within the Surficial Aquifer System; the Biscayne Aquifer along the 

southeast coast and the Chokoloskee or "Shallow Aquifer" (Parker 1982) of the 

southwest coast (Fig. 5). Geologic investigations including those by Parker (1 952), 

Parker et ale (19551, Parker and Cooke (1 944), Schroeder et al. (1958),. and Klein 

and Hull (1978) provide detailed qualitative informati~n and quantitative data on 

the Biscayne Aquif ere Reports by McCoy (1 962, 1 9721, Klein (1 972), and the Center 

for Wetlands (1 979) are sources of similar information on the Chokoloskee Aquifer. 

The Biscayne Aquifer is defined by hydrogeologic properties rather than by 

formational boundaries. It is wedge-shaped (Fig. 3), extending along the east coast 

and thinning westward to the Dade-Collier County line (Fig. 5). The bottom of the 

permeable limestone member of the Tamiami Formation (upper unit) forms the 

base of the aquifer. In most of Dade County the Miami Limestone forms the upper 

portion of the aquifer, with the oolitic facies forming the surface bedrock in large 

areas of Everglades National Park. Rapid infiltration into this oolitic limestone 

facilitates aquifer recharge, thus making the park a significant recharge source. 
LOCAL DISCONTINUOUS 

LOW YIELD MATERIAL 

PARK /PRESERVE BOUNDARY 

ATLANTIC 

FLOff/DA BAY 

GULF Of MEXICO 

Figure 5. Surface extent of the Biscayne and Chokoloskee Aquifers. 
Aquifer transmissivity varies with local changes in lithologic properties. Published 

transmissivity values range from 3.2 to 14 million gallons per day per foot (gpd/ft), 

with an average of 5 million gpd/ft (Parker et al. 1955). 

The Chokoloskee Aquifer or Shallow Aquifer extends along Florida's southwest 

coast and thins northward and eastward to the Collier-Dade County line. The 

limestone member of the Tamiami Formation is the basal unit of the aquifer as it 

is in the Biscayne Aquifer, but it extends to the surface in the Big Cypress 

Preserve. Although the bedrock near the surface is very porous, its cavities 

generally have been filled with marl and sand deposits to a depth of 10 to 15 feet, 

thereby, locally impeding infiltration (Parker, G. G., pers. comm., August 1983). 

Transmissivity values for the Chokoloskee Aquifer are lower than those for the 

Biscayne Aquifer. Values in the western Big Cypress Preserve range from less than 

1.2 to 3.5 million gpd/ft (Missimer 1981) with an average of 2.0 mgd/ft calculated 

for the northern portion of the preserve (~lein 1972). 

While both aquifers are composed of quite permeable formations, hydrogeologic 

differences in the surface bedrock and in the underlying geology result in the broad 

ranges of transmissivity and recharge rates. Local hydrologic studies, therefore, 

may require on-site transmissivity measurements. 

STUDY METHODS 

Data Com~ilation 

Appendix A summarizes deep well information available within and directly adjacent to the study area (Dade, Broward, and northern Monroe Counties). Sources 

included wells drilled by county, state, and federal agencies, and deeper exploration wells drilled by private industries. Well logs were obtained from files at the 

U. S. Geological Survey in Tallahassee, from private industries, and from various 

literature sources. Wells for which geologic logs were available are numbered 1 

through 215 in Appendix A, followed by listings of wells for which log descriptions 

were not available. Well log information in Appendix A includes location, log 

description parameters, and depth to the the confining zone of the Surficial 

Aquifer System (the "green clay" bed of the Tamiami Formation's lower unit). 

Literature references are identified where applicable, and a "comments" column 

lists other available information. 

Data analysis focused on wells drilled in Dade, Collier, and northern Monroe 

Counties within the boundaries of the park and preserve, however, well logs from 

outside the study area were also used for reference, continuity, and correlations. 

Of the 21 5 available well logs reviewed, only 67 contained information pertinent to 

determining the stratigraphy, composition, depth, and extent of the Surf icial 

Aquifer System. Figure 6 shows the locations of the 215 wells, with numbers (as 

assigned in Appendix A) representing locations of the wells ultimately used in 

determining aquifer depth and extent. A separate column in Appendix A also 

indicates whether or not t h e d a t a were used in the report. 
Figure 6. Locations of wells with descriptive logs available in Dade, Collier, and 

northern Monroe Counties, Florida. 
Methods of Interpretation 

Stratigraphic interpretations in the study were primarily based upon descriptive 

well logs. These geologic, lithologic, driller, and paleontological logs provided 

useful qualitative information, but varied in quality and content. Descriptions 

ranged from detailed records of texture, color, and mineral and fossil content at 

pre-determined intervals to driller logs which simply identify rock types. 

Geophysical logs, including self-potential, electrical resistivity, and natural gamma 

data, were a valuable supplement to the descriptive logs. Electric resistivity and 

self-potential measurements simultaneously respond to variations in temperature, 

salinity, and porosity. A corresponding decrease in these signatures reflects a 

change in composition, most likely indicating a dense, less permeable zone. The 

example of an electric resistivity log corresponding to a stratigraphic description 

in Figure 7 shows a sustained lower resistivity associated with the green clay lens 

beginning at 120 feet (36.6 m). Natural gamma logs detect the presence of 

radioactive elements generally concentrated in clays, silty clays, or sands. A 

relative increase in gamma readings indicates a zone with increased phosphates and 

clay content, suggesting a clay lens or aquiclude. 

Special considerations are necessary for interpretation of geophysical logs in 

coastal sedimentary environments of southern Florida. Signals may be affected by 

marine water trapped in sediments or by a fluctuating saltwater intrusion zone. 

Geophysical interpretations were, therefore, based on relative differences in 

recorded signals rather than actual signal magnitudes and were used only in 

supplementing descriptive logs. 

Depth to the Surficial Aquifer System's confining zone was based on the hydrogeologic properties of the sediments at each well. Strata considered part of the 

Surficial Aquifer System were primarily composed of porous unconsolidated sediments and permeable limestones capable of storing and transmitting water. The 

underlying fine-grained sediments are also quite porous, however, their low 

permeability impedes water movement. The depth of the aquifer was, therefore, 

defined as the base of the last relatively permeable stratum overlying the 

regionally continuous "green clay" zone. 

Definition of the "last relatively permeable stratum" is complicated by interstratification in lower portions of the aquifer system. Well W-7363 (Appendix 8, D3 in 

Fig. 121, which is representative of the general geologic character of southeastern 

Dade County, illustrates this structure. Relatively impermeable beds of clay and 

fine-grained sands begin at 63 feet (19.2 m) but are interstratified with layers of 

coarse sand and shell. Well drilling and pump tests by the U. S. Geological Survey 

(Miami Subdistrict) at several sites within and adjacent to the park (Fig. 6) have 

shown that yield from the clay and fine sand beds was poor, but that large volumes 

of water could be pumped from the more permeable coarse sand and shell beds 

(pers. comm., Carmen Causaras, U. S. Geological Survey, Miami Subdistrict). 

Observations at these sites verified that the low permeability beds are not 

regionally continuous and, thus, do not confine the more permeable zones. 

Therefore, the regionally continuous "green clayI1 zone (beginning at 225 feet 

(68.6 m) at well W-7363) was considered the confining stratum both in the park and 

for comparable structure throughout the study area. 
LITHOLOGY 

LIMESTONE j WHITE TO GRAY) MOLDIC 

FOSSILIFEROUS, MINOR OUARTZ 

--- - - 

--- - - 

SILT, CLAYEYJ OLIVE GREEN TO GREEN, 

--- 

- - MINOR QUARTZ AND PHOSPHORITE, 

TRACE LIMESTONE 

-7- 

--- 

- - 

Figure 7. Example of a descriptive well log with corresponding electric resistivity 

log* 
When correlating aquifer depths between well sites it was important to consider 

the nonconformity, and heterogeneous character of the underlying geology. Because the permeability of a lithologic unit is significant only relative to its 

thickness, extent, and the nature of the surrounding beds, stratigraphic interpretations were based upon trends in lithologic properties rather than simply by 

formational boundaries. 

RESULTS AND DISCUSSION 

Geologic Cross Sections 

Four geologic cross sections were prepared to profile the Surficial Aquifer System 

underlying Everglades National Park and the Big Cypress National Preserve 

(Fig. 8). Two transects, A-A', and C-C', traverse the preserve from north to south 

and a third transect, 8-B', runs west-east, paralleling U. S. 41. In Dade County a 

northwest to southeast transect, D-D', passes through the north central part of the 

park and extends to the southeast coastline. 

The lithology along transect A-A' (Fig. 9) is primarily a limestone unit interstratified and underlain by sandy and shelly beds (Al-AS). The low permeability green 

clay zone occurs at approximately 300 feet (91.5 m) below mean sea level along the 

transect except at well A6. Here the confining bed rises sharply, indicating a rapid 

thinning of the Surficial Aquifer System to the north. 

Transect B-B' (Fig. 10) shows that the Surficial Aquifer System structure is 

dominated by permeable limestones and shelly sands. The aquifer thickens from 

the gulf coast toward south central Collier County where it reaches a maximum 

thickness of 300 feet (91.5 m). A rapid thinning occurs from this point to the east. 

Strata near the gulf coast are relatively homogeneous, consisting primarily of 

limestone underlain by sands (B3) or sandy limestone (81). Calcareous marl is more 

prevalent in the west (82) than toward the eastern Big Cypress area. At site B4, 

the limestone and shelly sand is interstratified with silt and sandstone lenses. As 

the aquifer thins toward the east from this point, a marked increase in shelly sands 

occurs (B5) with strata becoming primarily limestone and sandy limestone further 

east. 

The north-south transect C-C' (Fig. 1 1 ) passes through the central and eastern 

portion of the preserve. The profiles give areal perspective to the eastward 

thinning of the aquifer indicated by transect B-8'; The Surficial Aquifer System 

thickness averages only 160 feet (48.8 m) along the transect compared to 300 feet 

(91.5 m) along transect A-A'. The lithology is primarily a surface limestone 

underlain by sands (C3, C4) or interstratified with sandstone (Cl, C2, C5) and 

shelly limestone beds (C2, C5). 

Profile D-D' (Fig. 12) through Everglades National Park shows a gradual thickening 

of the aquifer system toward the east coast. The maximum depth to the top of the 

confining zone reaches 260 feet (79.3 m) at D4. The stratigraphy at the northern 

part of the park (Dl) conforms with the lithologic properties in the southern Big 

Cypress Preserve. The heterogeneous sand and silt zones are interstratified with 

sandstone and shelly limestone beds. To the east, the limestone thickens (D3, D4) 

and is underlain by sand and sandy silt zones with lenses of coarse sand and shell 

beds. ? 





The four geologic cross sections verify the existence of two distinct aquifer zones 

beneath the park and preserve. The upper zone consists of permeable limestones 

and clastics and includes the Biscayne and Chokoloskee Aquifers. The lower zone 

is a more heterogeneous sandy and sandy-silt section interbedded with permeable 

sands, limestones, and shelly marls. As discussed previously, the two zones are 

hydrologically connected, and together comprise a regional Surficial Aquifer 

System. 

One important application of the profile information is in developing physically 

based hydrologic simulation models for use in park water delivery management. It 

is doubtful, however, that an expensive, finely detailed 3-dimensional aquifer 

representation of the vast Everglades and Big Cypress basins would yield significantly greater accuracy in regional water level prediction than would a simplified 

model. The following section, therefore, presents the data as a contour map of a 

simplified, homogeneous Surficial Aquifer System extending down to the system's 

confining zone. 

Contour Map of the Base of the Surficial Aquifer System 

Depths to the top of the confining material in each well used in the study were 

plotted on a base map and contours were constructed at 20 foot intervals (Fig. 13). 

The contours in the eastern portion of the study area reveal a wedge-shaped 

aquifer system with the thickest portion near the Atlantic Coast. There it reaches 

a depth of 260 feet (79.3 m) below msl and gradually thins both to the north and 

west to a minimum of 90 feet (27.4 m) below msl in eastern Collier County. 

West of the node in eastern Collier County the aquifer system again gradually 

thickens, reaching a maximum depth of 300 feet (91.5 m) below msl in a depression 

near the western border of the Big Cypress National Preserve. Contours based 

upon the intersection of transects A-A' and B-B' show this depression to be northsouth trending. The depression may have served as a funnel through which clastic 

sediments were deposited in a marine environment (Peacock 1983). West of the 

depression the aquifer system thins, conforming with the Shallow Aquifer depths 

determined by Jakob (1 983) for the area south of Naples. 

Extrapolated areas on the contour map indicate large areas of Dade, Collier, and 

northern Monroe Counties where subsurface geology data are vague or nonexistent. 

Field studies presently being conducted by the South Florida Water Management 

District and the U. S. Geological Survey (Miami Subdistrict) should make significant contributions to filling these gaps in lithologic information and determining 

corresponding transmissivity data. 

SUMMARY AND CONCLUSIONS 

Protection of Everglades National Park and the Big Cypress National Preserve in 

an atmosphere of increasingly competitive regional water needs requires sophisticated knowledge of the area's hydrology. Physically-based mathematical models 

integrating surface and subsurface hydrology should prove useful in simulating 

hydrologic processes and evaluating restoration proposals, however, considerable 

data aquisition and processing are necessary for their development and calibration. 
Figure 13. Contour map of the base of the Surficial Aquifer System in Dade, 

Collier, and northern Monroe Counties, Florida. 
This report summarizes the Surficial Aquifer System structure underlying the park 

and preserve and presents this structure in a form appropriate for use in most 

regional scale hydrologic modelling. 

Conclusions of the report are summarized as follows: 

(I) Sufficient well log information is available to profile the stratigraphy of four 

transects in the Big Cypress National Preserve and Everglades National Park. 

Data analyses from areas where logs were available show considerable 

heterogeneity in the aquifer lithologies and their corresponding hydrologic 

properties. The upper, more permeable unit consists of clastics and limestones comprising the Biscayne and Chokoloskee Aquifers. The lower unit is 

largely a shelly, sandy, marly aquitard interstratified with permeable clastic 

and limestone zones. More permeable beds within the lower zone store and 

transmit water and may be considered a functional part of the Surficial 

Aquifer System. 

(2) The green clay zone of the lower Tamiami Formation appears to be 

continuous throughout the study area and may be considered the base and 

confining bed of the Surficial Aquifer System within the park and preserve. 

(3) Though the stratigraphic profiles exhibit considerable heterogeneity, the 

aquifer structure may be simplified into a homogeneous, two-dimensional 

representation suitable for most regional, physical-mathematical modelling 

purposes. This simplification is presented as contours of the base of the 

aquifer system, with depths to the base ranging from 90 to 300 feet (27.4 to 

91.5 m) below msl. 

(4) Extrapolated areas on the contour map indicate areas where data are 

insufficient for analysis. Further investigations into aquifer structure and 

hydrogeology are necessary both to upgrade the contour map and 

to assure proper assignment of transmissivity values associated with the 

simplified aquifer model. 

ACKNOWLEDGEMENTS 

The authors wish to acknowledge all who have contributed to this study. We 

appreciate the valued contributions of MS. Paulette Bond of the Florida Department of Natural Resources and Ms. Carmen Causaras and Dr. John Fish of the U. s. 

Geological Survey (Miami Subdistrict). Special thanks to Dr. Garald Parker (Parker 

and Associates, Tampa, Florida) and to Mr. Howard Klein (U. S. Geological Survey, 

Miami Subdistrict) for their advice and manuscript review. We would also like to 

thank MS. Jessie Brundige for her editorial assistance and typing. 
LITERATURE CITED 

Center for Wetlands. 1979. Resource Inventory and Analysis of the Big Cypress 

National Preserve. Gainesville, FL. 699 p. 

Dames and Moore. 1972. Report Research Test Well Floridan Aquifer, Turkey 

Point, Florida. Florida Power and Light Company. Atlanta, GA. 65 p. 

Dunne, T. 1982. Models of Runoff Processes and Their Significance. In Scientific 

Basis of Water-Resource Management. National Academy Press, Washington, 

DC. 

Gleason, P. 1984. In Environments of South Florida, Present and Past 11. Gleason, 

P. ed. ~iam~~eolo~ical Society. P. 0. Box 144156, Coral Gables, FL. 

33114. 

Jakob, P. G. 1983. Hydrology of the Shallow Aquifer south of Naples, Collier 

County. South Florida Water Management District Technical Publication 83-3. 52 p. 

Klein, H. 1972. The Shallow Aquifer of Southwest Florida. U. S. Geological 

Survey Open-File Report 720 17. 

Klein, H., and J. E. Hull. 1978. Biscayne Aquifer, southeast Florida. U. S. 

Geological Survey Water Resources Invest. 78-107. 

Klein, H., W. J. Schneider, B. F. McPherson, and T. J. Buchanan. 1970. Some 

Hydrologic and Biologic Aspects of the Big Cypress Swamp Drainage Area, 

Southern Florida. U. S. Geological Survey Open-File Report 70003. 

Leach, S. D., H. Klein, and E. R. Hampton. 1972. Hydrologic effects of water 

control and management of southeastern Florida. U. S. Geological Survey 

Report of Invest. No. 60, Florida Geological Survey, Tallahassee, FL. 

McCoy, H. Jo 1962. Ground-water Resources of Collier County, Florida. Florida 

Geological Survey Report of Investigations No. 3 1. 82 p. 

McCoy, J. 1972. Hydrology of Western Collier County, Florida. Bureau of 

Geology Report of Investigations No. 63, U. S. Geological Survey. Tallahassee, FL. 

Missimer and Associates, Inc. 1 98 1. Hydrologic Investigations for the Everglades 

City Raw Water Supply. Report for Wilson, Miller, Barton, Sell, and Peek, 

Naples, Florida. Cape Coral, Fla. 53 p. 

Parker, Go G. 1952. Geologic and hydrologic factors in the perennial yield of the 

Biscayne Aquifer. Am. Water Works Assoc. Journ., V. 43, No. 10, p. 817-843. 

Parker, G. G. 1982. Aquifers of Florida In Florida's Fresh-yater Atlas. Florida 

State Univ. Press. Tallahassee, FL. 
Parker, G. G., and W. C. Cooke. 1944. Late Cenozoic Geology of Southern 

Florida, with a Discussion of the Groundwater. Florida Geological Survey 

Bull. 27. 1 1 9 p. Tallahassee, FL. 

Parker, G. G., G. E. Ferguson, and S. K. Love. 1955. Water Resources of 

Southeastern Florida. U. 5. Geological Survey Water-Supply Paper 1255. 

965 p. 

Peacock, R. 1983. The Post-Ecocene Stratigraphy of Southern Collier County, 

Florida. South Florida Water Management District Technical Publicat ion 83 - 

5. West Palm Beach, FL. 

Rose, P. W., M. D. Flora, and P. C. Rosendahl. 1981. Hydrologic Impacts of 

L-31(W) on Taylor Slough, Everglades National Park. South Florida Research 

Center Report T-612. 

Schroeder, M. C., and H. Klein. 1954. Geology of the western Everglades area, 

southern Florida. U. S. Geological Survey Circular 3 14. Washington, DC. 

26 p. 

Schroeder, M. C., H. Klein, and N. Dm Hoy. 1958. Biscayne Aquifer of Dade and 

Broward Counties, Florida. Florida Geological Survey Report of Investigations No. 17. 56 p. Tallahassee, FL. 
Appendix A. Index of wells investigated. 

EXPLANATION OF CODES. 

Identification number. 

Numbers identify wells with logs reviewed for the report. Listings without 

numbers at the end of the appendix are wells for which lithologic descriptions 

were not available. 

Well number refix codes. 

Wells drilled in various locations throughout the study area and filed with the 

U. S. Geological Survey (USGS) in Tallahassee are catalogued by the USGS 

"W" series numbers. Wells designated llC1l or llG1l were drilled in either 

Collier or Dade County, respectively, but are not on file with the USGS and, 

thus, were not redesignated with a "WI1 series number. Information for wells 

with the prefix "E" is available from Exxon Corporation. Log descriptions 

located in the literature are cited in the reference column. 

County. 

D - Dade County 

C - Collier County 

M - Monroe County 

Type of geologic log. 

1. None 

2. Descriptive (lithologic, geologic) 

3. Driller 

4. Paleontological ' 

Geophysical and hydrologic information. 

Types of available geophysical or hydrologic data: 

1. None 

2. Electric resistivity logs 

3. Self potential logs 

4. Natural Gamma logs 

5 Hydrologic data 

References 

Well listed is on file at the U. S. Geological Survey in Tallahassee unless 

otherwise noted. 
Information used. 

Y - Yes, the well log was used to determine the structure of the Surficial 

Aquifer System 

N - Well log data was reviewed but determined to be inappropriate for this 

analysis 

Comments. 

Lists any additional information pertinent to the well, other identification 

numbers found in literature, or references to this publication. 
Appendix A. Index of wells investigated. 

McCoy, 1962 

McCoy, 1962 

McCoy, 1962 

McCoy, 1962 

McCoy, 1962 

McCoy, 1962 

McCoy, 1962 

McCoy, 1962 

McCoy, 1962 

Appendix A continued. 

Peacock, 1 983 

McCoy, 1972 

Peacock, 1983 

McCoy, 1962 

Jakob, 1983 

McCoy, 1962 

Jacob, 1983 

Jakob, 1983 

Exxon Corp. 

Jakob, 1983 

Jakob, 1983 

Jakob, 1983 

Jakob, 1983 

Jakob, 1983 

McCoy, 1972 

Peacock, 1983 

Peacock, 1 983 

McCoy, 1972 

Y Cl in this report 

N 

Y C-2020, A3 in this 

report 

N C-185 

Y 

N 

N 

Y 

Y 

N 

Y 

Y 

Y 

Y 

N 

Y C-2022D 

Y 

N 

Y C-2023 D 

N 
Appendix A continued. 

Peacock, 1983 

McCoy, 1972 

Peacock, 1983 

McCoy, 1962 

McCoy, 1972 

McCoy, 1972 

Parker, 1955 

Jakob, 1983 

Jakob, 1983 

Exxon Corp. 

Jakob, 1983 

Peacock, 1983 

Peacock, 1983 

Jakob, 1983 

Jakob, 1983 

Jakob, 1983 

Jakob, 1983 

Peacock, 1983 

Peacock, 1983 

- - 

Y 

N 

N 

Y A5 in this report 

N 

N 

N 

N 

N 

N 

N 

Y 

Y Bl in this report 

Y 

N 

Y 

Y 

N 

Y B2 in this report 

Y W 

b- 
Appendix A continued 

Peacock, 1983 

Peacock, 1983 

Peacock, 1983 

McCoy, 1962 

Peacock, 1 983 

Peacock, 1983 

McCoy, 1962 

Exxon Corp. 

Exxon Corp. 

Exxon Corp. 

Exxon Corp. 

Peacock, 1 983 

Missimer, 1983 

Missimer , 1983 

Missimer, 1983 

Exxon Corp. 

McCoy, 1962 

A4 in this report 

C2 in this report 

C3 in this report 

C-554 143 

C-47 

C-42 

B3 in this report 

A2 in this report W 

w 
Appendix A continued. 

-4 L 5% 

gE 

wg 0 - t' a, 

5; 

aa, 

8.g 

Exxon Corp. N 

Peacock, 1 983 Y 

Peacock, 1983 N 

N 

Peacock, 1983 Y 

N 

Peacock, 1983 Y 

A3 in this report 

Exxon 23 8 

B4 in this report 

Exxon 248, B5 in 

this report 

Exxon Corp. Y 

Peacock, 1983 Y Exxon 241, B6 in 

this report 

Exxon Corp. Y 

Peacock, 1983 Y 

N 

N 

N 

Parker, 1944, 1955 Y 

N 

Parker, 1955 Y 

N 

N 

Parker, 1955 N 

B7, C4 in this report 
Appendix A continued. 

Peacock, 1983 

Exxon Corp. 

Exxon Corp. 

Exxon Corp. 

Exxon Corp. 

Exxon Corp. 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1944 

Y 

Y C-3 9 

N 

Y C-41, A1 in this 

report 

N 

Y 

Y 

Y 

Y 

N 

N 

N 

N 

N 

N 

Y 

N 

N 

N 

Y 
Appendix A continued. 

c t: 

G g 

04 

.r a, 

5: 

aa, 

dg 

Parker, 1944 Y G182 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

Y G183 

N 

N Wells along Dadel 

Collier county line 

N 

N 

N 

Y' W G223, Dl in this 

report 

N 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1944 

Schroeder , 1954 

Parker, 1944 
Appendix A continued. 

Parker, 1944 

Parker, 1944 

Parker, 1955 

Parker, 1944 

Parker, 1955 

Parker, 1955 

Parker, 1944 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

Parker, 1955 

GI88 

GlOl 

C5 in this report 

D2 in this report 
Appendix A continued. 

------ - -- 

181 G 226 D 5513 9/26 100 2 1 Parker, 1955 N 

182 G 552 D 5513 9/27 87 2 1 Parker, 1955 N 

183 W 215 D 55/40/12 5200 4 1 N 

184 G 553 D 55/40/16 127 2 1 Parker, 1955 N 

185 W 482 D 55/40/18 96 1 1 N G-448 

186 G 449 D 55/40/22 105 2 1 Parker, 1955 N 

187 G 72 D 55140125 98 2 1 Parker, 1955 N 

188 G 469 D 55140126 13 7 2 1 Parker, 1955 N 

189 G 450 D 55140127 104 2 1 Parker, 1955 N 

1 90 G 471 D 55/40/34 119 2 1 Parker, 1955 N 

191 G 451 D 55/40/35 107 2 1 Parker, 1955 N 

192 G 423 D 55/41 106 52 2 1 Parker, 1955 N 

1 93 G 425 D 55/41 107 97 2 1 Parker, 1955 N 

194 G 424 D 55/41 107 95 2 1 Parker, 1955 N 

1 95 W 13768 D 56/40/02 3200 2 23 0 1 Y 

1 96 G 474 D 56/40/10 107 2 1 Parker, 1955 N 

1 97 G 207 D 57/38/25 108 2 1 Parker, 1955 N 

198 G 214 D 57/38/26 61 2 1 Parker, 1955 N 

199 G 217 D 5713 9/15 120 2 1 Parker, 1955 N 

200 G 216 D 57/39/14 110 2 1 Parker, 1955 N 
Appendix A continued. 

- ------ -- - 

---- 

20 1 G 491 D 5713 9/24 38 2 1 Parker, 1955 N 

202 G 213 D 5713 9/27 78 2 1 Parker, 1955 N 

203 G 212 D 5713 913 1 79 2 1 Parker, 1955 N 

204 G 211 D 5713 913 1 88 2 1 Parker, 1955 N 

205 G 527 D 57/40/20 51 2 1 Parker, 1955 N 

206 W 7363 D 58/37/14 1333 2 255 5 Y NP 100, D3 in this 

report 

207 G 210 D 58/38/24 62 2 1 Parker, 1955 N 

208 G 209 D 5813 9/21 66 2 1 Parker, 1955 N 

209 W 12294 D 5813 9/26 17UO 2 250 1 Dames-Moore, 1972 Y 

210 W 11571 D 58140128 2000 2 250 1 Dames-Moore, 1972 Y D4 in this report 

21 1 S 30 D 59/35/ 64 2 1 Parker, 1955 N 

212 W 3011 M 59140124 1 1 968 3 1 N 

213 W 2402 M 60 127 /3 4 485 2 226 1 Y G-6 10 

214 W 1115 D 60135127 6024 3 1 N 

215 W 3510 M 62/32/18 12631 4 1 N 

W 3008 C 46/28/04 2858 1 1 N 

W 3007 C 46/29/06 4107 1 1 N 

W 3009 C 47/28/09 4048 1 1 N 

W 11763 C 47/29/12 11 936 1 1 N 

W 3006 C 47/29/18 4141 1 1 N 


Appendix A continued. 

* If no reference listed, well is on file at the U. S. Geological Survey, Tallahassee, Florida. 

** Homestead Air Force Base, Homestead, Florida. 
Appendix 8. Example of lithologic well log description. 

OWNER 

LOCATION 

COUNTY 

ELEVATION 

DRILLER 

STARTED 

COMPLETED 

DEPTH 

CASING 

HEAD 

DRAWDOWN 

YIELD 

QUALITY 

USE 

U.S.G.S 252235N080361101 

Field #NP100, Everglades National 

Park Ranger Station 

Dade 

5' top0 

J. P. Carroll Co. for Fla. Test. Lab. 

6-24-64 

7-2-65 

1,333' 

620' of 8" Pipe 

1,570 GPM 

Brackish 

Test 

REMARKS : 204 Samples Rec. 9-23-65 

5' - 1,333' 

PLEISTOCENE SERIES 

Miami Oolite 

5-20 Calcarenite, pale to yellow-orange, oolitic, calcitic and calcilutite, very hard, dense. 

20-30 Calcilutite, pale yellow-orange, dense, f ossilif erous 

30-40 Calcilutite, light gray, dense, and oolite as above. 

Pine Crest Formation 

40-50 Sandstone, white, quartz; and calcilutite, hard, dense. 

50-63 Sand and shells, and sandstone, white, quartz, specks of 

phosphorite. Barnacles (Pleistocene sp.) 

MIOCENE SERIES 

Tamiami Formation 

63 -70 Clay, pale yellow-orange to gray, very sandy, shells fragments and 

phosphorite. 

71-81 Clay, pale yellow-orange to gray, very sandy fossiliferous, pebbles of phosphorite and shell fragments. 

8 1-95 Clay as above, and sand, white, quartz, fine with phosphorite and 

shells. Nonionella sp. - ~lphidium- sp. 

95-110 Sand, pale yellow-orange to gray, quartz, very fine grained, sheli - 

fragments and phosphorite. 

110-115 Sand, pale yellow-orange, medium grained and shell hash. 
Calcilutite, gray, very sandy, with shells. 

Sand, gray, quartz, fine grained and shell hash. 

Clay, gray, very sandy, shells. Nonion advenum. 

Same as above. Elphidium sagrum. 

Same as above and frequent shell fragments. 

Same as above with phosphorite, shark teeth, claws. 

Calcilutite, yellow-orange to gray, dense and shell fragments. 

Calcilutite, yellow to gray, very sandy. Shell fragments. 

Hemicythere conradi. 

Sand, pale yellow to gray, fine grained, fossiliferous and clay, 

gray with shells. 

Calcilutite, gray, very sandy, phosphorite and shell fragments. 

Same as above. 

Same with increasing amount of shells, fragments of Ostrea sp. 

Same with fragments Pecten sp. 

Same with incrusting Bryozoa. 

Hawthorn Formation 

Sand, light orange yellow, quartz, medium to coarse and clay, 

gray, phosphorite and shell fragments. 

Same as above, fragments of calcilutite. 

Sand, gray, quartz fine to medium; argillaceous, with phosphorite. 

Operculinoides sp. (Miocene) 

Clay, dark green, very sandy, quartz sand and phosphorite. 

Clay, olive green, very sandy, micaceous, pebbles of phosphorite 

quartz and fragments of Ostrea normalis. 

Clay as above; phosphorite and shells. 

Same. 

Same. 

Same.