GEOLOGICAL SURVEY CIRCULAR 314

GEOLOGY OF THE WESTERN 

EVERGLADES AREA 

SOUTHERN FLORIDA

Prepared in cooperation with 

the Florida Geological Survey

UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary

GEOLOGICAL SURVEY 

W. E. Wrather, Director

GEOLOGICAL SURVEY CIRCULAR 314

GEOLOGY OF THE WESTERN EVERGLADES AREA, SOUTHERN FLORIDA

By Melvin C. Schroeder and Howard Klein

Prepared in cooperation with 

the Florida Geological Survey

Washington, D. C., 1954 

Free on application to the Geological Survey, Washington 25, D. C.

CONTENTS

Introduction ..............

Purpose and scope of investigation

Acknowledgments .........

Previous investigations ......

Topographic-ecologic divisions . . .

General features .........

The Everglades ..........

Big Cypress Swamp ........

Sandy Flatlands ..........

Geology ................

General features .........

Miocene deposits .........

Tamiami formation ......

Pliocene deposits .........

Caloosahatchee marl ......

Page

1 Geology Continued

1 Pleistocene deposits .....

1 Fort Thompson formation .

1 Anastasia formation ....

1 Pamlico sand .......

1 Recent deposits ........

1 Structural interpretation . . .

1 General features ......

4 Folding and faulting ....

4 Solution and erosion ....

4 Ground-water occurrence . . .

4 Correlation studies ......

4 General statement .....

5 Logs of wells 1 to 43 ...

5 Fauna found in wells 1 to 43

	Selected references .......

Page

5

5

5

5

6

6

6

6

6

7

7

7

8

19

25

ILLUSTRATIONS

Page 

Figure 1. Map of southern-Florida showing location of test wells and geologic cross sections ..... Facing 1

2. Geologic cross section along the sandy flatlands southeast of Lake Hicpochee .......... 2

3. Geologic cross section along the common margin of Big Cypress Swamp and the Everglades . . 3
 mim. -^g_Jy - ^SEJU. -.- £n=r"» | *^5ialB T =^SSS D «^F^

C,

EXPLANATION 

O TEST WELL 

_ TEST WELL WITH

SCALE IN MILES

20 30

Figure 1. --Map of southern Florida showing location of test wells and geologic cross sections.
GEOLOGY OF THE WESTERN EVERGLADES AREA, SOUTHERN FLORIDA

By Melvin C. Schroeder and Howard Klein

INTRODUCTION 

Purpose and Scope of Investigation

During 1950, a series of 43 test wells 30 feet deep 

were drilled by the United States Corps of Engineers 

along the western edge of the Everglades from the Tamiami Canal northward to the Caloosahatchee River (see 

figure 1). The cores obtained from the wells afford 

geologic data along a line from the lower Everglades 

of Dade County, where both the geology and water resources have been investigated, to the Caloosahatchee 

River area, where the surface geology has been studied.

This report has been prepared chiefly to record and 

interpret the information obtained from the test wells. 

It is one of a series prepared on ground-water investigations by the United States Geological Survey, in cooperation with the Florida Geological Survey. When 

ground-water data become available they will be correlated with the geology of this report and will be presented in a later report on the Glades-Hendry Counties 

area. A few generalized inferences concerning ground 

water are made.

The investigation was under the general supervision 

of A. N. Sayre, Chief, Ground Water Branch, U. S. 

Geological Survey, Washington, D. C., and Herman 

Gunter, Director, Florida Geological Survey, and under 

the direct supervision of Nevin D. Hoy, District Geologist, U. S. Geological Survey, Miami, Fla.

Acknowledgments

The U. S. Corps of Engineers granted permission 

to examine cored material from test wells. Garald G. 

Parker, C. Wythe Cooke, and F. Stearns MacNeil of 

the U. S. Geological Survey, and R. O. Vernon of the 

Florida Geological Survey, assisted in interpreting the 

geology at the various formation type localities and in 

identifying fossils.

Previous Investigations

Numerous geological studies have been made in the 

areas which terminate the line of test wells. The area 

covered in this report is included in the investigations 

by Parker and Cooke (1944) who presented geologic 

descriptions and correlations with a discussion of 

ground-water resources. In a later paper, Parker 

(1951) revised the stratigraphic correlations of the formations.

TOPOGRAPHIC-ECOLOGIC DIVISIONS 

General Features

The line of tes*wells (see figure 1) crosses 

three relatively distinct topographic subdivisions. The 

southern part of the line closely approximates the 

boundary between the Everglades and the Big Cypress 

Swamp in western Dade and Broward Counties. In eastern Hendry County, from the latitude of the BrowardPalm Beach County boundary, the line of test wells 

bears northward for about 20 miles along the western 

edge of the Everglades, then northwestward across the 

sandy flatlands to the western edge of Lake Hicpochee. 

Parker and Cooke (1944, p. 38-53) discuss these topographic-ecologic divisions in detail, hence only a brief 

discussion is included in this report.

The Everglades

The Everglades is a region covered by black organic 

soils. Although somewhat indefinite, the boundary between the Everglades and the areas to the east and west 

is generally placed where the saw grass (sedges) of the 

Everglades is replaced by true grasses or cypress. 

According to Parker and Cooke (1944, p. 48), the limestone which floors the Everglades is highest in the 

vicinity of the Miami Canal, 4 miles east of well 24, 

and slopes gently to the southern mar gin and northward 

toward LakeOkeechobee. The rock floor is composed 

of fresh-water and marine lime stone sand partially indurated marl of the Fort Thompson formation. Although 

the Miami oolite was not observed in any of the test 

wells, it occurs as a thin layer overlying the Fort 

Thompson formation in the southern part of the Everglades.

Big Cypress Swamp

To the west, the Everglades merges with the Big 

Cypress Swamp, which is a poorly defined region of alternating swamp and hammock areas. The elevation in 

general is slightly higher than the Everglades, but 

lower than the sandy flatlands on the north. The higher 

portions, where soils are aerated, support the growth 

of palmettos, pines, and bunch grasses, but the lower 

areas are marked with typical swamp growth of small 

cypress and sedges. In contrast with the Everglades, 

the surface material is mainly limestone and sandstone, 

but there are numerous small areas where thin marly 

deposits lie at the surface. The geology, as interpreted from the well cores, pertains only to the eastern 

edge of the Big Cypress Swamp.
& ~ 20 13

FORT THOMPSON^)

\

TAMIAMI^-

FORMATION

TAMIAMI FORMATION

FORTTHO

Figure 2. --Geologic cross section along the sandy flatlands southeast of Lake Hicpoc
TAMIAMI FORMATION

\

UNOIFFERENTIATEO PLIOCENE OR PLEISTOCENE

THOMPS

TAMI

FORT THOMPSONS) FORMATION

Figure 3. --Geologic cross section along the common margin of Big Cypress Swamp and the Eve
GEOLOGY OF THE WESTERN EVERGLADES AREA

Sandy Flatlands

The northern extremity of the line of test wells 

crosses the sandy flatlands, which is slightly higher 

than the Everglades and the Big Cypress Swamp but 

does not exceed 25 feet. The sands were deposited as 

part of the marine Pamlico sand of Pleistocene age and 

are dotted with small shallow ponds and poorly defined 

marshy areas, one of which is the Devil's Garden. 

Drainage is chiefly underground through the permeable 

sand with very little, if any, surface runoff.

GEOLOGY 

General Features

The materials penetrated by the test wells range in 

age from late Miocene through Recent; the oldest formation is the Tamiami formation of late Miocene age. 

Organic soils are still being formed in parts of the 

Everglades area. The Miami oolite of Pleistocene age 

occurs as a thin discontinuous veneer near the south end 

of the line but apparently was not penetrated by any of 

the wells. The late Miocene to Recent geologic formations in the area of the report are listed in the table 

below.

Miocene Deposits 

Tamiami Formation

Definition. --The Tamiami formation, as redefined 

by Parker (1951, p. 823), includes all deposits of the 

upper Miocene in southern Florida. Thus, it includes 

the Tamiami and Buckingham limestones of Mansfield 

(1939, p. 8-16) and the upper part of the material assigned to the Hawthorn formation by Parker and Cooke 

(1944, p. 98-112).

Development. --The Tamiami is the only Miocene 

formation penetrated by the test wells. The top of the 

Tamiami formation (see figs. 2, 3) is an undulating 

surface which varies as much as 25 feet in elevation 

within a distance of Smiles. Thisunevenness indicates 

that the upper part has been subjected to erosion. The 

deposition of the Caloosahatchee marl on top of and 

along the flanks of erosional remnants indicates that the 

Tamiami was dissected prior to Pliocene deposition 

and again during the Pleistocene. Apparently the deeper 

valleys were developed during the Pleistocene.

At Sunniland, Collier County, and Buckingham, Lee 

County, the Tamiami formation is about 50 feet thick. 

In Dade County, according to Parker (1954r), the formation has a relatively uniform thickness of about 100 feet.

Lithology. --The Tamiami formation changes laterally from shelly marl, as typified at Buckingham, to 

soft silty limestone at Sunniland, to the silty sand and 

clayey marl that underlies Dade County. The hard 

sandy limestones of Mansfield's (1930, p. 8) type localities along the Tamiami Trail were not encountered 

among the subsurface materials of the core line. The 

lithologic characteristics of the Tamiami formation as 

noted in the cores are as diversified as the lithology 

between the areas of its known distribution. Cream to 

white soft limestone and clayey marl are the common 

constituents, but shell marl and silty sand are also 

present in colors ranging from white and cream to 

green.

Age. --The Tamiami formation overlies the Hawthorn formation at every locality where the Hawthorn 

has been penetrated in this area. Hoy and Schroeder 

(1953, personal communication) reported that the 

Tamiami formation is overlain unconformably by the 

Caloosahatchee marl of Pliocene age along Alligator 

Creek in Charlotte County. The Buckingham and Tamiami limestones, referred by Mansfield (1939, p. 8-16) 

to the late Miocene and Pliocene, respectively, were 

tentatively placed by Parker and Cooke (1944, p. 59-65) 

in the Pliocene, equivalent in age to the Caloosahatchee 

marl. Parker (1951, p. 822-823) subsequently recognized the Buckingham marl and the Tamiami limestone 

to be different facies of the same formation of late Miocene age, for which he retained the name Tamiami.

The faunal assemblage of the Tamiami formation 

commonly contains the mollusks Ostrea disparilis, 

Chione ulocyma, and Turritella pontoni, which, F. 

Stearns MacNeil(1951, personal communication)states, 

"..... are not only characteristic upper Miocene species, but they represent groups that have no known postMiocene relatives, at least in this part of the world. " 

The echinoid Encope macrophora tamiamiensis, according to Cooke (1942, p. 20-21), is not known in any 

other beds except what are now called the Tamiami 

formation.

A specimen of Ecphora quadricostata umbilicata 

(Wagner) found in the marl along the Caloosahatchee 

River at Banana Creek also indicates that the Tamiami 

formation is of late Miocene age.

Formations Penetrated by Test Wells

Age

Recent and Pleistocene

Pleistocene

Pliocene

Miocene (late)

Formations

Organic soils and Lake Flirt marl.

Pamlico sand (shore at +25 

Fort Thompson formation. '

Anastasia formation. 

Caloosahatchee marl.

Tamiami formation.

feet).

Thickness 

(feet)

0

0 

3

0 

0

50

9

9 

9

- 25? 

- 20

- 100

Character

Undifferentiated peat, muck, 

and fresh-water marl.

Gray to brown sand. 

Alternating marine and 

fresh- water limestone

and marl.

Marine sand, coquina, and 

sandy limestone. 

Shells, sand, and marl.

Silty sand and marl.
GEOLOGY

Pliocene Deposits 

Caloosahatchee Marl

Definition. --The shell beds exposed along the upper 

reaches of the Caloosahatchee River were recognized 

in 1887 as Pliocene, but it was not until 1909 that Matson 

and Clapp (1909, p. 123) adopted the name Caloosahatchee marl for the beds. The Matson and Clapp definition has since been generally used.

Development. --The Caloosahatchee marl apparently 

is present in southern Florida as discontinuous erosion 

remnants. The most continuous exposures occur as 

thin beds along the Caloosahatchee and other rivers 

along the southwest Florida coast. The formation is at 

least 10 feet thick along the Caloosahatchee River and 

may be as much as 20 feet thick near Lake Hicpochee.

Lithology. --The Caloosahatchee marl consists predominantly of shells, sand, and silt. Freshunweathered 

exposures are generally pale cream-colored to light 

gray, although green clay marls near LaBelle have been 

included in the formation. Green silty sands or sandy 

marls included in the Caloosahatchee along the line of 

the test wells appear to be restricted to the flanks of 

the hills of the Tamiami formation. Probably the 

greenish elastics are redeposited green clay marls of 

the Tamiami formation. The sand and shell variations 

of the Caloosahatchee marl can be separated from the 

marine formations of Pleistocene age only by identification of the mollusk faunas.

Age. --Dall (1890-1903) recognized 639 species of 

mollusks, of which, according to Cooke(1945, p. 216), 

half are not yet extinct. Mansfield (1939, p. 27-28) 

lists 40 of the more characteristic species which he 

collected from the marl. Both Mansfield and Dall accepted the original designation of the age of the marl as 

Pliocene.

Pleistocene Deposits 

Fort Thompson Formation

Definition. --The alternating fresh-water and marine 

marls and limestones exposed at Fort Thompson were 

initially named the Fort Thompson beds by Sellards 

(1919, p. 71-72). Cooke and Mossom (1929, p. 211- 

215) later named this sequence the Fort Thompson formation and indicated that the beds lie unconformably on 

the Caloosahatchee marl and are overlain by the Lake 

Flirt marl of Pleistocene and Recent age.

Development. --The Fort Thompson formation at the 

type locality is about 6 feet thick. In the Miami area it 

attains a maximum thickness of 80feet and constitutes 

the major part of the Biscayne aquifer as described by 

Parker (1951, p. 820-823). The southern 18 miles of 

the line of test wells is approximately the western 

boundary of the Biscayne aquifer. In this area the Fort 

Thompson formation ranges from 3 to 9 feet in thickness. The strata of Pleistocene age between wells 10 

and 33 possibly are transitional beds between the Fort 

Thompson and Anastasia formations.

Lithology. --The Fort Thompson formation is composed of sand, marl, shell marl, sandstone, and limestone of fresh-water and marine origin. Marl and sand

are the predominant constituents along the line of test 

wells. The occurrence of limestone in the Fort Thompson and Tamiami formations appears to be related to 

fluctuations of the water table accompanied by cementation with calcium carbonate.

Age. Parker and Cooke (1944, p. 94-96) correlated 

the beds at old Fort Thompson with the inferred fluctuations of sea level during the Pleistocene epoch. 

Fresh-water beds have not bee"n reported in the Pliocene 

of the Atlantic Coastal Plain, l and they do not occur in 

the Caloosahatchee marl (Pliocene) in the outer op are a, 

although fresh-water shells are found, in places, mixed 

with the marine forms. Any sequence of marine and 

fresh-water beds,or fresh-water beds, older than the 

Lake Flirt marl is considered as representing the Fort 

Thompson formation.

Anastasia Formation

Definition. --The Anastasia formation was named by 

Sellards (1912) from outcrops of coquina on Anastasia 

Island, near St. Augustine, Fla. Cooke and Mossom 

(1929, p. 199) expanded this definition to include all the 

marine deposits of Pleistocene age underlying the lowest plain bordering the east coast of Florida, excluding 

the Key Largo limestone and the Miami oolite. Parker 

and Cooke (1944, p. 66) defined the formation as follows: "The Anastasia formation as here defined includes the coquina, sand, sandy limestone, and shelly 

marl of pre-Pamlico Pleistocene age that lies along 

both the Florida east and west coasts. "

Development. -- The pre-Pamlico deposits at the 

north and south ends of the line of test wells are definitely assigned to the Fort Thompson formation. The 

deposits of Pleistocene age between wells 10 and 33 

have been questionably identified as the Fort Thompson 

formation. Thin marine sandstones of the Anastasia 

formation, which are present along the southwest coast, 

extend as a tongue into Collier and Hendry Counties. 

In northeast Collier County and southeast Hendry County 

this marine sandstone has been found within 4 to 6 miles 

of the line of testwells. The strata of Pleistocene age 

between wells 10 and 33, tentatively assigned to the 

Fort Thompson formation, apparently are transitional 

between the Fort Thompson and Anastasia tormations.

Lithology. --The typical coquina of the Anastasia 

formation in the type locality does not occur -in the 

western part of southern Florida. Sand, shell beds, 

marl, and calcareous sandstone are the most common 

materials.

Age. --Fossil evidence is not adequate for determining the age of the materials in the test wells that 

may be Anastasia but are assigned to the Fort Thompson. The geologic cross sections, however, suggest 

that the deposits are of Pleistocene age. Elsewhere in 

southern Florida, molluscan faunas establish a Pleistocene age for the Anastasia formation.

Pamlico Sand

Definition. --The Pamlico sand was extended from 

the typical locality in North Carolina by Parker and 

Cooke (1944, p. 74-75). They include in it all the marine deposits of Pleistocene age younger than the
6 GEOLOGY OF THE WESTERN EVERGLADES AREA

Anastasia formation. These deposits are referable to 

terrace materials deposited during a+25-foot stand of 

the sea during the Pleistocene.

Development. --The Pamlico sand occurs along the 

test-well line only in the sandy flatlands of Hendry 

County, where its maximum thickness is about 9 feet.

Lithology. The Pamlico sand is generally gray or 

brown. It is composed of quartz.

Age. --The sand that is referred to the Pamlico in 

southern Florida lies unconformably upon the Miami 

oolite and Fort Thompson and Anastasia formations, 

all of Pleistocene age, and upon the Caloosahatchee 

marl of Pliocene age and the Tamiami formation of 

late Miocene age. The Lake Flirt marl and deposits 

of Recent age of peat and muck overlie the Pamlico 

sand. Cooke (1952, p. 43) refers the Pamlico to a 

marine shoreline at 25 feet above sea level, which he 

(1952, p. 51) correlates with the third interglacial 

stage (Sangamon).

Recent Deposits

The deposits that have accumulated since the end of 

the Wisconsin glacial stage are Recent. These include 

organic soils of the Everglades and the Lake Flirt 

marl, though their development may have started in 

late Wisconsin time. The marl and the parent material 

of most of the soils accumulated in fresh water.

The test-well line follows the western margin of the 

Everglades and in many places the peat and muck are 

sandy. The gray Lake Flirt marl is penetrated by only 

a few wells, although its occurrence in the Everglades 

is common. The conditions of deposition are similar 

to those that existed in the Everglades area prior to the 

digging of the drainage canals.

Parker and Cooke (1944, p. 20) supposed that the 

Lake Flirt marl was deposited during late Wisconsin 

(fourth glacial stage) and Recent time, starting after 

the recession of the sea from the level of +25 feet to a 

level below the present sea level. Cooke (1952, p. 43) 

infers that sea level in the third glacial epoch was below the present level, rose to +25 feet in Pamlico time, 

dropped to +6 feet during formation of the Silver Bluff 

terrace, and then regressed to below present sea level 

during the Wisconsin ice advance. F. Stearns MacNeil 

(1950, p. 104) tentatively correlates the Silver Bluff 

shoreline with the peak of the Recent interglacial stage. 

Obviously, it is difficult to determine which parts of 

the Lake Flirt marl were deposited in the late Wisconsin and which in the Recent. However, most of the material was deposited in the Recent, and all post-Pamlico 

fresh-water marl deposits are included in the Lake 

Flirt marl. All fresh-water limestones or marls older 

than the Pamlico sand are included in the Fort Thompson formation.

Structural Interpretation 

General Features

Structural interpretation of the geologic cross sections.in this report seems to be restricted to the possible alternatives and combinations of folding, faulting,

solution and slumping, and erosion. In interpreting 

the cross sections, all these items are considered and 

therefore, even though they are diverse, they are 

grouped together in this discussion.

Folding and Faulting

Most surface structural interpretations are based 

upon the identification and attitude of sedimentary 

structures such as bedding, ripple marks, swash 

marks, rill marks, and mud cracks in recognizable 

beds. However, of these features only bedding has been 

found in the sediments in southern Florida. Bedding 

is not common in exposures of the Tamiami formation 

or the Caloosahatchee marl, though locally it can be 

recognized by thealinementof fossils. In some places 

indivii ual beds of the Pleistocene formations can be 

identif ad. Surface observations of the beds and indications of stratification suggest that the beds of the 

formations ranging from late Miocene to Pleistocene 

are horizontal or dip so slightly, that the attitudes are 

determinable only by detailed plane-table or spiritlevel surveying.

Subsurface structural determinations are based 

upon identification of formations and contacts by differences of lithology or fossils. It is preferable to base 

structural maps upon conformable contacts rather than 

erosion surfaces. All the contacts shown in the cross 

sections of this report appear to be unconformable. 

The contacts between the formations observed in surface exposures in Charlotte, Glades, Hendry, and Lee 

Counties are all unconformable. Stratigraphic zones 

that can be used as markers are not recognizable by 

means of either lithology or fossils.

The data neither prove nor disprove that any of the 

beds are folded or faulted. If the beds shown in the 

cross sections are folded, the flexures are very slight. 

Faulting, if it is present, involves minor displacement. 

The major subsurface structure of Florida, the Peninsular arch, was formed during theMesozoic, according to Applin (1951, p. 3-5), and the Ocala uplift, a 

surface feature cresting in Citrus and Levy Counties, 

was formed during the early Miocene, according to 

Vernon (1951, p. 53). Vernon (1951, pis. 3, 4) indicates by cross sections in central and northern Florida 

that there has been no faulting in post-Hawthorn time. 

Major structural disturbances therefore antedate the 

Tamiami formation and so could not have deformed the 

younger deposits of southern Florida.

E. W. Bishop (1953, personal communication), 

however, believes that topographic and geomorphologic 

evidence indicates faulting and tilting of the Pleistocene 

marine terraces in Highlands County. The authors' 

opinion, based upon the available data, is that the late 

Miocene to Recent deposits discussed in.this report 

have not been folded or faulted. Parker and Cooke 

(1944, p. 19) suggest that there may have been a late 

Pliocene westward tilting of the Floridian Plateau.

Solution and Erosion

There are several places along the core line, such 

as at well 7, where sinkhole development is a possible 

explanation of the structure indicated by the formation 

contacts. Parker and Cooke (1944, p. 29-33) report
GEOLOGY

on three sinkhole lakes: Deep Lake in Collier County, 

Rocky Lake in Hendry County, and Still Lake in Lee 

County. The diameters of these lakes range from 300 

to about 1, 000 feet. The greatest depth of Still Lake is 

about 213 feet below the land surface, in an elliptical 

chimney 20 to 40 feet in diameter. The chimney probably extends down through limestones of the Tamiami 

formation into the Hawthorn formation. Deep Lake, 

midway between Sunniland and Everglades, is in limestone of the Tamiami formation, the greatest depth 

being 97 feet below the land surface. Rocky Lake, 

which is about 11 miles west of well 20, is about 50 feet 

deep, although there may be a chimney which was not 

detected by the preliminary sounding. A driller's log 

from a nearby well suggests that soft limestone of the 

Tamiami formation extends to about 65 feet in depth. 

The limestone does not appear to be a major constituent 

of the Tamiami formation along the core line, and it 

seems probable that the limestone section that predominates at Sunniland andlmmokalee makes up less of the 

Tamiami formation as one progresses eastward. The 

absence of sinkholes along the core line may be attributed to the thinness of the limestone there.

The top of the Tamiami formation varies as much as 

25 feet in elevation within a distance of 8 miles. This 

unevenness was probably produced by erosion rather 

than by deformation. The Caloosahatchee marl and 

Fort Thompson and Anastasia formations were deposited on this preexisting erosion surface, and erosion 

followed the deposition. The Pamlico sand was deposited on an eroded surface.

The position and shape of the beds shown in the cross 

sections of this report appear to be the result of deposition and erosion. Folding and faulting are believed 

not to be the cause of the configuration of the beds.

Ground-Water Occurrence

The southern part of the line of test wells is near the 

western edge of the Biscayne aquifer (Parker, 1951, 

p. 820-823); the Fort Thompson formation and younger 

deposits of Pleistocene age constitute the Biscayne aquifer over much of Dade County. About 25 miles west 

of the line of test wells, near Sunniland and east of 

Immokalee, the Tamiami formation becomes highly 

permeable and is an excellent aquifer. In that general 

area, soft fossiliferous limestones predominate over 

the silty sands of the formation. The highly permeable 

limestones of the Fort Thompson formation thin out or 

are missing, except possibly as solution-hole fillings 

in the Tamiami formation, in the vicinity of the Collie rDade County line. Although in many places boundaries 

of the Biscayne aquifer cut across geologic formations, 

there appears to be little, if any, continuity in permeability between the Biscayne aquifer and the fossiliferous 

limestones of the Tamiami formation in northern Collier County.

The available data concerning ground-water levels 

in the area across which the test wells were drilled are 

very limited; however, a few general inferences can be 

made. Water levels in southeastern Hendry County and 

northeastern Collier County rise during the autumn and 

are commonly highest in October. Similar fluctuations 

of water level occur in the Everglades, corresponding 

to rainfall, which commonly is the greatest from June 

through October. During periods of high water levels,

large areas are inundated and surface flow to the south 

occurs in both the Big Cypress Swamp and the Everglades. Generally, the greatest surface flow into and 

across the Tamiami Canal occurs near Monroe Station 

(14 miles west of the Dade-Collier County line) during 

September and October. The concentration of the'runoff commonly migrates eastward and by midwinter it 

is within 10 miles of the coastal ridge. The main factors related to this migration are rainfall and the variation and difference in storage of ground and surface 

water. The Everglades area is underlain by the very 

permeable Biscayne aquifer, whereas the Big Cypress 

Swamp is floored by materials of low permeability. 

Therefore, ground-water flow to the south is less in 

the Big Cypress Swamp than in the Everglades. The 

water table in the Big Cypress Swamp is generally 

nearer to land surface than in the Everglades, and, 

because of the small ground-water storage capacity, 

surface flow starts in the swamp soon after the rainy 

season begins. Also, because of the slightly greater 

slope of the land surface, the capacity for the storage 

of surface water in the swamp is less than that in the 

Everglades. As ground-water storage increases in the 

glades area, the water table rises above land surface 

and flow increases with the concentration of the flow 

moving eastward.

Correlation Studies 

General Statement

The correlations illustrated in the cross sections 

(figs. 2, 3) are based chiefly on lithologic similarity 

of the sediments. Vertical changes in lithology, although usually gradational, take place rapidly. There 

is almost no horizontal continuity of the beds, which 

makes exact correlation impracticable. Exposures of 

all of the formations along and near the western edge 

of the Everglades are scarce and therefore are of little 

use in substantiating the correlations.

The section which follows contains the logs of the 43 

test wells drilled by the U. S. Engineers. Each test 

well was drilled to a depth of 30 feet; thus the bottoms 

of the wells range from 8.5 feet below mean sea level 

in well 3 in northern Hendry County to 22 feet below 

mean sea level in well 41 near the Tamiami Canal. 

Also included is a list of macrofossils collected at 

various depths throughout the 30-foot core sections. 

The lists were prepared by F. S. MacNeil of the U. S. 

Geological Survey. Collections were made wherever 

a relatively large assemblage occurred; not all core 

holes are represented because the arealdistribution of 

shelly material was very inconsistent. If diagnostic 

fossils were noted, then that portion of the section was 

assigned to the indicated geologic age. Many of the 

species listed are of long stratigraphic range and were 

of little use in differentiating formations. Several 

forms occur in great numbers in both Pliocene and 

Pleistocene deposits; thus the boundary between the 

Caloosahatchee marl and the formations of Pleistocene 

age is usually indefinite unless a lithologic break or an 

unconformity is evident. Scarcity of these fossil forms 

in certain assemblages from the lower parts of the 

holes may be considered negative evidence of Miocene 

age. Unfortunately, identifiable specimens were not 

found in the cores in some critical areas. Boundaries 

between formations are tentative, for the writers believe that other interpretations are possible.
GEOLOGY OF THE WESTERN EVERGLADES AREA 

LOGS OF WELLS 1 TO 43

Well 1 

Location and description

NWiNWi sec. 31, T. 42 S., 

R. 32 E., Glades County.

Top of measured section (land 

surface) ...........

Depth (feet I/)

Pamlico sand:

Sand, fine to medium quartz,

carbonaceous, rust-brown . 

Sand, fine to medium quartz,

slightly marly, dark brown . 

Fort Thompson formation: 

Sand, fine to medium quartz, 

shelly, marly, tan (mainly 

Chione cancellata) ......

Limestone, fresh-water, hard, 

tan, shelly, tan to brown . . .

Limestone, sandy, shelly 

(mainly Chione cancellata), 

cream .............

Limestone, fresh-water, hard, 

tan to brown; in part, a deposit filling a solution hole 

in sandy, shelly lime stone of 

the Caloosahatchee marl . . . 

Caloosahatchee marl:

Marl, sandy, very shelly (mainly 

Chione cancellata), cream . .

Shell marl, silty, sandy, gray . .

Well 2

Center of sec. 6, T. 43 S., 

R. 32 E., Hendry County.

Top of measured section (land 

surface) ..........

+12.6

+12.0 

+8.2

+4.6 

+3.5

+2.6 

-2.4

-6.6 

-15.4

Pamlico sand:

Sand, fine to medium, shelly 

(mainly Chione cancellata), 

brown ............

Fort Thompson formation:

Sand, fine to medium quartz, 

slightly marly, very shelly 

in top 0. 5 foot, tan to buff .

Marl, very shelly, very sandy, 

tan to cream; in part indurated to sandstone ......

Sandstone, hard, porous, fossiliferous, marine(?), tan .

Limestone, fresh-water(?),

dense, hard, shelly, tan . . 

Caloosahatchee marl:

Sand, silty, marly, very 

shelly (Chione cancellata 

abundant), cream to tan . . ..

+18.4

+10.0

+8.0

+4.9 

+3.4 

+2.0

-11.6

Well 3 

Location and description

NWiNWi sec. 16, T. 43 S., 

R. 32 E., Hendry County.

Top of measured section (land 

surface) ..........

Depth (feet I/)

Pamlico sand:

Sand, fine to medium quartz, 

gray ..............

Sand, fine to medium quartz, 

dark brown ..........

Fort Thompson formation:

Sandstone, friable, calcareous, 

case hardened, fossiliferous 

(mainly Chione cancellata), 

cream, top 0. 3 foot ......

Sand, fine to medium quartz, 

slightly marly, cream.....

Sand, fine quartz, marly, shelly, 

cream; somewhat indurated 

to sandstone in lower part. . .

Sand, fine quartz, silty, very 

marly, shelly (Chione cancellata), cream ........

Sand, fresh-water, quartz, very 

marly, silty, fine, shelly, 

cream .............

Marl, sandy, fossiliferous, 

shelly (Chione cancellata with 

a few fresh-water gastropods), 

cream .............

Marl, sandy, shelly (fresh-water 

gastropods), cream ......

Caloosahatchee marl:

Marl, clayey, shelly, brown . . .

+21.5

+17.3 

+16.7

+14.5 

+13.5

+5.5 

+4.0 

+1.5

-1.5

-3.5

-8.5

Well 4

NWiNWi sec. 22, T. 43 S., 

R. 32 E., Hendry County.

Top of measured section (land 

surface) ...........

I/ Datum is mean sea level.

Pamlico sand:

Sand, fine to medium quartz, 

gray .............

Sand, fine to medium quartz, 

dark brown .........

Fort Thompson formation:

Sand, medium to coarse quartz, 

tan to cream ........

Sand, fine quartz, silty, shelly, 

cream ............

Sandstone, fine, silty, calcareous, fossiliferous, 

cream ............

Sand, fine quartz, shelly,

slightly silty, cream to tan .

Sand, coarse quartz, some 

quartz granules .......

+21.5

+20.0 

+13.0

+10.0 

+7.5

+6.5

-5.5

-8.5
Well 5 

Location and description

NW^NWi sec. 24, T. 43 S., 

R. 32 E., Hendry County.

Top of measured section (land 

surface)...........

LOGS OF WELLS

Well 7 

Depth (feet I/) Location and description

SE^SEi sec. 36, T. 43 S., 

R. 32 E., Hendry County.

Top of measured section (land 

surface) ...........

Pamlico sand:

Sand, carbonaceous, dark

gray .............

Sand, slightly marly, shelly,

dark brown, locally cream . 

Fort Thompson formation:

Marl, sandy, indurated,

shelly, cream ........

Sand, fine quartz, silty, marly, 

shelly, tan ..........

Sandstone, friable, silty, very 

shelly, cream ........

Sand, fine to medium quartz, 

shelly, tan ..........

Sand, fine quartz, slightly 

shelly, granules of quartz, 

in lower part, cream ....

Limestone, with coarse grains 

and granules of quartz and 

some pebbles; shelly and 

some friable sandstone in 

lower part, cream......

Sand, fine to coarse quartz, 

marly, slightly shelly, 

cream ............

+19.4

+18.2 

+14.4

+13.0 

+8.8 

+6.7 

+4.4

-.6

-5.6 

-10.6

Depth (feet I/)

Recent organic soils:

Muck, sandy, black .....

Sand, mucky, black ..... 

Pamlico sand:

Sand, fine to medium quartz, 

gray to tan .........

Sand, fine to medium quartz, 

white ............

Sand, fine quartz, white to 

cream ...........

Fort Thompson (?) formation:

Sand, fine quartz, silty, 

slightly marly, slightly 

shelly, tan .........

Sand, fine to medium quartz, 

very silty, very shelly, 

tan .............

Sand, fine quartz, slightly 

shelly, tan to cream . . .

Shell marl (shells are worn 

and smooth), sandy, silty, 

grayish-cream.......

Sand, fine to coarse quartz, 

some quartz granules, 

shelly, cream to white . .

+19.4

+18.5 

+16.0

+14.0

+12.0

+9.4

+7.3

+4.4

-5.6

-7.0 

-10.6

Well 6

SW^SWi sec. 25, T. 43 S., 

R. 32 E., Hendry County.

Top of measured section (land 

surface) ...........

Pamlico sand:

Sand, fine to medium, light 

gray ............

Sand, fine to medium, tan . . 

Fort Thompson formation:

Sand, fine to medium quartz, 

slightly marly, shelly, 

cream to light gray ....

Sand, fine quartz, marly, 

cream ...........

Sand, fine to medium quartz, 

shelly (Chione cancellata), 

light gray .........

Marl, clayey, sandy, gray 

and cream .........

Limestone, sandy, soft, fossiliferous, gray ......

Marl, clayey, sandy, shelly, 

cream ...........

Sand, fine to coarse quartz, 

marly, cream to tan . . .

Sand, fine to medium quartz, 

tan ............

Sandstone, friable, very calcareous, fossiliferous, 

white to cream.......

+20.9

+19.0 

+17.0

+16.2 

+15.9

+15.0 

+14.0 

+12.3 

+11.7 

+10.9 

+.9

-9.1

Well 8

NEiNE? sec. 7, T. 44 S., 

R. 33 E., Hendry County.

Top of measured section (land 

surface) ...........

Pamlico sand:

Sand, fine to medium quartz, 

tan .............

Sand, fine to medium quartz, 

rust ............

Fort Thompson formation:

Marl, sandy, somewhat indurated, tan ........

Limestone, fossiliferous 

(many Chione cancellata 

preserved as molds), tan 

to brown ..........

Marl, sandy, shelly (Chione 

cancellata), gray to tan . .

Sand, fine quartz, very shelly 

(Chione cancellata), silty, 

gray ............

Caloosahatchee marl:

Sand, fine quartz, slightly 

shelly, silty, tan, orange 

to light gray ........

Tamiami formation:

Marl, clayey, slightly sandy, 

shelly, greenish-tan to 

cream ...........

+20.6

+17.5 

+15.8

+14.4

+13.5 

+12.6

+7.5 

+1.5 

-5.6

I/ Datum is mean sea level.
10 GEOLOGY OF THE WESTERN EVERGLADES AREA 

Well 8--Continued. Well 10--Continued.

Location and description

Tamiami formation--Continued. 

Sand, very marly, shelly,

light greenish-tan .... 

Marl, very sandy, shelly,

greenish-gray ......

Depth (feet I/)

-8.0

-9.4

Well 9

NW^NWl sec. 10, T. 44 S., 

R. 33 E., Hendry County.

Top of measured section (land 

surface) ...........

Pamlico sand:

Sand, fine to medium quartz, 

tan .............

Caloosahatchee marl:

Sand, fine to medium quartz, 

shelly, rust .........

Sand, fine quartz, marly,

silty, shelly, cream.....

Marl, clayey, slightly sandy, 

phosphatic, shelly, cream .

Marl, clayey, very shelly, 

cream ............

Tamiami formation:

Marl, sandy, clayey, slightly 

shelly, cream to light 

grayish-green ........

Marl, very sandy, phosphatic, 

very shelly, gray ......

Marl, very sandy, very shelly 

(mainly fragments), grayishtan ..............

+19.0

+15.0

+12.3 

+8.0 

+5.0 

+2.0

-1.0

-4.0

-11.0

Well 10

NWiNWi sec. 14, T. 44 S., 

R. 33 E., Hendry County.

Top of measured section (land 

surface) ...........

Pamlico sand:

Sand, fine to medium, organic, 

dark brown .........

Fort Thompson (?) formation:

Sandstone, friable, silty, 

shelly (Chione cancellata), 

rust-yellow .........

Limestone, very sandy, fossiliferous (pectens and 

Chione cancellata), tan . . .

Sandstone, fine, calcareous, 

friable, slightly fossiliferous, cream .........

Caloosahatchee marl:

Marl, sandy, very shelly

(oysters), cream ......

Shell marl, sandy, cream . . .

Sand, fine quartz, very

silty, marly, shelly, creamgray .............

+18.6 

+16.6

+15.1 

+12.6 

+12.1

+5.1 

+4.0

+. 1

Location and description

Tamiami formation:

Marl, clayey, very shelly,

tannish-green ..... 

Marl, clayey, sandy, very

shelly, greenish-gray . 

Marl, very sandy, clayey,

shelly, cream ..... 

Sand, fine quartz, clayey,

light greenish-gray . .

Depth (feet I/)

-4.0

-6.7

-8.7

-9.9

Well 11

SWiSWi sec. 7, T. 44 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Pamlico sand:

Sand, fine to medium quartz, 

gray .............

Fort Thompson (?) formation, 

and Caloosahatchee marl (undifferentiated): 

Sand, fine quartz, very marly,

slightly shelly, tan to rust . 

Sand, fine quartz, silty,

slightly marly, very shelly, 

tan ..............

Sand, fine quartz, silty, marly, 

very shelly, greenish-brown 

Tamiami (?) formation:

Sand, fine quartz, silty, marly, 

clayey, light tannish-green . 

Sand, fine quartz, clayey, 

silty, marly, light olivegreen.............

Sand, fine to medium quartz, 

silty, greenish-gray.....

+17.4 

+12.4

+7.4

+2.4

-1.3

-3.3

-7.0 

-12.6

Well 12

SWiSWi sec. 9, T. 44 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Peat, dark brown ........

Pamlico sand:

Sand, fine to medium quartz, 

carbonaceous, black ....

Fort Thompson (?) formation: 

Sandstone, calcareous, friable, 

shelly, gray .........

Undif f e rentiated:

Sand, fine to medium quartz, 

silty, cream to white ....

Sand, fine to medium quartz, 

rust-yellow .........

Sand, fine to medium quartz, 

white .............

+16.4 

+9.4 

+8.4 

+5.9

+4.5

+3.4

-13.6

I/ Datum is mean sea level.
LOGS

Well 13 

Location and description

SWiSW| sec. 21, T. 44 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Depth (feet I/)

Recent organic soils:

Peat, dark brown ........

Pamlico sand:

Sand, fine to medium quartz, 

tannish-gray .........

Sand, fine to medium quartz, 

dark brown..........

Fort Thompson (?) formation:

Sand, fine to medium quartz, 

tan; locally indurated to 

friable sandstone ......

Sand, fine, silty, tan to buff . . 

Tamiami formation:

Sand, fine quartz, silty, shelly, 

cream; some fine phosphatic 

grains ............

Sand, fine quartz, silty, tan to 

greenish-gray ........

Sand, fine to medium quartz, 

silty, very shelly, brown to 

green; lower part indurated 

to greenish-gray sandstone, 

containing a few small pebbles of phosphate ......

+17.3 

+13.9

+13.5 

+11.6

+10.4 

+1.0

-2.7

-9.0

-12.7

OF WELLS 11

Well 15--Continued. 

Location and description Depth (feet I/)

Pamlico sand:

Sand, medium, light gray

to brown .............. +16. 4

Fort Thompson (?) formation: 

Sand, fine to medium quartz,

white ................ +15.7

Sand, dark brown; "hardpan"..... +14. 4

Sand, fine to medium quartz,

rust-brown. ............ +13.7

Sand, fine to medium quartz,

brown ............... +10.2

Sand, medium to coarse quartz,

brown ............... +6.7

Sand, fine quartz, slightly

marly, silty, tan ......... -1.7

Sand, fine quartz, silty,

brown ............... -3.6

Sand, fine quartz, grayishtan ................. -11.3

Sand, fine to medium quartz,

silty; cream to light gray ..... -12.7

Well 16

NW{NWi sec. 4, T. 46 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Well 14

SE{SEi sec. 8, T. 45 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Pamlico sand:

Sand, fine to medium quartz, 

brown ...........

Fort Thompson (?) formation:

Limestone, sandy, hard, 

tan to brown ........

Marl, very sandy, cream . .

Sand, fine to medium quartz, 

very marly, silty, cream .

Sand, fine quartz, silty, rustyellow ...........

Sand, fine quartz, silty, buff

Sand, fine to medium quartz, 

light gray .........

+17.9

+15.9

+15.0 

+14.2

+10.2

+8.7 

+7.2

-12.1

Well 15

SWiSWi sec. 21, T. 45 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ........... +17.7

Recent organic soils:

Sand, quartz, carbonaceous,

black .............

Fort Thompson (?) formation: 

Sand, quartz, carbonaceous,

dark brown..........

Sand, fine to medium quartz,

rust-brown .........

Sand, fine quartz, marly,

silty, light gray to cream . . 

Marl, clayey, light cream to

white .............

Marl, very sandy, shelly,

white to light cream . . . . . 

Tamiami formation:

Sand, fine quartz, very marly,

shelly, green-brown. . . . . 

Sand, as above, except very

shelly, green-tan; phosphate

granules at -6. 0 mean sea

level .............

Sand, fine to medium quartz,

marly, shelly, green-brown

Well 17

SWiSWi sec. 9, T. 46 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

+18.3

+16.3

+14.9

+11.3

+7.3

-2.0

-3.0

-5.6

-8.9 

-11.7

+16.2

\J Datum is mean sea level. Recent organic soils and marls:

Peat, brown. ............. +15.3

Marl, sandy, gray .......... +13.2
12 GEOLOGY OF THE WESTERN EVERGLADES AREA

Well 17 Continued. Well 19 Continued.

Location and description Depth (feet I/)

+8.6

+7.4

+3.3

+1.0

Fort Thompson (?) formation: 

Marl (Chione cancellata),

yellow; indurated, sandy

in part ............... +10. 2

Limestone, dense, hard,

rust-yellow ...........

Sand, fine to coarse quartz,

shelly (Chione cancellata),

marly, cream ..........

Marl, clayey, sandy, shelly,

white to cream..........

Tamiami formation:

Marl, clay, shelly, tan to

cream ..............

Sand, very marly, tan to

greenish-tan; some granules

and small pebbles of black

phosphate ............. -10.0

Marl, sandy, fine quartz,

silty, slightly shelly, green

to brown .............. -14.4

Well 18

SWiSWi sec. 21, T. 46 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ........... +15.8

Recent organic soils:

Peat, dark brown ........... +14. 8

Sand, mucky, black ......... +11.5

Fort Thompson (?) formation: 

Marl, sandy, yellow; in part

indurated, cream .......... +9.8

Sandstone, coarse to very

coarse quartz, friable,

silty, slightly shelly,

cream to white ........... +8. 8

Sand, fine to medium quartz,

marly, cream ........... +3. 8

Tamiami formation:

Sandstone, calcareous, fossiliferous, friable, silty,

cream to white ........... -.2

Sand, very marly, fossiliferous, cream to white; in

part indurated to friable

sandstone ............. -10.5

Sand, fine to medium quartz,

shelly, tan ............. -13.5

Marl, sandy, brown ......... -14.4

Location and description Depth (feet I/)

Fort Thompson (?) formation:

Sand, fine to medium quartz,

tan to brown ............

Sand, fine to medium quartz,

marly, shelly, brown .......

Sandstone, fine quartz, calcareous, fossiliferous 

(casts and molds), cream ..... 

Tamiami formation:

Sand, fine quartz, marly,

silty, phosphatic, cream .....

Sandstone, fossiliferous (casts), 

porous, calcareous, tan......

Marl, very sandy, silty, shelly,

cream ...............

Marl, very sandy, shelly, tan ....

Sand, fine to medium quartz,

marly, brown ........... -11.5

Sand, slightly marly, silty,

greenish-brown .......... -14.5

Well 20

SWiSWi sec. 9, T. 47 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

+11.1

+8.5

+1.0

-4.0

-4.8

-6.4

-8.5

+15.5

Recent organic soils:

Sand, carbonaceous, brown

to black .............. +12.5

Fort Thompson (?) formation: 

Sand, coarse to medium quartz,

rust-brown. ............ +10.7

Sand, fine to medium quartz,

shelly, silty, tan to cream .... +9.7 

Sand, coarse quartz, very shelly

(Chione cancellata), tan; some

small quartz pebbles ....... +8.5

Sand, medium to coarse quartz,

tan to cream ............ +6. 0

Sand, medium to coarse quartz,

slightly shelly, white ....... +2.1

Sand, fine to medium quartz,

marly, silty, slightly shelly,

light gray to cream ........ -6. 4

Sand, fine quartz, very silty,

phosphatic, brown ......... -9. 5

Sand, shelly, fine to medium

quartz, tan. ............ -11.3

Sand, fine quartz, shelly, phosphatic, marly, silty, tan ..... -14.5

Well 19

SWiSWi sec. 33, T. 46 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Recent organic soils: 

Peat, dark brown .

+15.5 

+13.5

Jt/ Datum is mean sea level.

Well 21

NE'iSWi sec. 22. T. 47 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Sand, brown; top part contains organic material. 

Sand, carbonaceous, black

+14.6

+12.1 

+11.1
LOGS OF WELLS 13

Well 21--Continued. 

Location and description

Fort Thompson (?) formation:

Sand, coarse quartz, rustbrown .............

Sand, fine to medium quartz, 

marly, light gray .......

Sandstone, calcareous, porous, 

fossiliferous, light gray to 

cream; in part friable .....

Sand, fine to coarse quartz,

very marly, cream ......

Sandstone, calcareous, fossiliferous, friable, cream ....

Sand, fine quartz, silty, marly, 

cream; contains very small 

phosphate specks .......

Marl, very sandy, cream ....

Sand, fine quartz, marly, very 

shelly, cream .........

Sand, fine to medium quartz, 

marly, light gray .......

Sand, fine to medium quartz, 

marly, silty, cream to tan . .

Well 22

SWiNEi sec. 35, T. 47 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Well 23--Continued.

Depth (feet I/)

+9.6 

+5.2

+3.3 

+1.5

-1.1

-3.5

-5.1

-7.5

-9.4

-15.4

+14.0

Recent organic soils:

Peat, brown. .........

Sand, fine to coarse quartz,

carbonaceous, dark brown 

Fort Thompson (?) formation:

Sand, fine to coarse quartz, 

brown ...........

Marl, sandy, clayey, brown .

Marl, sandy, cream .....

Sand, fine quartz, very marly, 

cream ...........

Marl, sandy, shelly, cream 

to light gray; in part indurated ............

Limestone, very sandy, fossiliferous, porous, friable, 

tan to brown ........

. +13.0 

. +10.5

+9.7 

+7.3 

+4.5

-3.5

-10.0

-16.0

Location and description

Fort Thompson (?) formation--Continued.

Sand, medium to coarse 

quartz, slightly silty, 

shelly, cream to 

white; some phosphate granules .....

Sand, fine to medium 

quartz, marly, slightly 

shelly, tan .......

Sand, fine quartz, silty, 

slightly marly, brown .

Sand, fine quartz, slightly 

silty, tan to brown , .

Depth (feet I/)

+.7

-4.0

-5.6 

-16.6

Well 24

NW^NWi sec. 10, T. 48 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface)...........

Recent organic soils and marls:

Peat, mucky, dark brown . . .

Marl, slightly sandy, gray . . . 

Fort Thompson (?) formation:

Marl, sandy, shelly, cream . .

Limestone, sandy, fossiliferous, porous, tan to gray .

Marl, sandy, shelly, white to 

cream; some pieces of indurated marl.........

Limestone, soft, fossiliferous, white ..........

Caloosahatchee marl: 

Marl, very sandy, shelly, 

with grains of black phosphate, cream ........

Sand, fine to medium quartz, 

marly, very shelly, phosphatic, cream to tan ....

Marl, very sandy, shelly,

cream to tan .........

Sand, fine to medium quartz, 

marly, shelly, gray .....

Sand, fine quartz, very marly, 

slightly shelly, tan to cream

+13.9

+9.6 

+9.0

+5.9 

+3.9

+.1

-2.7

-3.7

-8.0

-9.6

-11.5

-18.1

Well 23

NEiNEi sec. 12, T. 48 S., 

R. 34 E., Hendry County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Peat, dark brown .......

Peat and muck, sandy,

dark brown .........

Fort Thompson (?) formation:

Limestone, sandy, hard, cream 

to brown; perforated by solution holes ..........

+13.4

+12.4 

+10.4

+6.7

Well 25

SW{SWi sec. 15, T. 48 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface) ...........

I/ Datum is mean sea level.

Recent organic soils and marls: 

Muck and peat, dark brown. 

Marl, brownish-gray ....

Fort Thompson (?) formation: 

Limestone, sandy, fossiliferous, tan ........

Marl, sandy, shelly, cream 

to white; in places indurated to limestone ....

+13.0

+9.6 

+9.0

+8.0 

-5.2
14 GEOLOGY OF THE WESTERN EVERGLADES AREA 

Well 25--Continued. Well 27 Continued.

Location and description

Caloosahatchee marl:

Marl, very sandy, and very 

marly sand, shelly, 

greenish-brown to green

Sand, fine to medium quartz, 

silty, marly, very shelly 

(some Chione cancellata), 

cream ..........

Depth (feet I/)

-11.0

-17.0

Well 26

SWiSWi sec. 27, T. 48 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface) ...........

Recent organic soils and marls:

Peat, brown .........

Muck, sandy, black .....

Marl, sandy, clayey, gray 

to tan............

Fort Thompson (?) formation:

Limestone, sandy, fossiliferous, porous, light cream 

to gray ...........

Marl, sandy, shelly, light 

gray ............

Caloosahatchee marl:

Sand, fine quartz, with some 

larger quartz granules, 

marly, shelly (some Chione 

cancellata), buff ......

Tamiami formation:

Sand, fine to medium quartz, 

very marly, very shelly, 

brownish-gray; with 

granules of phosphate, 

black; at -5.0 feet mean 

sea level ..........

Sand, fine to medium quartz, 

very marly, white to light 

cream, shelly; pebbles 

and granules of phosphate .

Marl, clayey, sandy, shelly, 

brownish-green ......

+12.5

+7.1 

+6.3

+3.5

+2.5 

+1.0

-4.7

-6.5

-13.7

-17.5

Well 27

SWiSWi sec. 3, T. 49 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Peat, sandy, brown. . . .

Fort Thompson (?) formation: 

Sandstone, calcareous, 

tan to brown ......

Marl, slightly shelly, 

cream-tan .......

+12.1 

+10.6

+9.1 

+7.6

Location and description

Fort Thompson(?) formation-- 

Continued.

Marl, slightly shelly (casts 

of shells, some Chione 

cancellata), light graycream to white........

Marl, very sandy, light

cream-gray .........

Marl, very sandy, shelly, 

cream; with some phosphate granules ........

Caloosahatchee marl:

Sand, fine to very fine quartz, 

slightly silty, shelly (Chione 

cancellata), cream to light 

tan ..............

Tamiami formation:

Sand, fine quartz, slightly 

shelly, marly, tan. . . . . .

Marl, shelly, dark greenishtan ..............

Depth (feet I/)

+2.3 

+1.7

+.1

-12.3

-12.9

-17.9

Well 28

SW{SWi sec. 15, T. 49 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Sand, mucky, carbonaceous,

dark brown to black .... 

Fort Thompson (?) formation:

Marl, sandy, brown to tan . .

Sand, very fine to fine 

quartz, slightly shelly, 

marly, silty, light brown 

to white ..........

Caloosahatchee marl:

Sandstone, fossiliferous 

(some molds of Chione 

cancellata), calcareous, 

in part friable, tan to 

cream ...........

Sand, marly, shelly, cream 

to white ..........

Sand, fine quartz, silty, tan . 

Tamiami formation:

Marl, sandy, greenish-brown

Well 29

SW{SW{ sec. 27, T. 49 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface) ...........

+11.4

+9.2 

+3.4

-2.6

-3.0

-8.6

-11.6

-18.6

I/ Datum is mean sea level.

Recent organic soils:

Peat, sandy, brown. . . . . 

Fort Thompson (?) formation:

Sand, dark brown ......

Marl, sandy, silty, cream .

Sand, fine to medium quartz, 

very marly, cream ...

+11.1

+8.6

+7.5 

+4.0

+2.1
LOGS OF WELLS 15

Well 29--Continued. 

Location and description

Fort Thompson (?) formation-- 

Continued.

Sand, fine to very fine quartz, 

silty, tan. ...........

Sand, marly, cream .......

Tamiami formation:

Marl, sandy, fossiliferous, 

white; indurated to a fossiliferous sandy limestone in places.........

Sand, fine to very fine quartz, 

silty, cream ..........

Marl, silty, slightly shelly,

cream .............

Depth (feet I/)

-2.9

-6.2

-7.9

-13.7

-18.9

Well 30

Western Broward County, 3 miles 

east of the Collier County line 

and 12. 4 miles north of the 

Dade County line.

Top of measured section (land 

surface) .............

Recent organic soils and marls:

Soil, sandy, brown ......

Marl, sandy, gray ......

Fort Thompson (?) formation:

Sandstone, shelly, calcareous, 

hard, rust-yellow .....

Marl, slightly sandy, fossiliferous, indurated, cream .

Marl, slightly sandy, slightly 

shelly, cream; locally indurated ...........

Sand, fine quartz, very silty 

and marly, slightly shelly 

(some Chione cancellata), 

cream ...........

Tamiami formation:

Sand, very marly, clayey, 

shelly, brown to tan ....

Marl, clayey, sandy, shelly, 

greenish-tan ........

+11.4

+11.0 

+10.1

+9.9 

+9.0

-1.0

-6.9

-15.0

-18.6

Well 31

Western Broward County, 3 miles 

east of the Collier County line 

and 10. 4 miles north of the 

Dade County line.

Top of measured section (land 

surface) .............

Recent organic soils and Lake 

Flirt marl (undifferentiated): 

Peat, sandy, dark brown;

dark brown at base . . . 

Sand, clayey, dark gray; 

possibly fresh-water . .

+10.0

+9.0 

+8.5

Well 31--Continued. 

Location and description

Fort Thompson (?) formation:

Sandstone, calcareous,

fairly hard, tan ........

Marl, very sandy, shelly,

cream .............

Sandstone, calcareous, in

part friable, cream ......

Sand, fine, very silty,

marly, light cream; with 

some concretions .......

Tamiami formation:

Sandstone, calcareous, in 

part friable, slightly 

porous, fossiliferous, 

silty, light gray to cream 

gray ..............

Depth (feet I/)

+8.0 

+5.5 

+5.0

-11.5

-20.0

Well 32

Western Broward County, 2. 2 

miles east of the Collier 

County line and 8. 6 miles 

north of the Dade County 

line.

Top of measured section (land 

surface)...........

Recent organic soils and marls:

Peat, muck, dark brown . . .

Sand, carbonaceous, black . .

Marl, clayey, brown to

gray ............

Fort Thompson (?) formation:

Marl, sandy, partially indurated, cream ......

Sand, fine to medium quartz, 

marly, white........

Sand, fine quartz, very

marly, white........

Tamiami formation:

Marl, sandy, slightly shelly, 

white to cream.......

Marl, very sandy, shelly, 

cream; in places indurated 

to sandstone ........

Marl, sandy, silty, greenishbrown ...........

+10.2

+8.6 

+7.8

+6.8

+5.5 

+.7

-4.7

-8.8

-13.5

-21.2

Well 33

Western Broward County, 2.0 

miles east of the Collier 

County line and 6. 8 miles 

north of the Dade County 

line.

Top of measured section (land 

surface)...........

1 I/ Datum is mean sea level.

Recent organic soils:

Peat, brown. ......

Fort Thompson formation: 

Sand, brown.......

Sandstone, hard, dense, 

tan to cream . . . . .

+9.7

+9.1 

+8.9 

+7.3
16 GEOLOGY OF THE WESTERN EVERGLADES AREA 

Well 33 Continued. Well 35

Location and description

Fort Thompson formation-- 

Continued.

Sandstone, very silty, calcareous, very friable, 

cream ...........

Tamiami formation:

Limestone, very sandy, 

fossiliferous (preserved 

by molds), cream to 

white; in places a friable sandstone .......

Limestone, very sandy, very 

fossiliferous, soft, white .

Sandstone, shelly, calcareous, brown ........

Sand, fine quartz, marly, 

silty, brown ........

Well 34

SWiNWi sec. 9, T. 51 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Peat, brown ..........

Fort Thompson formation:

Marl, slightly indurated,

cream ............

Sandstone, very calcareous, 

slightly shelly, dense, 

hard, brown .........

Tamiami formation:

Marl, sandy, slightly shelly, 

in part indurated, tan ....

Marl, sandy, cream to tan . . .

Marl, sandy, fossiliferous, 

in part indurated to a soft 

sandy limestone, cream . . .

Marl, sandy, cream; very 

shelly at top .........

Sand, fine to medium quartz, 

very shelly, buff to orange .

Marl, very sandy, shelly, 

cream; in part cemented 

to calcareous sandstone . . .

Marl, sandy, cream; in part 

shelly ............

Marl, sandy, cream; in part 

cemented to sandy limestone containing fossils 

(mainly echinoids) ......

Marl, slightly sandy, slightly 

shelly, cream ........

Limestone, very soft, sandy, 

silty, fossiliferous, porous, 

cream to white........

Marl, sandy, shelly, cream . .

Depth (feet I/)

+4.0

-12.5

-15.3

-15.5

-20.8

+9.4 

+8.8 

+8.4 

+7.6

+5.7 

+3.5

+1.3

-2.0

-4.7

-8.4

-10.0

-12.6

-15.7

-19.6

-20.6

Location and description

SWiNWi sec. 21, T. 51 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface) ...........

Depth (feet I/)

Recent organic soils:

Peat, brown .........

Fort Thompson formation:

Limestone, sandy, dense, 

hard, cavernous, slightly 

shelly, tan to brown ....

Sandstone, calcareous, porous, in part friable, tan 

to dark gray ........

Tamiami formation:

Marl, sandy, fossiliferous 

(similar to limestone in 

Sunniland pits), white to 

cream; in part indurated 

to a soft limestone ....

Marl, very sandy, white to 

light gray .........

Sand, fine to medium quartz, 

silty, marly, slightly 

shelly, buff to tan .....

Sand, fine to medium quartz, 

very silty, marly, white .

Sandstone, calcareous, silty, 

very fossiliferous, in part 

friable, cream. ......

Marl, sandy, shelly, cream; 

in part cemented to a friable, calcareous, silty 

sandstone. .........

Marl, sandy, shelly, cream 

to buff ...........

Limestone, soft, silty, fossiliferous ...........

Marl, sandy, shelly, cream .

Marl, sandy, slightly shelly, 

tan .............

Well 36

SEiNWi sec. 33, T. 51 S., 

R. 35 E., Broward County.

Top of measured section (land 

surface) ...........

_!/ Datum is mean sea level.

Recent organic soils:

Peat, brown ........

Pamlico (?) sand:

Sand, marly, brown . . . .

Fort Thompson formation: 

Limestone, hard, sandy, 

containing some gastropods (possibly freshwater), light tan; possibly a deposit filling a 

cavity in underlying rock 

Limestone, sandy, fossiliferous, marine, cream; 

in part friable ......

+9.2 

+7.9

+5.0 

+3.2

.0

-2.0

-5.0

-6.8

-11.0

-12.8

-13.5

-14.4

-18.8

-20.8

+8.9

+8.3 

+7.2

+6.7 

+.6
LOGS OF WELLS 17

Well 36--Continued.

Location and description

Pliocene (?) or Pleistocene (?), 

undifferentiated:

Sand, fine quartz, very 

marly, silty, white to 

cream ...........

Tamiami formation:

Sandstone, silty, calcareous, 

fossiliferous, light gray; 

in part very friable ....

Sand, fine quartz, very

marly, silty, white ....

Sand, fine to coarse quartz, 

very marly, silty, cream .

Marl, very sandy, fossiliferous, light gray to cream; 

in places locally indurated 

to a fossiliferous sandstone

Marl, sandy, tan .......

Sand, fine, marly, tan to 

brown ...........

Depth (feet I/)

Well 37

SWiNEi sec. 9, T. 52 S., 

R. 35 E., Dade County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Peat, brown ..........

Muck, black ..........

Fort Thompson formation:

Sandstone, calcareous, hard, 

dense, tan to cream .....

Marl, very sandy, silty, cream; 

in part indurated.......

Sandstone, calcareous, brown 

to tan.............

Pliocene (?) or Pleistocene (?), 

undifferentiated: 

Sand, fine quartz, very marly, 

- silty, cream .........

Sand, marly, silty, fine to 

medium, tan .........

Tamiami formation:

Limestone, very sandy, very 

soft, friable, fossiliferous, 

cream to tan .........

Sand, shelly, calcareous,

silty, tan. ..........

Marl, sandy, shelly, grayishcream; indurated to a soft 

sandy limestone around 

the shells ..........

Marl, silty, sandy, fossiliferous, brown; in part indurated. ...........

I/ Datum is mean sea level.

-3.7

-6.4

-7.5

-10.3

-16.7

-18.2

-21.2

+8.7

+7.4 

+6.3

+4.6 

+2.1 

+1.2

-8.0

-10.4

-14.3

-15.4

-18.5

-21.7

Well 38 

Location and description

NWiNEi sec. 16, T. 52 S., 

R. 35 E., Dade County.

Top of measured section (land 

surface) ...........

Depth (feet I/)

Recent organic soils:

Peat and muck, sandy,

dark brown..........

Fort Thompson formation:

Limestone, sandy, dense,

cream to tan .........

Sandstone, calcareous, fossiliferous, in part friable, cream..........

Pliocene (?) or Pleistocene (?), 

undifferentiated:

Marl, very sandy, slightly 

shelly, light gray to cream .

Sandstone, silty, calcareous, 

very friable, fossiliferous, 

cream to white........

Sand, marly, silty, cream to 

white, fossiliferous; and 

white, calcareous, fossiliferous sandstone from -3. 8 

to -4.5 ............

Tamiami formation:

Marl, very sandy, shelly, 

cream to white; in places 

indurated to a sandy fossiliferous limestone .....

Well 39

SW|NW{ sec. 33, T. 52 S., 

R. 35 E., Dade County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Muck and peat, dark brown. . 

Fort Thompson formation: 

Sandstone, hard calcareous, 

tan to brown ........

Marl, partially indurated, 

light cream ........

Sandstone, calcareous, silty, 

white to light gray; fairly 

hard from +4. 8 to +2. 6; 

friable from +2.6 to +1. 4 . 

Pliocene (?) or Pleistocene (?), 

undifferentiated: 

Sand, medium to coarse

quartz, rust to light cream 

Sand, medium to coarse

quartz, white .......

Well 40

SEiNEi sec. 8, T. 53 S., 

R. 35 E., Dade County.

Top of measured section (land 

surface) ...........

+8.2

+7.6 

+4.5 

+1.6

-5.3

-21.9

+8.0 

+7.2

+6.7 

+4.8

+1.4

-7.0

-22.0

+7.4
18 GEOLOGY OF THE WESTERN EVERGLADES AREA 

Well 40 Continued. Well 41--Continued.

Location and description

Recent organic soils and 

Lake Flirt marl:

Peat and muck, dark brown. . . Marl, sandy, gray to cream . . 

Fort Thompson formation:

Limestone, sandy, hard,

dense, cream to brown . . . Marl, silty, sandy, tan. .... 

Pliocene (?) or Pleistocene (?), 

undifferentiated:

Sand, fine to medium quartz, 

very silty, marly, cream . , Sand, fine to medium quartz, 

slightly silty, buff ......

Sand, fine to medium quartz, 

marly, light gray ......

Marl, very sandy, fossiliferous, light gray; in part indurated, calcareous, fossiliferous sandstone .....

Sand, fine to medium quartz, 

very silty, grayish-tan; in 

lower part fine to coarse 

quartz sand .........

Sand, fine to medium quartz, 

light orange to rust .....

Sand, medium to coarse

quartz, marly, white; some 

friable fossiliferous sandstone from -14. 0 to -14-. 5

Sand, fine to medium quartz, 

slightly marly, shelly, 

cream ...........

Tamiami formation:

Marl, very sandy, fossiliferous, white; in places indurated to sandy limestone .

Depth (feet I/)

+6.8 

+6.2

+4.8 

+2.4

-.4

-1.5

-4.9

-6.3

-8.5 

-10.7

-17.0 

.- -19.2

-22.6

Well 41

NWiNEi sec. 20, T. 53 S., 

R. 35 E., Dade County.

Top of measured section (land 

surface) ...........

Recent organic soils and Lake 

Flirt marl:

Muck and peat, dark brown. 

Marl, sandy, gray .....

Fort Thompson formation: 

Limestone, hard, slightly 

shelly, tan ........

Marl, sandy, tan to buff; a 

few concretions around 

shell material ......

Pliocene (?) or Pleistocene (?), 

undifferentiated: 

Marl, sandy, shelly, white; 

lower part partially indurated ...........

+7.5

+7.1 

+6.0

+5.0 

.0

-12.5

Location and description

Tamiami formation:

Limestone, sandy, fossiliferous, friable, white . .

Marl, shelly, sandy, in part 

indurated, white to cream

Marl, sandy, shelly, light 

gray to white; some gray, 

very shelly limestone . .

Marl, sandy, shelly, tan to 

cream ..........

Depth (feet I/)

Well 42

NEiNWi sec. 32, T. 53 S., 

R. 35 E., Dade County.

Top of measured section (land 

surface) ...........

Recent organic soils:

Peat, dark brown .......

Fort Thompson formation: 

Limestone, sandy, silty,

soft, fossiliferous, cream;

in places an indurated

marl ............

Limestone, marine, sandy,

dense, hard, light tan . . . 

Limestone, sandy, hard,

dense, fresh-water (?),

dark gray .........

Limestone, soft; indurated

marl, sandy, rust-yellow . 

Limestone, fresh-water,

sandy, hard, dense, tan. . 

Limestone, soft, sandy,

cream ...........

Pliocene (?) or Pleistocene (?), 

undifferentiated: 

Marl, sandy, cream to white . 

Sand, fine quartz, marly,

tan to rust .........

Sand, fine quartz, white to

light gray .........

Sand, fine quartz, marly,

very shelly (some Chione

cancellata), white ..... 

Tamiami formation:

Shell marl, silty, sandy,

white ............

Marl, sandy, shelly, cream

to tan ...........

Well 43

SW|SWi sec. 5, T. 54 S., 

R. 35 E., Dade County.

Top of measured section (land 

surface) ...........

I/ Datum is mean sea level.

Recent organic soils and Lake 

Flirt marl:

Muck and peat, dark brown, 

Marl, clay, fresh-water, 

brown ..........

-15.3

-17.6

-20.8

-22.9

+8.1 

+7.9

+5.6 

+4.7

+4.0

+3.0

+2.6

-.8

-3.0

-4.3

-6.9

-9.2

-10.4

-21.9

+7.7

+7.1 

+6.5
Well 43 Continued. 

Location and description

Fort Thompson formation:

Sandstone, hard, calcareous, 

cream to brown; and limestone, hard fossiliferous, 

dark gray, as a cavity 

filling in sandstone (or the 

reverse) from +5.5 to +5. 0 . .

Sandstone, calcareous, dense, 

fossiliferous, cream to 

tan ...............

Limestone, dense, hard, dark 

gray, as a cavity filling . . . .

Sandstone, in part friable,

cream .............

_!/ Datum is mean sea level.

FAUNA FOUND IN WELLS 19

Well 43 Continued. 

Depth (feet I/) Location and description Depth (feet I/)

Pliocene (?) and Pleistocene (?), 

undif f e re ntiated: 

Sand, fine to medium quartz, 

and friable sandstone, 

white to cream, both 

shelly ............... -4.7

+4.1 Sandstone, calcareous, in 

part friable, silty, porous, fossiliferous, gray ..... -7.5

+3.7 Sand, silty, shelly, buff to

tan ................. -10.0

+3. 4 Tamiami formation:

Marl, sandy, silty, cream to 

-1.1 white; in part indurated to 

sandstone; in places very 

shelly ............... -22.3

FAUNA FOUND IN WELLS 1 TO 43

Well 1

Fossils and range

Fresh-water limestone containing 

Helisoma sp. ..........

Stratigraphic range: Fort 

Thompson formation.

Serpula sp. ...........

"Vitrinellid".

Calyptraea centralis (Conrad).

Turritella subannulata Heilprin.

Cerithium ornatissimum Heilprin.

Mitra sp.

Mitre lla sp.

Marginella precursor Dall.

Cancellaria conradiana Dall.

"Drillia" pogodula Dall.

Depth (feet I/) 

+4.2

-1.0

Terebra concava Say. 

Nuculana cf. N. acuta (Conrad). 

Arcopsis adamsi (Shuttleworth). 

Anadara sp. (fragment). 

Ostrea cf. O. sculpturata Conrad

(fragment). 

Phacoides (Parvilucina) multilineatus Tuomey and Holmes. 

Phacoides (Bellucina) tuomeyi

Dall. 

Gemma magna Dall.

Venus sp. (fragment). 

Chione cancellata Linne'. 

Corbula sp.

Stratigraphic range: Caloosahatchee marl.

Well 1 Continued. 

Fossils and range

Unidentified fragments of a large 

oyster and other pelecypods.

Stratigraphic range: Formation 

indeterminate.

Depth (feet I/)

-12.0

Well 2

Natica canrena Linne. -3.0 

to -4.0

Turritella subannulata Heilprin.

Cerithium sp.

Busycon pyrum (Dillwyn).

Oliva sp. cf. O. carolinae Gardner.

Terebra sp. aff. T. protexta

Conrad. 

Acteocina.

Arcopsis adamsi (Shuttleworth). 

Anadara cf. A. transversa (Conrad). 

Anomia sp. 

Corbula sp.

Chione cf. (J. cribraria (Conrad). 

Chione cancellata Linne'. 

Cardita (Carditamera) floridana

Stratigraphic range: Caloosahatchee marl.

I/ Datum is mean sea level.
20

Fossils and range

GEOLOGY OF THE WESTERN EVERGLADES AREA 

Well 3 Well 9 Continued.

Lunatia? sp. ..........

Several genera of fresh-water 

gastropods.

Stratigraphic range: Fort 

Thompson formation and 

Caloosahatchee marl.

Depth (feet I/) 

+2.0

Nuculana acuta (Conrad). .... 

Several genera of fresh-water 

gastropods.

Stratigraphic range: Fort 

Thompson formation and, 

possibly, Caloosahatchee 

marl.

Well?

-3.0

Anadara improcera (Conrad). 

Mulinia congesta (Conrad).

Stratigraphic range: 

indeterminate.

Formation

Turritella sp. .........

Oliva cf. O. carolinae Gardner.

Arcopsis adamsi (Shuttleworth).

Anadara sp.

Mytilus.

Parastarte ? sp.

Cardium sp.

+6.0

-6.5

Stratigraphic range: 

indeterminate.

Formation

Well 8

Turritella subannulata Heilprin. . .

Oliva cf. O. sayana Ravenel.

Arneria.

Dentalium.

Anadara cf. A. transversa (Conrad).

Chione cancellata Linne"

Dosinia sp.

Transenella? sp.

Stratigraphic range: Fresh-water 

and marine mixture of Fort 

Thompson formation and Caloosahatchee (?) marl.

Well 9

Cerithium glaphyrea var. litharium Dall. ..........

+11.0

+12.5

Marginella limatula Conrad. 

Chione cancellata Linne\

Stratigraphic range: Caloosahatchee marl.

Fossils and range

Marginella sp. ........

Anadara transversa Say. 

Mulinia cf. M. late rails (Say). 

Pecten sp.

Ostrea sculpturata Conrad. 

Phacoides (Belluclna) tuomeyi

Dall.

Dosinia sp. 

Cardium sp.

Depth (feet I/) 

+4.0

Stratigraphic range: 

hatchee marl.

CaloosaNatica cf. N. canrena (Linne). 

Turritella cf. T. variabilis

Conrad. 

Cunearca cf. C>. scalaris

(Conrad).

Anadara improcera (Conrad). 

Mulinia congesta (Conrad). 

Pecten sp. 

Chione (Lirophora) latilirata

athleta Conrad. 

Chione cancellata Linne. 

Cardium sp.

-2.0

Stratigraphic range: 

formation.

Tamiami

''Solariella" sp. ...........

Arcopsis adamsi (Shuttleworth).

Mytilus sp.

Ostrea sp.

Cardita (Carditamera) sp.

Venericardia (Pleuroineris) n. sp. ?

-8.0

Stratigraphic range: 

formation.

Tamiami

Well 11

Epitonium sp. ..........

Cunearca sp.

Anadara cf. A. delandensis

Mansfield.

Mulinia lateralis (Say). 

Anomia sp. 

Ostrea sp.

Eontia variabilis MacNeil. 

Chione cancellata Linne*.

Stratigraphic range: Caloosahatchee (?) marl.

Well 13

+2.0

Crepidula fornicata Say.

Turritella sp. (juvenile).

Mitrella sp.

Pleuroliria sp. (fragment).

Olivella sp.

Terebra dislocata Say.

Acteon sp.

.0

I/ Datum is mean sea level.
Well 13 Continued. 

Fossils and range Depth (feet I/)

Ostrea sculpturata Conrad. 

Phacoides (Lucinisca) cribrarius (Say). 

Phacoides (Parvilucina)

multilineatus (Tuomey

and Holmes). 

Chione cancellata Linne*.

Stratigraphic range: Tamiami (?) formation.

FAUNA FOUND IN WELLS 21

Well 16--Continued. 

Fossils and range Depth (feet I/)

Phacoides (Cardiolucina) multistriatus (Conrad). 

Chione cancellata Linne".

Stratigraphic range: Tamiami (?) formation.

Well 17

Neverita cf. N. duplicata

(Say). ............

Turritella sp. (juvenile). 

Turritella variabilis Conrad. 

Serpula sp. 

trNassatr cf. N. consensa

Ravenel.

Marginella limatula Conrad. 

Marginella denticulata

Conrad. 

Olive lla sp. 

*Cancellaria aff. (?. venusta

Tuomey and Holmes. 

Conus sp.

Drillia lunata (Lea). 

Nuculana trochilia (Dall). 

Nuculana acuta (Conrad). 

Anadara improcera (Conrad). 

Cunearca sp.

Mulinia congesta (Conrad). 

Mytilus sp. 

Pecten sp. cf. P. eboreus

Conrad.

Ostrea sculpturata Conrad. 

Dosinia sp. 

Chione cancellata Linne*.

Stratigraphic range: Tamiami 

formation.

-10.0

Well 16

Cerithium glaphyrea var. 

litharium Dall. ....

-6.0

Marginella limatula Conrad.

Oliva sp.

Opercula.

Anadara improcera (Conrad).

Mulinia congesta (Conrad).

Chione cancellata Linne.

Stratigraphic range: Tamiami (?) formation.

Oliva cf. O. carolinae

Gardner. ........

Anadara improcera (Conrad). 

Mulinia congesta (Conrad). 

Pecten eboreus Conrad var. ? 

Eucrassatella sp.

-10.0

_!/ Datum is mean sea level. 

* More like specimens from Duplin marl at 

Natural Well, N. C.

Tgrritella perattenuata

Heilprin. ............

Syrnola sp.

Opercula.

Nuculana acuta (Conrad).

Mulinia congesta (Conrad).

Phacoides (Bellucina) tuomeyi

Dall. 

Gemma magna Dall.

Stratigraphic range: Formation 

indeterminate, possibly the 

Tamiami formation.

-1.0

Well 18

Nothing identifiable 

Discinisca sp. ...

+1,0 

-14.0

Stratigraphic range: Formation 

indeterminate.

Well 22

Pecten sp. ..............

Arbacia sp. cf. _A. .waccamaw

Cooke (identified by C. W. Cooke).

Stratigraphic range: Formation 

indeterminate, though C. Wythe 

Cooke believes it is possibly 

Pliocene.

-7.0

Well 23

Cardita (Carditamera) sp. 

Chione cancellata Linnd.

+2.0

Stratigraphic range: 

indeterminate.

Formation

Well 25

Oliva sp. ............

Abra aequalis (Say).

Ostrea sp.

Phacoides (Callucina) radians

Conrad. 

Tellina sp.

Stratigraphic range: Caloosahatchee (?) marl.

-9.0
22 GEOLOGY OF THE WESTERN EVERGLADES AREA

Well 25 Continued.

Fossils and range Depth (feet I/)

Helisoma sp. -12.0 

to -13.0

Omphalius exoletus (Conrad). 

Turbonilla sp. 

Crepidula fornicata Say. 

Calyptraea centralis (Conrad). 

Polinices sp. 

Turritella perattenuata

Heilprin.

Cerithium muscarum Say. 

Cerithium caloosae'nsis cf.

var. heilprini Dall. 

Cerithium glaphyrea var.

litharium Dall. 

Busycon sp. (juvenile). 

Pyrazisinus scalatus Heilprin. 

Urosalpinx perrugatus

Conrad.

Nassa vibex Say. 

Mitrella n. sp. 

Operculum. 

"Mitrella" sp.

Marginella limatula Conrad. 

Oliva sp.

Oliva cf. carolinae Gardner. 

___ 7onussp. (fragment). 

Bulla striata BruguieVe. 

Gemma sp.

Anadara lienosa (Say). 

Cardita (Carditamera)

(juvenile). 

Phacoides (Pseudomiltha)

anodonta (Say). 

Chione (Lirophora) latilirata

athleta Conrad. 

Chione cancellata Linne*. 

Dosinia sp. (fragment). 

Cardium (Trachycardium) sp.

Stratigraphic range: Probably a 

mixture of Caloosahatchee 

marl and Tamiami formation.

Well 26

Turritella sp. cf. T. perattenuata

Heilprin. ...........

Cerithium n. sp. aff. C. callisoma

Dall. 

Nassa ambigua Montagu var.

antillarum d'Orbigny. 

Olivella sp.

Conus adversarius Conrad. 

Acteocina sp. 

Nucula sp.

Glycymeris pectinata (Gmelin). 

Phacoides (Bellucina) tuomeyi

Dall. 

Gemma magna Dall.

.0

Well 26 Continued. 

Fossils and range Depth (feet I/)

Chione cancellata Linne. 

Bryozoa.

Stratigraphic range: Caloosahatchee (?) marl and Tamiami (?) formation, possibly 

a mixture.

Turritella cookei gladee*nsis 

Mansfield. .........

Marginella sp.

Nucula sp.

Nuculana acuta (Conrad).

Cardita TCarditamer a) arata 

Conrad.

Mulinia (juveniles).

Chione sp.

Cardium sp.

Stratigraphic range: Tamiami formation.

-5.0

Turritella (juvenile). .... 

-7.0

Cerithium (juveniles). 

Marginella limatula Conrad. 

Oliva spT~(thick parietal

callus). 

Mytilus sp. 

Anadara sp. 

Pecten cf. P_. eboreus

Conrad. 

Venericardia (Pteromeris)

pe rplana"7 Conrad). 

Gemma magna Dall. 

Chione (Athleta). 

Chione (Lirophora) latilirata

athleta Conrad. 

Chione cancellata Linne'. 

Cardita (Carditamera) sp. 

Dentalium sp. 

Barnacle.

Stratigraphic range: Tamiami (?) formation.

Nuculana trochilia(Dall). ........ -17.0

Stratigraphic ranger Tamiami formation.

Well 27

Venus sp.

Stratigraphic range: Formation 

indeterminate.

_!/ Datum is mean sea level.

Epitonium sp. ........

Pecten (Nodipecten?) sp. 

Phacoides (Parvilucina) cf.

multilineatus (Tuomey and

Holmes). 

Crassinella sp.

+8.5

+2.5
Well 27 Continued. 

Fossils and range

Venus sp. 

Chione ? sp. 

Parastarte sp.

Stratigraphic range: Caloosahatchee (?) marl.

Cerithium n. sp. aff . caloosaensis Ball. .......

Oliva sp. (thick parietal callus). 

Dentalium sp. 

Chione sp. (juvenile).

Stratigraphic range: Caloosahatchee (?) marl.

Turritella sp. cf. T. perattenuata Heilprin. .......

Cerithium n. sp. aff. C_.

caloosae'nsis Ball. 

Marginella limatula Conrad. 

*Oliva spT (thick parietal

callus).

Conus adversarius Conrad. 

Operculum.

Cunearca scalaris (Conrad). 

Parastarte sp. 

Phacoides (Parvilucina) cf.

crenulatus (Conrad). 

Anomia sp.

Chione cancellata Linns'. 

Venericardia (Pleuromeris)

decemcostata Conrad. 

Pelecypod sp. 

Atrina sp.

Stratigraphic range: Caloosa 

hatchee marl.

FAUNA FOUNB IN WELLS 23

Well 30 Continued. 

Bepth (feet I/) Fossils and range Bepth (feet I/)

Acteocina sp.

Pecten sp.

Ostrea sp.

Phacoides (Cardiolucina) cf.

trisulcatus multistriatus

(Conrad).

Transenella n. sp. 

Bosinia sp.

+.1

-4.0

Nuculana trochilia (Ball). -17.0

Pecten (Nodipecten?) sp. 

Venus? sp.

Stratigraphic range: No definite 

evidence that Miocene was 

penetrated.

Well 29 

Anomia sp. ............... -18.0

Stratigraphic range: Formation 

indeterminate.

Well 30

Turritella pontoni Mansfield. 

Serpula sp. 

Olivella sp.

.0

Stratigraphic range: Formation 

indeterminate.

Pecten sp. -5.0

Stratigraphic range: Formation 

indeterminate.

Ostrea sculpturata Conrad. ....... -12.1

Phacoides (Cardiolucina) sp.

Chione sp.

Coral.

Barnacle.

Stratigraphic range: Tamiami (?) formation.

Dentalium sp. .............. -17.0

Nuculalp". 

Pecten sp. 

Corbula sp.

Stratigraphic range: Formation 

indeterminate.

Well 31

Unidentifiable fragments of 

Pecten and barnacles.

Stratigraphic range: Formation 

indeterminate.

Fragmental mold of large Cardita 

cf. C_. arata Conrad. .....

-9.5

-15.0

Stratigraphic range: Tamiami (?) formation.

Well 33

Glycymeris sp. cf. subovata 

(Say). . ..........

Pecten cf. eboreus Conrad.

-1.0

Stratigraphic range: Tamiami (?) formation.

Datum is mean sea level. 

Same form occurs in Buplin marl at Natural 

Well, N. C.
24 GEOLOGY OF THE WESTERN EVERGLADES AREA

Well 34 

Fossils and range

Chione cf. (?. cancellata

Linne*. .............

Cardita (Carditamera) sp.

Stratigraphic range: Formation 

indeterminate.

Well 36

Pecten sp. ...........

Phacoides (Here) densatus

(Conrad).

Phacoides (Cardiolucina) sp. 

Mulinia cf. M. congesta

(Conrad).

Transenella n. sp. 

Chione sp.

Cardita (Carditamera) sp. 

Encope sp.

Stratigraphic range: Tamiami (?) formation.

Phacoides (Cardiolucina) cf. 

trisulcatus multistriatus 

(Conrad). .........

Transenella n. sp.

Venericardia (Pleuromeris) 

decemcostata Conrad.

Bryozoa.

Barnacle.

Stratigraphic range: Tamiami (?) formation.

Depth (feet I/)

+5.5

+1.0

-3.0

Parastarte sp. ......

-7.0

Phacoides (Here) densatus

Conrad. 

Phacoides (Cardiolucina) cf.

trisulcatus multistriatus

(Conrad). 

Venericardia (Pleuromeris)

decemcostata Conrad.

Stratigraphic range: Tamiami formation.

Unidentified gastropod. ......... -11.0

Pecten sp. 

Encope sp.

Stratigraphic range: Tamiami formation.

Turritella sp. aff. T. variabilis 

Conrad. ........... -17.0

Pecten sp. (gibbus var. ?).

\J Datum is mean sea level.

Fossils and range

Turritella cookei gladee'nsis 

Mansfield. .......

Depth (feet I/) 

-11.0

Stratigraphic range: Tamiami formation.

Well 37 

Fragment of large oyster. . . -18.0

Stratigraphic range: Tamiami (?) formation.

Well 38 

Ostrea sp. ............... -2.0

Stratigraphic range: Formation 

indeterminate.

Pecten eboreus Conrad. .......

Ostrea sp.

Stratigraphic range: Tamiami (?) formation.

Anomia sp. ..............

Pecten sp. 

Encope sp.

Stratigraphic range: Tamiami (?) formation.

-7.0

-12.0

Pecten sp. ..........

Echinoid fragments.

Stratigraphic range: Tamiami (?) formation.

Echinoid fragments. .....

Barnacle fragments.

Stratigraphic range: Tamiami (?) formation.

Well 41

-16.0

-21.0

Ostrea sculpturata Conrad. -3.0

Chione aff. £. cancellata

Linne'.

Cardita (Carditamera) sp. 

(juvenile).

Stratigraphic range: Formation indeterminate.

Cardita (Carditamera) sp. ....... -15. 0

Stratigraphic range: Formation indeterminate.
SELECTED REFERENCES 25

Well 41--Continued.

Fossils and range Depth (feet I/) 

Anadara sp. .............. -20.0

Well 43--Continued.

Stratigraphic range: Formation indeterminate.

Well 42

Glycymeris sp. .......

Ostrea sculpturata Conrad. 

Transenella n. sp. 

Venericardia (Pleuromeris)

decemcostata Conrad. 

Turritella pontoni

Mansfield. 

Turritella cookei gladeSnsis

Mansfield.

-10.0

Stratigraphic range: 

formation.

Tamiami

Glycymeris subovata (Say).

Ostrea sculpturata Conrad. 

Phacoides (Cardiolucina)

trisulcatus multistriatus

(Conrad). 

Divaricella cf. D. quadrisulcata '(d* Orbigny). 

Macrocallista sp. 

Transenella n. sp. 

Cardium (Trachycardium)

isocardia Linnet 

Venericardia (Pleuromeris)

decemcostata Conrad. 

Omphalius exoletus (Conrad). 

Turritella cookei gladee"nsis

Mansfield.

Stratigraphic range: Tamiami 

formation.

-12.0 

to -16.0

Well 43

Ostrea sp.

Stratigraphic range: Formation indeterminate.

Venericardia (Pleuromeris) 

decemcostata Conrad. . . .

Stratigraphic range: Formation indeterminate.

Transenella n. sp. ......

Venericardia (Pleuromeris)

decemcostata Conrad. 

Turritella pontoni Mansfield.

Stratigraphic range: Tamiami 

formation.

-1.5

-5.0

-12.0

Fossils and range Depth (feet I/)

Pecten sp. ..........

Ostrea sculpturata

Conrad.

Donax fossor Say. 

Transenella n. sp. 

Venericardia (Pleuromeris)

decemcostata Conrad. 

Cardium cf. C. robustum

Solander. 

Turritella cookei gladegnsis

Mansfield.

Turritella pontoni Mansfield. 

Oliva mutica Say. 

Oliva sp. aff. sayana

Ravenel.

Stratigraphic range: Tamiami formation.

-15.0

-22.0

I/ Datum is mean sea level.

Ostrea sp. ..........

Venericardia (Pleuromeris) decemcostata

Conrad. 

Turritella cookei gladee'nsis

Mansfield. 

Turritella pontoni

Mansfield. 

Oliva mutica Say.

Stratigraphic range: Tamiami formation.

SELECTED REFERENCES

Applin, P. L., 1951, Preliminary report on buried 

pre-Mesozoic rocks in Florida and adjacent States: 

U. S. Geol. Survey Circ. 91, 28 p.

Cooke, C. Wythe, 1942, Cenozoic irregular echinoids 

of eastern United States: Jour. Paleontology, v. 16, 

no. 1, p. 1-62, 8 pis.

____ 1945, Geology of Florida: Florida Geol. Survey 

Bull. 29, 314 p., 47 figs., 1 pi., incl. geol. map.

____ 1952, Sedimentary deposits of Prince Georges 

County (Maryland) and the District of Columbia: 

Md. Dept. Geology, Mines, and Water Resources, 

Bull. 10, p. 1-53,

____ and Mossom, Stuart, 1929, Geology of Florida: 

Florida Geol. Survey 20th Ann. Rept., p. 29-227, 

29 pis., incl. geol. map.

Dall, W. H., 1890-1903, Contributions to the Tertiary 

fauna of Florida, with especial reference to the 

Miocene Silex beds of Tampa and the Pliocene beds 

of the Caloosahatchee River: Wagner Free Inst. Sci. 

Trans., v. 3, 1654 p., 60 pis., pt. 1, 189-0; pt. 2, 

1892; pt. 3, 1895; pt. 4, 1898; pt. 5, 1900; pt. 6, 

1903.

Hoy, N. D., and Schroeder, M. C., 1952, Age of subsurface "Tamiami" formation near Miami, Florida: 

Jour. Geology, v. 60, no. 3, p. 283-286.

MacNeil, F. Stearns, 1950, Pleistocene shore lines in 

Florida and Georgia: U. S. Geol. Survey Prof. 

Paper 221, p. 95-107.

Mansfield, W. C., 1939, Notes on the upper Tertiary 

and Pleistocene mollusks of peninsular Florida: 

Florida Geol. Survey Bull. 18, 75 p., 4 pis., 2 figs.
26 GEOLOGY OF THE WESTERN EVERGLADES AREA

Matson, C. G., and Clapp, F. G., 1909, A preliminary 

report on the geology of Florida, with special reference to the stratigraphy: Florida Geol. Survey 

Ann. Rept. 2, p. 25-173, incl. geol. map.

Parker, GaraldG., 1951, Geologic and hydrologicfactors in the perennial yield of the Biscayne aquifer: 

Jour. Am. Water Works Assoc., v. 43, no. 10, 

p. 817-834, 7 figs.

_____ and Cooke, C. W., 1944, Late Cenozoic geology of southern Florida, with a discussion of the 

ground water: FloridaGeol. Survey Bull. 27, 119 p., 

4 figs., 26 pis.

______ Ferguson, G. E., Love, S. K., and others, 

1954, Water resources of southeastern Florida, with 

special reference to the geology and ground water 

of the Miami area: U. S. Geol. Survey Water-Supply 

Paper 1255 (in preparation).

Sellards, E. H., 1912, The soils and other surface 

residual materials of Florida: Florida Geol. Survey 

Ann. Rept. 4, p. 7-79.

Vernon, R. O., 1951, Geology of Citrus and Levy 

Counties, Florida: Florida Geol. Survey Bull. 33, 

252 p., 40 figs., 2 pis.

INT.-DUP. SBC., WASH.. D.C«21S«
SELECTED REFERENCES 25

Well 41 Continued. 

Fossils and range 

Anadara sp. ............

Well 43--Continued.

Depth (feet I/)

-20.0

Stratigraphic range: Formation indeterminate.

Well 42

Glycymeris sp. .........

Ostrea sculpturata Conrad. 

Transenella n. sp. 

Venericardia (Pleuromeris)

decemcostata Conrad. 

Turritella pontoni

Mansfield. 

Turritella cookei gladee*nsis

Mansfield.

Stratigraphic range: Tamiami 

formation.

-10.0

Glycymeris subovata (Say). . .

Ostrea sculpturata Conrad. 

Phacoides (Cardiolucina)

trisulcatus multistriatus

(Conrad). 

Divaricella cf. D. quadrisulcata (d'Orbigny). 

Macrocallista sp. 

Transenella n. sp. 

Cardium (Trachycardium)

isocardia Linnet 

Venericardia (Pleuromeris)

decemcostata Conrad. 

Omphalius exoletus (Conrad). 

Turritella cookei gladefe'nsis

Mansfield.

Stratigraphic range: Tamiami 

formation.

-12.0 

to -16.0

Well 43

Ostrea sp.

Stratigraphic range: Formation indeterminate.

Venericardia (Pleuromeris) 

decemcostata Conrad. ....

Stratigraphic range: Formation indeterminate.

Transenella n. sp. .... 

Venericardia (Pleuromeris)

decemcostata Conrad. 

Turritella pontoni Mansfield.

-1.5

-5.0

-12.0

Stratigraphic range: 

formation.

Tamiami

Fossils and range Depth (feet I/)

Pecten sp. ..........

Ostrea sculpturata

Conrad.

Donax fossor Say. 

Transenella n. sp. 

Venericardia (Pleuromeris)

decemcostata Conrad. 

Cardium cf. _C. robustum

Solander. 

Turritella cookei gladegnsis

Mansfield.

Turritella pontoni Mansfield. 

Oliva mutica Say. 

Oliva sp. aff. sayana

Ravenel.

Stratigraphic range: Tamiami formation.

-15.0

Ostrea sp. .........

Venericardia (Pleuromeris) decemcostata

Conrad. 

Turritella cookei gladee'nsis

Mansfield. 

Turritella pontoni

Mansfield. 

Oliva mutica Say.

-22.0

Stratigraphic range: 

ami formation.

Tamil/ Datum is mean sea level.

SELECTED REFERENCES

Applin, P. L., 1951, Preliminary report on buried 

pre-Mesozoic rocks in Florida and adjacent States: 

U. S. Geol. Survey Circ. 91, 28 p.

Cooke, C. Wythe, 1942, Cenozoic irregular echinoids 

of eastern United States: Jour. Paleontology, v. 16, 

no. 1, p. 1-62, 8 pis.

____ 1945, Geology of Florida: Florida Geol. Survey 

Bull. 29, 314 p., 47 figs., 1 pi., incl. geol. map.

____ 1952, Sedimentary deposits of Prince Georges 

County (Maryland) and the District of Columbia: 

Md. Dept. Geology, Mines, and Water Resources, 

Bull. 10, p. 1-53,

____ and Mossom, Stuart, 1929, Geology of Florida: 

Florida Geol. Survey 20th Ann. Rept., p. 29-227, 

29 pis., incl. geol. map.

Dall, W. H., 1890-1903, Contributions to the Tertiary 

fauna of Florida, with especial reference to the 

Miocene Silex beds of Tampa and the Pliocene beds 

of the Caloosahatchee River: Wagner Free Inst. Sci. 

Trans., v. 3, 1654 p., 60 pis., pt. 1, 1890; pt. 2, 

1892; pt. 3, 1895; pt. 4, 1898; pt. 5, 1900; pt. 6, 

1903.

Hoy, N. D., and Schroeder, M. C., 1952, Age of subsurface "Tamiami" formation near Miami, Florida: 

Jour. Geology, v. 60, no. 3, p. 283-286.

MacNeil, F. Stearns, 1950, Pleistocene shore lines in 

Florida and Georgia: U. S. Geol. Survey Prof. 

Paper 221, p. 95-107.

Mansfield, W. C., 1939, Notes on the upper Tertiary 

and Pleistocene mollusks of peninsular Florida: 

Florida Geol. Survey Bull. 18, 75 p., 4pis., 2 figs.
26 GEOLOGY OF THE WESTERN EVERGLADES AREA

Matson, C. G., and Clapp, F. G., 1909, A preliminary 

report on the geology of Florida, with special reference to the stratigraphy: Florida Geol. Survey 

Ann. Rept. 2, p. 25-173, incl. geol. map.

Parker, GaraldG., 1951, Geologic and hydrologicfactors in the perennial yield of the Biscayne aquifer: 

Jour. Am. Water Works Assoc., v. 43, no. 10, 

p. 817-834, 7 figs.

_____ and Cooke, C. W., 1944, Late Cenozoic geology of southern Florida, with a discussion of the 

ground water: FloridaGeol. Survey Bull. 27, 119p., 

4 figs., 26 pis.

_____ Ferguson, G. E., Love, S. K., and others, 

1954, Water resources of southeastern Florida, with 

special reference to the geology and ground water 

of the Miami area: U. S. Geol. Survey Water-Supply 

Paper 1255 (in preparation).

Sellards, E. H., 1912, The soils and other surface 

residual materials of Florida: FloridaGeol. Survey 

Ann. Rept. 4, p. 7-79.

Vernon, R. O., 1951, Geology of Citrus and Levy 

Counties, Florida: Florida Geol. Survey Bull. 33, 

252 p., 40 figs., 2 pis.

INT.-OOP. SEC., WASH., D.C42186