Late Cenozoic geology of southern Florida, with a discussion of the ground water ( FGS: Bulletin 27 )

STATE
DEPARTMENT

FLORIDA

RICE,

HERMAN GUNTI

OF
OF

GEOLOGICAL

Supervisor
ER, Director

SURVEY

Conservation

, Geological Survey

GEOLOGICAL BULLETIN

LATE CENOZOIC GEOLOGY

OF SOUTHERN FLORIDA,

WITH A DISCUSSION OF THE GROUND

WATER

GARALD G.

PARKER AND C.

WYTHE

COOKE

UNITED STATES

GEOLOGICAL

URVEY

Prepared

United

States

Geological

Survey

cooperation

with

Florida

Geological

Survey,

Dade

County,

and the Cities

Miami

Miami Beach and Coral Gables

PUBLISHED

FOR

rn r

FLORIDA
CONSERVATION

-^J

n" r^

Manuscript received March 4, 1944

Published, September

1, 1944

LETTER

OF TRANSMITTAL

Honorable S.

Rice, Supervisor,

Florida State Board of Conservation.

Sir:

I have the honor to

Geology
Water"

States

Southern

Garald

Geological

transmit a

Florida
Parker

Survey,

report

With

and

entitled

"Late

Discussion

Wythe

published

Cooke

Geological

Cenozoic
Ground
e United
Bulletin

11 connection
southeastern

with

a detailed

Florida

investigation

United

States

water resources

Geological

Survey

cooperation with Dade County and the Cities of Miami, Miami Beach,

and

Coral

Gables an

excellent opportunity

presented

itself

to study

the geology of that region.

This was done by Garald G.

the progress of the water supply studies.

Cooke,

Parker during

who has studied

the geology of Florida for many years, accompanied Mr.

Parker in the

field for three

weeks.

This report is

an outstanding

contribution

our knowledge of the geology of

southern Florida.

It is replete with

photographs, graphs, and cross sections illustrating the succession and

thickness of the formations of

to unravel

the complicated and

region.

This report will

difficult geology

that area.

much
Com-

ing as it does at this time when there is much interest in the geology
of Florida I feel certain that it will receive an enthusiastic reception.

The

Florida

Geological
It comes to

Geological

Survey

Survey

is indebted

opportunity

Florida Survey without

to the

publishing

cost other than

United

this
that

States
report.

pub-

fishing.

Respectfully

submitted,

HERMAN

GUNTER,

Director

CO

NTENTS

Page

Abstract

Introducti

Previb

Presei

011 ............

)us investigations

nt investigation

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

* . .*S ...... *. S....... *....................S... ...
* C ** ** S C* ** S S *SO 5S *C S S .. .5 5. .

*a ** ** SO * 50 5 50 C a S

Acknowledgments

Floridian

Plateau

....... ... . ............................... . 1

Late Cenozoic history

Pliocene

Pleistocene

Recent

Solution

General features

Sink-hole lakes

Drainage

Arch

29

.. .C. S SSS.. S...CS. .S C.. C.. S .. .. ... .S. . . . 35

Creek

Topographic-ecologic

divisions

. ... ... .. .. .. .. .. . . . . 38

The Sandy Flatlands

General

. ... .. .. .. .. ... ........ .. .... . .. . ..... . .. .. 3

features

Okaloacoochee Slough and Devil's

Garden.

Allapattah and Loxahatchee Marshes...

...............O*....*....

.. .. .. .. .. ... .. .. ..S S * S

Sandy flatlands

Lake Trafford

south

of Loxahatchee Marsh

The Big Cypress Swamp

General

features

Everglades

General

features

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

CONTENTS-Continued

Page

Topographic divisions-Continued

The Atlantic Coastal Ridge

General

features

Origin of the Coastal Ridge and the Transverse Glades

. . .. . .. 5

"Bottomless holes" in New

River

. . . . .. .. .. . 5

Coastal marshes

mangrove

swamps

S. .. .. .. . ........ . ... 5

rocks

Caloosahatchee marl

Historical summary

Development .....

S.. . .. . .. . ... . . . 56

5
...... ..... ...... ..... ...... ..... ...... ....

* C ....... .. .. .................. ........ ..

................................ S SC SSS CSC. ..S......C ......*

Water-bearing characteristics

Buckingham marl

Historical

summary

Age and development

Water-bearing

Tamiami formation

Historical

. ............ .. . . . . . ...... 6

characteristics.

summary

*.C .. ...S . ..C. .S. ...C..S..C.C...*.S.. ...C. .S. ... . ..*.C.S. .S S C

S. C....C ..... CCS..... ....SS.. ..C.......S*...... ....C..C..S.S S

Development

Water-bearing characteristics

Pleistocene rocks

Anastasia

formation

Historical summary

Development

Water-bearing

characteristics

Largo

limestone

. .. . . . ... . . . . .... . .. 6

Historical summary

Development

Water-bearing characteristics

Miami

oolite

Historical summary

U nI

Pliocene

Im

I

CONTENTS--Continued

Pleistocene rocks-Continued

Page

Pamlico formation

Historical summary

Development

Water-bearing

characteristics

Talbot and Penholoway

Historical summary

formation:

S . ....... .. ... . .... ..
s *. * 0 * m ......... .... .... .... .... ....

... .... 75

Development

Water-bearing characteristics

Correlation studies

General

statement

Sections on and near Caloosahatchee River

Correlation

of Fort

Thompson

formation

. .......... .................. 9

Correlation of formations by means of exploratory test well data

General

Section

Section

statement

A-A'

B.B'

.. .. .S. . S S S96

S. . . 106

Summary

References

Index

ILLUSTRA

NS

FIGURES

Page

Generalized NNW-SSE geologic cross

section from

vicinity

Ocala to

Florida

City, Florida

. ... .. .. 1

Map showing contours on the floor of Deep Lake

Map

showing contours on the floor of Lake Okeechobee

Geologic cross

section at Station 3

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

, type localit

Thompson

formation

PLATES

Page

. Map of Floridian Plateau

showing co

tours on0

ocean

ttom

and area covered by this
Tentative correlation chart

report

of formations in

southern Florida

Hypsometric

map

southern

Florida

showing

approximate

distribution of Pleistocene terraces

and shore

lines..

Pocke

Recent and latb
in southern
Solution effects

Pleistocene wave-cut

benches and(

notches

Florida

in limestone in southern Florida

Deep Lake and Still Lake, Pleistocene sink holes

. Arch

Creek natural bridge and Hillsborough

Lakes

Mars

Everglades

Topographic.Ecologic

southern

Florida

In Pocket

Views of

the Sandy

Flatlands and

s Garden.

Views in the

Big Cypress Swamp.

Views in the Everglades

Map showing contours on the rock floor of the Everglades

Map of the Everglades

Drainage

District

showing

directions

surficial

drainage

Surficial deposits of

southern

Florida

exclusive of

organic soils

Pocket

Geologic map of

southern

Florida

exclusive

surficia

sands

Pocket

Sections

of Pleistocene and

Pliocene rocks expo

sed alone

ILLUSTRATIONS -Continued

PLATES

Page

Map of

stations

along the Caloosnhatchee River used

geologic

section C-C'

Geologic

section along the Caloosahatchee River, C-C'.

Map

southern

Florida

showing

location

geologic

cross

sections

certain

test wells

Pocket

Geologic

section from Lake Okeechobee to Miami Spr

Geologic section along

Tamiami Trail from Monroe-Dade County

to Miami,

B .B .......................

I

k

ABSTRACT

Southern

Florida

gives

evidence

repeated

oscillations

sea leve

little

structural

Caloosahatchee

deformation.

marl,

Caloosahatchee consists

e Buckingham
predominantly

oldest
marl

sand

outcropping

formations

re Tamiami
shell marl:

formation.

Buckingham

of calcareous clay with phosphate grains

and the Tamiam

of calcareous

sandstone

sandy

limestone with beds and

pockets

quartz

sand.

Well

records

show

the Caloosahatchee

marl

Tamianmi

formation

interfinger

essentially

contemporaneous,

though

outcropping

tongue

Tamiami

overlies
merges

overlying

faces

represented

the Caloosahatchee.

These

Pleistocene formations

Caloo

sahatchee.

Pliocene

formations

an erosional

Buckingham
are separated

unconformity

which

marl
from
indi-

cates that they were above sea

level

during

middle and

Pliocene

time

earliest

(Nebraskan

stage)

Pleistocene time.

They

have been

very

slightly

tilted toward the west at the time of their emergence.

Fort

Thompson

formation

(including

Coffee

Hammock

marl

member at the top)

consists of three thin marine shell beds separated

from

another by two fresh-water limestones

or marls, each of

the younger beds

filling

solution

feet.

holes in

marine

the older.

beds

The total

thickness

interpreted

at the

deposits

type

formed

locality

during

is about 8
Aftonian

Yarmouth, and Sangamon interglacial stages,

when the region was flooded b

sea to depths apparently

as great

as 270

100 feet.

solution

holes

the fresh-water

Kansan and Illinoian

limestones

glacial

stages,

marls
when

apparently

were

sea temporarily

formed

withdrew

coIln

siderable distances

below its present level.

Anastasia

formation

(predominantly

sand(

shells

Largo

limestone

extinct

coral

reef)

Miami

oolite

are contemporaneous

Pleistocene formations

which apparently accumulated on and along the southeastern

coast mainly during the Sangamon interglacial stage and therefore are equivalent

to only part of the Fort Thompson formation developed in the Everglades

and the

Caloosahatchee

River area.

Penholoway

Talbot

formations

which

coast

terrace

shore currents

deposits,

during

consist

sand

middle and

swept

down

parts

from

same

north

interglacial

long-
stage.

A thin sheet of sand

, the Pamlico formation,

was spread over part

of the

shallow

sea floor during a mid-Wisconsin invasion by the

sea.

. nIon P1- nr ntn I l rlt.nn.,-, il.nnn e- tn t c

are

one

tn tr ot im t a-l ttll^L-lACODCc

J-kll

T'l^- II nn,, I ,,1rtfr< nn

Jt- "

west.

northern

lowest

basin

is niow

occupied

Lake

Okeechobee, which,
southward across th

before drainage and diking operations

ie open Everglades more or less as

changed it, overflowed

a sheet flow that imposed

an aligned drainage pattern on the organic deposits of the Everglades.

Tests made in ground water investigations of the Miami area indicate that the

Tamiami formation is among the most productive

water bearing formations ever

investigated

Geological

Survey.

coefficient

permeability

about 3

which indicates

that through

a section of the formation a mile wide

and a foot thick 35,000 gallons

of water a day, at 60F,

would pass through under

a hydraulic

gradient

one foot.

Large areas

considered

of salty

to be

ground

remnants

water in1

sea water

the northern part

during

Pleistocene

Everglades are
sea invasions

and now altered by

dilution with fresh

water and by

chemical reaction

s, mainly

the base-exchange variety,

with the enclosing rocks.

FLORIDA

GEOLOGICAL

URVEY

BULLETIN

PLATE

PLATE

1-Map

Floridian

Plateau

area covered by this report.

showing

contours

ocean

bottom

t

LATE

CENOZOIC

GEOLOGY

OF

SOUTHERN FLORIDA

with a

DISCUSSION

GARALD

THE

PARKER AND

GROUND

WYTHE

WATER

COOKE-"

INTRODUCTION

Previous investigations-Interest in the geology of southern Florida

began
about

in the

first

region

half

was

nineteenth

confined

many

century

years

information

what

could

learned by making boat traverses along the coastal waters.

The interior

remained inaccessible.

The

first notable speculation

and geologic history was that of Louis Agassiz

(1852)

as to its origin
later modified

and

given

wider

circulation

in Joseph

LeConte's

(1878)

"Elements

Geology.
latitude

These

had

writers supposed

been

built

that

peninsular

successive

Florida

growths

south
coral

reefs on a sea bottom 12 to 20 fathoms deep, and that the waves and

winds

had

heaped

detritus

upon

reefs

a height

few feet above sea level.

They

assumed that Florida has now

ceased

to grow southward because the depth limit at which corals can grow

and flourish has been reached by the advancing reefs.

Later informa-

tion about the composition of the interior amply disproves this theory.

Angelo

Heilprin

(1887)

was

first

geologist

describe

interior of

southern Florida.

He explored

Caloosahatchee

River

in 1886 and recognized the Pliocene age of the shell beds in its banks.

These

beds

richest

collecting

ground

Pliocene

fossils

the United States.

"observations

failed to

bring forward

a single

fact

confirmatory

coral-reef

theory

formation

peninsula
LeConte"

such

a,3 had

(Heilprin,

been

advocated

1887, p.

. Dall

* Louis
(1887)

Agassiz
visited

and

Prof

region

about the same time and confirmed the Pliocene age of the

"Caloosa-

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

Alexander

Agassiz

(1895,

1896)

examined

coastal

outcrops

formation now

posit is of

known

aeolian

as the

origin.

Miami

Griswold

oolite
(1896)

and

decided

examined

that the

oolite

only

at the shore but also at

inland outcrops

and rejected

Alexander

Agassiz

's theory.

The keen observations of

amuel Sanford,

while acting

as geologist

Key

West

extension

Florida

East

Coast

Railway

1907

and

1908,

brought

to light

many new facts

contradicting

Louis

Agassiz

speculation.

paper

on "The

Topography

and

Geology

of Southern Florida

(Sanford,

1909)

presents an excellent summary

the physical features of

that region.

same

volume

Matson

and

Clapp

(1909,

123-128)

wrote

first formal

description

Caloosahatchee

marl.

The cutting of

drainage canals across

Everglades gave Sellards

1919)

first

opportunity to

compile

a geologic

section

from

Gulf

Mexico

Atlantic

Ocean.

described

several

new

Pleistocene

and Recent formations.

Descriptions

geologic

formation

southern

Florida

were

included in Cooke and Mossom

(1929)

"Geology

of Florida.

" They

were

first

geologists

Highway

mapped

area

The

cross
map

of Pliocene

state

along

accompanying

rocks

their

far south

Tamliami

report

formerly
9

Trail

extends
known

limit.

Richards

(1938)

made

a study

Pleistocene

stratigraphy

Florida and suggested a correlation of

certain formations and terraces.

Mansfield

(1939)

aided by

MacNeil, made a

correlation

posits

along

Caloosahatchee

River.

However,

MacNeil

(1942)

did not concur with Mansfield on the published description.

MacNeil'

correlation, especially

lower

argillaceous

beds,

is very

similar

to that of the present writers.

Cooke

(1939)

interpreted the

"Scenery

Florida

sea level

" in

and

light

Parker

(1942)

of individual beds in the Fort
glacial and interglacial stages.

long-known

first

noted

Pleistocene

possible

Thompson formation

with

oscillations
correlation
Pleistocene

PrPof n t

nI I-f" i' a l V i St fl i t III -me I a I-Iiii

S, St I- t. fl /

ifltW, tfi rtif j;v--Th 1i

f rn r]

+I.',,

***/^ *- /- **ft

J~r*-^J-

LATE

CENOZOIC

GEOLOGY

to the Gulf

of Mexico.

The extensive studies in the Everglades have a

direct bearing

on the

water resources

problem

of Dade

County

and

the municipalities within

thus the study was extended

northward

as far as the north

end of Lake Okeechobee.

Acknowledgments-This

water-resources of

paper

southeastern

results

from

Florida

investigation

made

Geo-

logical

Survey

in cooperation

with

Florida

Geological

Survey,

Dade County, and the Cities of Miami,

Miami Beach and Coral Gables.

To the officials of these cooperating agencies we are grateful for serv

ices, help,

and data contributed.

We have profited by the advice and

encouragement of O.
Water Division of the

Meinzer,

Geologist in

Charge of

Geological Survey, and V

of that Survey, under whose supervision

both have critically reviewed

proJect

this paper.

the Ground
Stringfield,

was carried

Unklesbay

Geological

Geological

Survey,

Survey,

and

Herman

John

Gunter,

Davis,

Director

that

Survey,

Florida
we are

especially grateful for helpful advice and for critically reviewing both
the manuscript and the interpretations of the geology in the field. In

addition,

library,

andl

SFlorida
museum

Geological

facilities

Survey

contributed

Tallahassee.

are

laboratory,

grateful

Harold T. Stearns for

his review

the Pleistocene

historical section

and helpful ideas and criticism.

Julia

Gardner

and

Richards

identified

fossil

mollusks,

. Cushman

Henbest

and

Storrs

Cole

identified

foraminifers, and Remington Kellogg identified tile cetaceans.

Water

samples were analyzed under the supervision of S. K.

Love.

Acknowl-

edgments

due

Nevin

Hoy

assistance

in field

and

laboratory

and

to Russell

Brown,

under

whose

direction

line of

test

wells

was

drilled

through

Everglades

and

who,

with

Goddard

sounded both

, aided in contouring Deep

Still

Lake

and

Salt Spring.

Lake.

The

Carlton
drawings

Lingham

were

made

by Ross A.

Ellwood and Robert

Hardin.

We are particularly indebted to C. K
both of the Soil Conservation Service,

;ay Davis and John C.

who made

Stephens,

possible and helped

the drilling of 15 exploratory

wells

in remote

heretofore

painstaking

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

was accompanied in the field for three

weeks by Cooke,

who

worked for many years on the geology of the Coastal Plain and who
has long been a student of the Pleistocene oscillations of sea level.

FLORIDIAN PLATEAU

The peninsula of Florida is the emerged part of a much wider pro-

jection f
Vaughan

:rom

continental

mass

(1910) the Floridian Plateau

North
(Plate 1)

America

named

. The Plateau sepa-

rates the deep water of the Atlantic Ocean from the deeper parts of

the Gulf of Mexico.

Its core is probably composed of metamorphic

and igneous rocks like those underlying the Piedmont region of the
Eastern States (Mossom. 1926; Campbell, 1939a), of which it seems

to be the southern extension.

The steep submarilie slopes that bound

it on the east, south, and west presumably represent fault scarps or

monoclinal folds

original

basement

complex,

though

their

outlines may have been modified by the accumulation of

sediments

upon them.

The core of the Floridian Plateau is overlain by a cover of

mentary formations that ranges in thickness from

sedi-

about 4,000 feet

in north-central Florida

(Marion County)

to more than 11,000 feet

in southern Florida,

where no

well has yet reached

basement

complex.

A deep well, drilled to a depth of 10,006 feet in the north-

eastern part of Monroe County about 50 miles west of Miami, began

in Pliocene calcareous sandstone (Tamiami formation)

and ended in

limestone and anhydrite supposed to

be Lower Cretaceous

(Camp-

bell, 1939b; Cole, 1941)

. Since that time two more wells have been

drilled to more than 11,000' in Collier Co., near Sunniland, Florida.
The first of these wells, drilled near the Sunniland railroad station

was 11,62
and has

deep

produce

(See Fla.
I oil in

C<

Geol. Surv. Bull. 26, pp. 162-163, 1943)
commercial quantities. The second well

about a mile west of the Sunniland railroad station is below

feet but has not been a producing well.

12,000

The rocks penetrated were

dominantly limestone. No sand or clay is reported below the Miocene
Hawthorn formation-an indication that southern Florida was long
remote from sources of elastic sediments.

/

,

LATE

CENOZOIC

GEOLOGY

is less than the slope of

many

sea bottoms,

doubtless involves

some deformation.

A further hint at deformation is found in the asymmetrical

profile

the Floridian

Plateau

and

pattern

geologic

map

Florida

the eastern

(Sellards, 1919, pp.

part of

105-131

Plateau

Cooke and Mossom, 1929)

stands

above

level

Only

western

half
fore

slopes gently out beneath

plunges

to greater

waters of

depths.

This

Gulf

suggests

Mexico

that

Plateau

FIGURE 1-Generalized NNW-SSE Geologic cross section from vicinity of

Ocala to Florida City, Fla.

Greatly foreshortened.

been

between

This,

Plateau

canted

successive

however,

was

westward.

geologic

indicate

deeper

might

eroded

Moreover, t
formations

merely

than

trend

that

eastern

boundaries

beneath
western

while

Gulf.

side

sea

stood

lower

on the

land

than

now

The

sloping

surface

Plateau

--- --n -^ --- i-A -- --- _- - *-. A

p

FLORIDA

GEOLOGICAL SURVEY

BULLETIN 27.

PLATE

TENTATIVE

CORRELATION

FORMATIONS

SOUTHERN

FLORIDA

PLIOCENE

TO RECENT)

GARALD

G PARKER

a C WYTHE

COOKE

'1

IZ

;Iz

W ,z
h s

i
1,I;

Wi'I
S1-
o

i >
5

Or
in

61
z
I

IL
.4

z
4

en
C
UJ
m
z

COASTAL
TERRACES

NOTE TERkACES ABOVE'
THE PENHOLOWAY ARE

PRESENT

AREA COVERED

IN THE
SBY THIS

REPORT BUT OCCUR TO
THE NORTH AS FAR AS

NEW JERSEY.

PAMLICO

LEVEL

+ 25 FEET

SOUTHWESTERN
COAST

SOLUTION AND EROSION.

FORMATION

RIDGES
MARL,
SOILS

OF BEACH

OYSTER

MUCK,

SOLUTION AND

EROSION

DUNES

PAMLICO

FORMATION

AND EROSION

CALOOSAHATCHEE
RIVER AREA

SOLUTION

SAND BARS AND OLD

CHANNEL

FILLS

TINUED DEPOSITION OF
LAKE FLIRT MARL AND
ORGANIC SOILS.

SOLUTION AND EROSION
RIVER CUTS AND FILL
LAKE FLIRT MARL

BED 8,

STA 325

PAMLICO FORMATION
BED 7. STA 325

EVERGLADES
TAMIAMI TRAIL
AREA

SOLUTION AND EROSION.
LAKE FLIRT MARL.

FORMATION

OF ORGANIC

SOILS:
PEAT AND MUCK

SOLUTION AND EROSION
LAKE FLIRT MARL

PAMLICO
(LOCALLY

FORMATION
PRESENT)

SOUTHEASTERN
COAST

SOLUTION AND EROSION.
FORMATION OF BEACH
RIDGES. LAKE FLIRT MARL.

MUCK, GROWTH OF

ER CORAL

REEF.

SOLUTION AND

LAKE

FLIRT MARL

DUNES

PAMLICO

FORMATION

z SOLUTION AND EROSION. SOLUTION AND EROSION SOLUTION AND EROSION SOLUTION AND EROSION
DUNES BLACK CARBONACEOUS DEEP CUTS IN MIAMI
SAND (IN PART). OOLITE

TALBOT

SEA LEVEL

+ 42 FEET

PENHOLOWAY
SEA LEVEL + 70 FEET
WICOMICO

LEVEL

ANASTASIA
AND TERRA

SOLUTION

SUNDERLAND
SEA LEVEL t 170 FEET ANASTASIA
COHARIE FORM ACTION
SEA LEVEL t 215 FEET

SOLUTION AND EROSION

BRANDYWINE

SEA LEVEL

+ 270 FEET

MISSING

COFFEE MILL HAM-
MOCK MARL

(MARINE
BED 6, G

HIGHEST
WATER L
LEDGE M
TO SOFT

SHELLS)
STA 325

FRESH-

IMESTONE
ERGING IN
FRESH-

MIAMI OOLITE
AND

LOCAL
MARINE

SOLUTION

WATER MARL B
BEDS 5A & SB.

OCJ,TE

ANAST AS'

KEY LLRGC

SOLUT:ChN

MARINE SHELL MARL
"PECTEN HORIZON" MISSING UNDIFFERENTIATED
BEO 4 STA 325.

LOWEST FRESH-
WATEl MARL LOCAL-
LY INDURATED MAK- SOLUTION AND EROSION I SOLUTION AND EROSION
ING A SHELF
BED 3, STA. 325

MARINE SHELLS

LOCAL.

BED 2. STA 325

MISSING

UNDIFFERENTIATED

SOLUTION AND EROSION

TAMIAMI

LOOSAHATCHEE
ARL

IAMIAMI

FORMATION

0<

EPOCH:

AND EROSION

OUT-

EROSION

RMATION
SAND

+ 100 FEET

PATCHES
SHELLS

AND EROSION

AND EROSION

TAMIAMI

CA
MJ

LATE

LATE

CENOZOIC

CENOZOIC

GEOLOGY

HISTORY

Inasmuch as the development of the surface and subsurface features

southern

Florida

was

profoundly

influenced

relations

land and sea

during late

Cenozoic time, it seems

desirable

to sketch

history

Floridian

Plateau

during

that

epoch

before

mining
Florida.

in more

Such

interpretation

detail

a general
f specific

topography

resumln

should

and

make

features.

geology

more

southern

intelligible

tentative

correlation

chart.

Pliocene-During

were

early

submerged,

Pliocene

time

west-central

southern

Florida

and

eastern

remained

Flor-
land.

The shore
to Sebring,

and

line

probably

thence

northwestward

formation

(Sellards,

circled

extended
1 westwar

across
1914,

southward
d through

Gulf

161.162)

through
Arcadia

to Tallahassee.

and

Bone

Lake
and
The

Valley

County
Sarasota
Alachua

gravel

(Sellards, 1915, pp.

-44)

both of which enclose early

Pliocene land

animals

deltas

(Simpson,

while

1928,

shell

marl

257),
beds,

accumulated

sandy

on the

limestone

and

land

and

calcareous

clay of the Caloosahatchee and Buckingham

marls and the

Tamiami

formation

were

being

deposited

sea.

The

The

late

Pliocene

was1

time

widespread

crustal

instability

Atlantic seaboard and other large areas in North America

were

variously warped

and

tilted.

was

probably then

that

Coastal

Plain north

Cape Hatteras was strongly

downwarped

towards

cast.

The

previously

northern
a plateau

and

eastern

about

extremities

thousand

feet

Coastal

high

crossed

Plain,
deep

gorges,

was completely submerged,

and its gorges became

submarine

canyons
more of
the west

(Cooke,

1930a, p. 589

Floridian

Plateau

1930b, pp.

emerged,

392-393)

was

probably

During this time

tilted

toward

, and was actively eroded.

Pleistocene-During

Pleistocene

epoch

Atlantic

seaboard

south
level

glaciated

areas

repeatedly

remained

and

relatively

rose

upon

stationary,
t responsive

to the

-t

---i-- _- -- 1 -. 1

ex-

1

'ql i

I

',It

1

FLORIDA

and marshes occupiedC

GEOLOGICAL SURVEY--BULLETIN

Lake Okeechobee-Everglades depression.

These five stages appl, ear to corresl)ond

to the

and Illinoian glacial stages, and to two sub-stages of

Iowan

(early

Wisconsin i

and tilhe

Post

Iowan

(late

Nebraskan, Kansan,

Wisconsin:
Wisconsin)

ICooke. 1935, p. 333)

. In the glaciated regions they are represented

by glacial drift, moraines, and other ice-borne and water-borne debris.

Florida

they

are

indicated

erosion

surfaces,

solution

holes.

soil zones. and fresh-water limestones and marl (Parker, 1942; Parker
and Hov. 1943).

Between each of

these major low-water stages came a mIajor stage

of high water. during which the sea stood upon the present land (see

Plate 3

These four major high-water stages appear to correspond to

Aftonian.

Yarmouth, and Sangamon interglacial stages and to a

Post-Iowan retreat of the Wisconsin ice referred to hv Cooke (1935. p.

333:

1943

, p.

1714)

"Peorian

interglacial

sub-st age"

Evi-

dence for these times of

deglaciation is yielded by deeply weathered

soil zones and by erosion within the glaciated regions and by

iment arv

deposits and shore-line

features

within

areas

sedi-

invaded

hv the sea.

The

location of

the former shore lines is indicated

beach ridges, dunes, the nip of the sea or wave-cut benches in sea-

cliffs, or by a change in slope.

Although only four intervals

(See Plates 4 and 18).

of deglaciation in the northern States

here cited at

least

seven

high-level shore

lines in1

southeastern

united States had been detected

Cooke, 1931) prior to the present in-

vestigation. Since then one more has been found.

The extra three or

more appear to record intermediate levels between the highest flood
of the interglacial sea and the lowest of tile succeeding glacial stage.
They may represent causes in the growing of the ice sheets or, possi-

blly. inactive periods in the intermittent enlargemnen

of the oceanic

1)asins.

The eight shore lines,

which still remain horizontal in tile south-

eastern states, stand at altitudes of approximately 270, 215, 170, 100,

, 25, and 5 feet above

present sea

level.

They form

inland boundaries of marine terraces (emerged sea bottoms)

naImed

are

LATIEk CENOZOI( (GEOIO(Y 23

RECENT AND LATE PLEISTO(:ENE WAVE.ClJT BENCHES
AND NOTCHES IN SOUTHERN FLORIDA

mi

-- -f -- *
vfr
m 5- .~~~r~--
I 9s
$a~~l~

d '~3.
10 '
i~r~~ A

~~B;d~s m ~r~a~\as ~ ~,Jj~j/PS~G~;=~E~~T~~r~f~BfJL
r~s'
rv - r .

aF

PLATE 4

FIGUIRE a--Vave-cut bench a(d notch developed inl the Key Largo lime-

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

boundaries of

the terraces as shown

on the hypsometric

map

in pocket)

and

except as they have been modified by subsequent erosion

solution.

Stearns

(1942),

Hawaiian

Islands,

records

high-level

Pleistocene

+70),

shore

and

Kaena

which

(+100oo)

Waimanalo

correspond

exactly

(+25),
to the

Laic

Panilico

Penholoway

and

Wicomico

shorelines.

teams

also

records

Kapapa, a wave-cut bench at +5 feet.

bench

likewise

5 feet

present at

above

Silver

level

Bluff

here

Miami,

and

named
I there

Miami

also

a wave-

cut notch at

+8 feet

(Plate 4)

. The Miami bench is traceable north-

ward from Miami toward Fort Lauderdale where

the highway

follows

feet

and

cut as the sea

closely

head

along

it for

wave-cut

withdrew

several
bench a

miles.

during latest Pamlico

The

feet

time.

notch

may
Both

have
may

been
have

been

developed

simultaneously,

8-foot

notch

storm

waves

anid

wave-cut

bench

may record separate

halting

tide

and

stands of

normal
the sea.

wave

action

or both

These features are preserved in southeastern Florida because of

ing developed in consolidated rocks.

Such features are not preserved

along

a sandy

ridges si
Counties

shore;

irmounted
were sue

however, it

dunes

cessively

is entirely

in Palm

Beach,

possible

Martin

built

that
and

withdrew

beach

St. Lucic
from its

8-foot and later 5-foot stands, but the difficulty of

establishing former

mean

sea

blown sand
-pretation.

level

at the base of

or obliterated

these old

by slump,

ridges,

is too

since

great

filled

prove

this

wind-
inter-

Nebraskan

tinmele

sea

withdrew

from

land

area

and

long interval of solution and erosion ensued.

There are no recognized

terrestrial

deposits

in southern

Florida

that

mark

this

interval

unconformity

between

Pliocene

and

later

Pleistocene

deposits

is quite

marked.

Brandywine

time

(Aftonian

interglacial

stage

nearly

Florida

was

"I _: 1 -

beneath

(Cooke,

1

1939,

1

and

much

a

m.

*1 *uIalul n E n |fl n" 0 flf lU. t h .fr nc wa n n nad n Jl t *L* S r I * *..

..~L ,,,,

-I

I

__ _

LATE

CENOZOIC

GEOLOGY

Florida

was occupied by

lakes andl
I

lllmarshes,

in which

thin

sheets of

marl

and

limestone

containing

fresh-water

shells

were

deposited.

Much of this deposit was probably removed

sea

(Yarmouth

interglacial

stage)

during the next invasion

which

stopped

first

height

land epoch)

feet

(during

receded to

Coharie

epoch)

and

later

170 feet above the present sea level.

(Sunder-
Sources

sediment

were

again

remote,

and

only

a thin

marine

shell

narl

and

calcareous

sandstone

Fort

Thompson

formation

ferred

tloni

to these epoch

they were once

partly removed them before

next

thicker,
deposit

erosion
was laid

and solu-

down.

Another

bed

fresh-water

marl

and

limestone,

in places

4 feet

thick,
stage.

was probably

These

deposited during the succeeding

fresh-water

beds

very

Illinoian glacial

conspicuous

along

Caloosahatchee

River

from

Fort

Thompson

eastward

Lake

Flirt.

When the sea next invaded southern

interglacial stage

present

lands

level,

and

Peninsula,

(Wicomico time)

a long

remained

narrow
above

Florida

during the

it reached only

peninsula,

water

here

in the

100 feet
named

adjoining

angainon
above its

High-

Highlands

County

. This

peninsula

was

attached

to the

mainland

at the

north

near

Avon Park,

and

Penholoway time

when

Highlands

water fell
Peninsula

to 70 feet

was only

above

sightly

sea level
enlarged.

However,
separated

broa d

from

area

south

Highlands

mainland

Peninsula

became

a narrow

gulf

nowV

land

oc-

cupied by the headwaters of Fisheating Creek.

The further

lowering

sea level to 42 feet in

Talbot time expanded the

land surface

into

Glades and

Charlotte Counties

(Cooke

1939, figs.

13-15)

During

glacial

part

this

stage)

southern

constituting

Wicomico-Penholoway-Talbot

oolite
while

was

; Miami
Florida

Anastasia

tunle

deposited

sandy

formation

were

(Sangamon

inter-

southeastern

limestone

and

shell

accumulating

beds
along

East

Coast north

Broward

County.

same

tunlllle,

multi-

tudes of the little clam Chione cancellata and numerous other marine

mollusks.

whose shells comniose the Coffee Mill Hammock marl merm-

are

|

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

oolite

became

deeply

pitted

solution

holes.

Sand

worked

southward along the shores, and bars and

dunes

were built in many

places.

Rise of

the sea

to the 25-foot level in Palmlico

southern Florida again

(Cooke,

1939, fig.

time flooded

. Most of the

much
region

north
island

Caloosahatchee

here

River

called Immokalee

was

land,

Island,

and

extended

south

river

beyond

Innnokalee.

A peninsula terminating south of Indiantown partly enclosed the site

Lake

During

Okeechobee,

Pamllico

time

which

was

(probably

open

relatively

short

duration)

south.
long-

shore

currents brought

sand

from

north

and

distributed

over

the Anastasia formation and

uneven surface of

Miamii

oolite

as far

south

as Miami.

The

channels

across

oolite

were

choked

with sand.
post-Iowan

Here and

sea

and

there

was

the sand

built

bar reached

into

dunes.

surface o
interior,

this
sand

covers

some

northern

part

Big

Cypress

Swamp,

it has only

Late

a slight

Wisconsin

extent into

time

was

he Everglades.
comply aratively

short

duration.

The

sea receded slowly

193'3)

25 feet or more

and as it did so left a series

below present sea level
of parallel beach ridges

and

bars

in parts of

southern Florida

east

coast,

beach

(Plate
ridges

13).
nIow

surmounted

dunes

were

built

prominently

Martin

Lucie

and

Palm

Beach

Counties.

west

coast

sand

was

carried

southward

beyond

town

Everglades,

and

dunes

were

built

there

and

at Marco.

The

dunes

near

Everglades now

foundation for

some

wholly

Tenl

or partly
Thousand

submerged

Islands,

and

make

at least

one

the Marco dunes stands as

high as 52 feet above

present

sea level,

and

another is

almost as high.

During

this

interval

solution

limestone

was

resumed,

Lake

Flirt
were

marl

began

to be

partly re-excavated,

deposited,

some80111

sand-filled

and several short streams on

channels

the east coast

were formed.

On the west coast the Caloosahatchee

River and Peace

Creek

cleared channels that had

probably

been

cut long before,

and

many shorter streams came into

being.

Stear ,COO

LATE

CENOZOIC

GEOLOGY

lakes, the largest being Lake Okeechobee.

Saw-grass took root

where

water

was

not

deep,

and

its compacted

remains

make

much

of the

peat and muck

Everglades.

Widespread

deposits

of fresh-water marl

(Lake Flirt marl)

continued to accumulate where

conditions were suitable.

Part of

higher

lands west

Ever-

glades proved congenial to cypress trees and became the

Swamp.
merged
broken

Mangroves

into

invaded

Gulf.

shells were

shifted

tidal

Along

east

zone
and

southward

where

west

coasts

currents

and

Big Cypress
Everglades

sand
built

and

present beaches, and a

new coral reef began to fringe the

keys.

SOLUTION

General--A

stone

and

other

large

part

calcareous

southern
deposits,

Florida

an(d,

as the

underlain

surface

lime-

waters

are

highly

charged

with

organic acids,

solution

plays a

conspicuous

role

development

features

andl

dominant

over

abrasion.

The same was true in previous epochs.

At times in the past when the

Floridian

Plateau

stood

high

carved in it by running water,

above
which

deep

carried

little sand

gorges

were

to act as an

abrasive.

Rather,

surface

was

etched

waters

carrying

cor-

rosive

acids,

and

much

run-off

passed

downward

through

solution

holes into

caverns.

excellent

illustration

corrosive

effect

acid-charge

water was noted near the Big Cypress

Swamp 40 mile

west

of Miami

where the

Miami

oolite has been etched

to a

depth

almost

a foot

leaving a lacy surface network supported

lars

ually

that

crumble

proJects

under

above

water

foot.

The

level

y jagged

surface

is better

preserved

and
rock

uneven
. which

than

us-

sub-

surface.

Solution

passages

several

feet

deep

comnulon

area,

and some

extend

deeper

(Plate

5a).

Apparently

though

no original

existence

cavity

is needed

a ready-made

hole

to start
hastens

a solution

hole,

process.

has been suggested that many vertical solution holes

began to

be dis-

solved

along tap

roots,

and

possibly

some

originate

in this

fashion

I

1 1 'I.r -~rr

.~ ... - ar ** n -r a~~ SL -A~I a -. Ilnr a -Il---t ~- *

-. n- .ta n e a Cl

.1 "

1 t

1 *

r~~ln

I

i

FLORIDA

GEOLOGICAL

SURVEY--BULLETIN

SOLUTION

EFFECTS

LIMESTONE

SOUTHERN

FLORIDA

. 4. _.

=t ~

PLATE 5

FIGURE a-Effect of acidic
a place where

ground waters
the water table

011
is

limestoi
generally

ie (Miami oolite) in
Sa few inches below

LATE CENOZOIC GEOLOGY

large areas of southern Florida it is evident that at least one-fourth

the total volume of limestone, once

miiore or

less solid rock, is

now occupied by solution holes, generally filled

with sand.

Trees

blown over by hurricanes rip up rock with their roots, thus leaving

a new and localized

depression for concentration

surface

water

and the start of more active solution holes.

Adjacent holes enlarge,

coalesce, and become increasingly effective in draining surface water
under ground. Many solution depressions of this kind, some as much
as 150 feet in diameter, may be seen in the pineland and wet prairies
south of Miami.

In certain areas, such as near S.

12th Avenue and the

Trail in Miami, some apparently solid foundations occasionally give

way beneath buildings.

The area is one of very active solution and

erosion.

In such a

place

water may

be heard

trickling in

caverns

underground, and

rain

water vanishes

quickly

dowIn

these sub-

terranean courses, often taking along with it the soil and larger rock

particles from the surface.

Test wells have shown some of these un-

derground solution channels to be as much as 11 feet from roof

floor;

their

horizontal

extent,

however,

is unknown.

These

chan-

nels occur, in some places, within a few feet of the surface; the largest

one noted at shallow

depths occurs between

10 and 21 feet

below

land

surface

and

was

penetratedI

exploratory

well

(G-189)

in the Silver Bluff area of Miami.

The effects of solution are. at times an aid and at other times a

hindrance in working out the stratigraphy in a limestone area.

For

example,

area

along

many

Caloosahatchee

the older

Pleistocene

River

deposits

have

Fort
been

Thomlpson
alhnost en-

tirely removed, but remnants still fill solution holes in a lower bed.

In this way the former presence of these deposits is proved.

Further,

a younger filled solution hole may partly penetrate an earlier filled

one,

thus defining three separate

deposits

unconformities

within a very

small

area.

Locally

an overlvingr

only

fills

vertical solution holes but also spreads out, filling a cavern below.

Close

scrutiny

is needed

to discern

actual

relationship.

Such

L .. . .. . .... . . . .. -... . . --1 ... __

Tamiami

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

DEEP

LAKE AND

STILL LAKE, PLEISTOCENE SINK HOLES

-I I C. *-
* C~
A;
-;t.~.-

!A

" !rt
,, ,.Z .gl~h~

PLATE 6

r... -- - U T_ *- C--. - .. .. .. - I. 1 nn .. ,, 4 .

LATE CENOZOIC GEOLOGY

Frc. 2-Map showing contours on floor of Deep Lake.

are Deep Lake in Collier County, Rocky Lake in Hendry County, and

Still Lake in Lee County.

The other two, just outside the boundary

this report,

are Salt Spring

and

Little Salt

Spring

in Sarasota

County.

Most accessible of these is Deep Lake (Plate 6a)

in the Big Cypress

r.~~~~ - n rr. rn r

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

Still Lake lies about 16 miles east and slightly south of Fort

Soundings made in May

Myers.

1943 show that its general form is that

funnel, and that the

face,
face.
filled

which,

This

at that

depth

to about

greatest

time,

occurs

feet

depth

stood

is 208 feet

about

in a sort

with

soft

five

feet

elliptical

organic

ooze.

below

below the

drain

The

water
land

sur-
8ur-

or "chimney

diameters

drain

are

about

and

40 feet.

The

floor

lake

deepens

rather

uniformly

with

gradually

increasing

slope

about

feet,

then

drops

abruptly

drain

or "chimney

The

average

diameter of this lake is about 600 feet, and the area is approximately
6.5 acres.
Rocky Lake lies in the Big Cypress Swamp about 17/2 miles east of

Immokalee.

nearly

circular

and

average

diameter

about 840 feet

area

is about

12.7

acres.

The

depth

is unknown.

All three of these sinks contain

potable water, normal for the area

which

each

is found.

Salt

Spring,

in Sarasota

County,

is about

miles

northwest

Murdock, and Little Salt Spring i

Both springs yield

aline

waters.

1.9 miles northeast

The greatest

depth

of Salt Spring.
in Salt Spring,

when sounded

in October

1942,

was

feet.

surface

then

stood

about
cular:

3 feet

below the

level

land.

The

its average diameter is about 250 feet

spring

is almost

and its area is approxi-

mately
shore,

acres.

then

floor

slopes

drops abruptly to

gently

about

to about

feet

where

feet

from

a shoulder

30 feet in width slopes to a

depth of 50 or 60 feet,

then falls precipi-

tously to the bottom.

Apparently the deepest part of the sink is along

and

near

includes

southeastern

a brief

wall

description

. A

Salt

report
Spring

and

Stringfield
a chemical

(1933b )
analysis

a sample

water.

The

chloride

content

was

9550

ppm

time

sample

was

collected.

However,

Stringfield

states

that

composition

water may vary

with

rainfall

in view

fact that relatively large quantities of surface water may flow through
the spring in rainy seasons.

Little

Salt

Spring

been

sounded.

ahnost

circular,

1,1 ;d fnlat ntrtnrl +n b0 n ntr- tit In f l 0+ Vnl+ Qn4 n r I n a w f

lr ,L

vtrot n,.

LATE CENOZOIC GEOLOGY

It may be that the difference in salinity of

33

their waters accounts

for their names, or it may be due to the difference in their flows.

Areal size has nothing to do

with it since

they

are essentially

the same diameter.
Few chemical analyses of their waters have been made; however,

in January

1943, Capt. A.

DeWolf,

U. S. Army

Engineer Corps,

collected samples which were analyzed by K.

Brehmi of

the City

of Miami laboratory.

This analysis follows; for others see page 34.

Big Salt Spring
No. 1
(ppn)

Chloride (Cl)...
SIardness (Soap)

little Silt Spring

(ppm)

9,300

Sulfate SO4 (Gravimetric

) . ... .. . .

1,615

Alkalinity (CaC(

) . .. .. .. .. .. .. . .

011 CO3 IICOa3
0-0-125

OII COa IICOs
0-0-134

C olor. . . . . . . . . . . . . . . .
C olor ...............................

These salty springs flow

because

tesian aquifer (Hawthorn formation)

their

bottoms

penetrate

which has a piezonetric head

higher than the rim of

the spring.

Salty zones above the

artesian

aquifer, probably remnants of sea water trapped during Pleistocene
invasions of the sea, contaminate the artesian water as it rises to the

surface.

The water in the artesian aquifer is probably not much dif-

ferent from that supplied by the various shallow artesian

the vicinity.

wells in

This artesian water is hard, sulfurous, and only slightly

saline; only near the Gulf shore is it high in chloride

(Stringfield,

1933b, p. 222-7, and Table 2).

The occurrence of deep sink holes in southern Florida gives 1)re-

sumptive evidence of former stands of

the sea much lower than the

present, for it is not likely that such sinks could develop much below

-*. n 4- n e +a. 1. 1 a

1..... "I

* i* li I** 11 | It. I *v f ItII S& '.'* *ESI l tFUrl ItilO

1 ..1

<"I^ritirr nn -I- r]- /- nn j \**-j^w *I k ^J

ANALYSES

WATERS

FROM

BIG

AND

LITTLE

SALT

SPRINGS

Feb. 10

Aug. 4,

Aug. 11

,1927..

1930..

,1943.

, 1943.

Total
Dissolved
Solids

17,812

17,770

17,670

3,220

Silica
(SiO2)

Iron
(Fe)

0.07

Cal-
cium
(Ca)

766

Mag-
nes-
lum
(Mg)

Sodium
and
Potassium
(Na&K)a

5,124

5,288

5,250

779

Bicar-
bonate
(HCO.3)

Sul-
phate
(S04)

Chlo-
ride
(Cl)

9,350

9,550

9,450

Ni-
trate
(NO3)

Total
hard-
ness as
CaCO.,a

3,846

3,853

3.,820

Tem-
pera-
ture
F.

a Calculated

b F, Margaret D. Foster, U. S. Geological Survey
L, S. Kenneth Love, U. S. Geological Survey
P, Garald G. Parker, U. S. Geological Survey
S, George W. Simons, Jr., Fla. State Board of Health

c No. 1 Big Salt Spring
No. 2 Big Salt Spring
No. 3 Big Salt Spring
No. 4 Little Salt Spring

No.c

Date of
Collection

r

(

LATE

CENOZOIC

GEOLOGY

tlone
sonme

that
of t

probably

other

corresponds

four

stands

to the

may

hav<

Illinoian
e been a

glacial

s low

stage,

as 1800

and
feet

below sea level

(Stearns, 1942)

If the holes were formed at an early

stage, subsequent submergence did

destroy them, for the supply

of sediment was too scanty to fill the sinks.

There are dry sinks of

Florida.

Falling

comparable

Water

depth

Washington

lime-sink

County

and

district
Devil's

Mill Hopper in Alachua

both

are

drained

County

are

underground

both

deeper than

channels

100 feet,
bottom.

and
The

Devil's

Mill

Hopper

apparently

extends

about

to the

water

table

for the bottom is sometimes dry, sometimes wet.
of such a sink is largely dependent upon the depl
channels that carry away the flow below the botta

The ultimate depth
th to the horizontal
omrs of the sinks.

DRAINAGE

Southern

Florida

is so

low

and

flat

that

drainage

most

is very

sluggish.

The

largest river is

Kissimmee,

which

flows

southeastward

into

Lake

Okeechobee

carrying

large

volume

water

from

seating

the central h
Creek. a much

ighlands
smaller

beyond
stream,

the
also

highlands and enters Lake Okeechobee from

northern

rises
west.

boundary.

central

The

outflow from

Lake

Okeechobee

passes

eastward

through

Lucie

Canal,

westward

-through

Caloosahatchee

Canal

and

River,
other

and

canals

, during

that

part

terminate

year,

between

southeastward

West

Palhn

through

Beach

and

several
Miami.

The St.

Lucie Canal

Lake Okeechobee

and the Caloosahatchee Canal

and River form links in the Intracoastal Waterway

Before the canals

were

and

high

dike

around

lake

was

built,

water

from

Lake Okeechobee overflowed into the
ward and southeastward more or less as

Everglades and

drained south-

a sheet through interconnected,

nearly parallel

courses.

On land

adjacent to the lake,

ditches,

dikes,

and pumps have been installed,

and a lowered controlled water

level

is maintained

lake.

This

resulted

in a greatly

reduced

outflow to the south from the lake

in fact

, during some

parts of

. -

J

I

f

_

FLORIDA

GEOLOGICAL SURVEY-BIULLETIN

tidal part of

tlihe river froni its headwaters

and has lessened tlie damage from floods.

(Heilprin, 1887.

The Caloosahatchee

221,

River

IlowV

idal to Ortona Lock.

The estuaries of Peace Creek and Miakka River, both leading

iarlotte

Harbor. cross the northwestern part

southern

Florila.

The directions of surficial drainage are shown on 11 e Ilaplt of

Everglades

Drainage District

Plate 13.

which is based on lmany field

data and careful studies of

the airpllane

all e II

for the

Conservation Service in 1940

. The arrows indicate linoriial

drailn-

directions in the area before the installation of thle canals.

In lost

instances the canals have affected

the greaterr part

Iallns

the iar'ea

tClllporarilY reverse

drainage

waVS.

this

lpatt ern

verve

reniainis u1chali1edl.

(directionl

season.

flow

Junlle

little

and

However.

hese

through

over
local
Ilat-

()cto

when tle lands are flooded and canals are overtaxed. thle flow

tern

indicated is

especially applicable.

A-rch Creek--Arch
waV in Dade Countyl

Ib)eneath

the only

Creek

(Plate

5 miles south of the

natural

bridge

crossetl'

Dixie

Broward County line, flows

lloIlida.

leads in a low llarshv

atca con(lliected(l with

Everglades. crosses

a ridge
t

F1ianmi

oolite

a vertical-waledh1

through
f111'11"t

onei place lv a narrow natural bridge, and

marshes to Biscavne Bay

STlie strieamn

thence wanders through
is tidal throughout most

2-inile

course.

rock

bridge

l)ro)bably

oriIinate( as follows:

The.

oolite

Archl

Creek

is p)erl'orate(d

I11any

vcrtlia.1

tubuila solutioll holes

leading" down to tle water table and

Fnlarieient

there

coalescence

with

a maze

su ch

horizontal

horizolt al

passages.
resulted

tle formation

ia cOlltllll OuIS

tunnel

through

oolite

ridge,

which permitted surface water and ground water back of

tlhe ridge

to pass through it as through a culvert into the tidal marshes beyond.
This sIwaipI water, being highly charged with or'galnic acids. deeply

southern

High-

TIe1

streIall

photograph hs

covered

The

thle vicinlity

connected

passages

LATE

CENOZOIC

CREEK NATURAL
LAKES MARSH

GEOLOGY

BRII)GE AND HILLSBOROUGH
OF THE EVERGLADES

dp

so

a -
d

IJ
YI I -a 1

* t -'a

t. .

a~~jl; -- ,----t~
::- -*

.3~~ $ c SI.C
5:
|

''.r~,
r2

PLATE 7

FIcGUiE a--The

L-a

natural

ii~hwav pass

bridge of Arch Creek over which the old Dixie
ses. The swamov acidic waters undercut the banks.

ARCH

Jk l.

FLORIDA

GEOLOGICAL SURVEY--BULLETIN

TOPOGRAPHIC-ECOLOGIC DIVISIONS

THE SANDY FLATLANDS

General features-Within the area of

this report

the sandyV

flat-

lands

(PI.

range

altitude

from

somewhat

than

above sea level to nearly 80 feet.

The greater part is lower than

feet

and forms

part

lowest

Pleistocene

marine

terrace,

Pamlico, whose shore line is now about 25 feet above sea level.

areas above 25 feet are not quite so flat.

The

They are called by Sanford

1909, pp. 185-186)

"Rolling Sand Plains.

These higher areas

within

Talbot

terrace

(shore

line

about

feet

and

Penholowav terrace (shore line about 70 feet).

The sandy flatlands surround Lake Okeechobee except on the south-
ern and southeastern sides, where the wide expanse of the Everglades

meets the lake.

On tile west the sandy flatlands extend

1)racticallv

without interruption to the Gulf of Mexico.

this western area beyond Naples,

They continue south in

where coastal marshes begin.

landI

they

extend

from

this

coastal

strip

irregular

llargilns

of tile Big Cypress Swamp and,
meet the western boundary of t

passing north
e Everglades.

East

Big Cypress,
Lake Okee-

chobee they extend as a broad belt alhnost to the ocean, limited on
the east by the narrow coastal ridge with its Pleistocene dunes, and

on the southwest and west by the eastern border of

Everglades.

This

strip)

contlllues

southward

between

Everglades

and

coastal ridge to Coral Gables, in the Miami area, with an occasional

break through the ridge north of Miami,
of old drainagewavs and tidal channels.

These

directly

sandy

flatlands are

into the surficial

poorly

sailnd

where they form the floor

drained

or is stored(

. Rainfall

shallow

either
pools.

sinks
The

whole

flatlands

area

is dotted

with

these

shallow

circular

ponds,

generally only a foot or so deep and rarely over 4 feet deep. Diameters

the ponds range up to several hundred feet.

The

ponds alpp)ear

over areas of deep sand as well as over areas where only a thin sand

mantle

covers

underlying

limestones

and

sh ell

marls.

Thev

1 1

1 -a

1 1

1

1

1 1

U - - -I -. ..- -I -r. *... *. -l r---- I -. ---- ~ r - r l r -*V

are

LATE

CENOZOIC

GEOLOGY

VIEWS OF THE SANDY FLATLAINDI)S AND

IN THE DEVIL'S GARDEN

PLATE 9

FH;.I-: a T -T pical view of tlie Sandy Flatlands west of Lake Hicpochee
with the Caloosahatchee River meandering to the west.

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

Clayton, Neller
a

and Allison

(1942)

have shown

that

transpiration

and evaporation may exceed rainfall, the deficiency being accounted
for by seepage and run-off from contiguous areas.
Drainage is sluggish and, except in the rainy season when lower

parts are inundated, there is generally

little or no surface run-off.

Though the surficial sands are

quite

permeable,

nmovemlent

ground

water is very slow

because the land is flat

and the

unlne-

diately underlying shell marls, calcareous marls, and clayey marls are
relatively impermeable.

In some

drainageways

more or

inherited

well-marked

from

past

areas oni

and

sandy

modified

flatlands
present

conditions are still used by surface waters.
are the Okaloacoochee Slough and Devil's

Most important of these
Garden, the Loxahatchee

Marsh, and the Allapattah Marsh.

Okaloacoochee

Slough

and

Devil's

Garden -The

Okaloacoochee

Slough and Devil'

Garden

(Plate 8)

form

a marshy

drainagewav

on the sandy flatlands south

of the Caloosahatchee

River,

west of

the Everglades, and, in general, north

Big Cypress Swamp.

The Okaloacoochee Slough extends southward about 50 miles from

vicinity

LaBelle

into

Cypress

Swamp.

average

width
Devil'

little

more

than

miles,

wide

prong,

called

Garden, extends northeast of Immokalee.

The northern end of the Okaloacoochee Slough has a number of

branches

mostly

discharging

into

little

creeks

flowing

into

Caloosahatchee

River.

The

southern

end

branches

out

likewise

but is lost in the maze of intertwining courses in the

Big Cypress

Swamp.

Fahkahatchee

Slough

southwestern

branch

Okaloacoochee.
The Okaloacoochee Slough drains both northward and southward

from about the latitude of the Devil'

Garden.

The Devil'

Garden

itself largely

drains westward

Okaloacoochee, but

times

of high water it may overflow in all directions-into the flatlands on
the north, the Everglades on the east, and into the Big Cypress on

the south.

See Plates 8 and 13 on which arrows indicate directions

of surficial flow.

LATE CENOZOIC GEOLOGY

Drainage from the Okaloacoochee Slough and Devil's Garden and

from

Allapattah

and

Loxahatchee

Marshes

retarded

rank growth of vegetation and by an accumulation of

organic peat

and muck that clogs the channels; therefore, the movement of water

is, at times, difficult to discern.

Direction of flow in the channels

may be changed, too, by local rains.

"Spot showers,

which typify

rainfall

in southern

Florida,

may

cover

only

a fraction

square

mile

or several

square

miles,

they

may

intense

that surface-water gradients are temporarily reversed in the sluggish
drainageways.

Allapattah and Loxahatchee Marshes-The Allapattah Marsh splits

into

two southern

prongs,

one

that

discharges

waters

Lake

Okeechobee north and west of Indiantown, and another that formerly
drained almost due south of that city into the Everglades, but is now
cut by the St. Lucie Canal.

The Loxahatchee Marsh is shaped like a wishbone with the apex

pointed toward Jupiter Inlet and with

glades.

prongs leading to the Ever-

Drainage usually flows in both directions from a low divide

in the middle of the northern prong, and also usually flows in both
directions from another divide in the southern prong not far west

of Kelsey City.

The southern prong drains directly into the Hills-

borough Lakes Marsh at a point a few miles southeast of Loxahatchee
(Plate 8).

Sandy

flatlands

south

Loxahatchee

Marsh-Southward

from

the Loxahatchee Marsh the sandy flatlands extend a short distance

past

Coral

Gables,

where

they

abut

against

coastal

ridge

oolitic

limestone

and

overlapped

Everglades soils.

Appar-

ently the sand never did extend farther south because the currents
that swept the sand southward lost their efficiency there.

Between

Fort

Lauderdale

and

Miami

several

low,

shallow

valleys, floored with sand of the Pamlico formation,

that reach

present

shore.

These

are

called

transverse

glades

because

their orientation and their characteristic vegetation.

They

occupy

FLORIDA GEOLOGICAL SURVEY-- BULIIETIN 27

,:(

1- --;
^;^^ -- *

IATE

(ENOZOI(:

VIEWS IN THE BIG CYPRESS SWAMP

PLATE 10

FIGURE a-Turner River, in the southwestern part of the Big Cypress
Swamp. Picture taken from a bridge of the Tamiami Trail
(U. S. Highway 94). Trees are bay, willow and cypress.

FIGURE b-A hammock in the Big Cypress Swamp showing
tion, and a "glades-buggy" used to get around in

typical vegeta-
the area.

FIGURE c-Typical view of
Swamp. A cypre
peripheral trees
where the talles
canal bank and
is on the margin
merge.

he stunted
ss "head"
ringing lar
trees arn
saw-grass
where tile

cypress g
appears to
*ger ones i
e found.
covers the
Everglade

growth in
the right
intil the c
Pickerel
Sinterven
s and Big

the Big Cypress
side with small
enter is reached
weed lines the
ing area. This
Cypress Swamp

FLORIIDA

(;EOlO(;GICAI SUTRVEY-

ported to 1be not deeper than 20 feet.

I1UL1,ET1N

It covers ao1)l0

5 square riiles,

tii area varVying g great wilth the stage of thle after .

Thli

)asill.

which

lies Inear tile

11111r llargill of

IPallico

race..

Ibottollm.

- represell
However.

original

hollow

soluble

calcareous

marl

SBuckinhanm miarl
L.

its bottom mav have been lowered I) solution.

Th'e presence of

numerous small circular lakes nearby

that

appear

o le solution features lend credence to this possibility.

THE BIG CYPRE

SWAMP

General

indefinitely
southeast b

fe(latures-The

defined area.

Everglades,

Cyp)ress Swamip

(Plate

a very

In general, it is bounded on the east and

which

is distinguished

its organic

soils. sedges. and lower-lying area.

The sandy flatlands adjoin it

the north.

where they are higher, and on the

west,

where they are

lower.

On the southwest and south the Big Cypress grades into the

low-lying

coastal

marshes

mnangrove

swamps.

marked

colln-

trast to the surrounding areas of mucky, sandy, and marly soils with
no outcropping rocks. the Big Cypress has large areas with rock at
thie surface. or where thin marly soil lies in shallow pockets in the

rock.

In old drainagewavs

this marly soil is suitable for truck farm-

water

table

adequately

controlled

ditches,

dikes,

dams and pumps.
Drainage is very defective, and in the rainy season the larger part

the Big Cypress is more or less flooded;

but even then the only

movement of water di

scernible is

in shallow, Ipoorly defined drainage

courses

locally

called

sloughs,

rivers,

or creeks.

Near the

Gulf

Slexico these courses are better defined though so intricate that the

service of

a guide is required by a stranger.

The Big Cypress is not a vast morass of huge moss-shrouded cypress

trees as

is supposed by many people unfamiliar with the area.

Rather,

it is an area of

alternating swailmpy

and higher land

(hammocks)

former

type.

Davis

1943 )

relationships and lists the principal members of'

describes

thie flora.

these

She dif-

r ------------- i- l- i- : -1 *

..I - _1 1 .... 1 < __ .. . 1 1

with

Illd-Wiscon sini

underlain

prevalent

,ATE

(IENOZOI(

(;'OI,O(; Y

VIEW S

N TIlE EVER(;IADES

r a

-R

PLATE 11

of ilie cmllril

Mia1nii

(X11111i

fro011

tol) of

lverglIdaes

looking

thit airpllln

lit

liv\e'r (anal.

\Sin
?

Ilnort Ies
ill (1((O f

a;1lon1

tihe ,onIflUInI(C 1

- -

So illh

NOw

I*

I;1 ;I--( ;cn Gc 0l'i] vicw

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

THE

EVERGLADES

General features-The Everglades, a region of

occupies an

surrounded by

irregularly

slightly

defined

higher

areas

area

on all

over
sides

organic soils

4,000

square

south

(Plate
miles

and

southwest.

An arm of

the Everglades borders the western side of Lake

Okee-

chobee,
eastern
pattah

and
side

Marsh

a narrow

about

and

tapering

Canal

cypress

arm

Point,

swamps.

extends

where

The

northward

merges

Everglades

along

with

extend

Alla-

south-

ward
miles

and

wide

southwestward

and

mile

from

long,

lake

merging

in a vast

near

sweep

Bay

about

Florida

and the Gulf of Mexico into salt-water marshes and mangrove swamps.

The

boundary

between

Everglades

and

surrounding

areas

very indefinite.

may

regarded

as the

place

where

sedges

Everglades

give

way to

true

grasses

and

pines

or cypress

to salt-marsh

plants

and mangroves.

Large

areas

in the

northern

and

eastern

parts

Everglades

almost

treeless

expanses

saw-grass

(Mariscus

jamaicensis)

sedge,

willow,

growing

bay,

as tall

and

as 10

custard

or 12

apple

feet.

Low

appear

shrubs
slightly

wax-myrtle,

higher

areas,

generally

alined
Trees

isolated

in accordance

grow

perennial

in the

water

clumps

with

Everglades

table

called

general

where

to allow

tree-islands,

drainage

there

more

pattern

is enough

less

(Fig.

height

aeration

above
along

spoil banks conditions are very favorable, and trees and shrubs grow

there in rank profusion

(Plate 11).

Floor of the Everglades-Sanford

(1909, pp.

192-193)

thought that

rock floor in

northern

part

Everglades

slopes

westward more steeply than in the southern

part;

that

depth

bed rock 5 miles west of the eastern rim

back

of Fort Lauderdale

probably not less

than 20 feet

and that the Everglades probably occu-

pies a series of comparatively shallow rock hollows. He states,"'Whether

these hollows were as deep

when

Everglades first occupied

them

as they now

are,

that is,

whether they

have

been

deepened by

solu-

. =

--I ___ V V

FLORIDA GEOLOGICAL SURVEY

BULLETIN

PLATE 12

UPITER

W. PALM
BEACH

ALL CONTOURS

DATUM

WHICH

U 5.C. A

SUBTRACT 5.44 FEET I
HERE TO CONVERT TO

DELRAY

MPANO

DERDALE

/ f I *,, J

I JF

* \

FLORIDA

GEOLOGICAL SURVEY--BULLETIN

limestone believed to be nearly

level.

Rarely, if

ever,

does it

below sea level, and nowhere, ini the Everglades proper, does it reach

the surface.

The fact

that it reaches

surface

margins,

except along the shore to the southwest, suggests that the Everglades

may owe their existence to an original rock basin.

slightly more uneven in

The rock floor is

the north than in the south, and various

explanations
deformation.

have

been

offered,

based

erosion,

solution,

Data gathered by the U. S.
erous exploratory test wells,

Geological Survey while drilling num-

and by the Soil

Conservation

Service

while making soil surveys in the

Everglades, shows that

Sanford'

observations were very

good.

Beginning

along the

eastern

rl'ni

the Everglades, from Lake Okeechobee to the latitude of Boca Raton,
there is a rapid descent from the Atlantic coastal ridge to the shallow
basin which contains the Hillsborough Lakes Marsh in its southern

end

(see Fig. 3 and Plate 8)

. Elevations drop off from +10 to +3

feet (M.S.L. U.S.C. & G.S. datum) within a distance of about a mile

a slope which, in southern Florida, is distinctly scarp-like.

Leading

into the shallow basin of the Hillsborough Lakes Marsh there is a

shallow

trough

from

southeastern

side

Lake

Okeechobee.

Southward

from

Hillsborough

Lakes

Marsh

this

trough

coln-

tinues to old spillways and tidal channels emptying into the Atlantic

Ocean

between

Fort

Lauderdale

and

Miami.

Some

these

channels have been deeply eroded in the rock and were later filled

with

sand;

and

was

these

sand-filled

channels

that

Sanford

alluded when he said that depth to bed rock west of Fort Lauderdale

is not less than 20 feet.

Sanford, however, did not know that these

depths exist only in channels because sufficient data were not avail-
able to him.

\West of

this trough,

which lies along the eastern margin

Everglades,

rock floor forms a

domelike

surface

with

about

10 feet

above

mean

sea level.

This

"high"

centers

Pahl Beach-Broward County east-west line about 6 or

7 miles east

of tile Pahn Beach-Hendry County north-south line, and due south
of Lake Okeechobee. From the top of this low dome the floor slopes

and

LATE CENOZOIC GEOLOGY

Cypress on the west and the Atlantic coastal ridge on the east, tilhe
floor of the Everglades slopes gently from the sides toward tile cen-
ter where a low, broad, flat valley swings gently to the southwest.

These major features of

marked by smaller

the floor

basins and higher

Everglades

areas.

general

are locally
, the floor

sags from the sides into the Lake Okeechobee-Everglades depression,

within

which

there are local ridges and

basins, none

higher than

the lands surrounding the Everglades, and few deeper than sea level.

Solution is actively engaged in etching out the floor of the Ever-

glades at the present time,

the ridges.

deepening the hollows and roughening

Deposition, too, is taking place in some parts, especially

in the soils of the hammocks where calcium carbonate is being de-
posited, making a carbonaceous marl that locally hardens to friable,
impure limestone.

The floor is composed

of Fort

Thompson formation

fresh-water

and marine marls and limestones in the north, Miami oolite in the
south, and Tamiami formation in the central, western, and southwestern
parts. A blanket of thin gray calcareous Lake Flirt marl covers large
areas of the rocky floor, and along the eastern and western margins

of the Everglades a thin mantle of Pamlico sand occurs.

are several kinds of peat and muck

Over these

(Evans and Allison, 1942)

Origin of the Everglades-This gently sloping basin was originally
the Pliocene sea bottom, which was not perfectly flat but had slight
inequalities. During the earlier Pleistocene glacial stages of the north-
ern states this floor was subject to erosion, solution, then deposition
of the first four beds of the Fort Thompson formation, and possibly

slight folding.

Then, probably

during Sangamon interglacial

tine,

Miami oolite, Anastasia formation, and

Coffee

Mill

Hanmmock

marl member of the Fort Thompson formation were deposited over

much of it.

Later, these younger deposits were subjected to erosion

and solution and still later were partly covered by sand of Pamlico

age.
area

During latest

that

became

Wisconsin time the sea withdrew, leaving a large

occupied

fresh-water

marshes

lakes

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

growth

plants

dies

and

sinks

below

surface

shallow

water and is incorporated in the organic mass below.

continue on a much steeper gradient than

And it

that existent in the

would
Ever-

glades

were

man

interference

through

drainage

and

farming.

Fenneman

(1938,

discussing

origin

Everglades says

and that of

: "The tendency of
moving water to cut

accumulating vegetation to

down

are

necessarily in

build

opposl-

tion.

In Dismal Swamp,

moving water is helpless on a gradient much

steeper than

that in

Everglades.

Vegetation

shown

what it can do in southern Florida.

If given a free field and no inter-

ference it would build much higher in the interior

before the steep-

ening slope would serve as a

check.

Meantime the vegetation

would

change,
steadily

though

larger

slowly.

and more

The

tree-clad

hammocks

numerous and should

would

ultimately

become

domi-

nant.

many

and

pattern

elongated
separated

in the

Everglades-In

tree-islands, arranged

from

one

more

another

Everglades

or less in

shallow

there

parallel

swaless,

are

rows

"runs,

"slough

s," or "lakes,

as they are variously called locally

. These tree-

islands and swales trend northwest-southeast in the upper part of the

Everglades

as far

south

spillways

through

Coastal

Ridge
begin
Miami

between
to bend

Miami

and

Fort

south,

, they swing abruptly to

and

Lauderdale

finally

(see

about

48),

miles

then

they

south

the southwest.

The

cided

linear
r, from
"grain"

arrangement

which

this

as Dickerson

a broad

sweep

pattern
(1942)
country

is most

says,

noticeable

"They

. . as if

reveal

a great

from
a de-
coarse

broom had been rudely brushed over the low-lying Everglades region.

This

arrangement is noticeable to one crossing the

Everglades along

Tamiami

Trail

where,

toward

western

side,

development

is best and

one crosses

alternate strips of

tree-islands

and

saw-grass.

Dickerson postulates that this "grain"

may be the result of Pleisto-

cene ocean

currents during Pamlico

time

when

this

whole area

was

a shallow sea bottom

. He notes that

"off the east coast of Florida

- -w - -

Drainage

'LA
"
I\

I

IMMOK

i-
1 I
I
II(

,'a
14l j

125
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,4i \ k
W'''^T "' *

_ I_1 1 / 12 21

_ \ / / / 'V,/ iI cani I.

LATE CENOZOIC GEOLOGY

currents, is developed entirely

on fresh-water peat and

miuck,

does not reflect an underlying pattern of marine bars.

It represents

merely a drainage pattern produced on a very gently sloping plain.

"grain"

is composed

tree-islands

and

swales that

trend

right angles to tile regional slope, just as one would expect of conse-

quent drainage.

Streams flowing across the Sunderland terrace into

()kefenokee Swampl
a similar pattern of

in Clinch and Warren Counties,

parallel lines.

terrace, especially in St. Lucie

rangcment of

On certain Iparts of
Martin Counties, a

dunes, beach

Georgia, show

the Pamlico

parallel

lagoons is notice-

able.

This pattern is directly

shore-line environment

a p)rodluct

is not

the saIIeIC

of lowering sea level

as t

!i a

the organic

Everglades soils.
The drainage pat tern in the Everglades is gradually being changed(

b)y mlan

s operations there.

"Subsidence valleys

[Evans and Allison,

1942,

have

developed

along

principal

drainage

canals,

and direction of flow in the northern end of the Everglades at certain
limes of the year is northward into the Lake, exactly opposite to the
original condition (Stephens, 1942) .

Lake Okeechobee--Lake

Okeechobee

occuliesi

northernmost

and largest of the interconnected series of basins and shallow troughs

which makes up the Lake Okeechobee-Everglades depression

and Plate 12)

(Fig. 3

It is an original hollow in the Pliocene sea floor, possi-

,ly modified by solution, erosion, and deposition of sediments during
lihe Pleistocene and Recent epochs.
The lake is a little less than 30 miles in average diameter. At a

stage

of 20 feet

above

level,

Okeechobee

datumi

(Okeechoeec

datuim is 1.44 feet below U

.C. & G.

M.S.L.

it has an area of

square miles; at a stage of 16 feet the area is about 710 square miles.
As the lake ranges in stage from about 13.5 to 20 feet its area changes
accordingly.

The lake is very shallow

its deepest.

parts

are approximately

sea level

(Fig. 3)

It is saucer-shape(d, andl

because of its physical

characteristics is subject to violent wind tides and wave action dur-

A 1 7 T 71 & / 1 P*r / ?

The

ridges, hars, and

-- r

I I

tr

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

records show that hurricanes with much greater wind velocity than

th at of 1928 have occurred

, notably that of the Florida Keys in 1935,

which hiad an estimated wind velocity of

approximately

and a maximum hurricane tide of 16 to 18 feet."

From these data it is easily understood that the bottom is rather

thoroughly scoured by tilhe action of

effectivelyv

cast

detrital

material

storm
loose

waves, and, since

sandl

these

scarce

I)ottonm.

Around portions of

lihe lake, especially oni

lie north western,

1 r ..-_ -

200 m.p.h

^

%.

f `

LATE CENOZOIC GEOLOGY

northern, eastern, and southeastern borders, a definite

53

"sand ridge"

has been built up.

This is a beach ridge,

waves, and lies outside the hurricane levee.

probably built by storm
It is the dwelling place

of most of the rural families who live around the eastern margin of

the lake.

Shallow sand-point wells, driven into this deposit, furnish

family supplies.
The accompanying map, Fig. 3, shows contours on a 5-foot interval
on the bottom of the lake.

Hillsborough Lakes Marsh-Hillsborough

Lakes Marsh

(Plates 8

and 7b)

is a Ioggy area occupying approximately 55 square miles in

Panlm Beach County.

It lies north of

the Hillsborough Canal, south

West Palm Beach Canal,

west of the strip of sandy flatlands

11that

borders the

Atlantic coastal

ridge,

and,1

in general,

east

north-south line drawn through
and West Palmn Beach Canal.

the confluence of

the Cross Canal

occupies one of

thie larger

and(l

(deeper

basins in

floor of

the Everglades

a basin that is now nearly filled with peat and muck.

These organic soils are being constantly

huilt up over the greater

part of

this area by aquatic and semiaquatic vegetation.

1panses of open water are dotted with small tree-islands of

Large ex-
peat and

nuck, and here and there are flotant masses or "floating islands."
In shallower portions sawgrass grows thickly; in deeper water pond
lilies and pickerel weed are the most common plants.

excavation

Hillsborough

Canal

along

southern

margin of

Hillsborough

Lakes

Marsh

lowered

water table

considerably and rejuvenated the better established drainage courses,
some of which already have become streams that have stripped off
the organic deposits from their channels and exposed the bed rock.

Ilndian

Run

(P1.

a good

example.

The

Soil

Conservation

Service is damming the outlets of

these streams, raising the

water

able, and

attemptillng to

restore conditions once

more

to approxi-

lately

their

original

status.

area

such

Hillsboroughli

Lakes Marsh is

valuable as a water an d wild-life preserve.

rl.nr1

A rlT A TITrm-rT

C/r A em A T

FlTTfCTr

r i U 5. l UT .-n

The

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

Jupiter.

Silver

Bluff

is notched

by wave

action

that

occurred

former higher stands of the sea; one notch is at 8 feet and the other
at 5 feet above present mean sea level (P1. 4b).
The highest parts of the coastal ridge (50+ feet above sea level)
are the summnnits of Pleistocene sand dunes, which lie in a series of
more or less parallel and discontinuous rows back from the present
shore. The southern end of the dune area lies in northern Broward
County, where the dunes are much lower and broader than in the

vicinity of West Palm Beach, Jupiter and Hobe Sound.

Northward

from

Hobe Sound, and

extending

into

Lucie

County,

belt

dunes surmounts old beach ridges, and is still better developed.

These

dunes

now"

quiescent

and

are

largely

overgrown

with

1,unch grasses, low shrubs, pines and palmettos.
South of the dune area sand extends as far south as Coral Gables.

This veneer of sand

(Pamlico formation)

was spread out

over the

limestone

bedrock

ocean

cu rrent s

during

mid-Wisconsin

The coastal ridge almost everywhere has a rock foundation.

tiune.
North

of Boca Raton it consists of

sandy

limestone and

calcareous sand-

stone

Anastasia

formation;

south

Boca

Raton

Miami oolite.

The oolite

lies at

or near the surface almost

every-

where from Miami southward to the point where the ridge finally

dies out on the mainland southwest of Florida City.

The height of

Coastal

Ridge

south

Fort

Lauderdale

averages

probably

feet above sea level with maximum altitudes of

about 25 feet on the

western shore of Biscayne Bav near Coconut Grove in Miami.

The

Coastal

Ridge

disappears

southwest

Florida

City

series of low "islands,

often called

"Everglades Keys,"

surrounded

Everglades

soils.

The

Coastal

the lower Florida Keys, Big Pine

Ridge
Key to

reappears

Key

West,

once

where

again

Miami

oolite is again the bedrock.

The highest

altitude observed on

Pine Key is less than 7 feet; that of Key West about 13 feet.

Cutting

across

coastal

ridge

several

places

are

marly

imucky strips called by

Harper

(1927,

176)

Stransverse

glades,

i I in b li lT I i ccoo i bl nur nf nluuita 1n1 t1 n Li nC tho 4I1 r-llr 1, r; t-l /r

LATE

CENOZOIC

GEOLOGY

It took the form of

an irregular limy bar, oolitic south of Boca Raton

and sandy and shelly farther north.

This bar,

which probably reached

slightly

above

ocean

surface,

between

broad

shoal

Lake Okeechobee-Everglades depression

and

deep

along

lie edge

Floridian

Plateau.

The

whole

area

southeastern

Florida was then much like the present

Bay

of Florida-Florida Keys

area

, but on a larger scale.

The surface of'

never

was

level

and1

probably

was made

more

uneven

accumulation

low

dunes

oolitic

material

heaped upon it above sea level,

and by tidal scour and wave erosion.

While

scoured
between

was

falling

and

Miami

lets until sea

and

level

at the

gaps

Fort

end

across

Lauderdale.

below

them,

Talbot

STihe
then

spots

gaps

thev

time,

tidal
bar,

persisted

became

currently
notably
as tidal

fresh-water

outlets during the early

Wisconsin

(Iowan)

glacial substage.

During

post-Iowan

spread sand over

choked

tidal

deglaciation

coastal

channels.

sea level

ridge
When

as far

, in late

rose

south

and

as Coral

Wisconsin

Pamlico
Gables

lllle,

and
sea

again
filled
more

withdrew

with

became

fresh

and

Lake

water,

Okeechobee-Everglades

lower

discharge outlets to

tidal

sea for

excess

depression

channels

water

once

from

northern

part

basin,

and

this

condition

continued

ever

s111ce.

Occasional

hurricanes

have

shifted

sand

about

invaded these low areas, but,

during Recent times,

the main changes

configuration .of

coastal

ridge

and

transverse

glades

has been brought about by solution.

South

with oolite.
Pleistocene

coastal

Coral
They
tidal

ridge.

Gables

transverse

represent modern

channels

They

were

, most
short

that

drainageways that are

which

tidal

runways

reach

ill the

) floored
modified

across

waning

stages

Talbot sea

(Pamlico)

, and again were likewise used by the mid-Wisconsin

sea.

"1Bottomless

holes"

New

River-New

River

a short

two-

forked stream that

nJls

i iat, a

connecting

occupies one of

the Lake

the old spillways and tidal

Okeechobee

deVression

with

Sa a /

chan-
ocean.

sea

glades

_ __

h

I

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

distant

past,

whence the name

"New

River."

Many

deeper

holes are situated at the outer edge of bends, and were scoured out

by the river, but others appear to
more or less modified by scour. Th<

be partly filled solution holes,
ey may have had their beginning

during the early Wisconsin time when sea level was lower than it is

no0w,,

were largely filled with sand during Pamlico time, and partly

re-excavated and modified in late Wisconsin and Recent time.
There are numerous sand-filled solution holes in the Miami oolite
ridge that may have had a similar history.

COASTAL

MARSHES

AND

MANGROVE

SWAMPS

The coastal marshes extend around the southern end of

the Pen-

insula

from

Naples

South

Miami

and

continue

northward

Fort Lauderdale as a narrow band behind the present sandy beach

ridge.

They are separated from

the sea

by the

mangrove

which fringe the coast and tidal lagoons and inlets throughout south-

ern Florida

(Plate 8)

and are best developed in the

Ten

Thousand

Islands and along the northern shore of Florida Bay.
The coastal marshes are characterized by marly soils mixed locally

with muck and sand.

In the strip bordering salt water the vegeta-

tion consists of

the usual salt-marsh subtropical assemblage,

which

gives way to fresh-water marsh plants at the outer edge of tli sandy

flatlands,

the Everglades, and

the coastal

ridge.

The general

rela-

tionshtlu of all these plants

and assemblages is discussed in a recent

paper

Davis

(1940).

Where

properly

controlled

water

table

(ban i)e maintained the coastal marshes are excellent for truck-farming_.

PLIOCENE

ROCKS

Rocks of Pliocene age lie at or near the surface in the southern

1)parts of

the Big Cypress Swamp and the

Everglades;

elsewhere

Southern Florida they are overlain by

trials (see Plate 14)

Pleistocene and Recent ma-

. From the Big Cypress Swamp Pliocene rocks

slope gently out under the Everglades to the Atlantic coastal ridge,

I I 11 1 1 i 1 U r

swai )ps

T1

LATE CENOZOIC GEOLOGY

neously;

the Caloosahatchee

as a

sandy, marly facies,

a favorable

habitat for mollusks,

Buckingham

as a

clayey

faces,

and

Ta miami where limy ooze mingled with

the sand.

Apparently the

locus of lime deposition migrated several times back and forth over
a distance of possibly 30 or 40 miles so that the Caloosahatchee marl

and the

Tamianmi formation interfinger at depth.

In its final phase,

however, the Tamiami overlaps

the Caloosahatchee marl in tile lati-

tude of Fort Lauderdale and

to the north

as far

as the

Tamiami

f oration

extends

(Plate 25,

cross section A-A')

CALOOSAHATCHEE MARL

Historical summary-Shell beds exposed on the upper reaches of

the Caloosahatchee River

(then spelled

Caloosahatchie)

were first

recognized as Pliocene by Heilprin

(1887, pp. 26-33), who proposed

to call them Floridian.

This was the first recognition

Pliocene

beds in the
after, Dall

United States east
(1887, pp. 161-170)

Pacific slope.

confirmed the

Shortly

there-

Pliocene age and re-

erred
marls.

deposits as

The

formation

Caloosahatchie

lnamel

beds

Caloosahatchee

nmarl

Caloosahatchic

wa s

adopted

Matson and Clapp

An extension of

(1909, p.

mnarl

123)

along

and has since been generally used.

tributaries of

Charlotte

Harbor

was noted by Dall in 1892

(pp. 140-149)

and later

(1903, pp. 1603-

1605) he listed species from Shell Creek, Alligator Creek, and Myakka

River.
report

The

map

shows

accompanying

Caloosahatchee

Matson

marl

Clapp

these

(1909,

creeks

and

along

Caloosahatchee River for about 15 miles below LaBelle.

Sellards

and

Gunter published in

1922

by the

Florida

A map1 by
Geological

Survey connected these areas and extended the formation somewhat
beyond them.

The opening of the

Tamiami

Trail in1 1928 permitted Cooke and

Mossomn

(1929, p.

156) to examine the rocks that underlie the Ever-

glades and the Big Cypress Swamp in Collier and Monroe Counties.
These rocks proved to consist of sandy limestone or limy sandstone

conutainino-

sim .

Caloosahatchee

fossils

though

-----

characteristic

_

\/VllbHIIIIIIL UVILIV VML\)VL yrLU V1V

FLORIDA

SECTIONS
EXPOSED

GEOLOGICAL

SURVEY-BULLETIN

OF PLEISTOCENE AND PLIOCENE
ALONG THE CALOOSAHATCHEE

ROCKS
RIVER

qa*"i I j 2 j~

,;I

PLATE 16

FIcuRE a-Banana Creek
sand (Pamlico
I ;a tnn- i f

cuts down
formation)
tih Pliarnoa

through almost 4 feet of Pleistocene
to the basal conglomerate that here
n Colonankiionbna mn-ml tPMa follao 1a

LATE

CENOZOIC

GEOLOGY

Development-The

sandy

Caloosahatchee

marl

underlies

most

southern

Florida.

interfingers

with

or grades

into

Tamiami

formation at depth in a zone

possibly

40 miles

wide centered in

latitude of Fort

Lauderdale.

The

Caloosahatchee

underlies

most

tile Everglades and is present in the subsurface

between

Lake

Okee-

chobee

and

Atlantic

coastal

ridge.

is probable

that

it inter-

fingers with or grades into the

Tamiami formation

under the coastal

ridge in the vicinity

of West Palm Beach.

See section A-A

The Caloosahatchee marl is a littoral and neritic deposit

', Plate 25.
composed

sand,

silt,

clay,

shells,

and

often

enough

calcareous

material

make

a true

mnarl

sand or clay, but

. It

contains

usual

many

condition

local
just

beds
what

or lenses

one

would

pure

expect

a deposit where constantly shifting

currents acted

upon a shallow

sea bottom and shores
only fine sediments.

adjacent

a low

land

mass

that

contributed

Many

exploratory

wells

have

been

drilled

through

Caloo-

sahatchee

in southern

Florida.

Preliminary

study

cuttings

from

these wells indicates that it thickens to the east, southeast, and south.

It ranges from about 30 to 50 feet in

thickness

zone

where

interfingers

with

Tamiami

formation.

Water-bearing

characteristics-The

permeability

Caloo-

sahatchee

whole
wells

marl

varies

formation

ending

with
is of

in it yield

lithologic

relatively

no water.

low

Where

characteristics
permeability,

and

formation

some

is more

permeable,

hard;

and

inland,

near

around

coast,

Lake

water

Okeechobee

is apt

and

to be
upper

potable

part

Everglades,

the water is always hard and often so highly mineralized

as to

be unfit for

human

consumption.

These

variously mineralized

bodies of
invasions

water near the lake are

during

probably the

interglacial

stages

result

and

Pleistocene
subsequent

partial
during

flushings

glacial

dilutions

stages,

and

fresh

various

percolating

chemical

ground

reactions,

water

especially

base-exchange

variety,

that

have

taken

place

and

are

still

going on.

- ~. n -.

*~~~~~~ II~ CI~C

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

Caloosahatchee

River underlain

soft

clayey

marl

that

hardens

into limestone on exposure.

Ten

years later,

Mansfield

(1939,

11-16)

proposed

the name Buckingham limestone

for the

deposits

so mapped, which he retained in the upper Miocene and described

as "chalky

limestone

that

contains

a little

sand

and

many

small

grains of brown phosphorite."
Age and development-Mansfield'

identification of the Bucking-

ham

Miocene

was

based(

more

affinities

than

definitely

identified species.

In his list of

mollusks

(Mansfield, 1939, p.

the only

definitely identified

species

that

was supposed

to be

stricted to the Miocene is Chione ulocyma.

All the other previously

described

species

range

from

Miocene

Recent.

Comparison

Foraminifera

from

Buckingham

with

Caloosahatchee

faunas

leads J

A. Cushman to report that the Buckinghain fauna includes

species that are common to both Miocene and Pliocene, but none that

are definitely restricted to the Miocene.

. Storrs Cole, who examined

foraininiferal faunas from Buckingham and from the Caloosahatchee

River at stations 24 and 390

(see

pp. 84 and

83), reports that

would liave little hesitation in placing the Buckingham marl in the
Pliocene, as he found no species restricted to the Miocene. He identi-
fied Rotalia beccari tepida Cushman, Diocibicides biserialis (Cush-

man and Valentine)

Discorbis subaraucanus

(Cu shman)

Cibicidcs

lobatus
gerilna

gny

(Cushmunan)
occidentalis

, Elphidium
(Cushman).

, and Elphidium incertum

fiimbriatulum
Buliminella
(Williamson).

(Cushiman), Angulo-

elegantissima

(d'Orbi-

A well-preserved jaw bone of a whalebone whale collected at station
24 was examined by Remington Kellogg, who finds that it represents
an undescribed species whose affinities are closer to known Miocene

than to Pliocene whales.

This same relationship, however, exists be-

tween tlihe pelagic mammals of the early Pliocene Bone

Valley gravel

of Florida and the Miocene of Europe (Kellogg, 1924, p. 765)

as Kellogg

cites

European

Pliocene

faunas

containing

mammals, the basis for his statement that those in the Bone

though
pelagic
Valley

are older than Pliocene is not apparent.

*1n /

ii .- ,- *1.- /--1..- -._1 __n "- _P

LATE CENOZOIC GEOLOGY

Uneven weathering in the transition zone has locally given a false
appearance of unconformity to the contact between the Buckingham

and the overlying tongue of the Caloosahatchee marl.

On Caloosa-

hatchee

River east of

the mouth

Banana

Creek

and

elsewhere rain water and waves from passing boats have washed away
the less cohesive sand and shells from above the sticky, more resistant

Buckingham marl,

which

projects as an undulant shelf

just

above

water level. At first glance this uneven surface suggests unconformity,

but more careful

examination

shows

that

clayey

Buckingham

merges gradually upward into the sandy Caloosahatchee.

Well records show that the Buckingham commonly lies on sandy

Miocene limestone similar to that on which the Bone

Valley gravel

lies unconformably.

(Cooke and Mossom, 1929, p.

166)

The Buck-

ingham is overlain nearly everywhere by thin deposits of Pleistocene
sand.

The Buckingham marl extends southward from the type locality

through

Lee

and

Hendry

Counties

into

Collier

County,

Where

is cut into by shallow ditches along Florida Highway

164 as far as

a point 17 miles north of the

Tamiamil

Trail, south of which point

it is succeeded by the Tamiami formation into which it presumably

merges.

northward limits

have

been

accurately

traced

cause of the cover of Pleistocene sand.

Nearly

everywhere

green calcareous clay.

case-hardened

and

ie Buckingham
Where exposed

stained

into

marl

to the

light-brown

a creamy

white

weather it has

solution-riddled

been
limie-

stone.

This facies was more conspicuous at Buckingham before tihe

pit there had been deepened and widened to its present extent and

accounts

for the

name

Buckinghamn

limestone

originally

given

the formation.

A notable feature of
phatic grains within it.

the Buckingham is the abundance of

phos-

These are noticeable in the pit at Bucking-

ham and increase in quantity

and size

with depth. The abundance

of phosphatic grains allies the Buckingham

with

Bone

Valley

'-1* 1o fl T bn oi nhn oA 1f'- ini roto fo m Olih' ii'I-li

rrifno m I

fl17 ~ll tJl

1 1l ^1

*

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

Depth

Pamlico formation

Absent front this well but consisting of as much a,

to creamy gray sand

feet of gray

in other nearby wells.

Biuckingham marl:
C:ream-colored, shelly lna
grains at a depth of

feet,

more

marl

containing

small

10 feel, larger grains and

material.

30 percent of total sample, at bottom..

hosphatic
odules at
perhaps

0- 30

shelly
0 ..S S

plhosphatic

marl
S S S

plus
. . . .

greenish
S. S . .. . S

:ream-colored, shellyv phosphatic marl, no green clay, at

iHa\\thorn formation:

Greenish-gray
phosphatic

sandy
marl

limestone
probably

mixed
fallen

withI
from

cream-colored,

above)

colored near bottom

lighter
......45-111

If ater-bearing

characteristics-The

Buckinghami

marl

very

>oor aquifer.

It is so impernleable that it acts as a seal to the under-

Iyin g

more

1)ermeable

beds.

which

artesian

head

A few of the shellier and sandier parts of the Buckingham

vield
point
S-c~c
J)OI lt

relatively

smial

quantities

water

wells

equipped

with

or screens, but most of the residents of the Buckingham area

collect rain water in cisterns or use the artesian sulphur water from

deeper formations.

TAM1AMI FORMATION

Historical

summa ry--The

Tamiami

formation

Mansfield,

1939,

was first noted by Sanford

(1909, pp. 222-224)

who named it

the Lostmans River limestone from exposures near the head of tha

water course.

He noted that the formation underlies the gray sands

I now called the Pamlico formation)

that mantle the margins of

mainland, and that it also underlies the marls of the coastal swamps,

the keys of

the southern border of

Ten

Thousand Islands, and

that

extends

along

southwestern

order

Everglades.

He did not ascertain the relationship with the Miami oolite

eline

-n -. -\

(Pleisto-

but correctly thought that the oolite was younger.

-a r

C-

* T - 1 I E L ff &n r \ I I *

abundant

phosphatic

(:ream-colored,
clay at....

built up.

^

_

LATE CENOZOIC GEOIO(Y 63

CONTACT OF THE MIAMI OOLITE AND THE TAMIAMI FORMATION

Ig i *

PLATE 17

1F1(;ulE a- -- A dredged rock fragment along the South New River Canal sio\-
wn1 ,t rll rihl t n1lftr PR to tih, w\ itP r :rf :1 tlrt .ilo onf im IP IIt-

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

the road bed of the Tamianmi Trail over a distance of about 34 miles

in Collier and Monroe Counties, Florida.

This was the same lime-

stone that

Cooke and Mossom

(1928,

p. 207)

had

correlated

with

the Caloosahatchee marl.

Mansfield

(1939, pp. 8-10)

assigned it to

the Pliocene and placed it tentatively below the Caloosahatchee marl

and above the Buckingham marl.

He had never observed this re-

lationship but correlated it thus on the basis of fossils from a spoil
bank.

The

Tamiaini place name is preferred to Lostmans River because

the exposures on the

Tamiami Trail are much more accessible than

those of the Lostmans River area, and further, the rocks along the

Trail

are exposed

above

water in spoil

banks and

canals

whereas

Lostmans River

area

they

are submerged.

The

term

lile-

stone

is not

appropriate

because

the formation

generally

contains

too much sand.

Parker

(1942, pp. 64-66)

correlated the

Tamiami formation with

highly

permeable

rocks

underlying

Miami

oolite

Atlantic coastal ridge

that had

previously

been

variously

assigned

to tile Pleistocene or to the Pliocene.
Everglades and Big Cypress Swamp

He noted that in the western

Tamlniami formation

over-

lies the Caloosahatchee marl and on this basis arrived at the conclu-

sion that the

Tamiami is younger than the Caloosahatchee.

Subse-

quent study of well cuttings and the drilling of additional exploratory
test wells showed that there is also an interfingering or grading to-
gether at depth of these two formations.

De velopm ent-The

Tamiami

formation

composed

principally

of white to cream-colored calcareous sandstone, sandy limestone, and

beds and pockets of

quartz sand.

Where it is exposed on and near

the surface

in Monroe

and

Collier Counties

is grayish-white

tan and is riddled by solution holes,

which are usually filled with

marly soil.

To the east of its outcrop area the

Tamiami formation

slopes gradually under the Miami oolite, and for several miles the
contact of the two formations is visible in big pieces of rock dredged

from the

Tamiami Canal.

At times of

extreme low water this con-

.. .. .. L . .-. *1 .. .1 . L .. I -- 0 --- r L. ?--.L- tT -" ....

LATE CENOZOIC GEOLOGY

west it is about 45 feet thick; 8 miles west it is about 80 feet thick;
and near the shore of Biscayne Bay at Silver Bluff it is about 100 feet

thick.

On a line due south from the 19-mile point

(Kronie Road, 19

miles west of Miami)

Tamianmi

holds its

thickness of

feet,

neither thinning nor thickening as far south as Florida City, at least.

Due south of the outcrop area of the

Tamiami very little is known

of its attitude or lithology because of lack of reliable well cuttings.

Water-bearing characteristics-In thile vicinity of Miami the

Tarni-

alli is one of the most highly permeable formations ever investigated

by the

U. S.

Geological Survey,

and

ranks with

clean,

well-sorted

gravel in its property of transmitting water.

Tests made by two dif-

ferent

methods indicate

that

each

foot

mile

of hydraulic

gradient,

water will pass through a section of the formation a mile

wide and a foot thick at the rate of

about 20,000 to 40,000 gallons

a (lay,

or more.

Thus,

about

1,500,000

to 3,000,000

gallons

a day

would pass through a section

75 feet thick.

Many 6-inch

dianleter

wells along the coastal ridge from Miami to Florida City yield 1,000
gallons per minute without measurable drawdown.

Everglades

and

north

Fort

Lauderdale

Tamiianmi

formation contains more sand than to the south of Fort Lauderdale,

therefore

yields

generally

In the Fort Lauderdale area

lower

drawdown

wells are often finished

with

greater.
Ecreenls,

whereas

southern

and

eastern

Dade

County

most

wells

"open hole"

wells, i. e., uncased and unscreened in the last 5 to 20

feet of the hole.

The quality of

the water is very good except

where it

has been

contaminated by sea water in a zone about 2 miles wide along the

shore, in Miami, and in narrow tongues that follow up

the uncon-

trolled drainage canals

(Cross and Love,

1942;

Parker and

others,

1940; Parker and others, 1944)

Undoubtedly contamination has oc-

curred elsewhere along the southeast Florida coast as a result of drain-
ing the Everglades and lowering the fresh-water head, but detailed

studies have not been made north of Dade County.

It has been neces-

sary to abandon many wells in these areas of contamination.

are

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

grew along the southern

edge of

Floridian

Plateau

from

Miami

to Big Pine Key.

relate.

These formations have been

Many geologists have

worked

with

most

them

difficult to
he past, but

cor-

lack

sufficient

data

hertofore

been

principal

handicap

arriving

at the

conclusions

reached

by the

present

writers.

ANASTASIA FORMATION

Historical

summary-The

Anastasia

formation

was

named

Sellards
near St.
deposit
Mossomn

(1912)

from

typical

Augustine, Florida.

coquina

(1929,

rock

199)

development

He applied

found

along

expanded this to

name

East

include

Anastasia

to "the

Coast.

"all

Island,

extensive

Cooke
marine

and

posits
the ea

Pleistocene

st coast of Florida

County."
a strip of

that

north

In the geologic map
Anastasia formation

underlie

lowest

the southern

plain

part

bordering

Palm

accompanying their text they

along the

west

coast

of Florida

Beach
showed

as far

north
eludes

Pamlico

west

as Tampa

Bay.

coquina,

The

sand,

Pleistocene

coasts.

This

Anastasia

sandy

that

excludes

formation

limestone

along

surficial

and

both
sand.

as here

helly

defined

marl

; Florida
Pamlico

east
age.

pre-
and
The

upper

part

Anastasia

is contemporaneous

with

Miami

oolite, the upper part of the Key Largo limestone,

and the Coffee Mill

Hammock

marl

member

Fort

Thompson

formation

which might be considered as facies of the Anastasia formation.

The

lower part

probably is

contemporaneous with

lower

part of

Key Largo limestone and with the older marine members of the For

Thomp

formation.

Develop ent-On

the eastern

coast

southern

Florida

Anas-

tasia
Boca

composes

Raton

backbone

andi

extends

Atlantic

westward

coastal

Lake

ridge

north

Okeechobee-Ever-

glades

depression,

where

merges

with

marine

members

Fort

Thompson

formation.

wedge-shaped,

thin

toward

interior

and

thick

toward

coast,

where

may

as much

60 feet thick.
I ~ a- -f - A

On the west coast it is a very thin irregular deposit ex-

*II I- *-

n~ a nn

-- r

r, -t

n fl -.

*S S*11r11t1 I | I 'W| -USS-i *ll** i l-il Ii*Yll L *11 iii *U '* U i |~1 iil ira i* i

a -* n ab I nr a)

T.,1. 1

LATE

CENOZOIC

GEOLOGY

cites

Vaughan's

(1910,

169)

study

a fauna from a

depth

feet at Delray, and

concludes that it

"indicates a

considerable

thick-

ness of the Pleistocene and may well represent an
the Miami-Anastasia."

earlier stage than

Study of

cores and sand

cuttings from S-394, a

test well

drilled

1940 near the Delray Beach c
20 feet above mean sea level,

ity water tower, at an altitude of

gives the

about

following lo

Pamlico

formation

Quartz

Depth
(feet)
0- 10'

sand

Anastasia formation

Quartz sand
formation

Calcareous sandstone
Coarse coquina

Calc.
Calc.
Calc.
Calc.
Calc.
Calc.

sandstone and
sandstone

42 42.5
42.5- 43

coquina

sandstone and shell
sandstone

sandstone and
sandstone

shell

Cale. sandstone and shell

Calc.
Calc.
Calc.

Coquina
Chalky
Calc. sai

sandstone
sandstone
sandstone

limestone
ndstone

Shells and sand
Quartz sand and shell
Soft rock, shell, sand
Sand and shell
Soft rock, shell, sand

shell

- 93
.108
-108.5

108.5-109

135 .140

This

agrees

with

Vaughan

's log

except

that

"quicksand"

between 43 and 108 feet is represented here by

calcareous sandstone,

shell and sand.

The well

Vaughan reports may

have

been

drilled in

an old solution hole filled

with sand.

Water-bearing

characteristics-The

Anastasia formation

is a good

aquifer, especially in its consolidated

screened)

must
yield

- -

wells, may

with
arge

finished
usually 1

developed.

well
and 1

points or

- --

portions,

the

screen

drawdown

where open-hole

sandier

and

small.

gravel

The

portions

packs.

aualitv

(un-
wells

The
the

's, L

Tamiami

t

FLORIDA

GEOLOGICAL SURVEY--BULLETIN

and has a maximum surficial width of about 3 miles; however,

its base

oolite.

is much

wider

It rests on the

and interfingers at
Taniami formation

depth

with

and may

Miami

be 50 feet

more thick.

Its upper part is definitely

contemporaneous with

Anastasia formation and the Miami oolite, but its lower part is older
and underlies part of the oolite.

The limestone contains a large amount of

coral, andl

the spaces

between and around the coral heads are filled with amorphous lime-

stone or detritus from wastage of the reef

(Plate 18a)

. These frag-

ments apparently fell or were washed into holes, and were then in-
corporated in the rock as a limestone breccia.

Water-bearing characteristics-Solution holes and

caverns,

which

are common in the rocks, allow sea water to move freely in and out

permllit

rain water to escape

rapidly

to the sea.

The Key

Largo limestone yields water freely, but it is

salty.

About the only

use made of tile water is for fire-fighting or flushing.

MIAMI OOLITE

Historical summ nl8ary--The

limestone deposits of

southern Florida

were first noted by

U. S. Armv officers during the Seminole Indian

Wars.

Later, Buckingham Smith

limestone, and on the basis of

(1848)

a study of

noted marine shells in the
these shells dated the de-

posit

as post-Pliocene.

Tuomecy

(1851

described

outcrops

rock along Miami River, and Louis Agassiz

them

describing

Florida

reefs.

(1852
Shaler

gave an account

(1890)

accepted

tile views of

Louis Agassiz and regarded the oolite as having been

formed on a coral reef.

He included tile oolite with other rock, pos-

siblv coquina, in his Miami Reef.

Alexander

Agassiz

his observations of

(1895)

was next to describe the oolite.

outcrops along Biscayne

Bay

Miami

From
River

he came to believe that the oolite was formed by acolian processes,

and in a later paper (1896

he presented his reasons fully.

Griswold

1896i

examined these outcrops of'

the oolite, but he also examined

them

as miiuch

as 20 miles

inland, and from

his observations

COIl-

LATE

CENOZOIC

GEOLOGY

VIEWS OF

CUTS IN THE KEY LARGO

LIMESTONE AND MIAMI

OOLITE

PLATE 18

FIcUtIE a-A quarry in the Key Largo limestone shows the porous, solution-
pitted characteristics of this coral reef rock. Windley's Key,
Floridan.

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

De velopm en t-The

ridge from a

Miami

transition zone

oolite

near

underlies

Boca Raton

Atlantic

to Florida

coastal

City

floors

Bay

Florida

and

reappears

above

water

level

once

again in the lower keys from Big Pine Key to and beyond Key West.
It is thickest along the coast, possibly reaching a maximum thickness
of 40 feet in places, and thins out in the Everglades to a feather edge.

To thle north and northwest the Miami oolite thinly overlaps the

Fort

Thompson formation and in some places is itself

overlain by

a thin fresh-water marl and limestone.

This latter relationship led

Parker

(1942)

and

possibly

Richards

(1938,

1280)

that at least part of the Fort Thompson formation is younger than

the Miami oolite.

However, the youngest fresh-water marl and lime-

stone is now classified as Lake Flirt marl,

very

late Pleistocene or

Recent in age.

The contact between the Miami oolite and the underlying Tamiami

formation is visible

in many places in

Everglades and in

southeastern part of the Big Cypress.
on a clean, solution-pocked surface

The contact (Plate 17) is often

calcerous

sandstone,

many places a limestone breccia or conglomerate separates the two.
This breccia is probably a result of erosion, solution and redeposition
that took place in some of the Pleistocene glacial or interglacial stages
preceding the deposition of the Miami oolite.

The Miami oolite is soft, cross-bedded to massive, and grades from
ahnost pure calcium carbonate to sandy limestone, becoming sandier

northward.

The

gradation

sandvy

Anastasia

formation

visible along the Hillsborough Canal a few miles west of Deerfield.

The

occurrence (
cross-bedded

large,

portion

well-developed

is notable.

cone-in-cone

Tarr

reports

structures

(Twenhofel,

1932) that heights of cones in limestone range from 1 to 200 milli-
meters; that those from 10 to 100 millimeters are most common, and

that

basal

diameters depend upon the heights and

angles of

slope

of the cones.

The cone-in-cone structures in the Miami oolite are all

suppose

LATE CENOZOIC GEOLOGY

Study of the structure of the oolite throughout its areal distribution

indicates

right.

that

both

Apparently

Alexander

steeply

Agassiz
dipping

and

Griswold

450)

were

partly

cross-bedded

portions are remnants of

calcareous dunes or

beach

ridge

posits, and the parts that are massive or have low-pitched dips and
contain numerous marine fossils are marine. Stearns (1943) observed
that the cross-bedded parts of the oolite are counterparts of Pleisto-
cene calcareous dunes as found on Maui, T. H., and elsewhere in the
Pacific.

some

places

steeply

dipping

cross-bedded

portions

truncated by horizontal beds including numerous marine shells.

The

occurrence suggests fluctuating sea level at the time of deposition so
that the ocean rose above previously deposited dune or beach ridge
material on the low oolitic bar, and new deposits of the same nature

containing marine

animals

were

laid

down.

Near the

large
oolite,

western shore of Biscayne

pieces

proof

cross-bedded

that

oolite

previously

formed

Bay

at Silver

embedded

oolite

was

Bluff

several

structureless

broken

away,

washed into the sea, and incorporated into the latter portions of the
deposit.
This might indicate that conditions were right for the formation
of oolite in this area during parts of two or more interglacial stages,
or it may simply indicate that calcareous dunes formed in an early

part of a stage were later attacked

(after consolidation)

and incor-

porated in the later-formed portion, all occurring within one stage.

The oolite is the product of

deposition in a marine environment

on a shoal or bar just about at sea level, so that at times and in cer-
tain places calcareous dunes or beach-ridge deposits may have been

built up above sea level.

Most of the building of this bar probably

took place in the Sangamon interglacial stage either at the beginning

of the stage (early Wicomico time)

or at the end

(near the close of

Talbot), or both.

However, the

basal

parts of

the oolite

may

represent low-sea-level deposits of the older

Pleistocene interglacial

stages.
rr *s * F1 1 *. - 1

FLORIDA

GEOLOGICAL

SURVEY-BULLETIN

VIEWS SHOWING DEVELOPMENT OF THE
FORT THOMPSON FORMATION

t:~t "1*
., -"
.: .1

-- -~~-2:

~3 "'i
* .0 o -
;,i;rr~~.
;c

:. t ..;
ya.' -

.* .;~ LC.F=:
.,y.,i
-L:'
I

I -
a9

PLATE

FIGURE a-View showing general development
tion across the Caloosahatchee R

of
ive

the Fort Thompson forma-
r from the type locality.

=

LATE CENOZOIC GEOLOGY

FORT

THOMPSON

FORMATION

Historical summary--Sellards (1919, pp. 71-72) proposed the name

Fort

Thompson Beds for the alternating fresh-

and

brackish-water

and marine shell marls and limestones typically exposed at old Fort

Thompson, about

miles east of

LaBelle.

noted

that

these

beds

underlie

a persistent

marine

shell

bed,

which

called

Coffee Mill Hammock marl from its typical development at Coffee
Mill Hammock about one-fourth mile west of the Atlantic Coast Line

railroad bridge at Goodno.

Cooke and Mossomn

1929, pp. 211-215

changed the name Fort Thompson beds to Fort Thompson formation,

and included the Coffee Mill Hammock marl in it.

They indicated

that the Fort Thompson lies unconformably on the Caloosahatchee

marl Pliocen
Recent age.

and is overlain by the Lake Flirt marl, of probably

This definition is followed in the present paper.

Development--The

Fort

Thompson

formation

thin,

not over 20 feet in its greatest thickness, and it averages

probably
less than

10 feet. It has its typical development at the site of old Fort Thomp-

son, between LaBelle and Lake Flirt,

where a thickness of

about 6

feet of alternating fresh-water and marine beds is exposed (Plate 19).
The beds differ in thickness from place to place within a very short
distance, and some may be altogether missing or only preserved in

solution holes in a lower bed.

Sections at Station 325 and at Station

(pp.

89 and 90)

indicate the lithologic composition along that

stretch of the river where the Fort Thompson formation has its best

exposed development, and they are typical of the formation

all or most of its members are present.

where

The inequalities of the sur-

face of the underlying Caloosahatchee marl give unequal thickness

to the Fort

Thompson, since it usually is thicker in the

low parts

and thinner on the high parts.

The

Fort

Thompson

formation

extends

eastward(

westward

from the type locality

but has only

a limited

development

west where, beyond

tron;

floors

Denaud,

Lake

merges

with

Okeechobee-Everglades

Anastasia
depression

forma-

south as the latitude of Fort Lauderdale and as far east as the Atlantic

e)

FLORIDA

GEOLOGICAL SURVEY-BULLETIN

However, the present writers favor the view that they represent al-
most uniform deposition over the inequalities in the Pliocene floor
on which they were deposited, possibly modified by sagging where

ground

water has removed soft calcareous marl

that gave support

to the overlying less-soluble beds.
beds lie almost perfectly flat for

In some areas the Fort Thompson
miles; however, since in most of

the area of its development the Fort Thompson formation is covered

with water, peat and muck, or sand, the structure of

the beds can

not be ascertained definitely.

Water-bearing

characteristics-Stringfield

(1933)

first

reported

on the water-bearing characteristics of the Fort Thompson formation.

is a

poor

aquifer;

its limestones

are

dense

and

hard,

and

calcareous muds or marls have very

low permeability.

The

freest

movement of water is in the sand and shell beds, but these commonly

have a low coefficient of
fine sand, silt and clay.

permeability because of the admixture of

Water is apt to be of

poor quality because

of residual mineralization from various invasions by the sea of the
area underlain by the Fort Thompson during the several interglacial

stages. Chloride ranging from 16
some of the exploratory test wells

to 3150 ppm. has been found in

(Parker and Hoy, 1943).

Treasury standards allow maximum chloride of 250 ppm in public

supplies,

and

most

people can

definitely taste

400-500

ppm.

The

fact

that some

wells drawing from

Fort

Thompson

formation

find usable water is due to the circumstance of having been drilled
in more permeable beds that were flushed of their highly mineralized

waters.

Heavy pumping on certain of these wells, however, has caused

mineralized water to be drawn in from adjacent mineralized zones,
and some of the wells had to be abandoned.

PAMLICO FORMATION
Historical summary-The Pamlico formation was named by Ste-

phenson

(1912, pp. 286-290)

Carolina, of fine sandy

and described as consisting, in North

loans, sands

and

clays,

and,

limited

extent, gravels.

The surface of these deposits forms a

nearly

level

wi1,.;k arlnn- ,014 i n,,, 1 n--n,, nf.l_ 1 i -.- 1 _A1_1- . _-_. . -1- nt .

LATE CENOZOIC GEOLOGY 75

the Pamlico formation into Florida and include in it all marine
Pleistocene deposits younger than the Anastasia formation. The
Pamlico generally lies at altitudes of less than 25 feet above sea
level on the east, south, and west coasts of Florida, and consists
chiefly of sand (Plate 3). Where dunes or beach ridges were formed
above the Pamlico shore line the deposits are higher than 25 feet.
Development-The Pamlico formation in southern Florida grades
from almost pure quartz sand to sandy shell deposits, which are locally
consolidated. The sand grains range in size from very fine to coarse
with medium-sized grains predominating. Most of it is white, though
in some places, especially in old spillways from the Lake Okeechobee-
Everglades depression, the sand is commonly stained black by an
organic material on the surface of the grains.
The Pamlico deposits extend down the east coast to Coral Gables,
mantling the Atlantic coastal ridge, and are in places overlapped by
Recent muck, marl, or sand beds. Pamlico sand is present on the
western fringe of the Everglades almost to the latitude of Fort
Lauderdale and mantles a large part of the surface of the western
part of southern Florida, including the northern part of the Big
Cypress. The formation usually does not extend above the 25-foot
contour, which was the approximate location of its shore line. The
Pamlico extends from the Gulf coast eastward up the Caloosahatchee
River Valley, where it is present except in abandoned cuts or fills
of the Caloosahatchee River. It is generally covered by muck, marl
and organic material in the swampy area near Lake Okeechobee.
Along the coasts it is in places preserved in dune form. The thick-
ness ranges from a feather edge to possibly 50 feet; the greatest thick-
ness being in the old beach ridges now surmounted by quiescent
dunes.
Water-bearing characteristics-The Pamlico formation is the source
of many small domestic water supplies along the coasts of southern
Florida. They are usually obtained by driving sand-point wells of
small diameter. The quality of the water varies in different localities
depending upon whether it has flowed through organic soils or sand.
Usually the water is good when derived from the sand distant from
swamp deposits.

TALBOT AND PENHOLOWAY FORMATIONS

Historical summary-The Talbot formation was named by Shat-
tuck (1901, pp. 73-75) after Talbot County, Maryland. The formation
is now recognized as extending from 'Delaware into Florida.
The name Penholoway was first applied to a terrace by Cooke
(1925, pp. 24-26; 1931, pp. 509-510) who later (1932, pp. 5, 8) ex-

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

VIEWS OF TALBOT TERRACE AND OF SCARP LINE WHERE
IT ABUTS UPON THE PENHOLOWAY TERRACE

vrr!~.:~
"5'

I a.
-":-t

PLATE 20

FIcGtRE a-Sandy flatlands developed on the Talbot terrace near the inner
boundary with the Penholoway terrace. Looking south from
Florida Highway 18, the Okeechobee-Arcadia road, about 4
miles west of the Kissimmee River.

FIGURE b-Inner boundary of the Talbot terrace where it adjoins the
Penholoway terrace. The scarp here is plainly visible. Along
the scarp line a woody-peat deposit is developed in the old
lagoon that once occupied this zone. This old shore line with
most of its features is plainly visible from the air, and still
looks like many modern sandy shore lines. Looking west along
Florida Highway 18, 3 miles east of Childs.

u,
~ 'i

:'; , '
.. .r

-.;i
:...~?. :0~. ; ;::

LATE CENOZOIC GEOLOGY 77

tended the name to the deposits formed when the Pleistocene sea
stood 70 feet above the present level. The name is derived from
Penholoway Creek in Georgia.

Development-The Talbot, Penholoway, and Wicomico formations
comprise a conformable sequence of deposits whose differentiation
is based mainly on the location of their respective shore lines, namely,
42, 70, and 100 feet above present sea level (Plates 2 and 3). Pre-
sumably the Penholoway everywhere merges downward into deposits
of Wicomico age, and the Talbot into Penholoway and Wicomico,
successively. The surficial deposits consist mainly of poorly sorted
gray to white quartz sand of various degrees of fineness and angu-
larity. Below the surface, the sands are gray to orange, tan, and
brown. In some places iron oxide has stained and cemented the
grains to make a hard reddish-brown to black sandstone.
The sequence unconformably overlies the Caloosahatchee marl.
It is likewise separated by a stratigraphic break from the Pamlico
formation, which fringes around it. Because the terraced surface
was very slightly dissected in this region before the invasion of the
Pamlico sea upon it, the boundary between the Pamlico formation
and the Talbot formation is very inconspicuous. The scarp at the
shore line of the Talbot terrace is very noticeable in many places,
and is seen to good advantage where one crosses it on Florida High-
way 18, the Childs-Okeechobee road (Plate 20b). The Talbot forma-
tion occupies Immokalee Island (Plate 3).
North of Caloosahatchee River there is a wide lobe of the Talbot
and Penholoway formations west of Lake Okeechobee. Another
lobe northeast of the lake extends almost to the latitude of Canal
Point. The boundary between the Talbot and the Pamlico forma-
tions is more conspicuous west of Stuart and Salerno, where it was
probably steepened by wave erosion. Streams, such as Fisheating
Creek, Taylor Creek, and Kissimmee River cut into these lobes and
occupy wide indentations in their borders. Old bars and inner lagoons
exert primary control on the direction of flow of surface runoff. and
are responsible for the existence of certain of the sloughs or sales
now filled with organic soils.
Water-bearing characteristics-Little is known of the water-bear-
ing properties of these formations, inasmuch as the present ground-
water investigation has not been concerned with the area in which
they occur. The area is sparsely inhabited, and most supplies are
obtained by driving wells of small diameter equipped with well points.

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

VEHICLES OF TRANSPORTATION USED IN THE EVERGLADES

,,/ .:/, /.i r! '' i i~ -'.I

t b m
.. : - .

PLATE 21

FIGURE a-A "glades-buggy" used to transport men and equipment over
the swampy soils covered with marsh plants, especially saw-
grass (a sedge, Mariscus janwmaicensis). These vehicles have a
wide bearing surface of many tires. Designed and built by
the Soil Conservation Service.

FIcGURE b-An "air-boat" used in those parts of the Everglades too wet to
support a "glades-buggy" or a tractor with wide-cleated treads.
A pusher-type propeller scoots them over weedy water at speeds
up to about 35 miles per hour. Designed and built by the Soil
Conservation Service.

LATE CENOZOIC GEOLOGY

CORRELATION STUDIES

General statement-Good exposures of rock are scarce in southern
Florida except during short periods of extreme low water. Continu-
ous exposures are rare; the land is so flat and the water table so high
that only a few feet of rock is exposed anywhere; indeed, most of
the exposures are in canal and spoil banks. Correlation of strati-
graphic units must therefore depend largely upon studies of data
gathered by drilling exploratory test wells. Both surficial outcrop
and exploratory test-well data have been fully utilized in these
studies, but neither is wholly reliable.

Changes in lithology often take place rapidly both horizontally
and vertically. The area has long been one of shallow-water deposi-
tion with shifting shore lines and currents. Bays, lagoons, and
estuaries with silty, clayey or marly bottoms and mangrove-covered
shores alternated with open sandy shore lines. On the very gently
sloping surface of the Floridian Plateau slight shifting of sea level
caused the shore to migrate many miles and thus brought about the
re-establishment of shore line features many miles away. Under
these conditions areas that had lately been under a marine environ-
ment became, with a drop in sea level, a part of the fresh-water
province in which marls or sands of fresh-water origin were laid
down. With even a slight rise in sea level great areas of land and
fresh-water marshes once again came under marine influences.
Furthermore, the swinging of the shore line back and forth over
southern Florida not only brought about a deposition of sediments
in any given place peculiar to the conditions prevalent there, but
caused a mixing of previously deposited materials with those being
deposited.

The changes of shore line have tremendously influenced the faunal
distribution. Ecologic conditions resulted in a number of dissimilar
faunas living not far apart; the fauna of an open sandy beach was
considerably different from that along a marshy mangrove shore;
that of a shallow ocean bottom was different from that of a shallow
brackish bay bottom; that of a tidal lagoon was different from that
of a coral reef. In addition to these original differences in faunas
a considerable amount of mixing of faunas has resulted from the
several advances and retreats of the sea, and from the action of hur-
ricanes, which whip up huge storm waves that thoroughly scour the
shallow sea bottom, and which, by shifting bars and sediments about,
as well as the faunas thereof, may actually change ecologic conditions.
Too, hurricanes often cause the flatlands to be inundated temporarily
by salty water, thus bring about the death of countless fresh-water

I FLORIDA GEOLOGICAL SURVEY

LOCATION OF STATIONS USED IN CORRELATION STUDIES ALONG CALOOSAHATCHEE RIVER

BUL'LET IN 27. PLATF.r 2'"

LATE CENOZOIC GEOLOGY

mollusks and sweep their shells into the ocean or bay, where they
mingle with those of marine animals. Floods caused by heavy rains
may likewise sweep fresh-water animals into marine or brackish
water and bring about their death.
Fossils in southern Florida are generally so perfectly preserved
that it is not uncommon to find them in better condition than many
shells picked up on existing beaches. Some Caloosahatchee fossils
(Pliocene) still retain their color. At the present time fossils are be-
ing washed out of Pleistocene and Pliocene sediments and are being
incorporated in modern deposits. Doubtless such mixing of faunas
took place in each succeeding deposit, at least since the Eocene. Cole
(1941, pp. 12-16) cites evidence of reworking of foraminiferal faunas
from mid-Eocene deposits by the Oligocene sea. Another method of
mixing is by the intrusion of later shells into solution holes or caverins
(see p. 89, fig. 4, and PI. 19b).
These conditions may be recognized and due allowance made for
them in the study of outcrops, but where it is necessary to rely upon
well cuttings and their fossils the task is more difficult. Cuttings from
many wells contain only long-range fossils; the well cuttings are such
a small part of the total formation that chances of getting representa-
tive fossil sampling are slight. Micro-faunas offer much better sam-
pling coverage, but owing to the conditions enumerated above they
are none too reliable in southern Florida.

SECTIONS ON AND NEAR CALOOSAHATCHEE RIVER

Exposures are almost continuous along the Caloosahatchee River
and Canal from Ortona Lock to Caloosa, below which the banks arc
very low. To study them adequately a boat traverse must be made
because of the rapid lithologic transitions. All of the following sec-
tions are in the river or canal banks except the first two, which are in
rock pits not far from the river.
Station 26-Buckingham pit, a borrow pit on south side of Florida
Highway 26 about half a mile west of Orange River near Bucking-
ham. This is the type locality of the Buckingham marl. Estimated
height of the land surface about 9 feet above low tide level in Caloosa-
hatchee River.

SECTION
Feet
Pamlico formation:
2b. Gray quartz sand 1/
2a. Brown quartz sand 1

81

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

Feet
Buckingham marl:
Ib. Tan-brown limestone, hard, irregular 1
la. Soft white to creamy fossiliferous
calcareous clay marl, contains brown
grains of phosphate; practically im-
permeable. To water level in pit 21/
Most of the fossils at Buckingham are preserved as casts or molds.
The ones commonly retaining their shells are species of Ostrea,
Anomia, and Pecten. Most of the Turritellas are strongly compressed.
The species are listed by Mansfield (1939, p. 11).
Station 365-Caloosa pit, an old borrow pit 0.2 mile south of Flor-
ida Highway 292 on the river road to Heitman Groves No. 3. This
road is 2.3 miles west of the bridge at Alva. Land surface about 71/%
feet above low tide level in Caloosahatchee River.

SECTION
Feet
Pamlico formation:
2b. Gray quartz sand 1/
2a. Brown to black carbonaceous sand %
Buckingham marl:
1. Creamy clayey marl with a few chunks
of nodular limestone and many phos-
phatic grains. The same fossils as at
Station 26. To water level in pit 5%
Station 363A-Alva, Florida, on left bank near southwestern corner
of southern bridge abutment.

SECTION
Feet
Pamlico formation:
2. Grayish-white quartz sand 1%
Buckingham marl:
lb. Tan-brown hard limestone ]/4-
aI. Creamy-white soft calcareous clay marl
or marly clay, as at Station 26. To low
tide level 11
It was near Alva that Dall (1892, p. 146) first noted that "The
uppermost strata of the Pliocene begins to appear above the level
of the river at low water .. "
Station 25-Right bank, across the river from the main grove
buildings at Floweree Grove. This is the place about which Mans-
field wrote (1939, p. 15) "The information so far obtained indicates
that the Buckingham limestone forms an arch that crosses the
Caloosahatchee River, the highest point of the arch being near
Floweree Grove." Top of bank about 61/2 feet above low tide level.

365

EXPLANATION
---- TOP OF LAKE FL RT MARL O"
TOP OF PAML/IG FORMATION (AND RECENT SANDS/ "QOp"
TOP OF FORT THOMP$ON FORMATION '*Qf
T OP OF ALOOSAHATQHEE MARL 'Pc'
------ TOP OF UCKINGHAM MARL "Pb"

go n* *m 9f
U-~s ...U,.
-'S U- U- U

SCALE IN MILES, BETWEEN LOGS
. . . . . . . . . . .. .: .i .

!1

2

SOp
00V00

LOGIC SECTION Al

RIDA GEOLOGICAL SURVEY

26

z

ax
ss

12

3"A

4

w
.J

C

2S

W w
o >
J ^

3

4

Pb

0

- .. ---. -- ---- - - ------- --r---~ --------.--~---- ---;----: ---- ----. -- -- -- ----- ---

358 24

49
4t w
Z w

386

384

a

h
a

20

ao

350

345

U

to
g

318
.w
hi
4

320

322 325

U)
0.
0
S ?L

LONG THE CALOOSAHATCHEE RIVER FROM

BUCKINGHAM TO
o . . . . .. . _

ORTONA

LOCK, FLORIDA,

14 330

327
z w
W x
J o.
(0 w

(0

02~p

C-C'

I

_ _

_ --- -- --

BULLETIN 27. Plate 23

322 325 327 14 330
z a U)
o zw

U o 0 U 0
= w
I- ...O
rn wYoz

332 334

IN THIS AREA THE LAKE
FLIRT MARL IS MIXED WITH
SAND OF THE PAMLICO FORMATION
A"-"-'=---- ---"--- "

338

341 343 343A
x 02

S<, oj

LEGEND

SAND

l LIMESTONE
t MARL

CLAY
MUCK
E SHELL BED
j SHELL MARL

SSHELLY SAND
I SANDY LIMESTONE
^ CLAY MARL
SANDY CLAY MARL
SMARLY CLAY

SMUCKY SAND
E 0 MARLY SAND
J SHELLY LIMESTONE

S SANDY CLAY
COVERED
SBASAL CONGLOMERATE
BLACK CARBONACEOUS
SAND

INA LOCK, FLORIDA, C-C'

LATE CENOZOIC GEOLOGY

SECTION
Feet
Pamlico formation:
3c. Gray quartz sand 1
3b. Black carbonaceous mucky sand 10/
3a. White marly sand 1/
Caloosahatchee marl transitional to Buckingham marl:
2. Grayish-green to brown quartz sand,
white oti surface due to wash from
marly sand above l1/'
1 Creamy-white sandy clayey marl, like
that at Station 26. To low tide level 2
Speaking of this same station, Mansfield (1939, p. 14) says: "Th'l
top of the Buckingham limestone is about five feet above water level
at Floweree Grove ." The writers visited this station at extreme
low tide during the dry season and found only 21/2 feet exposed at
the crest of the "arch." It appears likely, therefore, that Mansfield
included the overlying beds, No. 2 and No. 3a (section above) in his
Buckingham. This "arch" is apparently not constructional but is
produced by differential erosion in beds, the lower one of which is
clayier than the upper.

Station. 390-Goober Farm (also known locally as the "Turkey
Farm"). Station is at west end of an old cut-off at a point where it
joins the dredged section of the Caloosahatchee. Two small drainage
ditches from the groves empty into the river at this point. A fairly
complete whale skeleton was discovered at the base of this section.
Top of bank about 10 feet above low tide level.

SECTION
Feet
Pamlico formation:
4b. Gray quartz sand 11/
4a. Cream to brown to white sugary quartz
sand with lenses of black carbonaceous
to mucky sand 2
Fort Thompson formation:
3. Basal conglomerate containing mixed
fresh water and marine shells in
pockets 1/4 to %/0
Caloosahatchee marl transitional to Buckingham marl:
2. Gray-cream sandy marl as at Station 24.
Weathers out at base to give appear-
ance of being deposited on an uneven-
ly eroded surface. This is only superfi.
cial, however, for there is very little
difference between sediments above
and below this line except that there is
more clay in the lower part 3%1/ to 41/2
1. Creamy-white clayey marl, as at Sta-
tion 26 and 24. To low tide level 21/ to 21/1

83

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

Station 358-Left bank of Caloosahatchee River about 1/ mile up-
stream from mouth of Ft. Simmons Branch. Top of bank about 8
feet above low-tide level.

SECTION
Feet
Pamlico formation:
5d. Gray quartz sand 2-1'
Sc. Black carbonaceous sand
5b. Gray to tan quartz sand 2
5a. Black carbonaceous sand
Fort Thompson formation:
4. Gray sand and broken marine shells 0-%
3. Basal conglomerate or remnants of
former thin hard limestone bed. Thin
layer of Rangia cuneata shells above
and mixed in with the rounded lime-
stone cobbles 1
Caloosahatchee marl transitional to Buckingham marl:
2. Grayish-cream sandy clay marl 2/%.3%
1. Gray-tan.cream marly clay that disap-
pears below water level a few feet
west. To low tide level 0-1%
Station 24-Left bank of the Caloosahatchee River about 120 yards
upstream from the mouth of Banana Creek. Top of bank about 13
feet above low-tide level.

SECTION
Feet
Pailico formation:
5b. Gray quartz sand 2
5a. Black carbonaceous sand %
Fort Thompson formation:
4. White, gray to orange sand, marly in
places 1%
3. Basal conglomerate
Caloosahatchee marl transitional to Buckingham marl:
2b. Gray-cream sand 4
2a. Gray-cream sandy clayey marl; con-
tains cetacean bones 3%
1. Greenish-gray marly clay, very finely
sandy, contains cetacean bones. To low
tide level 1%
As at Station 390 there is a differential weathering process which
proceeds at uneven rates between beds 1 and 2 due to differing amount
of clay in the sediments. A fresh cut right across this false erosionall
unconformity" shows no change in lithology, nor are the fossils dif-
ferent; they are the same here as at Buckingham (Station 26) and at
other stations to the west. Samples taken 11/2 feet, 4 feet, and 8 feet
above low-tide line at Station 24 contain Foraminifera that have
been identified by J. A. Cushman as species that are common to both

LATE CENOZOIC GEOLOGY

Pliocene and Miocene but none that are definitely restricted to the
Miocene. Foraminiferal faunas from samples taken at 0, 2.5, 4, and
5.5 feet above water level were later examined by W. Storrs Cole. His
findings corroborate those of Cushman.

Station 385-Denaud, Florida, right bank near northwest corner
of northern bridge pier. Top of bank about 81/2 feet above low-tide
level.
SECTION
Feet
Pamlico formation:
5. Black carbonaceous sand 1
Fort Thompson formation:
4. Gray fresh-water calcareous marl 1/
3. Marine shells and fine sand, locally
mixed with bed 4 1
Caloosahatchee marl transitional to Buckingham marl:
2. Hard gray nodular sandy limestone
and shells; indurated, weathered, and
perforated by solution holes. Upper-
most portion makes a ledge, and
younger material from above fills
solution holes in it 4
1. Soft sandy marl, appears to grade up-
ward into Bed 2. To low tide level 1
Station 384-Walker farm, 0.7 miles east of Denaud store by way of
old road to LaBelle. Station is on left bank of Caloosahatchee River
about 50 yards east of Walker house. Top of bank about 10:3 feet
above low-tide level.

SECTION
Feet
Pamlico formation:
6b. Gray quartz sand 14-2
6a. Black carbonaceous sand 1-1%
Fort Thompson formation:
5. Marine shells 0-.
4. Grayish-white sandy marl 2-2%
3. Hard, tan, fresh-water limestone ledge;
may be equivalent of basal conglomer-
ate at other stations. Some parts en.
tirely separated from others and
rounded by solution %
Caloosahatchee marl transitional to Buckingham marl:
2. Shell marl, hardened in places to a
calcareous sandstone with nodular
structure. Many coral heads. Toward
base many fresh-water and land shells.
At contact with bed 1 an oyster bed
overlies a Barnea zone 5
1. Whitish marly clay. Fossils as at Buck-
ingham outcrops. To low-tide level 1

85

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

It is worthy of note that here, as elsewhere, the beds vary greatly
in a short distance, and rise and fall with respect to water level. For
instance, in less than 50 yards to the west bed 1 dips completely out
of sight below water level, and all the rest of the beds lose altitude
likewise; bed 3 is discontinuous; bed 5, about 15 or 20 yards west,
contains a few cobbles of rounded, fresh-water limestone, probably
remnants of a former thin overlying bed.

Station 20-LaBelle Chamber of Commerce Picnic Grounds. Two
miles southwest of Court House by Florida Highway 25, thence 0.6
mile by Denaud Road to entrance to grounds. Top of bank about
9 feet above low-tide level.

SECTION
Feet
Pamlico formation:
5b. Gray (quartz sand /2
5u. Black carbonnceous sand '/2- 1'
Fort Thompson formation:
4. Marine shells (more or less mixed
with overlying sand in many places) 1~/l
3. IaIrd tan-to-gray limestone ledge A-l
Caloosahatchee marl:
2. Hard nodular sandy, shelly limestone;
probably a consolidated shell marl
altered by solution and redeposition 2
1. Creamy-tan shell marl, weathers out
very rough on exposed surfaces. An
excellent area for collecting Caloosa-
hatchee fossils. To low-tide level 4

This station is located in an area where wide variations in lithology
are common. In some places nearby the entire Pliocene section con-
sists of soft unconsolidated shell marl; in other places the top layer
of ledge rock is entirely missing, or is represented merely by scattered
cobbles. The Caloosahatchee contains many coral heads at this station
and nearby.

Station 350-Right bank of Caloosahatchee River at a point a few
yards west of the mouth of Bee Branch, about 11/2 miles west of
LaBcelle. Top of bank about 81/2 feet above low-tide level.

SECTION
Feet
Pamlico formation:
7. Gray quartz sand and marine shells 2%]
6. Black plastic muck 1/1

LATE CENOZOIC GEOLOGY

Feet
Fort Thompson formation:
5. Gray calcareous fresh-water marl in
places stained black from overlying
muck %
4. Black carbonaceous sand
3. Marine shell bed mainly preserved in
solution holes in underlying rock 0.1
2. Fresh-water limestone layer riddled by
solution holes generally filled with
marine shells 1
Caloosahatchee marl:
1. Grayish-cream shell marl with oyster
zone at top and bottom. A good fossil
collecting station. To low-tide level 2

Station 345--Right bank of the Caloosahatchee River about % mile
west of the bridge at LaBelle. Top of hunak about 121/% feet above low-
tide level.

SECi(:TION
Feet
Pamlieo formation:
3d. Gray quartz sand 1%
3c. Black carbonaceous sand /
31. Tan sand grading down into grayish-
white sand 21
3a. Black carbonaceous sand 1
Fort Thompson formation:
2. Marine shells, somewhat mixed at base
with sand from bed below 1
Caloosahatchee marl:
1. Grayish.green or light greenish-gray
sand containing considerable calcare.
ous material and a fine assemblage of
Caloosahatchee fossils. A Vermicularia
zone is prominent here 2%
Covered by talus. To low-tide level 21

Station. 318-Right bank of Caloosahatlchee River about 75 yards
east of the bridge at LaBelle. lop of bankk about 131/ feet above
low-tide level.

SECTION
Feet
Pamlico formation:
5c. Gray quartz sand /
5b. Black carbonaceous sand, unevenly
distributed laterally A
5n. Gray quartz sand mingled with black
carbonaceous material 2.3
4. Black carbonaceous sand that follows
the old erosion surface on top of the
underlying Fort Thompson

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

Feet
Fort Thompson formation:
3. Broken marine shells underlying and
in places mixed in with carbonaceous
sand above 0-1
Caloosahatchce marl:
2. Greenish-gray clayey sand or marl. Very
few fossils 61/2
1. Stratified greenish sandy clay; no fos-
sils. To low-tide level 21/

Station 320-Right bank of the Caloosahatchee River 0.7 mile east
of bridge at LaBclle. Top of bank about 9 feet above low tide level.

SECTION
Feet
Panllio formation:
5c. Gray quartz sand 1/.34
51. Black carbonaceous sand 0.1/4
5n. Gray quartz sand 2-21/
Fort Thompson formation:
4. Fresh-water shell bed 0.1/4
3. Marine shell bed. In places the fresh-
water shells from bed 4 are mixed in
with the marine shells 0.1/
Caloosahatchee marl:
2. Gray-cream calcareous shelly marl,
with a few lenses of clayey marl; a
hard, irregular, calcareous sandstone
layer near the base 2-2%
1. Greenish-gray marly clay; no fossils
noted to low-tide level 31/%

Station 322-Right bank of the Caloosahatchee River about 11/
miles cast of the bridge at LaBelle. At this point the first hard lime-
stone ledges of the Fort Thompson formation appear. Top of bank
about 9 feet above low-tide level.

SECTION
Feet
Lake Flirt marl and Pamlico formation:
7. Black carbonaceous sand %
6. Gray quartz sand with admixed fresh.
water shells. Apparently this resulted
from a mixture of materials by waves
of a fresh-water lake working on a
floor of Pamlico sand 1%
Fort Thompson formation:
5. Marine shell bed 2
4b. Fresh-water hard limestone ledge l
4a. Fresh-water soft calcareous marl 3
3. Marine shell bed 34

LATE CENOZOIC GEOLOGY

Feet
Caloosahatchee marl:

2. Consolidated shell marl of linearly
aligned concretionary structure con-
taining an excellent fauna of Caloosa-
hatchee fossils 1/
1. Creamy-gray shell marl, to low-tide
level 21/2

Station 325-Type locality of the Fort Thompson formation. Left
bank of the Caloosahatchee River near site of the old fort, 1% miles

STA, 325

25 FT.

"------ ---------- -------- T'--. -r- ---9----L-- T -- "-T

cl1 SPOIL. DREDGED OUT IN DEEPENING ,,^"-, .j MARINE SHELL BED WITH MIXTURE
Sb

6 5b 6 6 Sb
'6

66

LOW TIDE

EXPLANATION

SPOIL, DREDGED OUT IN DEEPENING MARINE SHELL BED WITH MIXTURE
AND STRAIGHTENING CALOOSAHAT- OF FRESH WATER SHELLS AT
SCHEE RIVER. BASE. YARMOUTH INTERGLACIAL
STAGE.
.m~4 ~ ~ '" u

S BLACK CARBONACEOUS SAND,
S OF THE LAKE FLIRT MARL.

GRAY CALCAREOUS QUARTZ SAND
7 WITH A FEW FRESH WATER SHELLS,
HELISOMA AND AMERIA SPS., WASHED
IN FROM NEARBY LAND AREAS.
PAMLICO.

[fz o MARINE SHELL BED, THE COFFEE
6 MILL HAMMOCK MARL. SANGAMON
S. INTERGLACIAL STAGE.

5 FRESH WATER GRAY MARL (5 )
CONSOLIDATED IN UPPER PORTION
TO MAKE A HARD FRESH WATER
LIMESTONE (Sb ). HELISOMA AND
AMERIA SPS. ILLINOIAN GLACIAL
STAGE.

FRESH WATER GRAY CALCAREOUS
T7's i MARL, LOCALLY HARDENED IN UP-
PER PORTION TO A HARD GRAY
LIMESTONE. HELISOMA AND AMER-
IA SPS. KANSAN GLACIAL STAGE.

MARINE SHELLS, FOUND ONLY LO-
i 2 CALL IN SOLUTION HOLES OR DE-
PRESSIONS IN BED NO. I, OR LY-
ING ON OR MIXED IN WITH A THIN
BASAL CONGLOMERATE, AFTONIAN
INTERGLACIAL STAGE.

7 --"- MARINE SHELL MARL. CALOOSA-
k I TI HATCHEE MARL. PLIOCENE.

NOTE: CORF

RELATIONS TENTATIVE.

GEOLOGIC CROSS SECTION
at Sto.325- Type locality of the Fort Thompson formation

FIGURE 4-Idealized geologic section at Station 325, old Fort Thompson,
Florida, showing relations of formation and various members.
(See also PLATE 19 for photographs of this station.)

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

east of the court house at LaBelle. Section is about 30 yards east of
the big gap through the high spoil bank. Top of bank is about 81/2
feet above low-tide level. See Fig. 4.

SECTION
Feet
Lake Flirt marl:
8. Black carbonaceous sand 1/-1

Pamlico formation:
7. Gray quartz sand with fresh-water and
land shells mixed in A/-l

Fort Thompson formation:
6. (Coffee Mill Hammock marl mem-
ber): Marine shell bed usually pre-
served only in solution holes or caves
in lower beds but in places is a few
inches thick over the top of the under-
lying rock 0-3
5b. Hard fresh-water limestone riddled
with solution holes usually filled with
overlying marine shells 2-3
5a. Soft fresh-water calcareous marl cut
through by solution holes and usually
filled with overlying marine shells 1-2
4. Marine shell bed 0-1
3. Fresh-water shell marl locally harden-
ed in top 6 inches to a hard limestone 11/.2
2. Marine shells, present only in low and
protected areas in the underlying bed.
Probably remnants of a once much
thicker bed. Associated with the shells
is a thin basal conglomerate 0-1

Caloosahatchee marl:
1. Creamy-gray shell marl with an oyster
zone at top. To low-tide level 0-1

This section is further discussed on page 73.

Station 327-Right bank of the Caloosahatchee River. This station
is at the western end of the Lake Flirt basin; it is about %/ mile east
of Fort Thompson. Top of bank is about 10 feet above low-tide level.

SECTION
Feet
Lake Flirt marl and Pamlico formation:
7. Black carbonaceous sand '
6. Gray quartz sand with admixed fresh.
water shells %
Fort Thompson formation:
5. (Coffee Mill Hammock marl mem-
ber): Marine shell bed that fills solu-
tion holes in underlying limestone and
has a thickness of about 3-31% feet
above it 3.5

90

LATE CENOZOIC GEOLOGY

Feet
4. Fresh-water hard limestone ledge with
many solution holes usually filled
with overlying shells. Partially ad.
mixed at base with underlying marine
shell bed 1%.2
3. Marine shell bed 0-1
2. Fresh-water marl 11.3
Caloosahatchee marl:
1. Creamy-gray soft shell marl. To low.
tide level %.

Station 14-On left bank of the Caloosahatchee River at a point
reached by driving 3.0 miles east of court house at LaBelle on Florida
Highway 25, then through fields to the river at right angles to road.
Top of bank about 61/ feet above low-tide level.

SECTION
Feet
Lake Flirt marl and Pamlico formation:
5. Gray non-carbonaceous to black car-
bonaceous sand 0-1
4. Creamy-gray fresh-water calcareous
marl 2-2%
3. Black carbonaceous sand 1-1%
Fort Thompson formation:
2. (Coffee Mill Hammock marl mem-
ber) : Marine shell bed 1-
1. Grayish fresh-water marl consolidated
in place to a hard limestone. To low-
tide level 1.2
300 yards upstream bed 1 disappears below water level by dipping
east and bed 2 is partially hidden.

Station 330-About 25 yards east of Station 14 and on opposite
(right) bank. Top of bank about 51/4 feet above low-tide level.

SECTION
Feet
Lake Flirt marl and Panilico formation:
6. Black carbonaceous sand 0-%
5. Gray quartz sand with admixed fresh-
water shells 1%-2
4. Black carbonaceous sand 1
3. Fresh-water marl or calcareous mud 0-%]
Fort Thompson formation:
2. (Coffee Mill Hammock marl mem-
ber) : Marine shell bed 1-2
1. Fresh-water marl. To low-tide level %
Station 332-Right bank of Caloosahatchee River about 1% mile
east of old Lock No. 3. Top of bank about 71/2 feet above low-tide
level.

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

SECTION
Feet
Lake Flirt marl:
7. Black, compact, sticky muck '
6. Fresh-water, gray, calcareous marl 11/'
5. Black sandy muck '/
4. Fresh-water gray calcareous marl 1
3. Black carbonaceous sand with con-
siderable humus '/2.1
2. Fresh-water gray calcareous marl 1-2
Painlico formation (?) :
1. Black carbonaceous sand. To low-tide
level 11/2.2

Station 334-Right bank of Caloosahatchee River about 11/2 miles
east of old Lock No. 3. This point lies at the east end of a big bend
in the Caloosahatchee River. Between it and Station 332 the sequence
of alternating mucky, carbonaceous, and marly beds is fairly constant,
but the beds thicken and thin irregularly, and in places the section
is almost entirely marl. Top of bank about 8 feet above low-tide level.

SECTION
Feet
Lake Flirt marl:
8. Black compact sticky muck /
7. Grayish quartz sand 1/
6. Black compact sticky muck '/4-
5. Fresh-water gray calcareous marl
4. Black muck .1/
3. Fresh-water gray calcareous marl 1
Pamlico formation:
2b. Brown to black carbonaceous sand 1%
2a. Brown to gray quartz sand 2
Fort Thompson formation:
1. Gray sand with a nodular, calcareous
sandstone layer about three inches
thick at top. To low-tide level 11/

Station 338-Right bank of Caloosahatchee River at a point about
3 1/3 miles east of old Lock No. 3. Top of bank about 61/2 feet above
low-tide level.

SECTION
Feet
Lake Flirt marl:
3. Gray fresh-water marl 4-41
Pamlico formation:
2. Black muck and carbonaceous sand 3%-
1. Gray to brown quartz sand 1-1
Upstream, 200-300 yards, the section is the same except that the
upper foot is occupied by a black compact muck layer.

LATE CENOZOIC GEOLOGY

Station 341-Right bank of Caloosahatchee River about 25 yards
west of Atlantic Coast Line railroad bridge. Top of bank about 11
feet above low-tide level.

SECTION
Feet
Pamlico formation:
8e. Black carbonaceous sand 0-1
8d. White sugary quartz sand l
8c. Black carbonaceous sand 1/4.1
8b. Light-brown quartz sand 1-1
8a. Dark-brown quartz sand 1/4'l-

Fort Thompson formation:
7. (Coffee Mill Hammock marl mem-
ber): Marine shell bed 2-21/2
6. Fresh-water gray calcareous marl 1/1
5. Marine shell marl, fills solution holes
that cut through all the lower beds.
Panope zone at base 2.6
4. Gray sandy limestone containing mix-
ture of fresh-water, brackish, and
marine fossils 1-11/
3. Marine shell marl 0-1

Caloosahatchee marl:
2. Hard marine sandy shelly limestone 11/.2
1. Creamy calcareous shell marl. To
low-tide level 1.2

Station 343-Left bank of Caloosahatchee River in and adjacent
to the cut at the end of the road from Florida Highway 25 at Goodno
store. Top of bank very irregular due to spoil heap but averages
about 111 feet above low-tide line. The spoil covers top portion of
section so that it can not be determined here.

SECTION
Feet
Pamlico formation:
Covered by dredgings (spoil) com-
posed of mixed sand, shells, and lime-
stone, Pliocene and Pleistocene 4.51

Fort Thompson formation:
7. (Coffee Mill Hammock marl mem-
ber) : Marine shells generally partially
or completely hidden by spoil 1(?)
6. Hard gray marine limestone ledge 1-11/2
5. Creamy-gray shell marl, a mixture of
both marine and fresh-water shells 3/4.11/
4. Hard gray sandy limestone 3%-1/

Caloosahatchee marl:
3. Vermicularia bed 3.1
2. Hard gray sandy limestone %'11/4
1. Creamy-gray shell marl. To low-tide
level 1.-2

93

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

Station 343A-East end of U.S.E.D. Reservation above Ortona Lock.
SECTION
Feet
Pamlico formation:
Black carbonaceous sand. To water level 1/-I
CORRELATION OF THE FORT THOMPSON FORMATION
Figure 4, which is drawn to scale with no vertical exaggeration, is a
graphic section of the left bank of Caloosahatchee River at the site
of Fort Thompson, 13/ miles cast of LaBelle. This section at the
type locality of the Fort Thompson formation (Station 325, p. 89),
is especially instructive because it gives indisputable evidence of the
repeated oscillation of sea level during the Pleistocene epoch. Four
separate Pleistocene marine invasions of this region are attested by
beds 2, 4, 6, and 7; and five withdrawals of the sea are shown by
erosion surfaces and fresh-water deposits below, between, and above
them. These alternations agree in number with and presumably cor-
respond to the oscillations of sea level recorded by the marine ter-
races along the Atlantic coast.
The first withdrawal of the sea is indicated by the erosional un-
conformity that separates the marine Caloosahatchee marl (bed 1)
from the overlying Pleistocene deposits. This unconformity probably
represents late Pliocene time and the Nebraskan glacial stage.
The earliest Pleistocene marine invasion deposited a bed of marine
shells (bed 2) that is now represented only by patches filling hollows
in the surface of the Caloosahatchee marl and often mixed with the
overlying fresh-water shells of bed 3. This bed presumably was
deposited during Brandywine time (Aftonian interglacial stage?).
Bed 2 was eroded and then covered by fresh-water marl (bed 3)
containing numerous fresh-water shells. Still later the bed became
perforated by solution holes and the water drained off. Bed 3 in-
dicates an epoch of low sea level that may correspond to the Kansan
glacial stage.
The second Pleistocene invasion by the sea filled the solution holes
in bed 3 with marine shells (bed 4) and also spread them over the
top of bed 3, which has been locally hardened into limestone. The
lower part of this marine shell bed includes some fresh-water shells,
which doubtless were reworked from the bed below it. Bed 4 prob-
ably accumulated during Coharie and Sunderland time (Yarmouth
interglacial stage).
Bed 4 is covered by fresh-water marl (bed 5) the upper part of
which is consolidated into hard limestone. This fresh-water deposit

94

LATE CENOZOIC GEOLOGY

is perforated by solution chimneys, some of which extend only through
the hard upper limestone, others extend to the porous shell bed (4)
below it, and still others reach all the way down to the Caloosahatchcc
marl. This indicates that when the Yarmouth sea withdrew the region
became at first occupied by a fresh-water lake or marsh, which later
drained away, then the area was subjected to the solvent activity of
downward percolating ground water. This may have happened dur-
ing the Illinoian glacial stage.
The solution holes in the fresh-water marl and limestone (bed 5a
and 5b) are filled with an accumulation of Chione cancellata and(
other marine shells (Coffee Mill Hammnock marl member of the
Fort Thompson formation, bed 6), which also overlies bed 5 in dis-
connected patches. This third marine invasion probably corresponds
to Wicomico, Penholoway, and Talbot time (Sangamon interglacial
stage).
Evidence for a fourth withdrawal of the sea (early Wisconsin glacial
substage) is found in the uneven surfaces of beds 5 and 6, from which
part of the Coffee Mill Hammock marl has been stripped off, leaving
it in disconnected patches.
Return of the sea in post-Iowan (Pamlico) time brought with it
chiefly barren sand (bed 7) and a few fresh-water shells washed in
from the land, which was only a mile or two away on the north
and 3 or 4 miles on the south. The scarcity of marine shells during
this epoch may indicate that the water was too cold for the warm-
water mollusks that had inhabited the region during the earlier
interglacial epochs, or that the currents and food supply may have
been unfavorable. This was the only Pleistocene epoch during which
sand accumulated in notable quanttities at this locality, which, during
Pamlico time, lay in a strait between Immokalee Island and the main-
land. The depth of the water in this strait was only 15 to 20 feet, and
sea level stood about 25 feet higher than now.
Sand of the Pamlico formation is overlain by a layer of black car-
bonaceous sand, which probably is a swamp deposit of late Wiscon-
sin or Recent age and corresponds to the Lake Flirt marl and the
peat and muck of the Everglades.
The typical Fort Thompson formation, as here interpreted, com-
prises all of the Pleistocene deposits older than the Pamlico forma-
tion. These include marine and brackish-water shell beds that may
represent the Aftonian, the Yarmouth, and the Sangamon interglacial
stages and marls and limestones deposited in fresh-water lakes and
marshes during the intervening glacial stages. Most of these beds are
of very local occurrence because they were subjected to solution and

95

FLORIDA GEOLOGICAL SURVEY-BULLETIN 27

erosion whenever the water table was low enough to permit the active
circulation of ground water-or whenever the overflow from the
interior through ancestral Caloosahatchee River became of great
enough volume.

CORRELATION OF FORMATIONS BY MEANS OF
EXPLORATORY TEST WELL DATA

General statement-In the course of this investigation more than
60 exploratory test wells have been sunk for the purpose of obtaining
data on the occurrence of water, which, of course, is dependent upon
the geology; therefore considerable effort was made to collect and
identify fossils and to gather complete data on lithology.

These test wells are scattered over southeastern Florida. Reference
to other papers (Parker, 1942; Parker and Hoy, 1943; Parker and
others, 1941) will give data on many of these. The present paper
is concerned with two lines of wells, a northwest-southeast line A-A'
and an east-west line B-B' (Plate 24 shows these lines and gives the
location of the wells).

The formations involved have already been discussed in their re-
spective sections. Following is a description of the well logs:

SECTION A-A' (front northwest to southeast)
WELL GS-3 (4" DIAM.)

Site is near the south corner of the water tower at the U. S. Sugar
Corporation, South Shore Camp, Bean City, Florida, sec. 8, T. 44 S.,
R. 36 E., Palm Beach County. Land surface about 15 feet above mean
sea level.
LOG
Thickness Depth
in referred
feet to M.S.L.
Recent organic soils:
Black muck (may include a thin layer of Lake Flirt
marl at base but cuttings did not definitely
prove this) ................................ 7.4 +7.6
Fort Thompson formation:
Hard limestone layer ...................... 0.8 +6.8
Shell marl ................................... 2.1 -4.7
Hard limestone layer .............................. 0.9 +3.8
Shell marl, sand, and shell beds .................... 12.3 -8.5
Caloosahatchee marl:
Dark-gray shell marl and sand with a few strata of
hard rock in layers an inch or two thick ...... 11.8 -20.3
Hard sandy limestone layer ........................ 1.4 -21.7
Very fine shelly sand to bottom of hole ........... 14.0 -35.7

96

FLORIDA GEOLOGICAL SURVEY

BU LETIN

27.

Plate 25

rt)
I0
10
!

N
0)

Ni

z

AS

M-

M.S.L.

0Qo

Ua tt -64i H H

6 -20

o -30'
F-

0
Li -40
X

S-50-

F-
S-60

z -70

c. -80,
-Jj
0-

-1101

Of

Pc

t d

CcI

i a

Qo
-- - -- -- -- -- -- -- -- -- -- ---

Of

PC

SCALE IN MILES
SI 2 3 4 0 20

LEGEND
o o-QUATERNARY, RECENT ORGANIC SOILS
01 -QUATERNARY, LAKE FLIRT MARL
Qp QUATERNARY, PAMLICO FORMATION
Qm QUATERNARY, MIAMI OOLITE
Of *QUATERNARY, FORT THOMPSON FORMATION
Pt -PLIOCENE, TAMIAMI FORMATION
Pc PLIOCENE, CALOOSAHATCHEE MARL
Mh=MIOCENE, HAWTHORN FORMATION

- -- -. -------- --- 7 0

0
0)

0
I
N

0

3cLJJ -1

lo 4 t
492 wa a
cu 0 >

> h w O;w

)BISCAYNE BAY

0)
01
o3

P-
0D
0

OD
00
0

tO to
cc ac

0 0U
5r i
>,
ac >1
ww
F- 2
znzi
N~
Zt i2

NORTHWEST-SOUTHEAST CROSS SECTION ALONG FLA. 26 FROM LAKE OKEECHOBEE TO MIAMI SPRINGS, THENCE EAST TC

SECTION A-A'

	Title Page
	Front Matter
	Table of Contents
	List of Illustrations
	Abstract
	Main
	Index

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