THE PHYSICAL SETTING
General Geography, Topography and Geology of Collier County
Collier County covers about 2,032 square miles of
S .southwestern Florida (Figure 1). The Golden Gate Tract
(Figures 2 g 3) covers about 175 square miles, or 8.5 percent
of the county land area.
Collier County, along with Monroe, Dade, Broward,
Palm Beach, Hendry and Lee counties, lies in what is known
as the Floridian sector of the Atlantic Coastal Plain
physiographic province (Meinzer, 1923, cited by McCoy,
1962), and is part of the coastal lowlands physiographic
region of Florida (Puri and Vernon, 1959).
Cooke (1931) described a series of eight seashores
which formerly stood at elevations 270, 215, 170, 100, 70,
42, 25 and 5 feet above present sea level. These elevations
represent the inland shorelines of old seas named Brandwine,
Coharie, Sunderland, Wicomico, Penholoway, Talbot, Pamlico
and Silver Bluff.
Collier County contains portions of two of these
terraces, the Talbot and Pamlico. The Talbot shoreline lies
at elevation 42 feet relative to present sea level while the
Pamlico sea covered land lower than 25 feet.
Tracing the 25 foot contour around Immokalee it
is possible to ascertain the shoreline of what has been
called Immokalee Island (Parker and Cooke, 1944). The main-
land shore in Pamlico times occupied the land north of the
S Caloosahatchee embayment; Immokalee Island stood alone offshore.
Examination of U. S. Coast and Geodetic Survey
topographic maps show (Figures 4 S 5) that contours run
i| roughly in concentric fashion down gradient from the highest
point of 44 feet near Immokalee to 3.3 feet in Everglades
ii City, 5.9 feet at Carnestown, 6.0 feet in South Naples and
e(-~-~eet~l~iBr~"~-71.isb~ --~-'-Tr:T1;-I'.------ -----. .-j--T:ilf- .
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Figure 1. General Location Map.
____ ___ _I_ __ _7__ 1_
ALABAMA / GEORGIA
0 100 miles
Figure 2. Collier County, showing location of
Golden Gate Estates.
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S MAJOR HIGHWAYS
- PROPERTY BOUNDARY
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Golden Gate Estates: Road and canal system.
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1131 I -
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2 1 211
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Figure 4. Ground contours of central and western
SLEE COUNTY 20
5 ItI' ATIO1 CIllIll
IE > [LEA IIIAI I BASES 11 MEAN SEA
LEEL DA TU i M l1h
Ground contours of Golden Gate Estates.
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864 SR 951
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t" B rant
about 4.0 feet along-the Tamiami Trail at Collier-Seminole
State Park. The land slope varies between 8 and 16 centi-
meters (3-1/8 to 6-1/4 in.) per kilometer (Carter et al.,
Natural drainageways across this terraced terrain
are marked by tall cypress and mixed swamp forest associations
many of which are named. In the far northeast Kissimmee
Billy and Goddens strands lead in a southeasterly direction
toward the western fringes of the Everglades Basin. Moving
west one then encounters the Okaloacoochee Slough, a portion
of which overflows to the Deep Lake Strand in the south.
Another portion flows southwesterly to merge with the Fahkah4
Strand (McElroy and Alvarez, 1975).
\ The Fahkahatchee Strand is separated on the west
from another major system by a low rock ridge. The western"
neighbor to the Fahkahatchee is the Picayune Strand, which.
receives surplus surface water flows from Lucky Strike Stran d
Stumpy Strand, Winchester Strand, Camp Keasis Strand, and,
finally, some water from Bird Rookery Strand in the north-.
western corner of the County.
Lake Trafford west of Immokalee is a large collect
basin. Some of the overflow from Lake Trafford flows north
into the Caloosahatchee River but another path for overland
flow goes west into Corkscrew Marsh and then turns southward-
to flow throughBird Rookery Strand. From there, some flow
passes down gradient 'to the Cocohatchee River, while the
flows southeast toward the Picayune Strand.
These'drainage systems form one of the bases for i
drawing boundary lines around the Big Cypress Watershed
All these major and minor upland drainage S~gte
eventually contribute fresh-water to coastal marshes butd
in the western edge.of the County where topographic con
were not as conducive for major strand development, the
small stream drainages which are named for the streams
themselves, not for any strand. Starting with the Cocohatchee
River and going south along the coast these are the Gordon
River Basin, Rock Creek Basin, Haldeman Creek Basin, Stopper
Creek-Rattlesnake Hammock Basin, Henderson Creek Basin and
the Royal Palm Hammock Creek-Blackwater River Basin.
The many-layered geological structure upon which
the living system sits has been described on numerous
occasions. (Cooke, 1930, 1931; Cooke and Mossom, 1929;
Mansfield, 1931, 1939; Matson and Clapp, 1909; Matson and
Sanford, 1913; Mossom, 1926; Parker and Cooke, 1944; Klein,
1954; Parker et al., 1955; Puri and Vernon, 1959; Schroeder
and Klein, 1954, 1961; Stringfield, 1936; McCoy, 1962).
A summary of their findings shows that sedimentary
rocks exist under Collier County to a depth of more than
12,000 feet. The sediments making up this base are mainly
quartz sand, limestone and clays in the upper 700 feet and
limestone and dolomite below that. Rocks originating in
the Miocene period are called the Tampa, Hawthorn and Tamiami
formations. The Tampa Formation apparently lies at depths
greater than 200 feet. This formation seems to supply most
of the artesian flow from shallower wells drilled to the
Floridian Aquifer (Parker, 1951). The Hawthorn Formation
lies on top of the Tampa. It contains much clay of very
sticky character which apparently forms the upper confining
layer of the Floridian Aquifer.
The boundary between the Hawthorn and the overlying
Tamiami Formation is marked by layers of gray-green, sticky
clays below, grading into sandy clays higher up. McCoy
(1962) estimated the thickness of the Hawthorn Formation
in Collier County to range between 250 and 300 feet and
its top lies at .depths of less than 100 feet to more than
200 feet. The top of the Hawthorn is apparently nearest
the surface in the Immokalee area and deepest (i.e. 25 to
50 feet below the surface) along the west coastal sector.
The Tamiami Formation, exposed along the Tamiami
Trail, underlies nearly all of Collier County. It seems to
range between 10 and 50 feet in thickness, although this
has not been 'clearly established. This formation is capped
by hard rock under which are found sandy silts and clays,
shell marls and shell-free, greenish clay.
More recent deposits lie on top of the Tamiami
Formation. In Some areas east of Immokalee the Pliocene
Caloosahatchee marl is said to occur. It is of low
permeability, forming a seal over the more porous Tamiami
Of much greater significance to the present study
are sands of Pleistocene to Recent origin. The coastal
dune area of Collier County, inland for several miles, is
made up of Anastasia Formation sand and shelly sand deposits.
McCoy (1962) reports that limestone rock layers associated
with the Arnastasia Foundation have proved so hard that they
have restricted the depth of well drilling. He mentions
the presence of cross-barred venus shells, Chione
cancellata, in association with this hard Anastasia limestone.
During our own study of the hard surface limestone
layers in the Golden Gate (see section on Hydrology), we
had concluded that the dense deposits of Chione cancellata,
under this topmios~i caprbck indicated that the' rock and an
underlying-~4 to -t' off' clay, sand and rock were Fort
Thompson Formation resting on top of the Tamiami cap
(Figure 6).- Chione cancellata is named the "indicator
fossil" for the'~ort'Thompson -(-PAA4rk e4t al. 1955, p. 92;
Parker and Cooke 1944, p. 25). Missimer (personal communica-
tion) stated that thi' is a very -complex problem which needs
On top of the rock over most of the rest -of the
County is a blankets of- sand, sandy marl., clay and fine shell
of Pamlico Sea origin. These sands and their- recent inclusions
of organic material form the substratum for the biological
system of the County aid, prior to canal drainage, were in
Figure 6. Arrangement of rock and water-bearing
surface layers`qf Goldep Gate "Highlands",
illustrating principle.Dof infiltration,
runoff, pand shallow' a4i4fer flow.
Irr;ln I~TI~S 3("9~-71 _~~_LCS"~FI _~P--l ~17C-P--l~l~ -LICli~C~ ~~J~d~~ ~r(r_~bA~ CC -~ ~p. ~-
direct or close contact with the water table. It has always
been from this upper layer containing organic material, that
the organic acids have come which are responsible for solution
of the underlying lime material.
Although a good deal has been written about solution
and its effects on surface and sub-surface rocks (Parker and
Cooke, 1944), the unique and very practical problems posed
by solution-riddled terrain had received little attention
until LeGrand (1973) wrote an important paper on hydrological
and ecological problems of Karst regions.. Only a few
references exist which even mention the import of karstifi-
cation to Collier County. In the words of LeGrand:
"The term karstt' has long been used to
define the sum of the phenomena characteri-
zing regions where carbonate rocks, chiefly
limestone, are exposed. 'Karstification'
refers to the many processes that result in
the development of surface and sub-surface
features that are distinctive in many
carbonate rock terranes. Karst features
develop where water containing carbon
dioxide has been able to move on and through
carbonate rocks and to remove some of the
rocks in solution.
"The development of karst features, parti-
cularly caverns and other large openings,
depends on (i) the presence of soluble
rocks, (ii) the presence' of carbonic acid,
(iii) ample precipitation, (iv) openings
in the rocks, and (v) a favorable topographical
and stru tural- setting.
"The ecology of carbonate rock regions ranges
greatly, depending on climate, of course,
but also on several gross geologic factors.
There are delicate balances in the develop-
ment of karst areas that are related to the
character of the rock: whether it is
essentially pure, whether it contains
insoluble material throughout or only in
thin discrete beds, and whether it has
primary permeability or secondary per-
meability through fractures and caverns.
Geologic structure and history are every-
where involved in karst development because
carbonate rocks must be uplifted from below
sea level to the landscape environment
where fresh water can infiltrate and move
through them. ... Only within the fresh
water system can the full interplay of
climate, topography, and geology exist
to develop karst features."
Having these statements and a considerable bulk of
erosion examples at hand, we must conclude that vast areas
of Collier, Lee and Hendry counties show karst characteristics
and we further conclude, using the data on sink hole lakes
given by Parker and Cooke (1944), that the karstification
process has been going on for a very long time. Deep Lake
near Copeland on S.R. 29 is about 97 feet deep. Still Lake
in Lee County is .in excess of 210 feet deep. Rocky Lake
which is located some 17.5 miles east of Immokalee is
another sinkhole of great surface area and unknown depth.
According to Parker and Cooke (p. 33) "the occurrence of
deep sink holes in southern Florida gives presumptive
evidence of former sea stands much lower than the present."
Although these are the only open sink holes known
from the general study area there are hundreds of circular
potholes running along the Hendry-Lee county boundary with
northern Collier County which are suggestive of many smaller
sinks, and are now filled with more-or-less impervious recent
material. If these are, in fact, surf ace signs pf subterranean
erosion, they may be allowing some infiltration, to a
sub-surface cavern system at the present time. Shallow
surface and sub-surface karstification seems, however, to
be the most likely active process at present unless there
is solution going on below sea level in areas of seaward
flowing water along the salt-fresh interface.
One observation related to us by Mr. Rudolph Swain,
now Manager for the Turner Corporation and formerly in
i;b;l~hl~Z~-L- ii ~-~i~j~J;lOi~Cl~iiP~;~:r ~*i ~iaiilL~iik~~L~ixlul In-CL- -;-~LIC~~as~Li-~
charge of timber cutting operations for the Lee Cypress
Company, is of special interest. He stated that, when
timber cutting was in progress in the Fahkahatchee Strand
during the 1940's and 19%30, thA 0 1n. 1' serve
early rainy season rains iBuilding up to the north before
they came in the south reaches of the Strand. Shortly
after the beginning of such rains water could be heard
underfoot in rock channels in the southern part of the
Strand. This does not surprise us because we have made
similar observations on Key Largo where rainfall becomes
impounded west of the island mass and, at a certain depth
of impoundment, begins to flow downhill to the Atlantic
side directly through the cavernous limestone of the
One final comment regarding this aspect of the
geology of Collier County seems appropriate. The strands
named above follow old erosion features in the surface
rock. The erosive force, judging by the presence of rock
pinnacles in these strands, has apparently been solution
by acidic fresh water and we believe these channels are
still functioning. If we are correct, failure to appreciate
this factor may produce much more severe problems than are
presently visualized. LeGrand (1973) gives a succinct
summary of the problem, as follows:
"The uneven distribution of permeability
in most karst aquifers leads to several
types of problems. The preferential
circulation of water along some fractures
and the enlargement of these fractures
by solution causes an arterial system
in which water tends to collect in large
openings and to discharge as widely
spaced large springs."
If a similar situation has existed in the Fahkahatchee-
Picayune Strand (i.e. "preferential circulation" has long been
established there), then the Golden Gate Canal system, as
well as neighboring canals to the east, may have ecological
and water wasting consequences far greater than is now
thought possible by decreasing the residence time of water
in the regionof greatest infiltration to deeper strata.
This may explain why there seems to have been a major
advance landward of coastal salt-tolerant forests in the period
1930 to 1940 and abrupt decline of hard clam populations in
the Ten Thousand Islands during the period 1940-1950. The
few canals built until that time did not seem especially
significant but LeGrand's comments show that they might have
been far more effective than would seem possible. The same
process may explain why the major cypress stands were dry
enough to cut in the same time period when ancient knee
growth indicates flood depths of perhaps 6 feet generally
in the Fahkahatchee and 4 feet in the lower Picayune.