Annual report

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NANDINA
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BERKELEY
LIBRARY
UNIVERSITY OF
CALIFORNIA

EARTH
SCIENCES
LIBRARY

zed by Googe

FLORIDA STATE GEOLOGICAL SURVEY

THIRD ANNUAL REPORT
1909-1910

E. H. SELLARDS, Ph.D., STATE GEOLOGIST

PUBLISHED FOR
THE STATE GEOLOGICAL SURVEY
TALLAHASSEE. 1910

LETTER OF TRANSMITTAL.

To His Excellency, Hon. Albert W. Gilchrist,
Governor of Florida.
Sir:-In accordance with the Survey Law I submit herewith a
report of the progress of investigations made by the Geological
Survey for the year ending June 30, 1910. The work of the Survey
has progressed actively during the past year. This report contains
papers on the phosphate deposits, the peat deposits, the lakes and
the artesian water supply.
In connection with the report on water supply I would respect-
fully call attention to the evidence of the loss of flow in some of
the artesian wells, and to the danger of a material reduction in the
artesian supply in some localities, if tne waste of water is not pro-
hibited by law.
The generous interest you have taken in the work of the State
Survey is appreciated.
Very respectfully,
E. H. SELLARDS,
State Geologist.
Tallahassee, Florida,
October I, r91o.

2842699

CONTENTS.
PACE
Administrative Report ............................................... 9

A Preliminary Paper on the Florida Phosphate Deposits.
By E. H. Sellards. (Plates r to 5) ................................. 17

Some Florida Lakes and Lake Basins.
By E. H. Sellards. (Plates 6 to 9; text figures I to 5).............. 43

The Artesian Water Supply of Eastern Florida.
By E. H. Sellards and Herman Gunter. (Plates xo to 15; text figures
6 to 16) ................................................... 77

A Preliminary Report on the Florida Peat Deposits.
By Roland M. Harper. (Plates 16 to 28; text figures 17 to 3) ......... 197

Index ....................................... ..................... 377

ILLUSTRATIONS.

PLATE NO. FOLLOWING I'ACE.
I. Fig. I. Phosphate washer ...................
Fig. 2. Drill used in prospecting for hard rock phosphate.......
Fig. 3. View of incline to pit .................................. 3-
2. Fig. I. Pit of hard rock phosphate mine.....................
Fig. 2. Top surface of Miami oolitic limestone .................
Fig. 3. View showing laminated structure of plate rock deposit. 32
3. Fig. I. Pit of land pebble phosphate, Mulberry. .................
Fig. 2. View showing indurated overburden in pebble phosphate.
Fig. 3. View of abrupt break in the phosphate stratum.......... 32
4. Fig. i. Irregular top surface of bed rock of land pebble...........
Fig. 2. Unconformity of the phosphate stratum ................
Fig. 3. Irregular line of contact between yellow and gray sand.... 32
5. Pit of plate rock phosphate mine showing very irregular top sur-
face of limestone ....................................... 32

A PRELIMINARY PAPER ON THE FLORIDA
PHOSPHATE DEPOSITS

E. H. SELLARDS.

THE HARD ROCK PHOSPHATE.-DUNNELLON
FORMATION.

The area of hard rock phosphate at present productive, lies
in the western part of central peninsular Florida and extends as
a narrow strip parallel with the gulf coast in a general north and
south direction from southern Suwannee and Columbia Counties
to Hernando County, a distance of one hundred miles. Mining
has been carried on continuously in this section since 1888. Sev-
enty-four plants under the ownership of twenty mining com-
panies operated in this section during 1909. These plants were
distributed as follows: Suwannee County, one; Columbia Coun-
ty, three; Alachua County, twenty-two; Marion County, twelve;
Citrus County, thirty-four; Hernando County, two. Owing to
the depressed condition of the phosphate market a number of
these plants closed either temporarily or permanently early in the
year while many others closed before the end of the year. At the
beginning of 191o, the number of plants in actual operation was
thirty-seven. These plants were distributed as follows: Suwannee
and Columbia Counties, one plant each; Alachua County, four-
teen plants; Marion County, eight plants; Citrus County, twelve
plants; Hernando County, one plant. Each phosphate plant opers
up in the process of mining one to several pits offering exception-
ally good exposures of the phosphate bearing formation. The
following notes are based on observations of the exposures made
at these and at the many other plants that have operated in this
section during the past several years.

LITHOLOGIC DESCRIPTION.

The phosphate-bearing formation as developed in this sec-
tion includes a mixture of materials from various sources and
of the most diverse character, further complicated by pronounced

22 FL6ORDA GEOLOGICAL "SURVEY-THIRD ANNUAL REPORT.

chemical "ativihy within the formation itself. Although exceed-
ingly variable from place to place the prevailing phase of the for-
mation is feebly coherent, more or less phosphatic, light gray
sands. Aside from these sands the principal materials of the for-
mation are clays, phosphate rock, flint boulders, limestone inclu-
sions, pebble conglomerate, erratic and occasional water-worn
flint pebbles, vertebrate and invertebrate fossils.
The gray sands may be observed in every pit that has been
excavated in this section. Moreover, from drill and prospect
holes it is known that these sands occur very generally over the
intervening or barren area. The sands are of medium coarse
texture, the grains being roughly angular. The amount of phos-
phate associated with the sands is variable. They are also more
or less calcareous in places. Upon prolonged exposure, as seen in
numerous abandoned pits, these sands oxidize at the surface assum-
ing a pink or purple color. When affected by slow decay and by
water carrying more or less iron in solution they become reddish
or ochre-yellow in color.
The clays in this formation occur locally as clay lenses imbed-
ded in the sand, or separating the sand from the phosphate rock,
or overlying the phosphate rock. The clays are often of a light
buff, or blue color. When lying near the surface, however, they
often oxidize to varying shades of red. The relative amount of
clay in the phosphate-bearing formation increases in a general
way in passing to the south. The exposures in the southern part
of the area show as a rule more clay than do similar exposures in
the northern part of the area.
Flint boulders occur locally in this formation in some abun-
dance, and occasionally phosphate pits which are otherwise work-
able are abandoned on account of the number of flint boulders
encountered. The flint boulders are usually oval or somewhat flat-
tened in shape and are of varying size, some weighing several tons.
The exterior is usually of a light color. Some of the boulders are
hollow and are occasionally filled with water. Others are solid,
compact and of a bluish color throughout. Fossils or casts of fos-
sils occur frequently within the boulders. Limestone inclusions
from the Im,., i. ;;- formations are frequent in this formation.
The pebble conglomerate feature is not of frequent occur-
rence but may occasionally be observed in the northern part of the
Jhard rock section. Such an exposure of a true pebble con-
glomerate may he seen in one of the pits of plant No. 5 of
the Cummer Lumber Company about one mile southwest of New-
berry. The matrix at this exposure consists of more or less water
worn fragments of varying sizes together with round or oval wate:

THE FLORIDA PHOSPHATE DEPOSITS.

worn, dark colored flint pebbles. This phase of the formation
may be seen through a distance of ten or fifteen feet along the
side of the pit. Water worn pebbles weighing one or more pounds
occur occasionally in the northern part of the field.
The invertebrate fossils found are mostly contained in the lime-
stone inclusions which come largely from the underlying Vicks-
burg limestones. The vertebrate remains occurring in the phos-
phate include among others, shark teeth, manatee, turtle and mas-
todon remains.
Phosphate rock, although the constituent of special economic
interest, nevertheless makes up a relatively small part of the forma-
tion. The phosphate in this section occurs as fragmentary rock.
boulder rock, plate rock or pebble. A certain portion of soft phos-
phate, unavoidably lost in mining, is also present. The relative
amount of material that it is necessary to handle to obtain a definite
amount of phosphate is always variable with each pit and with the
different parts of any one pit. In general the phosphate rock ob-
tained from the matrix of the grade demanded by the market will
not exceed ten to twenty percent of the whole. The workable
deposits of phosphate lying within this formation or representing
locally a phase of this formation, occur very irregularly. While
at one locality the phosphate may lie at the surface, elsewhere it
may be so deep as not to be economically worked; while a deposit
once located may cover more or less continuously a tract of land
of some acres in extent, elsewhere a deposit appearing equally prom-
ising on the surface, may be found to be in reality of very limit-
ed extent. As to location, depth from the surface, extent into
the ground, lateral extent, quantity and quality, the hard rock
l hosphate deposits conform to no rule. The desired information
regarding location, character and extent of deposits is to be obtain-
ed only by extensive prospecting and sampling.
The phosphate rock may lie beneath the gray sands, or above
the gray sands or may be entirely surrounded by them. In some in-
stances the phosphate is interbedded with the sands. Such inter-
bedding of sand and phosphate was observed by the writer in the
Central Phosphate Company pit No. 25 about three miles west
of Clark. This phase of the relation of sand and phosphate occurs
not infrequently and is confined to no particular part of the phos-
phate field. Gray sands surrounding the phosphate rock may be
observed as previously stated in practically every pit throughout
the phosphate section. As a rule the phosphate rock extends to
and rests upon the underlying limestone. This relation, how-
ever, is by no means invariable as gray sands were observed under-
lying the phosphate rock at several localities. Gray sands above

24 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

the phosphate are ordinarily of frequent occurrence both in pits
and in prospect holes.

MATERIALS LYING ABOVE THE PHOSPHATE.

A superficial deposit of pale yellow incoherent sand occurs
generally throughout the phosphate section. The thickness of
this sand varies exceedingly. Five to fifteen feet may be given
as an average as seen in the pits, although a thickness of as much
as thirty feet has been observed. The character and manner of
occurrence of these sands leads the writer to the belief that they
may be residual in origin.
These incoherent sands rest in some localities upon a red clay-
ey sand stratum known to the miners as "hardpan." This
sand stratum contains sufficient clay to give it coherence and
stands usually as a vertical wall in mining. This stratum is fre-
quently absent, and when present varies greatly in thickness.
The top surface of this red sand stratum presents irregularities
which might be taken to mark an unconformity between this for-
mation and the incoherent sands above. Such irregularities as
occur in the top surface, however, present rounded depressions
rather than sharp irregularities. Moreover the top surface of
the red sands frequently conforms to the surface contour. Both
the superficial sands and the red sands are, as far as the writer
has observed, non-fossiliferous.

RELATION OF THE PHOSPHATE-BEARING FORMATION TO THE
UNDERLYING FORMATIONS.

The phosphate-bearing formation rests in this section, wher-
ever observed, upon the Vicksburg limestones. In the northern part
of the section the pits are ordinarily worked out to the limestone.
affording favorable opportunity for observing the contact. The
top surface of the limestone is strikingly irregular, the rock pro-
jecting as rounded peaks. The numerous shells and other inver-
tebrate fossils of which the limestone is largely made up are eroded
off plane with the surface of the limestone. Passing to the south
the limestone lies as a rule at a greater distance beneath the sur-
face, and frequently is not reached by the ordinary processes of
mining. It is occasionally reached, however, and wherever seen,
throughout this entire section the relation between the phosphate
formation and the limestone is the same, that is, the phosphate-
bearing formation lies upon and fills up irregularities in the top sur-
face of the limestone. (PI. 2, Fig. r and Pl. 5)

THE FLORIDA PHOSPHATE DEPOSITS.

LOCAL DETAILS.

SUWANNEE COUNTY.
The southern and southeastern part of Suwannee County has
produced some phosphate although only one mine was in operation
in this county during 1909. A variable thickness of pale yellow sand
occurs in the pits of this section. At the pits of plant No. o1 of
Dutton Phosphate Company, 2 miles north of Hildreth from two to
twelve feet of this incoherent sand rests directly upon the phos-
phate bearing matrix. In one of the pits of this plant the phos-
phate matrix grades at the bottom into a yellow phosphatic clay
overlying the limestone to a depth of 4 or 5 feet. In one of the
pits at this plant are observed, as frequently seen elsewhere in the
hard rock section, many large round elongate siliceous boulder
interbedded in the phosphate matrix. The underlying formation
here is the Ocala Limestone which occurs as peaks, and as "hog
backs" of lime projecting into or even through the phosphate mat-
rix.

COLUMBIA COUNTY.
The southern part of Columbia County adjacent to Suwannee
County has produced considerable phosphate, although only one
mine in this county was in actual operation at the close of 90o9.
At plant No. 2 of the Dutton Phosphate Company about one-
half mile west of Ichatucknee Springs the following section was
obtained:
Pale incoherent sand................................... 10 to 20 feet
Phosphate-bearing matrix .... ........ .. .............20 to 25 feet
Buff yellow phosphatic clays ..... ........................ 5 to 6 feet
Dark sandy phosphatic clays (exposed) ................ 4 feet
The incoherent sands in this pit, as at Dutton No. o1, rest di-
rectly upon the phosphate stratum the top of which is exceedingly
irregular. Clay lenses 6 to 12 inches thick are of frequent occur-
rence especially near the top. The underlying Ocala Limestone
is reached in places. The buff yellow phosphatic clay observed in
Dutton No. Io is seen here also and is underlaid by 4 feet of dark
sandy phosphatic clay.
The following section was made in one of the pits of the
Schilman & Bene Phosphate plant about two miles northwest of
Ft. Wlite:
Pale yellow incoherent .sand........................... 3 to 5 feet
Red clayey sands ............... ....... ......... : ..... 5 to to feet
Phosphate matrix ................... ............... 15 to 25 feet
Limestone at the bottom of the pit.

26 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

This section differs from the preceding chiefly in.the presence
of the red clayey sands which are sufficiently coherent to form a
vertical wall in the pit. This clayey sand stratum when present
is referred to by the miners as "hardpan."
The phosphate matrix in this exposure as in Dutton No. Io,
grades below into yellow phosphatic clay. The overburden at
this pit, is not removed as it is found practicable to allow the en-
tire overburden to be taken up with the phosphate and to pass
through the washer.
In the pit of the Fort White Hard Rock Company one-half
mile southeast of Ft. White, the foundation rock, as is usual in
this section, is the Ocala Limestone. The top of this limestone
is exceedingly irregular, projecting as rounded peaks. Shells, sea ur-
chins, and other fossils are partly eroded away, the limestone
having a comparatively smooth surface. The phosphate rock
consists chiefly of angular fragmental pieces, plates, pebbles and
boulders imbedded in a sandy or clayey matrix. This matrix
fills up the irregularities in' the underlying limestone. In sev-
eral instances the phosphate matrix was seen to fill up cavities and
solution channels in the limestone. Slickensides occur due to the
settling of the phosphate matrix as the underlying limestone dis-
solved away. Limestone inclusions and siliceous boulders occur
in the phosphate stratum. The following section is seen in an
abandoned pit of this plant.
Pale yellow incoherent sand .............................. to 15 feet
Phosphate matrix .......... ... .. ........... .......... to 20 feet
Limestone top surface exceedingly irregular

The phosphate producing area of southern Columbia and Su-
wannee Counties lies adjacent to and in the angle between the Su-
wannee and Santa Fe Rivers including the low lying and intensively
eroded parts of each County. The limestone lies near the surface
in this section and as a rule the phosphate is mined out by dry min-
ing, the limestone being exposed in the abandoned pits. Dredging
which is applicable in the southern part of the phosphate area is
not used in this section.

ALACHUA COUNTY.

The west central part of Alachua County is actively produc-
ing phosphate, twenty-two plants having operated in this county
during 1909.
Pit No. 25 of the Central Phosphate Company west of
Clark, gave the following section:

THE FLORIDA PHOSPHATE DEPOSITS.

Pale yellow incoherent sands............................ 5 to Io feet
Red clayey sands................................ ....... 5 to To feet
Phosphate-bearing formation....... .....................to to 25 feet
Limestone at bottom of pit.

The phosphate matrix consists of gray sands, yellow, buff and
blue clays, and phosphate rock. At one place in this pit a stratum
of gray sand V' to 2 feet thick is seen interbedded with the phos-
phate rock.
The incline leading to a new pit being opened up by M. C. and
T. A. Thompson near Neal gave the following section:

Pale yellow incoherent sands ............................5 to o1 feet
Red clayey sands ...................................... 7 to Io feet
Gray phosphatic sands (exposed) ........................ 15 feet
The gray sands give place laterally to phosphate rock.

Pit No. 2 of the Cummer Lumber Company is perhaps the
largest single pit in operation in the hard rock phosphate section.
This pit is reported to include at the present time about thirteen
acres. Pit No. 5 of this Company, one mile west of Newberry,
gives an exposure of the sandstone and flint pebble conglomerate al-
ready referred to as occurring occasionally in the hard rock de-
Fosits. The pebbles are round and more or less flattened. They
vary in size from very small pebbles to pebbles weighing five to sev-
en pounds.
In the pit of the Union Phosphate Company at Tioga a con-
siderable number of rounded elongate siliceous boulders occur.
These vary in size, the largest approximating a ton in weight.
They are embedded in the phosphate-bearing matrix.
The many other pits which are now being worked, or which
have recently been abandoned, although varying much even within
a single pit in details are in general much the same as those de-
scribed.
The limestone in this county as a rule, lies relatively near the
surface. In most instances the limestone is encountered before or
very soon after reaching the water level. The phosphate is thus
largely worked out by dry mining and dredges are not in use.
The limestone is encountered at varying depths. One pit may
show a great.deal of limestone projecting as peaks, while another
pit of equal depth near by may scarcely reach the limestone.
Some of the limestone peaks project 15 to 25 feet above the
general level of the bottom of the pit. The ph sphate-bearing
matrix here as elsewhere fills up the irregularities in the lime-
stone. The top surface of the limestone is as elsewhere entirely

28 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

irregular. In general clay lenses in the phosphate matrix are most
frequent in the upper part of the formation.
The red clayey sand called "hardpan" by the miners may be
present or lacking in the pits of this section. The loose pale yel-
low sand is practically always present varying in thickness from
I to 25 feet.

MARION COUNTY.

The plate rock deposit found in the vicinity of Anthony and
Sparr in the north central part of Marion County represents an
eastward extension of the phosphate-bearing formation. The
relation of the phosphate matrix to the underlying limestone is the
same as previously described. The limestone projects into the
phosphate matrix as rounded peaks. (P1. 5.) Circular depres-
sions similar in appearance to pot holes or to "natural wells" are
frequent in this section. These through subsidence are filled with
the phosphate matrix. One of these depressions observed by the
writer had been cut into, in the process of mining. This depres-
sion was about three and one-half feet in diameter at the top.
fifteen feet deep and narrowed gradually to the bottom. Other
depressions variable in diameter and in depth occur. The lime-
stone lying below the line of the underground water level has us-
ually a rough and jagged surface owing to solution by water in
contact with the limestone. Above the water level the limestone
has a smooth rounded surface. The shells and other fossils below
water level are often removed by solution; above this level they
are eroded off plane with the general rock surface. The plate
rock beds show evidence of having been originally faintly strat-
ified. Much of the stratification that originally existed, however,
has been destroyed through repeated local subsidence as the un-
derlying limestone was removed by solution. The stratification
lines in the plate rock are frequently much curved and distorted ow-
ing to this irregular subsidence. (P1. 2, Fig. 3.)
The chief difference noted between the plate rock and the ty-
pical hard rock region is in the relatively large amount of fragmen-
tary phosphate rock and small amount of boulder rock. In other
words the mechanically transported rock in this section predom-
inates over the rock formed chemically in situ. Flint and lime-
stone boulders chemically formed are likewise absent or rare.
The deposits at Standard and at Juliette in the western part of
Marion County are similar in general character to the hard rock
deposits as previously described. The mines in this section are

THE FLORIDA PHOSPHATE DEPOSITS.

dry mines and usually reach to the bottom of the phosphate
formation in places encountering the limestone.
In the southwestern part of Marion County and in Citrus
County the hard rock phosphate-bearing formation reaches its
maximum thickness. The underlying limestone dips in passing
to the south, and is ordinarily encountered at a considerable depth
from the surface. Many of the phosphate pits in this section
are worked as dry mines to the underground water level and
afterwards as dredge mines to such depth as the dipper will reach.
Some of the pits on higher lands are mined as dry mines only.
The pit at the Dunnellon Phosphate Company plant No. Io
was one of the first pits regularly worked in the phosphate section
and has been continuously in operation for the past twenty years.
This mine is operated by a dredge. The bottom of the phosphate
is not reached in this pit and the full thickness of the formation
at this place has not been determined.

CITRUS COUNTY.
The conditions in Citrus County are in a general way similar
to the conditions in the vicinity of Dunnellon in Marion County.
The underlying limestone is only occasionally seen in the pits in
this section. It is, however, frequently reached in the dredge
operations below the water level. The surface of the limestone
wherever seen projects as rounded peaks similar in character to
the conditions further north. There is on an average more clay
to be seen in the phosphate formation in this section than in the
northern part of the field. In a few instances, notably that of
the pit of the Istachatta Phosphate Company, the water level is
within a few feet of the surface and the phosphate formation is
entirely submerged. Only the pale sands of the overburden are
here visible.

HERNANDO COUNTY.
Phosphate is being produced in Hernando County in the vic-
inity of Croom. The mine in operation here is a dredge mine.
The relation of the phosphate formation to the underlying lime-
stone as seen in an abandoned pit several miles west of Croom is
the same as that in other parts of the phosphate section, the lime-
stone projecting as rounded peaks. The material above the phos-
phate stratum consists largely of incoherent sands. The usual
gray phosphatic sands weathering purple on exposure are seen sur-
rounding the phosphate rock. In the mines near Croom a con-
siderable amount of clay is associated with the phosphate.

80 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
THICKNESS.

The phosphate-bearing formation is exceedingly variable in
thickness. In general it is of reduced thickness in the northern
part of the area. In Suwannee, Columbia, Alachua and northern
Marion Counties, the formation may reach a thickness of from 30 to
50 feet, although in places it is much reduced or even absent.
The maximum thickness of the formation is probably found in
southern Marion County and in Citrus County. Drillings made by
the Dunnellon Phosphate Company along the Withlacoochee. River
indicate a thickness of from 60 to 70 feet on the particular tract of
land being prospected. Similar drillings by the J. Buttgenbach
Company gave in one instance for the phosphate formation along
the river, a thickness of about 75 feet.
Extensive prospecting carried on by the Southern Phosphate
Development Company near Inverness, indicated for the phos-
phate formation a thickness of 50 tbo oo feet; 70 feet being
a fair average for the particular deposits prospected. It is prob-
able that the depth may in places approach 200 feet, although this
maximum thickness is probably only local.

SOURCE OF MATERIALS.

The very complex and mixed character of the material making
up the phosphate-bearing formation has already been mentioned.
The determination of the source or sources of all this material is
a problem of no little difficulty. A part of the material is of
chemical origin formed in situ. This applies particularly, in the
writers' opinion, to boulder phosphate rock and to flint boulders.
Of the limestone inclusions some constitute a part of the for-
mation as originally accumulated: others doubtless represent less
soluble remnants left behind as the surrounding limestone dis-
solved permitting the phosphate stratum to subside and enclose
them.
The gray sands find their closest resemblance lithologically
to the sands of the Alum Bluff formation. Indeed as developed
locally at many places one scarcely finds characters on which to
distinguish the gray phosphatic sands of this formation from the
similar gray phosphatic sands of the Alum Bluff formation, as
seen at the type locality on the Apalachicola River. That these
sands are residual from the Alum Bluff formation seems probable
although the possibility of their origin from some of the later for-
mations must be admitted. That they remain as residual from
the Vicksburg Limestone the writer cannot believe.

THE FLORIDA PHOSPHATE DEPOSITS.

The source of the dark colored water worn flint pebbles and of
the pebble conglomerate occasionally observed especially in the
northern part of the field is at present scarcely more than con-
jectural.. So far as the writer's observations have extended, ma-
terials of this character occur more frequently in the Miocene than
in any other of the formations of the State. 7 he presence of
mastodon remains indicates admixture of Pliocene material from
some source.
The origin of the phosphate is perhaps the most difficult prob-
lem connected with these and, in fact, with phosphate deposits
in general. In the case of the Florida deposits the writer is in-
clined to the view that the phosphoric acid has been very gradual-
ly concentrated from various formations in which it exists in
only very small quantities. Enrichment by the addition of phos-
phoric acid is a well known process. Many instances have come to
light of shells originally calcareous now completely phosphatized, the
phosphoric acid having replaced the carbonic acid. In many in-
stances the shape and markings of the shell are retained. The bones
imbedded in the phosphate also are more or less completely phos-
phatized. The formation of the phosphate boulders in situ seems
evident. The plate and fragmental rock represent boulders
formed during a preceding stage and subsequently broken, more
or less transported and finally deposited in their present position.
The pebble phosphate found among the rock phosphate is prob-
ably largely water worn detritus mechanically accumulated.

CONDITIONS OF DEPOSITION.

The variable and mixed character of the formation, the fre-
quent clay lenses, the faint tendency to stratification, the occasion-
al local accumulation of loose or conglomerate material indicate
to the writer that the material accumulated in shallow water with
conflicting currents. Much of the material may indeed have been
scarcely at all transported being residual from formations that
have decayed in place. The local accumulation of pebble con-
glomerate, however, as well as the local occurrence of clay lenses
implies conflicting currents in comparatively shallow water. The
faint tendency to stratification leads to the same conclu-
sions. Such stratification as existed, however, has been much
distorted by the settling of the formation as the underlying lime-
stone was removed by solution. The conditions of deposition do
not, in the writer's opinion, necessarily indicate complete resub-
mergence of this area, although such may have been the case. It
is extremely probable that the formations which have gone to decay

32 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

in this section include, aside from the Vicksburg limestones of
Lower Oligocene age, Upper Oligocene formations of the Apal-
achicola group, Marine Miocene formations, and more or less of
Pliocene or later materials since all of these formations occur
in position in the adjacent and uneroded high-lands to the north-
east. In the course of the decay and lowering of the general land
surface there is naturally more or less shifting of material attended
probably by the formation of temporary small lakes and streams.
It is possible that the conditions thus arising may have been suffi-
cient to account for the mixed condition of the materials, the ten-
dency to stratification in places and other evidence of action by
water without the necessity of assuming a complete resubmergence.
On this point, however, the writer feels that evidence has not been
accumulated to form a final opinion.

FORMATION NAME.

It is thus apparent that the formation contains a mixture of
material largely residual from several formations from as early
as the Lower Oligocene and as late at least as the Pliocene, fur-
ther complicated by subsequent chemical action within the for-
mation itself. The residual material moreover has been reworked
and in places transported and redeposited. The term Dunnelion
formation is suggested for these deposits since they were first
found and are best developed in the vicinity of Dunnellon, Florida.

EXPLANATION OF PLATE I.

Fig. I. Phosphate washer for hard rock phosphate in use at pit No. 3, Cummer
Phosphate Company, Alachua County.

Fig. 2. Drill for prospection for hard rock phosphate, in use by the Southern
Phosphate Development Company. The prospect holes are drilled
through the phosphate formation to the underlying formation, the
Vicksburg Limestone, which is reached at this locality at a depth
of 75 to o10 feet.

Fig. 3. View of incline to pit, in the Croom mine of the Buttgenbach Phosphate
Company.

FLORIDA GE(TOI.OICG\I. SURHVEY.

THIRD ANNUAL REPORT. PL. I.

EXPLANATION OF PLATE 2.

Fig. r.-View in ph No. 25 of Central Phosphate Company in Alachua
County, showing irregular top surface of the Vicksburg Limestone (Ocala for-
mation) after removal of the phosphate deposit. The limestone here as else-
where in the phosphate section projects as peaks.

Fig. 2.-View showing the irregular top surface of the Miami oolitic lime-
stone, Dade County, after the removal of the superficial sands. Photo by R
M. Harper.

Fig. 3:--View in the plate rock phosphate pit at Anthony, showing the
laminated structure of the plate rock deposit. The solution of the underlying
limestone has permitted subsidence of the phosphate deposit, the folding being
due to irregular subsidence.

THIRD ANNUAL REPORT. PL. 2.

V LAtt

:gle

FLORIDA GEO)LOGICAL, SURVEY.

EXPLANATION OF PLATE 3.

Fig. .--View in pit No. 5, Prairie Pebble Phosphate Company, Mulberry,
showing overburden of land pebble phosphate. The contact between the light-
colored incoherent sand and the somewhat indurated sand is well marked. The
overburden in this pit is being removed by hydraulics.

Fig. 2.-View in pit of Florida Mining Company, showing a place where
the overburden beneath the superficial sand is indurated, making it necessary
to resort to blasting.

Fig. 3--View in pit of the Pierce Phosphate Company, Pierce, Fla., showing
an abrupt break in the pebble phosphate stratum. The break is seen near the
right side of the picture, where slickensides have developed as the overburden
slid down past the phosphate stratum.

lTIIl D AN N UAL REPORT. PL. 3.

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FLORIDA GE010CICAL SIANFY.

EXPLANATION OF PLATE 4.

Fig. .--View in pit of Pierce Phosphate Company, showing the irregular
top surface of the bed rock (Arcadia marl) after the removal of the phosphate
stratum. Phosphate plant in the background.

Fig. 2.-View in the pit of the Coronet Phosphate Company, Lakeland,
Fla. Unconformity between the coarse phosphate above and the finer pebble
phosphate below. This unconformity, although imperfectly shown in the pho-
tograph, is well marked at this locality. The material above is a coarse con-
glomerate, that beneath is fine pebble imbedded in clay.

Fig. 3--View in pit of Standard Phosphate Company, showing irregular
line of contact, apparent unconformity, between the loose surface sand and the
more indurated sand beneath.

THIRD ANNUAL REPORT. PL. 4.

:gle

FLORIDA GEOLOGICAL SURVEY.

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THE FLORIDA PHOSPHATE DEPOSITS.

THE LAND PEBBLE PHOSPHATE-BONE VALLEY
FORMATION.

LITHOLOGIC DESCRIPTION.

The land pebble formation to which Matson and Clapp applied
the term "Bone Valley Beds" was briefly described in the Second
Annual Report. This formation includes a lower phosphate bear-
ing member and an upper sand or sandstone member. The lower
member of the formation contains the workable phosphate de-
posits. The upper member forms the overburden which must be
removed in mining.
The phosphate bearing member of this formation is more or
less definitely stratified, the stratification line being frequently
continuous along the full length of the pit, a distance of a half
mile or more. Elsewhere the stratification is irregular and cross
bedding is evident.
Although variable from place to place this part of the forma-
tion has an average thickness of from 8 to 12 feet; its maximum
thickness is possibly 18 or 20 feet. The matrix in which the phos-
phate pebble is imbedded consists largely of clay, sand and soft phos-
phate. The pebble phosphate makes up in the workable deposits
some ten to twenty-five per cent. of the whole. This member shows
certain characteristics which are fairly persistent. The lower 2/2
to 3 feet is usually olive green in color, and contains pebble im-
bedded in clay. The next 3 to 5 feet is frequently dark blue in
color although oxidizing on exposure to drab or yellow. The up-
per 2 to 4 feet of this member differs much particularly in the
northern part of the area from that which lies below. This upper
part contains coarser material and has a highest percentage of
pebble phosphate in proportion to the matrix. The break between
the coarser material at the top and the more clayey material be-
neath is particularly well marked as seen in the pit of the Coro-
net Phosphate Company in Hillsboro County (PI. 4, Fig 2.) The
break is here so abrupt as to constitute a distinct unconformity.
The line of contact is marked by the presence of water worn
corals, bone fragments and very coarse conglomerate of phosphate
pebbles. Passing to the south the contact line becomes less marked,
the conglomerate character of the upper part largely disappearing at
the south end of the phosphate area.
The indurated sand above the phosphate has an average thick-
ness of from 10 to 14 feet. Its maximum thickness, however, is
much greater. On the other hand owing to decay and erosion these
sands are in places much reduced and may be locally entirely

34 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT..

absent, the phosphate lying at the surface. Usually the sand con-
tains sufficient admixture of clay to give it coherence. Under
these conditions it oxidizes red near the surface. While this is
the prevailing phase of the sand it is nevertheless subject to con-
siderable variation from place to place. Not infrequently the sand
is firmly cemented forming the so called "hardpan" which gives
much trouble in prospecting and frequently necessitates blasting
in mining. (Plate 3, Fig. 2.) In places the sand has a calca-
reous or phosphatic cement. Locally it varies also to an indurated
rock with innumerable small cavities which gives a vesicular ap-
pearance to the mass. A sample of this rock was found to contain
I5.56% phosphoric acid (equivalent to 33.97% tri-calcium phos-
phate).
The phosphate bearing member contains vertebrate remains
including both marine and land animals. Most of the bones are
more or less rolled and water worn although occasional whole
skeletons are found. In the sands above the phosphate, fossils are
rare. The writer has obtained, however, through the kindness
of Mr. M. A. Waldo, Manager of the Dominion Phosphate Com-
pany a single tooth of the mastodon preserved as a cast in the
phosphatic sands of the overburden. Aside from a few casts
near the bottom of the phosphate bed invertebrates have not been
found in this formation.

MATERIALS LYING ABOVE THE PHOSPHATE FORMATION.

As in the case of the hard rock section the surface material con-
sists of incoherent pale yellow sand. The depth of this sand is vari-
able, ranging from four to ten or more feet. A very definite and
often irregular line separates these loose sands from the formation
beneath. (P1. 3, Figs. I and 2, and P1. 4, Fig. 3.) This line Matson
interprets as an evident unconformity.* This may be true al-
though the fact must not be overlooked that seeming unconfor-
niities in materials lying near the surface may in reality repre-
sent only lines of decay. The writer is inclined to regard the
loose surface sands in this section as residual, the irregular
line representing the line of complete disintegration of the
original sandy formation. A similar explanation has been
offered previously by the writer for the surface sands of Gadsden
County as well as for the sands overlying the hard rock phos-
phate formation. (ante P. 24.)

*Florida Geol. Survey. Second Annual Report, p. 139, 1909.
tFlorida Geol. Survey. Second Annual Report, p. 263, 1909.

rHE FLORIDA PHOSPHATE DEPOSITS.

RELATION TO THE UNDERLYING FORMATION-ARCADIA MARL?

The land pebble formation rests upon a pale yellow phosphatic
marl, referred to by the miners as "bed rock". The relation is
apparently as stated by Matson, that of unconformity. This is
observed in the pit of the Pierce Phosphate Company, six miles
south of Mulberry. The marl as exposed in this pit has a very
roughly eroded surface. (PI. 4, Fig. I.) The phosphate
matrix fills these irregularities. The "bed rock" although varying
in character is found to underlie the phosphate wherever observed
in Hillsboro, Polk and DeSoto Counties. The marl beneath he
phosphate is probably of Pliocene age.
In 1892 Dall applied the term Arcadia marl to a marl exposed
on Mares Creek, six miles above Arcadia.* This marl Dall' re-
garded as slightly older than the Caloosahatchee marl. Matson is
of the opinion that the Arcadia marl may be only a phase of the
Caloosahatchee marl. The exposure on Mares Creek examined
by the writer occurs at and near the mouth of the creek. The marl
as seen here has in lithologic character no very striking resemblance
to the Caloosahatchee marl but is lithologically very similar to the
marls seen at numerous places elsewhere on Peace Creek and un-
derlying the Bone Valley formation. From the continuity of
exposures and similarity in character it seems probable that the
"bed rock" of the land pebble phosphate is the Arcadia marl.

LOCAL DETAILS.

HILLSBORO COUNTY.
The northernmost plant in the land pebble section is that of the
Coronet Phosphate Company located in Hillsboro County three
miles southeast of Plant City. The following sections were ob-
served in pits Nos. I and 2 of this plant.

SECTION IN PIT NO. I, CORONET PHOSPHATE COMPANY.
Pale yellow incoherent sand .............................. 4 feet
Gray indurated sand...................... .... ... ........ 4 feet
Conglomerate of phosphate pebble, bone fragments, water
worn flints and pebbles ............................. to 1 Y feet
Buff yellow and olive green clay ...................... 2 to 5 feet
Yellow clay and marl, "bed rock" at bottom of pit.

SECTION IN PIT NO. 2, CORONET PHOSPHATE COMPANY.
Incoherent sand.................. ............................. 6 feet
Indurated sands grading at base into a conglomerate of phos-

*Dall, Wm. H., U. S. Geol. Survey, Bull. No. 84, 892, pp. 131-132.

36 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

phate pebble, bone fragments, water worn flints and coral..34 .feet
Buff yellow and olive green clay matrix in which phosphate
pebble is embedded .......... ......... .............. 5 feet

The superficial pale yellow sand is of fine texture and is non-
fossiliferous. The indurated gray sand is also non-iossilifen-us
in the upper part. Towards the base, however, this sand grades
into the conglomerate previously mentioned, the lower one to one
and one-half feet being a very rich phosphate conglomerate.
The break between the phosphate pebble conglomerate and the
underlying phosphate matrix is very abrupt representing a local
unconformity. (PI. 4, Fig. 2.) Aside from the phosphate there
is found in this conglomerate lying along the line of contact a con-
siderable amount of coral occurring as water worn fragments, some
of which weigh as much as 8 or io pounds. The larger corals us-
ually lie immediately upon the contact line. Water worn flint
pebbles of one or two pounds in weight, also occur together with
fragments of bone.
The phosphate stratum lying beneath this unconformity is
chiefly of.bluish color which upon exposure oxidizes to a light
buff yellow. Occasional bones and flint pebbles are found also
in this part of the formation. The-water worn corals, however.
were not observed below the unconformity. That part of the
phosphate matrix below the unconformity contains also many
rounded pieces of soft phosphate while that above the unconformi-
ty contains hard pebble rock only.

POLK COUNTY.
A pit operated by the Standard Phosphate Company near
Medulla is notable for the extreme irregularity in the stratifica-
tion of the phosphate bearing member. The strata here are ob-
served to dip at an angle of as much as 45 degrees from the hori-
zontal. The bed rock which consists of the usual yellow clay marl
is likewise irregular and is observed to rise as much as fourteen
feet in a horizontal distance of 50 feet.
In the pit of the Medulla Phosphate Company at Christina,
the following section was observed:

Incoherent pale yellow sand............................ 2 to 5 feet
Gray sand, iron stained near surface....................... 8 feet
Phosphate bearing matrix.............................. I5 to 20 feet
Yellow clayey marl, "bed rock" (exposed) ................ 4 feet

In Pit No. 3 of the Prairie Pebble Phosphate Company,
near Mulberry the following section was observed:

THE FLORIDA PHOSPHATE DEPOSITS.

Incoherent sand ............................. ....... .... 2 to 4 feet
Indurated gray sand grading below into phosphate matrixI2 to 16 feet
Workable phosphate stratum........................... 10 to 12 feet
Yellow clay marl, "bed rock" (exposed).................. 5 feet
The upper 5 or 6 feet of the sand of this section contain some
clay and are stained red by iron oxide. At the base the sands pass
gradually into the pebble rock conglomerate. Beneath the pebble
rock conglomerate the matrix is more clayey while near the base the
clays of the matrix are olive green in color. The conglomerate as
seen in this pit differs from that seen in the pit of the Coronet Phos-
phate Company in the absence of corals along the contact line.
The relation between the phosphate bearing formation and
the underlying marl or limestone is well seen in the pit of the
Pierce Phosphate Companiy, six miles south of Mulberry. The
marl exposed in this pit, as previously stated, has a very roughly
eroded surface. (PI. 4, Fig. I.) The phosphate matrix fills these
irregularities. At this pit there is observed in places below the
workable phosphate matrix one to three feet of material consisting
of quartz sand intimately mixed with small black phosphatic peb-
bles. An old stream channel crosses this pit. In the bed of the
stream is fine loose, more or less stratified dark colored sand. This
stream where examined has cut down to the coarse part of the
phosphate matrix and at one point almost cut out this coarse part
of the matrix, that is it has cut through the sand and the
upper part of the phosphate formation. This stream occupies
approximately the bed of an existing stream and probably indicates
that conditions were such formerly as to permit the stream to cut
its bed deeper than now, the channel subsequently having been ag-
graded. Near by in the same pit is a sudden dip in the sand over-
burden. (Pl. 3, Fig. 3.) The point of break gives very much the
character of a sink hole.

CONDITION OF DEPOSITION.
In attempting to determine the condition under which the land
pebble phosphate formation accumulated, the characteristics of the
formation itself should be borne clearly in mind. The formation
is more or less definitely stratified. The stratification, however,
is irregular, and cross bedding and local sand deposits occur.
The phosphate bearing part of the formation is highly fossilifer-
ous containing both land and marine vertebrates. Most of these
fossil bones are more or less eroded and water worn, indicating
that they have been rolled or washed before reaching their final
resting place. Occasionally, however, a complete skeleton occurs.
Water worn bones of both the land and marine vertebrates could

38 FLORIDA GEOLOGICAL SURVEY-THIRD 'ANNUAL REPORT.

have as suggested by Matson*, washed into this deposit from some
pre-existing formation. This can not apply, however, to the oc-
casional complete skeletons that are found in these deposits. It
is probable that the formation accumulated in comparatively shallow
water. That the water was not deep is evident from the irregu-
larity of the stratification and from the occasional cross bedding.
Also that the place of accumulation was not far removed from
land is indicated by the comparatively coarse material and by the
presence of numerous bones of land animals.
CHANGE OF CONDITIONS DURING DEPOSITION.
The land pebble phosphate formation, as previously stated, is
not of uniform character throughout, indicating that the conditions
varied from time to time during the accumulation of the material.
The earliest phase of the formation observed consists of clear
quartz grains and very small black pebble phosphate forming
a stratum one to four feet in thickness. This material occurs
only locally and is non-workable, the phosphate pebble being too
small to separate from the sand. This phase of the formation
may be observed in the pit of the Pierce Phosphate Company, six
miles south of Mulberry. The formation divides itself into the
workable phosphate stratum and the indurated sands forming a
part of the overburden previously described. Stratigraphically
the most pronounced break in the formation is that which occurs
within the phosphate stratum itself, particularly in the northern
part of the phosphate field, where the pebble phosphate con-
glomerate rests upon the underlying clayey phosphate matrix.
This conglomerate grades above very gradually into the overlying
gray sands. A change in condition in deposition is clearly in-
dicated. This change probably indicates elevation of the land to
the north. Following this elevation there was brought in first the
coarse phosphatic material accompanied by the flint and corals,
and later the sands which make up the upper member of the for-
mation.
STATE AND GOVERNMENT LANDS IN THE PHOSPHATE SECTION.
Both the State and the National Governments still own lands
in the phosphate sections of the State. All State lands have been
withdrawn from sale by order of the Internal Improvement Board
until properly classified.
The President, by executive order has withdrawn during the
year 27,400 acres of Government land in the phosphate section of
Florida.

*Florida Geol. Survey, Second Annual Report, p. 140, 19o9.

THE FLORIDA PHOSPHATE DEPOSITS.

PHOSPHATE COMPANIES OPERATING IN FLORIDA DURING 1909
Thirty-six companies in all were engaged in mining phosphate
in Florida during all or part of the year 9gog. Of these twenty
companies operated in the hard rock section. Of this number,
however, not more than fourteen were actually producing phos-
phate during any considerable part of the year, others being tem-
porarily closed or preparing for subsequent operations. In the
land pebble district sixteen companies were engaged in mining
phosphate during all or a part of the year.

List of companies operating during all or part of 1909:
NAMES. OFMCEL MINES.
I Arm6ur Fertilizer Co.......... Fort Meade........ Pebble
2 Bradley, Peter B. and Robert S.Floral City......... Hard Rock.
3 Buttgenbach, J. & Co........... Dunnellon.... .. .. Hard Rock.
4 Camp Phosphate Co............ Ocala... ......... Hard Rock.
5 Campagnie Generale des Phos-
phates de la Floride............ Anthony............. Plate Rock.
6 Charleston, S. C. Mining and
Manufacturing Co.... ........ Charleston, S. C..... Pebble.
7 Central Phosphate Co............ Newberry.......... Hard Rock.
8 Coronet Phosphate Co......... Lakeland.... .... .. Pebble.
9 Cummer Lumber Co............Jacksonville...... .Hard Rock.
zo Dominion Phosphate Co........ Bartow.... ..... Pebble.
zi Dennis & Blanton ...... .......Gainesville...... ... Hard Rock.
12 Dunnellon Phosphate Co......... Rockwell. .. ...... Hard Rock.
13 Dutton Phosphate Co........... Gainesville........ Hard Rock.
14 Florida Mining Co............. Mulberry ...... .... Pebble.
15 Fla. Phosphate Mining Corpo'n.. Norfolk, Va.........Pebble.
i6 Franklin Phosphate Co........... Newberry.. .. .... Hard Rock.
17 Ft. White Hard Rock Co........ Baltimore, Md.. .. Hard Rock.
18 Germofert Mining Co........... Charleston, S. C.... Pebble.
19 Holder Phosphate Co........... Ocala.... .. .. .. ..Hard Rock.
2o International Phosphate Co..... Ft. Meade.. .. .... Pebble.
21 Istachatta Phosphate Co........ Istachatta.. .... Hard Rock.
22 John McDowell................Newberry..........Hard Rock.
23 Medulla Phosphate Co.......... Christina.. ...... Pebble.
24 Mutual Mining Co............ Savannah, Ga.. .... Hard Rock.
25 Palmetto Phosphate Co......... Baltimore, Md.. ...Pebble.
26 Phosphate Mining Co.......... New York...... ..Pebble.
27 Pierce Phosphate Co............ New York........ Pebble.
28 Prairie Pebble Phosphate Co.... Savannah Ga.... .. Pebble.
29 Schilman & Bene.............. Ocala.... ........ Hard Rock.
30 Southern Phosphate Develop-
ment Co.................. ... Ocala.... .. .......Hard Rock.
31 State Phosphate Co........... Bartow...... .. .Pebble.
32 Standard Phosphate Co........ Christina ......... Pebble.
33 Thompson, M. C. & T. A........ Willeford...... ....Hard Rock.
34 Tilghman Phosphate Co.........Bowling Green...... Pebble.
35 Union Phosphate Co.......... Tioga.. .......... Hard Rock.
36 Williams Phosphate Co.........Inverness...... .. Hard Rock.

40 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
THE PRODUCTION OF PHOSPHATE DURING 9og9.

The total production of phosphate in Florida for the year 1909
shows a slight decrease over that of the preceding year. The total
production for 19o8, exclusive of river pebble, was 1,918,o0 long
tons. Including river pebble the total production for 1908 was
1,950,961 long tons, while for the year 1909 the total production
was 1,862,151 long tons. The decrease in production occurred
entirely within the hard rock section, the output of land pebble hav-
ing actually increased.
The shipment of phosphate for the year 1909 practically equall-
ed the production both of hard rock and of land pebble. Hard
rock shipments amounting to 514,1To long tons have been reported
as against the production of 527,582 long tons. For the pebble
rock, shipments have been reported amounting to 1,329,102 long
tons against the production of 1,334,569 long tons.
The phosphate market continued very much depressed during
the year. Hard rock phosphate was reported to have been sold
as low as from $5 to $6 per ton f. o. b. at mines, while land pebble
was sold from $2.75 to $4.25 per ton f. o. b. at mines.

HARD ROCK PHOSPHATE.

The production of hard rock phosphate during 1909 shows a
decided falling off from that of the preceding year, the output hav-
ing been curtailed by the operators on account of the l,,w prices.
The amount mined during 1908 was 768,0II long tons, while for
the year 1909 the total production reported is 527,582 long tons,
a decrease of about 240,000 tons, or about 30 per cent.
As in former years practically all of the hard rock phosphate
shipped, was consigned to foreign markets. The total amount
of hard rock phosphate consigned for use in the United States
during 1909 was 17,456 long tons. Of this amount 13,726 tons
were used in Florida. The amount exported during 1909 was
496,645 long tons.

PEBBLE PHOSPHATE.

While the production of hard rock phosphate was reduced dur-
ing 1909, the output of pebble was increased. The amount of
pebble rock mined in 1908 was approximately I,I5o,ooo long tons.
For the year 1909 the total production of pebble phosphate was
1,334,569 long tons, an increase of over 150,000 tons.
Shipments listed by the "American Fertilizer" show that the
total pebble rock exported during 1909 was 509,341 long tons.

THE FLORIDA PHOSPHATE DEPOSITS. 41

The amount consigned for use within the United States as reported
by the operators was 819,761 long tons.
The mining of pebble rock on Peace River discontinued during
the latter part of 1908 was not resumed during 1909. A small
shipment of 3,215 tons of this rock during 1909, mined in 1908,
is included in the total domestic shipments of pebble rock as given
above.

SUMMARY OF PRODUCTION AND SHIPMENTS FOR THE YEAR 1909.

Hard rock......

LONG TONS.
Total production. ............ ................... 527,582
Consigned for use in U. S.......................... 17,456
Exported ........... ... ................... 496,646
Total shipments... ....... ...................... 514,10

Pebble rock......
Total production ......... ... ............... ,334,569
Consigned for use in U. S.......................... 819,761
Exported......................................... 509J41
Total shipments .............................. ,329,102
Total production of hard and pebble rock...........................1,862,151
Total shipments of hard and pebble rock.............................. 1,843,203

COMPARATIVE TABLE OF PRODUCTION AND SHIPMENT OF
FLORIDA PHOSPHATE FOR THE YEARS 1908 AND 90o9.
(LONG TONS.)

PRODUCTION Consned for Ue EXPORTED
t in e U EXPORT D

1908 1909 1909 190 1909

768.011 9.900 17456 631,001 496645
1,150,000 I 2 .. 421,781 819.701 470,270 509,341

1.918.011 1,862.151 431.681 837.217 1,101,271 1,0.5,986

Total Shtpments

1908 1909

631,001 r61 1^i
90J.519 ^', r

1,531,520 1,843,208

Hard Rock...........
Pebble Rock........

Totals .................

---

SOME FLORIDA LAKES AND LAKE BASINS

BY E. H. SELLARDS.

_ _~~_____ ___~~_ ~__~~_~11_11_~___.1_1_____1_~__1__

CONTENTS.
PAGE
Introduction ............... . ...... ................. ............... 47
Location of the Lakes .............. . ................................ 48
Characteristics .................................................... 48
Origin and History of Development.................................... 49
Relation of the Basins to the Level of Permanent Underground Water.... 52
Descriptions of Typical Lakes.......................... ............ 53
Lake lamonia, Leon County...................................... 53
Lake Jackson, Leon County......................................... 56
Lake Lafayette, Leon County ........................................ 57
Lake Miccosukee, Jefferson County ..... .......................... 58
Alligator Lake, Columbia County.................................. 61
Alachua Lake, Alachua County.................................... 62
Ocheesee Lake, Jackson County.................................... 67
Methods of Drainage-
By Surface Ditching .................. ........................... 68
By Wells ..................... ................................ 68
Summary .......... ............. ...................... 74

-. |

ILLUSTRATIONS.
PLATE No. FOLLOWING PA;K,
6. Miccosukee Basin, Low Water Stage of 19o9 ........... .......... 64
7- Fig. i. Lake Jackson ...........................................
Fig. 2. Alligator Lake ........... ............................. 64
8. Fig. i. The Sink of Lake Lafayette................ .........
Fig. 2. Paynes Prairie, Looking Out From the Sink..............
Fig. 3. View of Paynes Prairie From Near the Sink............. 4
9. Two views of Spouting Well Near Orlando ..................... 64

TEXT FIGURE No. PAGE
I. Sketch Map Showing Location of Lakes lamonia, Jackson, Lafay-
ette, and Miccosukee ................. ..................... 54
2. Lake Jackson ............... ............ .. ............ 56
3. Lake Lafayette ........................................ 58
4. Lake Miccosukee .................... ..................... 60
5. Sketch Map of Hogtown Prairie and Surroundings............... 66

SOME FLORIDA LAKES AND LAKE BASINS.

E. H. SELLARDS.

INTRODUCTION.
Florida is justly celebrated for the number and beauty of its
lakes. These lakes vary in size from the small ponds which scarce-
ly exceed a few rods in circumference to the great Okeechobee, the
surface area of which exceeds 700 square miles. Okeechobee is
in fact noteworthy as being, with the exception of Lake Michigan,
the largest fresh water lake lying wholly within the United States.
In depth the Florida lakes are likewise variable, and in fact the
depth is frequently in inverse ratio to the size. Many of the large
lakes are comparatively shallow, while some of the small lakes are
deep. This is particularly true of the small sink-hole lakes, some
of which, while not exceeding a few rods in circumference have a
depth of one to two hundred or more feet. In origin and his-
tory of development the Florida lakes are as variable as in other
characteristics.
The lakes described in this paper include only a few of the many
Florida lakes and represent a type peculiar in character and in
manner of development. They are fresh water lakes, often of con-
siderable size, although usually relatively shallow as compared to
their areal extent. Moreover they are variable in character. Un-
der normal conditions they are clear water lakes abounding in fish
and the favorite haunt of the wild duck. They have as a rule no
surface outlet, yet from many of them the water has at times
disappeared in a manner seemingly inexplicable. In most instances
the lakes thus disappearing have refilled slowly. Some of them,
however, have remained dry a number of years. A correct under-
standing of these lakes together with the origin and development
of the basins which they occupy is necessarily based on a study of
the geologic formations which underlie them.
The fall of 1909 offered an exceptionally favorable time for in-
vestigating lakes of this character. The prolonged dry weather
of the past few years had reduced these lakes to a low stage offer-
ing an opportunity of examining the soil and vegetation as well as
the geologic structure of their basins. At the Tallahassee sta-
tion in Leon County, near which several of these lakes are located,
the rainfall at the close of 1909 had been below normal as shown
by the weather bureau records for two years in succession. At
the Gainesville station in Alachua County, the rainfall had been

4S FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

below normal during the preceding four years and at the Lake
City station the rainfall had been below normal for at least three
years in succession and apparently, from some imperfect records,
had not reached normal during the preceding seven years.
Under these circumstances it was deemed advisable to make use
of the favorable opportunity during the fall of 1909 for investigat-
ing the geology of these lake basins.
Attempts have been made to drain some of these lakes as the
land is more or less valuable for agricultural purposes. In some
instances drainage operations have been delayed owing to
legal difficulties arising from the variable character of the
lakes. The lake basins claimed by the State under the title of
swamp and overflowed lands were likewise claimed by abutting
property owners under the privilege of riparian rights. A recent
decision of the State Supreme Court vests the title of the lands in
question with the State, not, however, as swamp and overflowed
land but as navigable water.

LOCATION OF LAKES.

The lakes described in this paper occur in the upland section
of the interior of Florida. In general they may be said to occur in
a belt extending with interruptions from the Ocklocknee Rivex
east and south paralleling the Gulf of Mexico to Hernando and
Pasco Counties. The largest and best known examples are found
in Leon, Jefferson, Columbia and Alachua Counties. Smaller but
no less typical lakes of this type occur in Madison, Suwannee,
Marion, Levy, Orange, Hernando and probably some other counties
adjacent to those mentioned. West of the Apalachicola River
small lakes of similar character occur in Jackson County and pos-
sibly also in Holmes County.* The lakes selected for description
as illustrating this type include Lakes Iamonia, Jackson, and La-
fayette, in Leon County; Lake Miccosukee in Jefferson County:
Alligator Lake in Columbia County; Alachua Lake in Alachua
County; and Ocheesee Lake in Jackson County. The belt >f
country through which these lakes occur, although now broken up
through natural processes of erosion into several more or less well
defined sub-divisions, was probably at one time continuous.

CHARACTERISTICS.

The leading characteristics of these lakes have been mentioned.
They do not occur along the coast nor in the level low lying parts

*For location of counties, see map plate 1o, following page 121.

SOME FLORIDA LAKES AND LAKE BASINS.

of the state. On the contrary they are on the uplands, and occur
in sections having a hilly or rolling topography. Sinks or open-
ings occur through which the water escapes into the underlying
formations. These sinks are located ordinarily, at the foot of a
steep bluff bordering the lake. Around the main sink one finds
ordinarily other sinks of more recent formation indicating the man-
ner and direction of enlargement of the basin. The sinks through
which the water escapes are variable in depth but reach in all cases
to underlying limestones. A channel as a rule leads back from this
sink across the lake bottom representing the main channel of flow of
trater to the sink. Aside from this channel the bottom of the lake is
relatively flat and- level, although slight local depressions occur
involving in some instances differences of level, of ten to fifteen
feet. The soil in the lake basins varies considerably. In some
of the lakes-those which seldom go dry-there is an accumulation
of muck or peat formed largely from pond lilies and other aquatic
vegetation. Local depressions in the lake often have an accumu-
lation of this material amounting to several feet. Some of the other
lakes which frequently go dry have little or no muck except in de-
pressions which hold water even in dry seasons. Beneath the
.,uck is usually found light colored sand washed and blown from
the neighboring highlands. This sand may be several feet deep in
places, elsewhere it is largely absent. Ordinarily a sandy clay
occurs beneath the sand.
When these lakes dry up the water is commonly reported as
running out very suddenly. This, however, is usually not the case.
As long as the lake has sufficient water to cover the entire basin
the lowering of the water surface proceeds very slowly. Subse-
quent-ly when the total surface area of the lake becomes much re-
stricted the lowering of the water surface proceeds much more
rapidly. This leads to the statement that the water of the lake dis-
appeared suddenly while as a matter of fact in many cases the
water escapes through the sink no faster and indeed hardly so
fast during the dry season as-it had been escaping when the lake
was full during the season of normal rainfall. It is true, however,
that new sinks occasionally form in the bottom of the lake. In
the case of the formation of new sinks the rate of escape of the
water is increased.

ORIGIN AND HISTORY OF DEVELOPMENT.

The origin of these lake basins is a part of the history of de-
velopment of the general topography of the region. In this ce-
velopment both mechanical erosion and erosion by .:,lut;.-i have

50 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

had a part.. The land surface when first elevated above sea was
evidently much more nearly level than at present. Upon being
lifted above sea level irregularities in topography rapidly develop.
A first step in the process of erosion is the development of
stream channels and valleys, largely through mechanical erosion. In
addition to mechanical erosion, crusion by solution due to under-
ground water is likewise in process especially in sections underlaid
by limestones.
As illustrating the efficiency of underground water as an erod-
ing agent, the writer in a previous report computed the rate of
erosion by solution in the sections of the state underlaid by lime-
stones.* The estimate of the rate of solution given below is taken
from that report.
Solution is the most apparent, and geologically the most im-
portant result of underground water circulation. Rain water, while
passing through the air, takes into solution a small amount of
C02 gas. To this is added organic and mineral acids taken up
while passing through the soil. Increased pressure, as the water
descends into the earth, enables the water to hold in solution greater
quantities of gases, acids and salts, all of which greatly increase the
dissolving power of the water.
That underground water is efficient as a solvent is evident from
the analyses of well and spring waters. 'Rain water entering the
earth with almost no solids in solution, returns to the surface
through springs and wells with a load of mineral solids in solution
determined by the length of time it has been in the ground, the
distance traveled, and the character of the rocks and minerals with
which it comes in contact.
The mineral matter thus taken into solution is carried along
with water, and, while some of it is re-deposited, a large amount is
removed annually.
An estimate of the total mineral solids thus removed is difficult.
A conception of the largeness of the amount removed is obtained
from a consideration of some of the individual springs.
The water of Silver Springs contains, as shown by analysis, 274
parts solids per million parts water. Otherwise expressed, each
million pounds of water is carrying with it 274 pounds of solids in
solution. Silver Spring is estimated to flow a little more than
three million pounds of water per minute (368,913 gallons). The
interior of Florida is thus being carried into the ocean through Sil-
ver Springs at the rate of more than 340 pounds per minute, or
about six hundred tons per day.

*Fla. Geol. Survey Bulletin No. I, pp. 46, 47, 48, 19o8

SOME FLORIDA LAKES AND LAKE BASINS.

The total solids removed in solution through six other springs
of central Florida, expressed in tabular form, gives the following
results:*

Name of Spring County.

Blue ................. Marion
Blue ...................Levy
Ichetucknee ........... Columbia
Newland ............... Suwannee
Weekiwachee .......... Hernando
White Sulphur ........Hamilton
Suwannee .............Suwannee

Total solids Est. flow
(parts per (gals. per
million) min.)
112.1 349.166
196.8 25,00o
211.6 18o,ooo
233.5 75,00o
227.8 o00,000
166.6 32,400
332-7 19,747

As the basis of an estimate of the total solids removed annually
from the interior, let it be assumed, ( ) that the average total solids
in spring water amount to as much as 219 parts per million, this
average being obtained from eight of the typical large springs of
central Florida; (2) that the annual escape of the underground
water approximates the annual in-take, amounting, as previously
estimated to 460,536,689 gallons per square mile. Upon these
estimates the mineral solids removed amount to a little more than
four hundred tons annually per square mile.
Of the minerals thus removed, calcium carbonate or limestone
greatly predominates, exceeding the combined weight of all other
minerals. From the analyses it appears that magnesium carbonate,
magnesium and calcium sulphates are present in variable, although
usually limited, quantities. Chlorides are normally present in small
amount, although occasionally, as in the case of Perrian Spring,
they are exceptionally high. Silica is present in amounts varying
from 5 to 25.5 parts per million. Traces of phosphoric acid and of
iron and alumina are usually present.
The several undetermined factors which enter into the above
estimates of mineral solids removed make it difficult to formulate
a concrete statement of the rate of lowering of the general surface
level. Nevertheless, such statements are desired and have a com-
parative value. Assuming for the rock removed, most of which is

*For 340 in the second line from the bottom on the preceding page read 840.
tOrganic matter is deducted from the total solids as given for Suwannee
Sulphur and White Sulphur Springs. The organic matter occurring in the
other springs is of small amounts and was not separately determined. Analyses
of the water of these springs were given in Bulletin No. I, pp. 72-75, 1908.

Solids re-
moved lbs.
per day.
469,698
59,040
457,056
210,150
273,360
64,771
78,8z6

62 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

limestone, an average specific gravity of 2.5, a layer one foot thick
over one square mile should weigh about two and one-sixth million
tons. The calculated rate of removal of this rock is about four
hundred tons per square mile per year. From these estimates it
would appear that the surface level of the central peninsular sec-
tion of Florida is being lowered by solution at the rate of a foot in
five or six thousand years.
With due allowance for a wide margin of error in the above
estimates it is still evident that a very great amount of mineral
solids is being removed annually in solution. The first effect of
solution in limestone is to develop cavities through the rock along
the line of ready flow of underground water. These cavities grad-
ually enlarge until the overlying material, no longer able to support
its own weight, caves in, forming a sink.
The formation of a sink is a first step in the development of the
many basins large and small occupied by these temporary lakes.
A sink usually retains connection with the underlying limestone
for some time after its formation and water entering the sink
escapes into the limestone. Under these circumstances more or
less of the material lying immediately around the sink is carried
by surface wash through the sink. Moreover the large amount of
water entering through the sink results in rapid solution in the
limestone of that immediate vicinity. The result is frequently the
formation of other sinks in close proximity to the first. As old
sinks become clogged or partly filled, new sinks form by this pro-
cess continually enlarging the basin.
Not infrequently a sink forms in or near the bed of a stream.
When this occurs the lower course of the stream, or a part of it,
may be reversed. Where many sinks form in succession or through
a long period of time the valley of the stream is thereby enlarged
and is frequently carried to a level lower than the original oulct.
Lakes lamonia and Lafayette in Leon County and Alachua Lake in
Alachua County are illustrations of basins of this type.

RELATION OF THE LAKE BASINS TO THE LEVEL OF
PERMANENT UNDERGROUND WATER.

It is important to note the relation of the3j lake basins to the
permanent underground water level of the formation into which
they drain. It is a well established fact that solution by under-

SOME FLORIDA LAKES AND LAKE BASINS.

ground water goes on more rapidly above the level of permanent
underground water than below this level. The term "belt of
weathering" is commonly applied to that part of the earth's crust
lying above the underground water level; while the term "belt of
cementation" is applied to that part lying immediately below this
level. According to Van Hise "the most characteristic reaction oc
the belt of weathering is solution. In contrast with this the most
characteristic reaction in the belt of cementation is deposition in the
openings of the rocks."* The rapid solution in the belt of weather-
ing is due to a number of causes. First of all the water in this
part of the earth's crust moves freely, while in the belt of cemen-
tation the water often moves very slowly. Moreover water is cap-
able under given conditions of carrying a definite amount of min-
eral solids in solution and as the water from the surface enters
the earth with little or no load, until it becomes saturated it takes
materials into solution readily.
In accordance with this principle it is found that the largest
of these basins are, as a rule, reduced practically to the level of un-
derground water. Many of the smaller basins, it is true, have not
reached the permanent water level, and stand at varying heights
above that level. The relation of the basins to the underground
water has a practical bearing and will be referred to again in con-
nection with methods of drainage of the lakes.

DESCRIPTIONS OF TYPICAL LAKES.

LAKE IAMONIA.

Lake lamonia lies near the north line of Leon County. The
lake basin is irregular in outline, but has an average width of
from one to one and one-half miles. The total length of the lake
is from twelve to thirteen miles. At its west end the lake basin
connects with the swamp of the Ocklocknee River. During 11-..t
seasons the river overflows into the lake. Similarly a high stage in
the lake results in an overflow into the river. Small tributary
streams enter the lake from both the north and the south side as
well as from the east end. The tributaries are small flat-bottomed
streams which are dry. except during the rainy season. The lake
fluctuates much according to the rainfall. The lake basin when full
covers an area of about 65oo acres. Except at the west end, where

*Treatise on Metamorphism Mol. U. S. Geol. Survey, XLVII, p. 165, 1904.

54 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

it joins the Ocklocknee River, the lake is largely surrounded by the
red clay hills characteristic of this part of the State. These hills
rise to an elevation of from 50 to 75 feet above the level of the
lake.

Fig. I.-Sketch map showing the location of lakes lamonia, Jackson,
Lafayette and Miccosukee in Leon and Jefferson Counties.

The sink through which the water escapes from this lake occurs
along the north border. When visited May 7, 1910, the sink was
practically dry, having only a small amount of water in the bottom.
Limestone rock, probably of Upper Oligocene age, is exposed near
the bottom of the sink, the water escaping through or under these
rocks. Above the limestone partly decayed sandy clays occur.
These contain few fossils, although oyster shells were found in
abundance at one locality. The total depth of the sink below the
general level of the lake is not less than 50 feet. The sink occurs,
as is usual in this type of lake, facing an abrupt bluff 30 feet or
more in height. A considerable number of sinks occur around the
border of the lake especially in the vicinity of the one large sink
which receives ,the drainage of the lake. The formation of these
sinks is doubtless due, as previously stated, to the fact that the water
entering the drainage sink spreads laterally in the underlying lime-
stone and dissolves the rock rapidly. The result is the formation by
subsidence of numerous sinks adjacent to the drainage sink. The
presence of these sinks also indicates the manner of enlargement of
the lake basin, and indicates in each case the direction of most
rapid enlargement at the present time. At other times the enlarge-

SOME FLORIDA LAKES AND LAKE BASINS.

ment by solution and subsidence may have been most active in some
other locality or direction or part of the lake basin.
This lake only occasionally goes entirely dry and as a result a
covering of muck or peat occurs over the greater part of the bottom
of the lake. This deposit of muck reaches a considerable thickness
in such natural depressions as occur over the lake bottom. Be-
neath the muck is usually found a deposit of light colored sand and
beneath this is the red sandy clay.
The fact that the Ocklocknee River at flood stage flows into
this lake makes any attempt at drainage doubtful of success. An
effort which proved unsuccessful was made at one time to prevent
the river water from entering the lake by means of a dam. It
seemed to be the views of the party constructing the dam that if
the water of the Ocklocknee River could be kept out the sink
would carry off the water from the lake. This, however, is not
probable, since in the several other lakes to be described the sinks
have not proved sufficient to carry off the water except in times of
greatly reduced rainfall. Lake Iamonia basin represents apparently
a stream valley lowered by solution and enlarged laterally by sub-
sidence through the formation of sinks. Originally a small stream
tributary to the Ocklocknee River flowed through this section. In
this part of the county soluble limestones occur at no great distance
from the surface, and in the course of -the natural processes of ero-
sion the stream approached sufficiently near this limestone to permit
of the formation of sinks and the escape of the water of the
stream through the sinks. The enlargement of the valley to its pre-
sent size has proceeded through the formation and partial filling of
successive sinks. As each sink forms, it carries down to or below
the lake level, a certain small area of land. Moreover the water
passing through the bottom of the sink carries with it more or less
detrital material so that the surrounding area is somewhat lower-
ed by wash through the sink. In the course of time other sinks
form, while the older sinks become clogged and usually partly fill
up. The direction of active enlargement of each lake can be de-
termined from the location of the recent sinks. As previously re-
marked this rapid enlargement is usually around the sink which is
at present actively receiving the drainage.

68 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

LAKE JACKSON.

SLake Jackson lies
near the western border
S of Leon County within
one and a half or two
miles of the Ocklocknec
River. This lake is ir-
regular in shape, and has
a total area of about 4,-
500 acres. The bound-
aries of the basin are
sharply marked by the
surrounding highlands
which rise 75 to 1oo feet
Above the level of the
lake. Several sinks oc-
Scur in the southern half
of the lake. The largest
Sof these, known locally as
the "lime sink," is located
well out in the basin and
in the angle between the
north and east arms.
(See map). An opening
in the bottom of this sink
Fig. 2.-Lake Jackson.
e in May, 1907, permitted
the water to run out, leaving the sink dry, and also draining
the lake or such part of it as was connected with the sinks. An
indefinitely defined broad depression or slough extends to the
south-east from the lime sink. Several water holes representing
old sinks occur along the line of this depression. A new sink oc-
curred along the bottom of the depression.about one mile south-
east of the lime sink in June, 1907. A compact limestone showed
in the bottom of this sink at a depth of about 25 feet from the sur-
face. At the time this sink formed the lake was low, a part of
the water having been carried off through the opening which had
formed in the lime sink a month earlier. All the water that could
reach the new sink was carried off in the course of two or three
days. leaving the lake dry except for occasional water holes. When
examined in September, 1909. a small open sink was found in the
slough which carried away all of the water that reached it from
the surrounding parts of the lake.

SOME FLORIDA LAKES AND LAKE BASINS.

The surface soil in the basin is quite generally a gray sand dark-
ened by admixture of organic matter. In the lower parts of the
lake, quite generally covered by water, more or less muck or peat
occurs formed from the accumulation of aquatic vegetation. Sand
lighter in color and lacking the organic matter occurs at a depth of
I /2 or 2 feet to 3 or 4 feet. Beneath this sand is the usual red
sandy clay.
This lake as already mentioned became dry, or nearly so, in
the early spring of 1907. It was partly filled by the summer rains
of the same year, but became dry or nearly so again during the
summer of 1909. The accompanying photograph of this lake was
taken July 5, 1909 and shows an unusually low water stage of the
lake for that season of the year. (PI. 7, Fig. I).

LAKE LAFAYETTE.

Lafayette Basin or Lake Lafayette lies in the eastern part of
Leon County between Tallahassee and Chaires. The basin begins
three and one half miles east of Tallahassee, and extends to within
one mile of Chaires, having a total length of about five and one-half
miles, and a width of one-half to one mile. An arm of the lake
extends north from near the east end of the lake. The bottom of
the basin is nearly level with the exception of occasional slight de-
pressions. The tributaries to the lake are flat-bottomed streams
with relatively broad valleys and no well defined channel. The soil
in these stream valleys is a sandy loam, and the streams are or-
dinarily dry, carrying water only during the rainy season.
A drainage sink in this basin occurs near the west end of the
lake along the northern border (See Fig. 3). The sink when
measured in September, 1909. was found to have a total depth of
75 feet. The sink is found, as is usual in this type of lake basin,
facing a prominent bluff. A second sink is formed beyond the lake
border, thus indicating the enlargement of the lake basin in that
direction by subsidence, due to underground solution. This new
sink is one hundred yards or more in circumference, and when
formed carried down to the lake level, land which stood fifty feet or
more above the lake and was being used previous to the subsidence
as a cemetery.
That part of the lake basin which surrounds the sink lies at a
slightly lower level than the more remote parts of the basin and
is the first to be submerged at the approach of the rainy season.
This area is entirely devoid of trees, and during the dry season(
becomes a prairie. The greater part of the basin lying to the south
of the railroad is thickly set with small cypress trees.

58 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

The soil in the basin is prevailingly a gray sand usually darkened
by the presence of organic matter. At a depth of from one to two
feet the amount of organic matter is reduced, the sand being lighter
in color. Sandy clays are reached as a rule at a depth of from
two and a half to three feet.
During a season of normal rainfall this basin is occupied by
a lake having a total area of approximately two thousand acres.
Following a period of prolonged drought the basin becomes entire-
ly dry, water remaining only at the sink. In times of excessive
rainfall the lake overflows at the east end, the water discharged
reaching streams tributary to the St. Marks River.

Fig. 3.-Lake Lafayette.

This basin has much the character of an elongated valley. The
general course of the streams of this part of the county, the shape
of the basin and particularly the topography of the surrounding
country indicate that the drainage of this section was originally
through these streams into the St. Marks River. The formation of
sinks diverted the drainage to a subterranean course, the west end
of the basin having been reduced to a level somewhat lower than the
east end. The further enlargement of the basin is being carried
on through the formation of sinks along the border. The largest
of the newly formed sinks is found near the present drainage sink.

LAKE MICCOSUKEE

Miccosukee Basin or Lake Miccosukee lies between Leon and
Jefferson Counties, the west border of the lake forming the county
line. A small arm of the lake, however, near the north end reaches
into Leon County.

SOME FLORIDA LAKES AND LAKE BASINS.

Miccosukee Basin has a total area of about 5,000 acres. In its
northern part the basin is bordered by sharply defined bluffs, which
rise from 50 to 75 or 1oo feet above the lake bottom. Farther
south these bluffs fall back and give place to a gradual rise of
elevation from the lake border. At the south end bluffs are lack-
ing. A drain known as Miccosukee drain enters from the east
side. This drain consists of a low, swampy area from one-fourth
to three-fourths mile in width. This swamp land supports a thick
growth of hardwood trees.
When full, Miccosukee Basin is covered with water to a depth
of from 2 to 5 feet. Toward the south end around the border of the
lake grass and button bushes project above the water even when
the lake is full.
The sink of Lake Miccosukee is located near the north-west
corner (see Fig. 4). The sink is bordered by a bluff having an
elevation of from 75 to 1oo feet. Landslides along the border of
the sink show recent enlargements of the basin. Numerous
sinks occur along the border of the lake at this locality, showing
enlargement of the lake basin through subsidence. The greatest
depth of water found in the sink when examined September 7,
1909, was 38 feet. A channel leads back from this sink across the
prairie in a south-easterly direction. This channel has cut to a
depth of from twenty to twenty-five feet. Followed back from
the sink the channel is of gradually reduced depth finally at
a distance of about two miles merging into the general level of
the lake bottom. When examined September 8, 19o9, this stream
was carrying water into the sink at a rate estimated to be 200 gal-
lons per minute. Notwithstanding the inflow from the stream
the water in the sink was being gradually lowered. Heavy rains oc-
curred in this vicinity on September 21, 1909, and this stream when
seen two days later was carrying approximately 7,000 gallons of
water per minute. At this time the sink was being rapidly filled, hav-
ing filled several feet during the two preceding days. From these
observations it appears that the opening at the bottom of this sink
permits the escape of water at a rate in excess of 200 gallons per
minute, but much less than 7,ooo gallons per minute. From the
behavior of the sink it is probable that not more than I,ooo gal-
lons of water are escaping per minute, and the rate of escape may be
much less.
The principal escape of water from Lake Miccosukee when the
lake is full is through a drain which leads out from the south end of
the lake and enters a sink about two and one-fourth miles from
the south end of the lake. This sink is formed in a light colored
limestone of Upper Oligocene age, probably representing the Chat-

60 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

Fig. 4.-Lake 'Miccosukee.

SOME FLORIDA LAKES AND LAKE BASINS.

tahoochee formation or the Tampa formation. The drain from the
lake as it approaches the sink passes through a narrow gorge cut
in this limestone.
About one-half mile farther south (Sec. 14) another sink is
found. This third sink receives the flow from Mill Creek, a small
stream draining considerable territory lying south of the Seaboard
Air Line Railway and east of Lloyds.
During a season of excessive rains these sinks are unable to
carry away the water. Under these conditions the overflow from
Lake Miccosukee as well as from Mill Creek ultimately finds its
escape by flowing to the south-west past Lloyds to the St. Marks
River.
The surface in Miccosukee Basin is covered with muck to a
varying depth. Borings put down near the north end of the basin,
out from the margin of the drain, indicated the presence of muck
for a depth of from six inches to one foot. Beneath the muck in
this part of the basin was found a gray sand. This sand is un-
derlaid, at a variable depth, by the usual red sandy clay. At the
south end of the lake the sand is largely absent, the muck which is
from one to three or more feet deep resting, so far as observed, di-
rectly upon the red clay.
Lake Miccosukee probably represents a basin developed by solu-
tion near the headwaters of streams originally tributary to the St.
Marks River. Previous to the formation of 'Miccosukee Basin the
drainage of this part of the country doubtless passed through
small streams, to the south past the present village of Lloyds, thence
to the Gulf through the St. Marks River. The lake basin since its
formation has enlarged to the north-west, the lowest part of the
basin now being found near the sink in the noith-west corner.
Mill Creek which now enters from the south and disappears
through a sink a few miles north of Lloyds illustrates the reversal
of flow of a stream due to the formation of a sink This stream,
previous to the formation of the sink, flowed south-west to 'the St.
Marks River. At the present time it flows north and enters the
sink. At times of excessive rainfall the sink is unable to carry
off the water and the stream under these conditions flows in its'
earlier course to the St. Marks River.

ALLIGATOR LAKE.

Alligator Lake lies in the central part of Columbia County,
from one and a half to two miles southeast of Lake City. The lake
basin has a total area of about i,ooo acres. Numerous smaller
lakes occur to the west and north of this large lake. The sur-

62 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

rounding country is in general level or rolling and lies at an eleva-
tion approximating 200 feet above sea. The basin along its
western side is bordered by a bluff which rises to an elevation of
from 50 to 75 feet above the level of the jake. .\long the eastern
and southeastern side the basin passes gradually into low lying
swampy hammock land, or cypress swamp. The sink of Alligator
Lake occurs along the southwestern border. The escape of water
at the present time is through this sink. In the country bor-
dering the lake around this sink numerous other sinks occur. The
lake is said to overflow at high water stage to the south through a
small stream known as Clay Hole Branch.
A soil boring put down fifty yards from the edge of the basin
along its southwest border gave the following section:
Black muck with admixture of clay ........................... ft.
Yellow sand loam .............................. .............. V ft.
Fine light gray sand........................................... I ft.

A pit made by Mr. Greer in his garden near the border of the
lake gave the following section:
Brownish colored imperfectly decayed vegetable matter (peat)....I ft.
Black muck with admixture of sand and clay ...................2 ft.
Red very sandy clay ............ ..... ... .................. ft.

It is reported that at the time of the early settlements in Co-
lumbia County, 1835 or thereabouts, Alligator Basin was a prairie
or savanna and was used at that time by the Indians as pasture
land. The lake was dry in the fall of 1891, and again in the fall
of 1899 or 19oo. It was dry again during the winter and
spring of 1909, but was partly filled by rains during the following
summer.
Approximately complete records of rainfall are available at
the Lake City station for the year 1897 and succeeding years.
The rainfall for the year 1899, at which time the lake became dry,
was much below normal, amounting for the year to only 30.49
inches. The next period of unusually low rainfall was the year
1908. During this year the rainfall amounted to only 29.83. The
rainfall during the year 1909 was likewise slightly below normal.
amounting at Lake City to 49.68 inches.

ALACHUA LAKE.

Alachua Lake or Paynes Prairie is the central and largest of the
several lake basins of southeastern Alachua County. This basin
is about eight miles long and varies in width from one and a half

SOME FLORIDA' LAKES AND LAKE BASINS.

to four miles. It contains about twelve thousand acres. Low
divides scarcely exceeding ten feet in elevation separate this basin
from Kanapaha and other prairies on the west and from Levy, Led-
with, and numerous smaller lakes on the south, and from Newnans
Lake on the northeast. The total area embraced within these vari-
ous basins is not less than fifty square miles. For a map of this
section the reader may consult the Arredondo topographic sheet
of the U. S. Geological Survey.
When dry or nearly so, this basin supports a dense growth of
grasses and weeds. On the more elevated and dryer parts dog-
fennel prevails, growing to a height of eight or ten feet, while on
the lower and wetter parts of the basin maiden cane abounds.
The principal stream entering this basin is a creek flowing from
Newnans Lake. This creek enters at the east side of the basin and
flows west and northwest to the sink.
The "sink" of Alachua Basin is located in the northeast border.
Two sinks occur here. The waters from these sinks enter the
Vicksburg Limestone. The sinks are partly surrounded by bluffs
rising to an elevation of thirty or forty feet above the general
level of the basin. Numerous sinks occur along the border of the
lake showing enlargement of the lake basin in this direction. The
stream entering the more westerly of the two sinks was car-
rying water when examined in October, 1907, at an estimated
rate of 20,ooo gallons per minute. At this time the water level in
the sink was only 2.01 feet above the general level of water in the
Vicksburg Limestone as shown by the Gainesville city well,* in-
dicating that the sink was carrying water at its full capacity or near-
ly so.
In November, 1909, the water in the sink stood approximately
one and one-half feet above the level of the water in the sur-
rounding limestone.
During seasons of heavy rainfall the stream draining from
Newnans Lake and other smaller streams carry water so rapid-
ly that the water is unable to escape through the sink as rapidly
as it flows in. Under these conditions the basin fills, becoming tem-
porarily a lake. It is probable also that the drainage sink be-
comes more or less completely clogged at times retarding the escape
of water, and in this case the prairie may continue as a lake through
a succession of years.
Variation in this lake has been more or less perfectly recorded
since the time of the earliest settlements in this section. When

*Bull No. I, Fla. Geol. Survey., p. 60, Igo8.

64 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

visited by Bartram in 1776 this basin was known as "Alachua
savannah" and served as grazing ground for stock belonging to the
Indians.* The basin was visited by James Pierce in 1824 and was
dry at that time. The water in the basin is said by W. W. Cameron
who lives near its margin to have been very low in 1861. When
visited by Dr. E.'A. Smith in 1880 the basin was comparatively full,
forming a lake. The basin in fact is reported to have continued
as a lake from 1871 or 1873 to 1891. In the fall of 1891 the basin
became dry, and, with the exception of' temporary overflows has
been dry much of time since that date. It is possible that the higher
water stage in the basin during the years from 1871 to 1891 was
due to partial clogging of the sink. The records of rainfall during
these years for this section is unfortunately lacking.
The following account of the disappearance of Alachua Lake
appeared in the Providence Journal for September 14, 1891. The
account is given with some omissions as quoted by Dr. W. H. Dall
in Bull. 84, U. S. Geol. Survey p. 94, 1892.

"A curious spectacle was to be seen on the outskirts of Gainesville, Florida,
recently. Alachua Lake * is no more. On its banks were lying thou-
sands of dead fish * and the atmosphere was heavy with noxious
gases. Men and boys were there in throngs with hoes and rakes, dragging to
shore hundreds of fish which had sought the pools for refuge. The waters
were fairly alive with their struggles for existence. Except for a small stream
known as Payne's Creek flowing from Newnan's Lake into the Sink, the two
main basins of the Sink, and a few stagnant pools, no water is now to be
seen where a few years ago steamers were ploughing their way. This is tne
second time since 1823 that a similar occurrence has taken place. At that
time the bed of the lake was a large prairie-Payne's Prairie-having in it a
body of water called the Sink and a small creek. In 1868 heavy rains filled up
the prairie, but the water disappeared after a short time and the prairie was
again dry land. In 1873, after a series of heavy rains, the Sink overflowed
and the creek swelled to the dimensions of a lake. During several years the
waters increased till a larger lake was formed, and for fully fifteen years
sufficient depth of water stood over the prairie to allow of small steamers.
During the last two years, however, the waters have been gradually low-
ering, and about four weeks ago they commenced going down with surprising
rapidity, the lake falling about eight feet in ten days, until now nothing is left
of Alachua Lake but the memory of it. The Sink is considered the cause of
this change. There is evidently an underground passage connected, and for
some reason not understood, this underground passage has been acting as a
drain until all the water in the lake has been drawn off."

In this account the fact is noted as is usually the case that after
the lake became somewhat restricted the water seemed to escape

*Bartram's Travels, First Edition, page 203, 1791. Philadelphia.

Digitized by Google

EXPLANATION OF PLATE 7.

Fig. i.-Lake Jackson. View taken from the north end of the lake. Pho-
tograph by R. M. Harper.

Fig. 2.-Alligator Lake. View taken from the bluff overlooking the lake.
Photograph by A. M. Henry.

j 40

S4,
Dt-

Digitized by Google

EXPLANATION OF PLATE 8.

Fig. I.-The sink of Lake Lafayette.

Fig. 2.-Paynes Prairie at low water stage. View from the sink. Photo-
graph by E. Peck Greene.

Fig. 3.--Paynes Prairie at low water stage. Photograph by R. M. Harper.

THIRD ANNUAL REPORT. PL. S.

gIe

__ ~Y

FLORIDA GEOLOGICAL SURVEY.

THIRD ANNUAL REPORT. FL. 9.

4 -. '

q O' s

*. **I
S.'-.'. .

. .* .*. '
*., I'
.5 ha .. I
.-., .'. .' .

Spouting well near Orlando. Photograph by T. P. Robinson.

FLORIDA GEOLOGICAL SURVEY.

SOME FLORIDA LAKES AND LAKE BASINS.

with great rapidity. The rapid lowering of the surface is due, how-
ever, as previously stated, not to greater rapidity in the escape of
the water, but to the fact that the total surface area of the lake be-
came greatly restricted so that the escape of a given amount of
water lowered the surface much more rapidly.
The following remarks regarding the lake appeared in the
Washington Evening Star of September 19, 1891. This quotation
is also from Dr. Dall's report.

"The Star recently printed an account of the disappearance of Alachua Lake
in Florida, a lake that was so well established that a steamboat line was main-
tained on it. A U. S. Geological Survey party has been engaged at work in
that region. A member of this party, Mr. Hersey Munroe, who is now in the
city, gave an interesting account of the lake, or rather the ex-lake, to a Star
reporter. "Alachua Lake," said Mr. Munroe, "is situated in north latitude 290
35' and west longitude 820 20'in Alachua County, Fla., and 2 miles south of
Gainesville, the county seat. The lake was formerly a prairie, known as Alachua
prairie before the Seminole War during 1835-37. It has since been named
Payne's Prairie, after King Payne, an old Seminole chief of an early day. The
prairie was a great grazing spot for the Indians' cattle and later was used for
a like purpose and for tillage by the whites, some fine crops of corn and cotton
being grown. The prairie lands are immense meadows, covered by the finest
grass, interspersed with clumps of beautiful oak trees and palmettoes. These
lands are subject to inundation during the summer season. Hatchet Creek
rises 3 miles north of Gainesville and flows in every direction of the compass
for a distance of Io miles, emptying into Newnans Lake, a beautiful sheet of
water covering o1 square miles.

"HOW THE LAKE WAS FORMED.
"The overflow from Newnans Lake forms a large creek named Prairie
Creek, which wended its way through Paynes Prairie to Alachua Sink, one of
the curiosities of the State. There the waters found their way into a subterra-
nean passage. Visitors, to have their curiosity gratified by seeing what the effect
would be to have logs thrown into the sink, were the probable cause of the over-
flow of Paynes Prairie. The legs would float out to the center of the sink, whirl
around in a circle and suddenly disappear. This choking of the outlet to the
waters of Prairie Creek caused the overflow and made a sheet of water sufficient
to float small steamers and other crafts.
"One steamer in particular had a splendid freight traffic, during the vegetable
season carrying shipments of vegetables from its wharf on Chacala pond across
Alachua Lake to the mouth of Sweetwater branch, the nearest point to Gaines-
ville, the principal place for shipment north. After the overflow and the forming
of a lake it was christened Alachua Lake. This name has been decided tuon by
the United States Board on Geographic Names. Alachua Lake is 8 miles long,
east and west, and in one place 4 miles in width, north and south, covers 16,ooo
acres, and the average depth is from 2 to 14 feet.

"LOWERING FOR SEVERAL YEARS.
"For several years the lake has been gradually lowering. The elevation of
the water above sea level as given by the Savannah, Florida and Western Rail-

6 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

road some years ago is 64 feet. By accurate levels run by one of the topograph-
ical parties of the Geological Survey working in this section during the winter of
I89o-g9 the elevation of the water was found to be 58 feet, thus showing that the
lake had been changing elevation; and about two weeks ago I was informed that
Alachua Lake had disappeared entirely, that only small pools remained and the
usual amount immediately around the sink."

The early geological history of that section of Alachua County
now occupied by these larger basins and lakes was apparently as
follows: Originally the surface runoff from southeastern Alachua
County made its way through Orange Creek and the Ocklawaha
River into 'the St. Johns River. These streams were then heading

Fig. 5.-Sketch map of Hogtown Prairie and surroundings, illustrat-
ing a stage in the development of a solution basis. From the
Arredondo topographic sheet, U. S. Geol. Survey. The 6o-foot
contour line borders the prairie.

back in the plateau region of Alachua County, and were fed both
by the surface runoff and by the numerous small springs issuing
from the clays and sands of the Apalachicola group underlying the

SOME FLORIDA: LAKES AND LAKE BASINS.

plateau. In the course of time the streams cut down to or nearly
to the underlying Vicksburg Limestone. The result of the close
approach to this limestone was the formation of sinks due to sold-
tion in the limestone. After the formation of the sinks it became
possible for the water to pass through the sinks and find its escape
by subterranean drainage. This process of solution and subsidence
continued through long intervals of time has resulted in the forma-
tion of these numerous basins. Some of these basins have been
carried to a level equal to or below their original outlet through
Orange Creek.
Basins may be seen at the present time in varying stages of de-
velopment. In the plateau itself no basins are found. Even here,
however, are found occasional sinks, the first evident effect of the
reduction by solution. An illustration, of a partially developed
basin may be found in Sanchez Prairie near Hague. The country
surrounding this small basin stands at a level of about I80 feet.
The basin itself occupying an area of a few hundred acres is re-
duced to an elevation of about Ioo feet above sea. Hogtown Prai-
rie near Gainesville (Text figure 5) represents a more advanced
basin. Hogtown Creek probably originally flowed through Ala-
chua Basin, thence to the St. Johns River through Orange Creek.
The formation of the sink, however, permitted a subterranean
escape and around this sink is formed Hogtown Prairie, now sepa-
rated from Paynes Prairie by elevations amounting to twenty
or thirty feet.

OCHEESEE LAKE.,

Of the few lakes occurring in Jackson County Ocheesee Lake
is perhaps the largest. This lake lies in the southeastern part of
the county extending from near Grand Ridge in a southeasterly di-
rection to within three or four miles of the Apalachicola River.
The total length of the lake is six or seven miles. In breadth it
varies from a few rods to possibly three-fourths of a mile. At the
northwest end the surrounding country rises very gradually. The
southwest part of the lake, however, is surrounded by red sandy
hills which rise from 75 to Ioo feet above the bottom of the lake.
The lake is perhaps best described in this instance as a swamp. the
greater part of the lake bottom being occupied by a growth of cy-
press. Near the east end open water occurs over an area of about
Ioo acres. The water sinks into the Chattahoochee Limestone at
the south-east end of the lake.
The history of the development of this lake is very clear.
Originally the drainage from this part of the county passed by

68 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

a surface stream to the Apalachicola River. At a distance of three
or four miles from the river, this stream, after cutting its channel
some depth, reached the Chattahoochee Limestone. When this
formation was reached the water passed into the earth, the drain-
age becoming subterranean. Subsequent erosion carried the basin
to its present level.

METHODS OF DRAINAGE.

Two methods of draining basins of this type may be considered.
(I) drainage by surface ditching to some stream or other outlet
lying at a lower level: or (2) drainage into the underlying water
bearing formation.

DRAINAGE BY SURFACE DITCHING.

Surface ditching usually suggests itself as the more natural
method of drainage, and it is often inferred in the absence of de-
finite information that the lakes lie at a higher level than near-by
streams. This is not always the case, and such an assumption may
lead to a very costly error. A lake or prairie of this type a few
miles southeast of Citra was connected many years ago by canal
at considerable expense with a tributary of the Ocklawaha River.
Upon completion of the canal it was found that the lake basin was
at a lower level than the stream bed. The peculiar method of
formation of these lake basins by solution, as previously explained,
carries them frequently to a lower level than the stream which
served in earlier stages as an outlet. Lake lamonia as previously
stated lies practically on a level with the Ocklocknee River, and
receives the overflow of that river during high water stages.
Alachua Lake basin lies, as shown by the topographic map, at practi-
cally the same level as Orange Lake and the headwaters of Orange
Creek which served formerly as the outlet.

DRAINAGE INTO THE UNDERLYING FORMATIONS BY WELLS.

Drainage into the underlying formations takes place naturally
through the sinks already existing. Artificial drainage consists
either in enlarging the sinks, or in making artificial openings in
the form of dug or drilled wells through to the water bearing for-
mation. In either case the principle is the same. The underlying
limestone is porous and cavernous, and is filled with water to a
definite although slightly variable line or level known as the per-
manent underground water level.

SOME FLORIDA LAKES AND LAKE BASINS.

Solution in the limestone occurs both above and below the water
line, but chiefly above. As solution continues the overlying ma-
terial is no longer able to support its own weight and caves in, form-
ing a sink or natural opening from the surface to the limestone. As
long as this sink remains open, water passes through and escapes
readily into the limestone. Drilled or dug wells serve as artificial
openings to the same formation. Wells drilled into this limestone
will serve either as supply wells from which water may be pumped
or as drainage wells into which water may be conducted. It is
generally the case that a well entering this formation that can not
be appreciably affected by pumping, will also conduct water readily.
If the openings at the mouth of the well are sufficiently free to per-
mit ready flow to the well when being pumped, they are, converse-
ly, sufficiently open to allow the water to spread rapidly from the
well when used as a drainage well. The amount of water held in
the pores and cavities of the limestone is so great that the water
level is not appreciably affected either by the water removed when
a well is being pumped, or by the water added when a well or sink
is used for drainage purposes.
Attempts to enlarge existing sinks or to re-open sinks that have
become clogged have usually proved futile. It is doubtless true that
the opening through sinks is a more or less winding channel and to
re-open this when clogged with debris is difficult.
Better success has been obtained by dug or drilled wells. Where
the underlying porous formation into which the well is to be drained
lies near the surface, dug wells can be used to advantage and may
be preferable. Dr. H. Bjystra has used this method in draining a
small lake or "prairie" on his farm near Brooksville, Florida. At
this locality the cavernous limestone lies near the surface and is
reached by relatively shallow wells. The one difficulty experienced
as reported by Dr. Bjystra is the fact that during the summer rainy
season in one or two instances the rainfall has been so heavy within
a short space of time that the wells were unable to carry away the
water as fast as it fell, the result being temporary overflow of the
farm and serious injury to growing crops. It is probable that this
danger can be removed in this instance by digging additional
wells.
Drilled or bored wells have been in some instances notably suc-
cessful. An advantage in the drilled well is that it can be put
down to any required depth. When properly cased and screened
drilled wells are permanent. The effectiveness of the well is de-
pendent upon the structure of the formation penetrated. If the
water-conducting power of the formation reached by the well is

TO FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

slight a limit is thereby placed on the effectiveness of the well. Un-
less the flow of water at the bottom of the well is tree the in-take
of water is necessarily limited.
Assuming free movement of the water at the bottom of the well,
the rapidity of in-take and hence the efficiency of the well is in-
fluenced by (a) size of well; (b) construction of well; (c) depth
of water above the mouth of the pipe; (d) distance from the top
of the pipe to the underground water level.*
(a) The capacity of a drain pipe increases rapidly with in-
creased diameter. The area of the section of the pipe is propor-
tionate to the square of the diameter. Thus the area of the cross
section of a 12-inch well is nine times that of a 4-inch well. More-
over, for a given velocity the friction of movement is less in a large
than in a small pipe.
(b) The construction of a well also affects its rapidity of in-
take. When the pipe is cut off squarely at the top according to the
usual custom, the full capacity of the well is not realized. The
rapidity of in-take may be appreciably increased by the use of a
flared or bell-shaped mouth at the top of the pipe.
(c) If the underground water level lies some distance, from
the surface and if there is free discharge at the bottom of the well.
siphonage or draft-tube action increases the rate of flow. When the
distance from the top of the pipe to the underground water level is
33 feet or over, the maximum possible draft-tube head of 32.8 feet.
may be available.
(d) The influence of the depth of water above the mouth
of the pipe is as follows: Assuming that the water flows into the
pipe as through an orifice, the in-take at the mouth of the pipe will
be proportionate to the square root of the depth of the water above
the mouth of the pipe.
The velocity of flow in the drainage well may be measured by
means of Pitot's tube. This is a bent tube one arm of which is
graduated, used to determine the velocity of running water. To
make the measurement insert the tube vertically in the top of the
pipe, the short end projecting upward and having its mouth a few
inches below the top of the drain pipe. The velocity of flow in the
pipe is expressed within close limits by the following formula in
which h is the height in inches to which the water rises in the long
arm above the surface of the lake.*

V- V 64.32 22
12 .32 VR

*U. S. Geol. Surv. Water Supply Paper, 145, p. 36, 1905. R. E. Horton.

SOME FLORIDA LAKES AND LAKE BASINS.

The flow in cubic feet per second into the well will be

d2 T7
Q = 0.0055 dV 80 nearly

In this formula Q represents the flow in cubic feet per second;
d is the inside diameter of the pipe in inches, and h the height in
inches to which the water rises in the long arm alive the surface
of the lake. V is the velocity of flow.
A notably successful instance of drainage by wells where the
interests of a municipality were involved occurred at Orlando,
Florida, and was given in Bulletin No. I, as follows:
"A very considerable land area south and east of Orlando, em-
bracing possibly fourteen square miles, lies in an irregular basin
with many lakes, marshes, and ponds. The overflow from this
area originally drained to and disappeared through a natural sink
about one mile east of the city. This sink became clogged in April.
1904. Unsuccessful efforts were made to re-open this sink, first
by removing hyacinths accumulated around the opening, and later
by the use of dynamite. In the meantime, heavy and continued
rains formed a lake around the sink, overflowing the surrounding
lands. In August, 1904, efforts were made to dispose of the water
through drainage wells. The first well put down was a two-inch
test well. The well reached a porous stratum and was thought to
justify the expense of a larger and deeper well. Difficulty and de-
lay were experienced in the drilling, but by August, 1905, two wells,
one eight-inch and one twelve-inch, put down at the side and near
the original sink, had been completed. Two other wells were
started and abandoned owing to the difficulties in drilling. The
two successful wells were running at full capacity. It was thought
probable that the two wells already put down would prove suffi-
cient. Heavy rains followed, and by January, 1906, a considerable
area, including some cultivated ground, was flooded, practically
all county roads leading into Orlando from the east were partly un-
der water and impassable. The colored settlement known as Jones-
town in the suburbs of Orlando was partly under water and unin-
habitable; the water was approaching the city of Orlando itself and
the situation was becoming alarming. Levels taken by the county
authorities indicated that drainage through surface canals was im-
possible or impracticable. Two additional twelve-inch wells were
bored in November and December of 1906. The effect of these-
was evident at once, the lake beginning to fall. By February a
third twelve-inch well had been completed, making in all one eight-

72 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

inch well and four twelve-inch wells running at this time. By the
end of March the water had returned practically to its normal
level and has since been kept under control.
"Four of these drainage wells are located near the original sink
and have a uniform depth of 140 feet, a cavity several feet in
diameter having been reached at that depth. The fifth well is lo-
cated one-half mile west of the sink, and terminates- in a porous
stratum at a depth of 340 feet."
Since the completion of these wells by the city a number of other
drainage wells have been put down by individuals, used largely
to reclaim trucking and farming lands.
One of these drainage wells near Orlando developed recently
the unusual phenomenon of spouting. The well is located three
miles north of Orlando on land belonging to Charles T. Myers.
It was drilled in 1907 jointly by Mr. Myers and Messrs. McNeal
and Davis, the latter gentlemen having the property leased for
farming purposes. The well is twelve inches in diameter and has
a total depth of 260 feet, and is cased 60 feet. It is located at the
edge of a small lake. The level of permanent underground water
at this locality is 33 feet from the surface. Trucking is carried on
around the border of the lake and the well is intended, by carrying
off the surplus water, to prevent the lake from rising above a given
level, since to do so would flood the farming land. The well is
similar in character to the other drainage wells of this locality and,
as in the case of most of the other wells, terminates in a cavity in
the limestone.
The well was first seen by the writer October 4, 1910. At this
time the water-of the lake stood a few inches above the level of the
pipe and the well was receiving water at much less than its full car-
rying capacity. At intervals of a few minutes the well would re-
verse itself and spout, throwing a column of water into the air.
The spouting comes on gradually. First the well ceases to receive
water and begins bubbling; the column of water follows rising with
considerable force to a height of twenty feet or more above the
surface, the spout occurring with tolerable regularity at intervals
of four minutes. Mr. R. D. Unis, who has charge of the farm,
states, however, that the intervals between spouts vary from two
to fifteen minutes, being probably influenced by varying conditions
under which the water enters the well. (P1. 9).
Although drilled about three years ago and receiving water
more or less constantly since that time the phenomenon of spout-
ing developed for the first time on September 26, 1910o, the first
spouting having occurred about eight o'clock on the morning of that

SOME FLORIDA LAKES AND LAKE BASINS.

day. The well continued spouting without interruption for a little
more than a week and until shut off by the owner.
Various fanciful theories have been advanced to account for the
spouting, including supposed occurrence of gas and oil, and the
supposed influence of recently formed sinks in the interior of the
State. The true explanation is evidently much more simple. At
the present stage of the lake the well is receiving water at less than
its full carrying capacity and as the water enters the vertical pipe
it forms a suction carrying a large amount of air into the well,
which doubtless collects in a chamber or cavity along the side or
at the bottom of the well. As the well continues receiving water
the air accumulates under pressure in this chamber until ulti-
mately the pressure under which the air is confined is sufficient to
overcome the weight of the overlying water and hence rushes out
with considerable force carrying the column of water with it.
The fact that the well when first drilled did not spout and
afterwards began spouting doubtless indicates that the essential
conditions were subsequently developed either by caving or by
other changes in the underground conditions.
The spouting of the well is therefore on the principle of the air-
lift pump in which air under pressure is conveyed into the
well through a special tube for that purpose and being liberated in
the well lifts a column of water to the surface. In this spouting
well, however, the air pressure is developed within the well. This
well may, therefore, be classed as a self pumping well.
When partly shut off so that only a limited amount of water
enters, the air taken into the well is able to return to the surface
freely. Under these conditions spouting ceases. It is probable
that if an elbow is placed on the well, allowing the water to enter
laterally instead of vertically, the amount of air taken into the well
will be so far reduced that the spouting will cease. Likewise
when the lake rises so that the water stands several feet above the
top of the pipe entering the well it is to be expected that the spout-
ing will cease, since the pipe will then be carrying water at its full
capacity, and little or no air under these conditions entering the
well.*
The drainage wells are themselves remarkable and found in
such perfection only under geological conditions similar to those
existing in Florida. Of the many peculiarities of these wells,

*Since the above was written very heavy rains attending the storm of
October 17, I9xo, caused the lake to rise 18 or 2o inches, and Mr. Unis writes
that when the water rose in the lake the well ceased spouting. A similar well
at Albany, Georgia, is reported by McCallie. Science, XXIV, p. 694, 90o6.

74 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

however, that of spouting is certainly the most striking and re-
markable.
In considering the use of wells for drainage purposes the re-
lation of the lake basin to the underground water level should
first be definitely determined. The effectiveness of the well is re-
duced as the water level is approached, and it is of course obvious
that the water in the lake can in no case be carried below the under-
ground water level. Many of the larger lake basins are known to
lie very close to the water level. If the lake basin lies as low as the
permanent water level it is obvious that the water in the lake can
not be drained by wells, moreover since the effectiveness of the well
is affected by the near approach to the water level, it is hardly prac-
ticable to reduce the water in the lake quite to the permanent under-
ground water level. It must also be borne in mind that while the un-
derground water is a permanent supply the water level or water line
is not stationary, but varies with the seasons. The amount of varia-
tion for the locality concerned should be determined.
The fact that a lake basin stands somewhat above the water line
at the close of a long dry season is not proof that it will be found to
stand above the water line after a season of heavy rainfall. In
some sections of the state the range of variation of the water line
has been found to be as much as ten feet, and may in some instances
exceed that amount.
The relation between the level of the lake basin and the under-
ground water has been determined for a few of the lakes. Meas-
urements of Alachua Lake were made in 1907 and again in 1909.
When measured in October, 1907, the water level in Alachua Lake-
was found to be 2.01 feet above the level of the underground
water of the Vicksburg Limestone formation as determined from.
the Gainesville City well.* When measured in November, 1909.
the water in the sink stood approximately 1.4 feet above the water
level in the limestone as indicated by the city well. At the time-
these measurements were made the lake was at a low water stage.
The underground water level was likewise at a low stage. From
these measurements it appears that Alachua Lake during the dry
seasons at least is lowered by natural drainage through the sink
to or practically to the underground water level. During the rainy
season the water in the lake doubtless rises above this level, although
it must be borne in mind that the water line also rises during the
rainy season. It is evident, therefore, that the difference between
the water level in the lake and the underground water line is great-

*For a record of this well, see Bull. No. I, pp. 30 and 88-89, 1908.

SOME FLORIDA LAKES AND LAKE BASINS.

est during the rainy season when the lake is receiving a large amount
of surface drainage.
Approximate measurements of the water level in Alligator
Lake near Lake City have also been made. This is one of the
smaller basins and the measurements indicate that the level of the
water in the lake stands appreciably above the underground water
level. In this instance the measurements of the water level and the
lake level were made at different seasons of the year and the results
can be only approximately compared. The data on this lake are as
follows: Levels made by Professor N. H. Cox, on June 19, 1903,
showed that the water in Alligator Lake stood 94.22 feet below the
Union Depot at Lake City.
The lake at the time the levels were made was at medium full
stage. The water of the Lake City public well located near, and
on about the same level as the depot was found at the time the
well was completed in 1907 to stand 134 feet from the surface.
Allowing for any correction that it might be necessary to make
owing to the fact that the measurements of lake level and ground
water level were not made at the same time it would still seem that
the -lake basin in this instance stands somewhat above the water
level. The drainage of this lake by wells should be possible pro-
vided the underlying limestone at this locality proves to be suffi-
ciently porous and cavernous to conduct water readily.
SUMMARY.
The basins of the temporary lakes have their origin in erosion
by solution and by mechanical wash. Some of them appear to
represent the enlarged valleys of what was originally a small
stream. Sinks form along these streams diverting the course of
the water into the underlying limestones. Other basins originate
from sinks in no way connected with stream valleys. The origin
of the sink was due primarily to solution in the limestone. After
the sink is formed the general level of the surrounding area is low-
ered somewhat by mechanical wash, the material being carried into
the sink. Subsequently other sinks form in the immediate vicinity.
The formation of these new sinks is due also to solution. The large
amount of water which entered the limestone from the first sink
facilitates solution and results in the formation of additional sinks.
The continuance of this process through a long period of time re-
sults in the development of the large basins occupied by these lakes.
From their manner of development it follows that the steepest bluffs
as a rule are those immediately facing the active sinks. Likewise
for reasons already given new sinks occur most frequently in the
area immediately surrounding the active sink.

T7 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

It is doubtless true that some of the lakes, especially the
smaller ones, could be drained by surface ditching. Any attempt
at drainage should be preceded, however, by the preparation of a
*carefully made topographic map of the region, or at least suffi-
cient exact leveling should be made to determine definitely the rela-
tion of the lake basin to the proposed outlet, and to the intervening
country.
While some of these lakes can be drained by bored wells it is
not to be assumed that all can be so drained. As has been shown
some of these lake basins, especially the larger ones, have been low -
ered by solution practically to the permanent underground water
level. Before attempting drainage by wells definite data should
be obtained as to the relation between the level of the lake basin and
the underground water level of that locality. This information
can often be obtained by running a line of levels from the lake to a
near by deep well and comparing the level of water in the lake with
the level at which the water stands in the well. If necessary, test
wells may be drilled before undertaking large wells. Such lakes
as have been lowered by natural drainage actually to the under-
ground water level can of course be lowered no further by wells

TESIAN WATER SUPPLY OF
FLORIDA

BY E. H. SELLARDS AND HERMAN GUNTER.

THE AF

EASTERN

I

_ _____..

CONTENTS.
PAGE
Introduction ......................................... .... ......... 85
The area treated ..................................................... 86
Geology ...................... ....... .................................... 86
Oligocene ........................................... ................. 86
Vicksburg group .................. ....................... ........... 86
Apalachicola group ................ ......................... 88
Miocene ........................................................... 89
Pliocene ....................................................... go
Pleistocene ...... ................................................. 9
Earth movements during the Pleistocene .............................. 91
Topography and Drainage ............................................. 92
Elevations ....................................... .................... 92
Rivers ................. . .. ... ........ ....... ..................... 92
The Lake Region.............. .................................. 93
Clim ate .................................. ........ ..................... .. 94
Temperature ....................................... ..... ....... 94
Precipitation .......................................... ....... 95
Soils ......................................... ... ...... . 96
General discussion of underground waters ............................ 99
Source ..................................... ........ ... ......... 99
Annual rainfall ................. ......... ............ .....
Disposition of rainfall .......................................... .... aoo
Amount available for the underground supply....................... o02
Underground circulation of water..................................... 102
Cause of movement......... ....................................... 102
Rate of movement................................................. 102
Depth of underground water ........................................ 102
Hydrogen sulphide in underground water.............................. 104
Sulphur water not evidence of beds of sulphur....................... 1o6
Sulphur deposits formed from hydrogen sulphide..................... 106
Absence of hydrogen sulphide from certain waters in Florida........... o6
Amount of hydrogen sulphide influenced by pressure.................. T07
Artesian water .................... ... .... ............. ................ 107
Artesian water defined.................................... ........ 107
Conditions necessary to retain artesian water.......................... 108
Artesian basin .................... ................................. o8
Artesian slope ............................................... Io
Artesiam water from unconfined horizontal beds ...................... Io
Artesian water from solution passages.............................. III
Source of artesian water in Florida.................................. II
Formations supplying artesian water.................. .............. 112
Depth of artesian water ............................................. 112
Cost of wells ..................................... .... ......... 2
Increased flow with increased depth ................................ 113
Increased head with increased depth.................................. 113
Increased temperature with increased depth............................. 114
Loss of head and reduction in flow.................................... 115
Cause of the loss of flow ........................... .............. ix6

CONTENTS.-(Continued.)
PAGE
Table showing loss of flow of artesian wells .......................... 117
Waste of artesian water......................... ........... ri8
Method of measuring flow of artesian wells ............................ t
Tables for determining yield of artesian wells...................... 12
Area of artesian flow in Florida .................... .... ........ 122
Discussion by counties ............. ............... .... ....... 125
N assau County ................. ................. ................ 126
Location and surface features .......................... ........... 126
Water-bearing formations ..................................... 126
Area of artesian flow........... ................................ 128
Local details ................ ................................... 128
Callahan ................... .................. ............ 128
Crandall ............ .............................. 130
Evergreen .................. ........... ............... ..o
Fernandina ..................................... .. ...... 3
Hilliard ................................ .. ..... ......... r33
Italia .............. ....................... .. ...... .. 133
King's Ferry ................................... ... . 33
Lessie ............ ... ..... ............... .... .... :33
Lofton .... ...................................... 133
Duval County .................. ... ..... .................... 135
Location and surface features ............. .. .............. .. 135
Water-bearing formations ...................................... 136
Area of artesian flow....................... ............ 137
Local details .......................... ........................ T ..
Baldwin ......................... .. .... ..................... 138
Bayard ..... ................................................ 133
Jacksonville ............................. ................... ri
Mandarin .. ........... ... .............................. 141
Maxville....... ..... .................................. 41
St. Johns County......................... .... ..................... 141
Location and surface features ............ .................. 1.
Water-bearing formations .......... .... .................... 142
Area of artesian flow ... ............ ..... ... .......... 144
Local details ................. ..... ...... .................... 144
Anastasia Island ................................. .... 144
Armstrong ............ ........................................ 144
Bunnell ............................... ............. 1r44
Dinner Island ...................... ....................... 145
Elkton ........... ........... ............ .... .... ..... 145
Espanola ... .............. ....... ..................... 145
Federal Point ................. ............................. 145
Hastings.. ............. .......................................... 146
Holy Branch ...................... .. ........ .............. 147
Hurds ........... ............. ........................ 148
Moultrie ... .............. ... .... .. ....................... 148
Picolata ................ ......... . ....... ... ............ 148
Riverdale .............. ..... ................. ............ 149
Roy .................. .... ............... ............... 50
St. Augustine. ..................... ....... ... ... ... ....... 150
Switzerland ............. ..................... ... ....... 152

CONTENTS.--(Continued.)
PAGE
Yelvington ............................... ............. 153
Clay County ... ............. ...... ............. .......... ..... I53
Location and surface features ....................... ....... .. 153
Water-bearing formations ..................................... 154
Area of artesian flow ............ ... . .................. ........ 154
Local details ........................................................ 156
Doctors Inlet ................... ................... ............. 56
Green Cove Springs ...................... ............... ....... 156
H ibernia ................. ..................... ..... .... ....... 157
Leno ............. .. ........................................ 158
M agnolia Springs ................................ ....... .. .. ... 158
Middleburg .......................... .......... ........... 15
Peoria ............................. .. ........... .. 159
Russell .................... .. ............... .. .... .......... 16
Walkill ...................... ............. .............. 6o
West Tocoi .................... ................... 6o
Williams Crossing ............................................ 16o
Putnarp County ...................................................... 160
Location and surface features ....................................... i6o
Water-bearing formations .......................................... 61
Area of artesian flow ............................................... 161
Local details ........................................................ 161
Bostwick .................................................. 161
Crescent City .................................................. .52
Orange Mills ................................................... 162
Palatka ............................................. .... 163
Penial ...................................................... 16
Rice Creek ....................................................... 16
Rodman ........................................................... 16
San Mateo ...................................................... 165
Satsuma .................................... ................... 166
Welaka .................................................... 166
Woodburn ................ ................................ 67
Orange County ................. .................... ...... ... ..... 107
Location and surface features ....................................... 167
Water-bearing formations ................ ........................ )6U
Area of artesian flow ................ ............................. 168
Local details ..................................... ............. .... 168
Chuluota .............. ...... ...... .................. ........ 168
Geneva ................ ..................... ........... 168
Orlando ........................ ....................... 69
O viedo .............. ..................................... 170
Sanford ............... ... ........... ..... ................ 170
Volusia County ................ ................. .... ...... ....... 174
Location and surface features........................... ......... 174
Water-bearing formations ........................................ 174
Area of artesian flow............................................... 175
Local details ................................................ 175
Daytona .............................................. 175
DeLand .................................................. 176
Enterprise ....................................................... 177

CONTINTS.-(Continued.)
PAGE
Lake Helen ................ ......................... ......... 178
N ew Sm yrna ..... ....... ....... .................. ............ 179
Oak Hill .......... ........................ ...... ............. 179
Orange City ............ ... ........................... 80
Ormond ............. ................................ ........... i8o
Pierson ..... ........... ............. ..... ......... 181
Seville ........................................ ..... ........ 18r
Brevard County ................ .. ..... ............. ............. 182
Location and surface features ................................... 182
Water-bearing formations .............. ........................ 182
Area of artesian flow ............................................ 182
Local details .......... .... ........... ...................... 183
Chester Shoals ............... ................... .......... 183
City Point ............. ........... ......... ..... ........ 183
Cocoa ............. ................... ......... .......... 184
Eau Gallic .................. ............................. 185
Frontenac ......................................... 85
G rant ................ ... ........ ....... ..... 186
Malabar ......... .............................. ........ 186
Melbourne .......................................... 86
M erritts Island ................. .. ........................... 188

RMio ..c................... ....... ......................... 189
Sharpesdge ................ .......................... ........ 190
Shares ............. ........................................ zgo
Tillman ................. ......................... 191
T itusville ........................................................ I91
Valkaria ..................................... ........ 192
St. Lucie County .............. ...................... ............... 192
Location and surface features .................. ................... 192
W ater-bearing formations ................... .......... ... .... 193
Area of artesian flow............................................. 193
Local details.............. ........................... ........... 193
Eden ................................. . .......... 93
Ft. Pierce ......................................... .. ......... I93
Narrows .......... ............................ ..... 19
Orchid ................................ ............. ........ .. 194
SRoseland ............. ................. ....... ......... 194
Sebastian ........... ....... ................................ 195

ILLUSTRATIONS.
PLATE No. FOLLOWING PAGi
10. Fig. i. Exposure of hardpan at Black Bluff on Clark's Creek,
eight miles from Fernandina.......................
Fig. 2. Artesian well used for power, Melbourne, in Brevard
County ......................................... 88
II. Fig. r. Palmetto flatwoods, Amelia Island.....................
Fig. 2. Palmetto flatwoods, Ft. Myers ......................... 6
12. Fig. I. Scrub, east side of Lake Kingsley, Clay County..........
Fig. 2. Sandy pineland, DeLeon Springs......................
Fig. 3. Open flatwoods, three miles east of DeLeon Springs...... 96
13. Fig. r. Everglades west of Ft. Lauderdale...................
Fig. 2. Small prairie, four miles west of Sebastian.............
Fig. 3. Turnbull Hammock, one mile west of Daytona.......... 96
14. Fig. x. Sand dune near Mayport .........................
Fig. 2. Ancient sand dune, two miles west of Daytona...........
Fig. 3. Exposure at Saw Pit landing, St. Marys River........ 96
15- Map showing areas of artesian flow in Florida .................. 22

TEXT FIGURES.
Fig. 6. A rtesian basin .................... .................... .... o
Fig. 7. Artesian slope ........................ ................. .... o
Fig. 8. Artesian flow from unconfined horizontal strata................. I
Fig. 9. Artesian flow from cavities in limestohe..................... II
Fig. 1o. Method of measuring artesian flow ............................ 9
Fig. II. Map of flowing area of Nassau and Duval Counties................ 135
Fig. 12. Map of flowing area of St. Johns County ....................... 43
Fig. 13. Map of flowing area of Clay and Putnam Counties............. 155
Fig. 14. Map of flowing area of Orange County ........................ 167
Fig. 15. Flowing well on Lake Jessup, Orange County .................... 172
Fig. 16. Map of flowing area of Volusia County .............. ....... 175

THE ARTESIAN WATER SUPPLY OF EASTERN
FLORIDA

E. H. SELLARDS AND HERMAN GUNTER.

INTRODUCTION.

A study of the water supply of Florida was begun in 1907
as co-operative work between the Florida State Geological Survey
and the National Geological Survey. The first paper was issued
in I908 as Bulletin No. I of the Florida State Geological Survey,
and relates to the underground water of central Florida. This
paper, the second of the series to be published by the State Survey,
extends the study of the water supply to the counties of eastern
Florida.
The writers are indebted tcd the many well drillers and well
owners who have contributed data regarding wells. Among the
many who have given assistance the following should be especially
mentioned: Messrs. Bellough & Melton, J. M. Chambers, C. I.
Cragin, Dr. E. S. Crill, Capt. R. N. Ellis, Hughes Specialty Well
Drilling Co., W. E. Holmes, John McAllister, Dr. J. N. Mac
Gonigle, McGuire & McDonald, W. J. Nesbitt, Hugh Partridge.
H. Walker. Dr. De Witt Webb, J. W. Wiggins, H. Van Dorn and
W. D. Holcomb. Extensive well records made in 1907-1908 in
cooperation with the U. S. Geological Survey by Messrs. Geo. C.
Matson and F. G. Clapp have been utilized in the preparation of
this report. Data regarding climate and rainfall have been sup-
plied by Hon. A. J. Mitchell, Director of the Florida section of
the U. S. Weather Bureau.
Most of the analyses included have been made in the office of
the State Chemist especially for this report. Others have been
made at various times by other chemists. Credit is given with
each analysis. The general discussion and introductory chapters
of this paper were written by the senior author. The account of
the public, city and private supplies and of individual wells was
written chiefly by the junior author.

8s FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

THE AREA TREATED.

The area considered in detail in this report includes the follow-
ing counties: Nassau, Duval, Clay, St. Johns, Putnam, Volusia.
Orange, Brevard and St. Lucie. This section borders the
Atlantic Coast for a distance of 250 miles, and comprises the princi-
pal artesian area of the east coast.
While central Florida, described in the preceding paper on water
supply* is prevailingly a limestone country, having limestone for-
mations at or near the surface, this eastern section of the State is
prevailingly a section free from limestones. These differences, due
primarily to differences in geologic structure, have given rise to
marked differences in the topography, drainage, soils and water
supply of the two sections.

GEOLOGY.

A knowledge of the geologic structure is essential to a clear
understanding of the underground water conditions. The prevail-
ingly level country of East Florida renders geologic observations
difficult. Some favorable exposures occur, however, and these
together with data obtained from well samples and well records
permit a reasonably full understanding of the structure of this part
of the State.
The geologic periods in eastern Florida in the order of occur-
rence are: Oligocene, Miocene, Pliocene and Pleistocene. Of
these divisions the Oligocene is the oldest; the Pleistocene the most
recent.

OLIGOCENE.

VICKSBURG GROUP.

The oldest or deepest formations reached in well drilling ii
eastern Florida are the Vicksburg limestones. The Vicksburg is
an extensive deposit underlying all of Florida and extending into
adjacent states. In central peninsular Florida from Columb-a to
Sumter Counties, as described in the preceding paper on water
supply, these limestones are frequently exposed at the surface.
Passing to the east from central Florida they dip beneath the surface
and while nowhere exposed at the surface in eastern Florida, are
reached by all deeper wells. It is in fact from these limestones
that the principal water supply of eastern Florida is obtained.

*Fla. State Gc:l. Surv. ull. No. i, 1908.

THE ARTESIAN WATER SUPPLY OF EASTERN FLORIDA.

The Vicksburg is very characteristic in appearance and structure,
and when once seen is not likely to be mistaken for any other for-
mation in this part of the State. The first one or two hundred feet
is of light color. This limestone as seen in well samples has a granu-
lar appearance and may contain many small shells. This phase of
the limestone is frequently spoken of by the drillers as the "coral"
formation. As a matter of fact, however, the formation contains
relatively few corals. After passing through this limestone one
or two hundred feet a more compact limestone is encountered.
This part of the formation often has a slightly pinkish cast, the
rock being very hard, and the drilling difficult. While these are
the general characteristics of the Vicksburg, yet its texture is not
uniform. Hard layers usually alternate with soft layers, the water
supply as a rule increasing as each hard layer is penetrated. Not
infrequently masses of flint are found imbedded in the limestone
which in some instances have given much difficulty in drilling.
While, as already stated, the Vicksburg limestones dip on pass-
ing to the east approaching the Atlantic, yet the dip is not uniform
and the depth at which it is encountered varies from place to
place.
In the wells at Jacksonville the Vicksburg is reached at a
depth of from 500 to 525 feet. At Callahan and at Fernandina
in Nassau County, although no samples have been obtained, the
Vicksburg is believed, from well records, to be reached at about the
same depth as at Jacksonville.
Along the St. Johns River the Vicksburg maintains a similar
depth for some distance. At Ortega, seven m'les south of Jack-
sonville, the limestone was reached at a depth of about 500 feet.
At Magnolia Springs, and Green Cove Springs, thirty miles south
of Jacksonville, and on Black Creek, while no well samples were ob-
tained, the Vicksburg is believed from well records to occur at :t
depth of from 325 to 400 feet.
Passing to the south the Vicksburg lies nearer the surface.
Samples of drillings from wells at St. Augustine and at Hast'ngs
in St. Johns County and at Orange Mills in Putnam County show
that the Vicksburg in this section lies at a depth of 13o to 225
feet, the greater depth being at St. Augustine and the minimum
depth at Orange Mills. Passing to the south the Vicksburg lies,
so far as well records indicate, at a fairly uniform level for a dis-
tance of 150 miles. At Sanford, 75 miles south of Orange Mill's.
the Vicksburg is reached at a depth of from 113 to.125 feet.
At Daytona, although samples are lacking, the depth of this
formation is believed, judging from well records, not to ex-
ceed 150 feet. At Cocoa the Vicksburg is reached at a depth not

88 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

exceeding 190 feet, while at Melbourne Beach, 150 miles south
of St. Augustine, its depth in one well was found to be 221 feet.
Passing to the south from this point the Vicksburg dips rapidly.
At Palm Beach, Ioo miles farther south, this limestone was reach-
ed at a depth of approximately I,ooo feet, *a dip of about 750 feet
in 1oo miles or 7Y2 feet per mile. The Vicksburg was not reached
in a well 700 feet deep drilled by the Florida East Coast Railway
Company at Marathon Key, 175 miles south of Palm Beach.t
At Key West, however, the formation is believed to have been
reached at a depth of 700 feet.f
It is thus seen that the Vicksburg forms a broad arch extending
from central Florida to the Atlantic Ocean. St. Augustine lies
near the north slope of this arch, while Melbourne, as nearly as
can be determined, lies near the south slope. On either side of
the arch the limestone dips at a moderate rate. On the north side
of the arch the maximum depth recorded in Florida is 500 feet.
Passing to the south a maximum of approximately I,ooo feet is
recorded at Palm Beach. While the occurrence of this formation
is thus known in a general way the data are as yet imperfect.
In view of the importance of the Vicksburg as an artesian
water reservoir the depth at which it is to be expected is a matter
of very great importance and it is to be hoped that well drillers
will find it possible to keep accurately labeled well samples in order
to determine more definitely the distribution of this formation.

APALACHICOLA GROUP.
The Apalachicola group of formations is of a much less uniform
character than the Vicksburg and is also of less importance in
connection with the water supply. A full description of this group
of formations will be found in the preceding Annual Report of
this Survey, pp. 67-106.
The formations which make up the Apalachicola group include
the Chattahoochee and Alum Bluff formations, well exposed along
the Apalachicola River; the Hawthorne formation in central Flor-
Sida; and the Tampa formation in southern Florida. The relative
position of three of these, the Chattahoochee, the Hawthorne and
the Tampa formations has not been definitely determined, and they
may be largely contemporaneous. The Alum Bluff formation lies
above the Chattahoochee formation. The limestone of this group
consists largely of impure clayey material which upon decay

*Darton, N. H.; Amer. Journ. Sci. (3) XLI, p. 105-6. 189i.
tFlorida Geol. Survey. SecondAnnual Report, p. 206, 9gog.
tHovey, E. O. Mus. Comp. Zool. Bull. XXVIII, pp. 65-91, 1896.

THIRD ANNUAL REPORT. PL. 10.

Fig. i.-Exposure of hardpan along Black Bluff on Clarks Creek, eight
miles from Fernandina.

Fig. 2.-Artesian well used for power belonging to H. T. Bowden, Mel-
bourne, Brevard County. The water from the artesian well affords
power by which water is pumped from a near-by shallow well.

Digitized by Coogle

FLORIDA GEOLOGICAL SURVEY.

THE ARTESIAN WATER SUPPLY OF EASTERN FLORIDA.

weathers to a sticky blue clay. The Chattahoochee Limestone Is
difficult to recognize in well samples. Fossils in this formation are
comparatively rare and such as occur are preserved as casts and are
largely destroyed in drilling. In surface exposures it may be recog-
nized by its lithologic characters and by the characteristic cubical
blocks into which some of the strata break upon exposure.
The Apalachicola group has not been recognized from well
drillings in East Florida. Clays taken by Mr. S. L. Hughes from
the new city well at Jacksonville at the depth of 320 feet have
a very close resemblance to the fullers earth clays which occur
in the Apalachicola group above the Chattahoochee Limestone.
Onr the other hand Matson obtained from Jacksonville a Miocene
shark's tooth from a well sample supposed to come from the depth
of 496 feet. In order to determine more fully the area and extent
of the Apalachicola group of formations in eastern Florida it will
be necessary to obtain large and carefully collected well samples.
The wide distribution of this group in West and South Florida leads
one to believe that it is likely to occur very generally underlying Eas;
Florida.

MIOCENE.

The Miocene deposits are well developed in eastern Florida. At
the city water works at Jacksonville this formation was encountered
in excavating for the basin for the city water supply,* and was
also reached in the city wells at a depth of from 35 to 36 feet. At
Jacksonville this formation has a considerable, although un-
determined, thickness. It consists of a buff limestone grading to
a lighter color, more or less phosphatic, grading below to phosphatic
sands and sandy marls. The formation is in places fossiliferous.
although the shells are usually preserved as casts.
In Clay County the Jacksonville formation is extensively ex-
posed along Black Creek. The exposure of this fo nation appears
along both the south and north fork, of Black Creek some miles
above Middleburg, and may be observed for five or six miles below
Middleburg. The following section was observed at High Bluff.
on the south fork of Black Creek about five miles above Middle-
burg:

*Dall, W. H., U. S. Geol. Surv. Bull. 84, 124-125, 1892.

J90 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.

Covered and sloping ................ ..................... 5 feet
Sloping, some sticky clay exposed ..... ................. 5 feet
Yellow sand ................. ............. .. ........ 8 feet
Buff colored sandy limestone, containing a small proportion of
black phosphatic pebbles ....................... ........ 12 feet
Same, with greater amount of phosphate ...,.................. 5 feet
Same, with some phosphate ............ ..... .. ...........12 feet

This is the thickest exposure of the Jacksonville formation ob-
served at any one place along Black Creek.
The following section was observed in the pit of the Jackson-
ville Brick Company two miles southwest of Jacksonville:

Incoherent sand and soil.................... ....... ...... 2.4 feet
Sandy clays, the top 5 or 6 feet oxidized yellow. .............6 feet
Bluish fossiliferous marl .......... .... ............... 4 feet

Beneath this marl as shown by numerous well drillings the
sandy limestones of the Jacksonville formation occur.
Miocene deposits in Florida were first recognized by Dr. E. A.
Smith,* at Rock Springs in the northwestern part of Orange
County. The limestone exposed here is a light sandy fossiliferous
limestone and is probably of the Jacksonville formation.

PLIOCENE.

Pliocene is known to occur in eastern Florida, although the
extent and distribution of the deposits have been but imperfectly
determined. The shell deposits of this period occurring in the St.
Johns valley and along the east coast have been described' by
Messrs. Matson and Clapp.t Localities mentioned by them are
Nashua on the St. Johns River in Putman County and at DeLand
;and near Daytona in Volusia County. Other localities at which
these deposits were observed to be exposed are one-half mile above
the Atlantic Coast Line bridge over the St. Johns River in Putnam
County; on the east side of the St. Johns River about five miles
north of the Atlantic Coast Line bridge in Volusia County. Plio-
cene beds were also recognized from a well near Kissimmee. From
the exposures thus recognized it is evident that Pliocene beds under-
lie a considerable area of eastern Florida.

SirM;tlh. E. A, On the Geology of Florida. Amer. Journ. sci. 3d Ser., V 1.
XXI, pp. 302-303.
lla (l;-. Snrv. S c. Ann. Rpt.. pp. 12 7133. 1 (Q09.

THE ARTESIAN WATER SUPPLY OF EASTERN FLORIDA.

PLEISTOCENE.

The marine Pleistocene deposits have been recognized at several
localities in eastern Florida. Messrs. Matson and Clapp obtained
collections from Eau Gallie, Titusville and Minis in Brevard County.
It 'is probable that marine Pleistocene shell deposits are somewhat
widely distributed along the east coast and perhaps in the St. Johns
River valley. Here again satisfactory determination can be made
only from large and carefully kept samples obtained in well'drill-
ing. The coquina rock which occurs extensively at St. Augustine
and extends along the coast to the south for 250 miles, is also to
be placed with the Pleistocene. Some of the older sand dunes of
the east coast also probably belong to the Pleistocene.

EARTH MOVEMENTS DURING THE PLEISTOCENE.

Changes in the relation of land and water have occurred recently
along the east coast, probably during Pleistocene time. The best
evidence of these changes is that offered by the sand dunes and
the coquina rock bordering the east coast: The line of sand dunes
along the coast is well developed and largely continuous. From
Daytona south these dunes occur, not on the present beach, but back
from the beach a variable distance depending upon the configura-
tion of the country. At Daytona the sand dune lies back from the
Halifax River about two miles. From Daytona to Titusville
the dunes are to be seen lying mostly to the west of the East Coast
Railroad at a distance of one or two miles from the coast. At
Titusville -the dunes lie back from the Indian River two to two
and one-half miles. At Rockledge the dunes approach closer to
the coast. They recede again, however, to the south and at no
place directly face the ocean. The dunes are now quiescent and
are covered with a thick growth of trees indicating that they have
been undisturbed for a long time. In the same way the coquina
rock, found facing the ocean at. Anastasia Island in St
Johns County, falls back from the coast to the south extending at
places a few miles inland. The presence of this ledge of coquina
rock bordering the coast together with the sand dunes lying back
clearly indicates that the land level formerly stood lower than at
present, the coquina rock and sand dunes having accumulated along
what was then the beach.
Conrad as early as 1846 noted the occurrence of marine shell,
of post-Pliocene age along the bank of the St. Johns River at ani
elevation of from ten to fifteen feet above the present high tide.

	Front Matter
	Front Cover
	Title Page
	Letter of transmittal
	Table of Contents
	List of Illustrations
	A preliminary paper on the Florida...
	Some Florida lakes and lake...
	The artesian water supply of eastern...
	Preliminary report on the peat...
	Index of plant names
	Index
	Back Cover

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