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FGS FEOL



The Pensacola terrace and associated beaches and bars in Florida
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Permanent Link: http://ufdc.ufl.edu/UF00000434/00001
 Material Information
Title: The Pensacola terrace and associated beaches and bars in Florida
Series Title: Bulletin - Florida Geological Survey ; 7
Physical Description: 44 p. incl. illus., maps, tables. : fold. map (in pocket) ; 23 cm.
Language: English
Creator: Leverett, Frank, 1859-1943
Harper, Roland M ( Roland McMillan ), 1878-1966
Publisher: s.n.
Place of Publication: Tallahassee, Fla.
Publication Date: 1931
Copyright Date: 1931
 Subjects
Subjects / Keywords: Physical geography -- Florida -- Pensacola terrace   ( lcsh )
Prehistoric peoples -- Florida -- Pensacola terrace   ( lcsh )
Shorelines   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography on "Fossil man and Pielstocene vertebrates on the Pensacola terrace": p. 33-35.
Bibliography: Includes bibliographical references.
General Note: At head of title: Florida State Geological Survey. Herman Gunter, state geologist ...
General Note: "Some economic features of the Pensacola terrace in Florida, by R.M. Harper": p. 38-44.
Statement of Responsibility: by Frank Leverett.
 Record Information
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier: ltqf - AAA1718
ltuf - AKM4751
alephbibnum - 002036991
oclc - 01338715
lccn - gs 31000175
System ID: UF00000434:00001

Table of Contents
    Front Cover
        Front cover 1
        Front cover 2
    Front Matter
        Page i
    Table of Contents
        Page ii
        Page iii
    Main
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
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Full Text



FLORIDA STATE GEOLOGICAL SURVEY
HERMAN GUNTER, State Geologist.







BULLETIN NO. 7







THE PENSACOLA TERRACE AND ASSOCIATED
BEACHES AND BARS IN FLORIDA

By FRANK LEVERETT


TALLAHASSEE, FLORIDA,
July, 1931.





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LETTER OF TRANSMITTAL


To His Excellency, Hon. Doyle E. Carlton,
Governor of Florida.

SIR: I have the honor to submit herewith for publication as Bul-
letin 7 of this Department a report entitled "The Pensacola Terrace
and Associated Beaches and Bars in Florida" by Dr. Frank Leverett,
of Ann Arbor, Michigan. Dr. Leverett was a member of the staff of
the United States Geological Survey from 1886 to his retirement in
1929, and during that time became recognized as an authority on the
glacial geology of the northeastern United States. Among his leading
studies was that of tracing ancient shore-lines and terraces in the
vicinity of the Great Lakes, and he has published many papers on
the subject.
Since his retirement he has spent his winters in Florida, and studied
the marine terraces which can be seen a few to several miles back
from the present shore-line at a number of localities, indicating that
the ocean level was higher than now in comparatively recent times.
The present bulletin, which Dr. Leverett has kindly prepared for us
without remuneration except for necessary traveling expenses, deals
with the lowest and most clearly marked of these terraces, which has
been named the Pensacola terrace.
Although the location of this terrace is still indefinite in places,
owing to the lack of topographic data and the inaccessibility of por-
tions of the country traversed by it, the results already obtained are
deemed of sufficient interest to be presented at this time for the benefit
of students of physiographic problems.
This terrace is of more than academic interest. On it are located
all our seaport cities, and on account of its level nature it is peculiarly
adapted to intensive scientific farming, and agricultural practices there
are quite different from those prevailing on the uplands of the State.
At Dr. Leverett's suggestion a chapter has been appended showing
some of the ways in which the Pensacola terrace differs from the rest
of the State in population, agriculture, etc. This chapter was pre-
pared by Dr. R. M. Harper, Geographer, whose intimate knowledge
of such facts peculiarly fits him for making such a contribution.
Respectfully,
HERMAN GUNTER,
State Geologist.
Tallahassee, Florida,
June 9,1931. -'7- -
















CONTENTS

PAGE
THE PENSACOLA TERRACE AND ASSOCIATED BEACHES AND BARS IN FLORIDA.... 7-37
By Frank Leverett.
Introductory statement ..................................... ........ 7-9
The Pensacola shore-line ........................................... 9-32
Position on the Atlantic coast.................................. 9-13
Islands and off-shore bars on the Atlantic coast.................... 14-17
Southern limit of the peninsula in Pensacola time ................. 17
Position on the Gulf coast ...................................... 17-24
Off-shore bars in western Florida ............................... 24-25
Buried peat near Milton ................... ..................... 25-26
Tilting of the Pensacola shore-line ............................... 26-30
Probable age of the Pensacola shore-line ......................... 30-32
Fossil man and Pleistocene vertebrates on the Pensacola terrace....... 33-37
Bibliography ...................... ................. ......... 33-35
SOME ECONOMIC FEATURES OF THE PENSACOLA TERRACE. ................... 38-44
By Roland M. Harper.
Geography ....................................... ............. 38-39
Statistical comparisons ................ ........ ..... ............... 39-44
Population .................. ............ ....... ............... 40-41
Farm ing .......................... .......... ............. .. 41
W health and education .......................................... 41-42
Explanation of table .............................. ............. 42
Statistical table ............... ........ ..... ................... 43
Application to other states .......................................... 44

























LIST OF ILLUSTRATIONS

TEXT FIGURES

1. Topographic map of part of the Interlachen quadrangle, showing the Pen-
sacola shore-line running about north and south near the center.......... 11

2. Part of the Palm Valley quadrangle, showing an island and neighboring
bars in the Pensacola sea near Durbin ................................ 13

3. Part of the Jacksonville quadrangle, showing a dune-covered island and
neighboring bars in the Pensacola sea ................................. 15

4. Map of the Pensacola shore-line in the vicinity of Tampa................ 19

5. Part of the Baton Rouge (La.) quadrangle, showing some features appar-
ently referable to the weight of the Mississippi delta ..................... 28

6. Ground plan showing the location of human bones found in the canal bank
at Vero ....................... .......... .... ............... ....... 36



PLATES
1. Map of the Pensacola Sea in Florida................................ In Pocket





THE PENSACOLA TERRACE AND ASSOCIATED
BEACHES AND BARS IN FLORIDA


By FRANK LEVERETT, Senior Geologist (Retired),
U. S. Geological Survey.


INTRODUCTORY STATEMENT
The writer's studies in Florida, and in parts of the Gulf Coast
farther west, have been undertaken for the purpose of determining
whether one of the best-defined raised beaches, that bordering the
Pensacola terrace, has been subjected to differential uplift, or instead
holds a uniform altitude above sea level throughout the district ex-
amined. The determination of the probable length of time since the
Pensacola terrace became exposed has also been a leading object, for
on this terrace have been found remains of several extinct species of
animals closely associated with human remains. The state of preser-
vation of the Pensacola shore-line and the degree of erosion of the
Pensacola terrace have received close attention. In such study the
writer has drawn comparisons with results of work on the shore-lines
and terraces around the Laurentian Great Lakes, the approximate
ages of which have been determined.
Concentration of study on the Pensacola terrace and associated
beaches and bars is dud partly to the brief period of time available
for the investigation, and partly to the fact that higher terraces and
shore-lines have become so broken down and toned down by erosion
and solution in much of the region covered as to make continuous
tracing and correlation difficult and uncertain. This was found to be
the case even where excellent topographic maps are available.
No attempt is made here to review the literature pertaining to the
Pleistocene features and deposits of the Atlantic and Gulf coastal
plains. Much of it is fragmentary, as the studies were usually taken
up incidentally in connection with studies of underlying older forma-
tions. The literature pertaining to the Pensacola terrace and shore-
line is embraced in a few references. The name Pensacola was applied
to the terrace by Matson in 1913, and is interpreted by him to merge
with the Satilla formation in Georgia.' Both are said to be below 40
feet above present sea level. The Pensacola terrace and Satilla for-
mation are discussed by Cooke in recent papers on the Pleistocene Sea
IGeorge C. Matson, Water Supply Paper 319, U. S. Geol. Survey, 1913, pp. 34-35.
For discussion of the Satilla formation see Veatch and Stephenson, Bull. Geol.
Survey of Georgia No. 26, 1912, pp. 334-445.
[71





8 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

Shores.2 These papers deal mainly with features on the Atlantic
coastal plain from Georgia northward, but the interpretation of ter-
races given, namely, that they show no tilting, or deformation, is in-
ferred to have application in Florida, and on the Gulf coast farther
west.
Two important papers on features of the Gulf coast in eastern Texas,
recently brought out by Barton,3 have an important bearing on the
extension of the Pensacola terrace and shore-line.
In determining the altitude of the Pensacola shore-line several
sources of information have been drawn upon. For northeastern
Florida the topographic maps of the U. S. Geological Survey with
10-foot contours have been used. For western Florida around Pensa-
cola Bay the Fire Control maps of the U. S. Army Engineers with
10-foot contours have been found useful. For the St. Johns River
drainage, maps and profiles by the U. S. Army Engineers, and for the
region around Lake Okeechobee maps by the U. S. Army Engineers
and lines of levels by the Commissioners of the Everglades District
have been very useful. Data on Collier and Hendry Counties have
been supplied by D. Graham Copeland of Everglades, Engineer of the
Florida Development Company. In many cases state and county
highway profiles have furnished data, and in Tampa and St. Petersburg
bench marks given by city engineers. In some cases soil maps by the
Bureau of Soils, U. S. Department of Agriculture, have been fo-upd
to denote the position of the shore by a peculiar class of soil. These
sources of information when combined with field observations have
served to give a fairly accurate knowledge of the position and altitude
of the old shore-line.*
The Pensacola shore-line or scarp is easily traced where it has been
cut into a slope sufficiently steep to permit strong wave action. There
are, however, parts of Florida in which roads are so few that consid-
erable sections have not been accessible. In places where the land
has a very gentle seaward slope it has been found difficult to determine
the limits of the Pensacola sea, as scarps are indefinite or wanting.
Where altitudes are available its theoretical position can be fixed, but
elsewhere in these flat areas the position of this old sea shore can only
2C. Wythe Cooke, Pleistocene Sea Shores, Jour. Wash. Acad. Sci. Vol. 20, 1930,
pp. 389-395. Correlation of Coastal terraces, Jour. Geol. Vol. 38, 1930, pp. 577-589.
3Donald C. Barton, Deltaic Coastal Plain of Southeastern Texas, Bull. Geol. Soc.
America, Vol. 41, 1930, pp. 359-382. Surface Geology of Coastal Southeast Texas,
Bull. Am. Assoc. Petroleum Geologists, Vol. 14, 1930, pp. 1301-1320.
*Since this report was submitted for publication I have had the privilege of a
trip with Prof. D. W. Johnson, of Columbia University, over part of the Pensacola
terrace and shore-line in Florida and in neighboring states. He thinks the attempt
to fix the sea level so definitely as is done in this report may not be warranted, for
in many places it is a difficult matter to determine so exactly where it stood. The
altitudes given should thus be taken as tentative and approximate.





PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


be conjectured. But in spite of this indefiniteness of the coastal
features in some places, the position as indicated on the map is likely
to be within a very few miles of the actual extent of this former sea.
The stage of the sea at the time it covered the Pensacola terrace
seems appropriately called the Pensacola stage, and the beach and
scarp on its border the Pensacola shore-line.

THE PENSACOLA SHORE-LINE
POSITION ON ATLANTIC COAST OF FLORIDA.
Before beginning the description of this shore-line a few remarks
seem necessary concerning the difficulty in some places of distinguish-
ing between bluffs or scarps cut by waves and those cut by streams.
In places the scarp cut by the sea has been modified by subsequent
stream action. In other cases, of which there are notable instances near
Palatka and along the borders of the St. Johns River between Palatka
and Sanford, the stream action appears to have preceded marine action
and cut into a plain in such a way as to leave island-like remnants.
The wide spaces between such remnants were probably cut out by
stream action rather than by marine, the marine action being re-
stricted to a moderate notching of the borders of these higher tracts,
causing steeper scarps. No attempt has been made to work out the
fluvial history that preceded the occupancy of the area by the Pensa-
cola Sea.
In Nassau County, the northeasternmost county of Florida, a bay
of the Pensacola sea extended up the St. Marys valley some 25 miles,
but it was only one to two miles in general width, and the bluffs clear
down to Boulogne rose considerably above the level of the sea, which
at that locality appears to have been about 40 feet above present sea
level. This valley no doubt has had considerable modification by the
river since the sea withdrew. About 3 miles below Boulogne the shore
turns away from the St. Marys valley and bears southward across
Nassau County, passing east of Hilliard and west of Callahan and
entering Duval County near Plummer. It continues a course east of
south across Duval County, passing near Cambon and Marietta and
entering Clay County about 6 miles west of the St. Johns River. There
was, however, an island in the northeastern part of Clay County, 2 to
31/2 miles west of the St. Johns River, and another bordering Doctor's
Lake, which occupies a recess of the St. Johns valley. This island lies
west of the Atlantic Coast Line Railroad near Peoria station. These
islands probably were developed by river action prior to the marine
occupancy. Back of these islands, as may be seen by reference to the
Middleburg topographic map of the U. S. Geological Survey, there





10 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

were extensions of the sea some miles up tributaries of Black Creek,
covering areas below the 40-foot contour. South of Black Creek the
shore bears eastward and crosses the southwest corner of the Orange
Park quadrangle.
The part of the shore thus far traced, down to latitude 300, is
covered by the Boulogne, Hilliard, Cambon, Middleburg and Orange
Park topographic maps of the U. S. Geological Survey, and the limits
are quite definitely fixed, as they fall near the 40-foot contour n
these maps. /
The part of the shore between latitude 300 and latitude 290 45' is
not covered by topographic maps, but it lies just west of the Atlantic
Coast Line Railroad from Green Cove Springs about to Bostwick
station. Between Bostwick and Rice Creek stations the railway
crosses a cape-like spur which extended out to the edge of the St.
Johns valley. A part of this spur appears in the north part of the
Palatka topographic map. A large island directly west of Palatka is
also shown on this map, as well as an island east of the St. Johns River
at San Mateo, and a large area east of the river between it and Crescent
Lake. All of these seem to be residual of a plain that had been eroded
by river action. The extent of the Pensacola sea westward from the
St. Johns River from latitude 290 30' to 290 45' is shown on the Inter-
lachen topographic map. There were bays extending some miles up
the Ocklawaha valley and some of its tributaries, but high land borders
the river closely on the south in the Ocala National Forest.
In Figure 1 the Pensacola shore-line is near the 40-foot contour.
The map shows the youthful condition of drainage on the Pensacola
terrace below the shore-line, drainage lines being few and the surface
wet although there is a descent of 20 feet on the terrace within a space
of only a mile. A higher Pleistocene shore-line, the Newberry, prob-
ably follows the base of the ridge below the 110-foot contour.
The limit of the Pensacola Sea appears to be near the west bank
of the St. Johns River and Lake George throughout the length of the
Ocala National Forest, though the sea probably extended back over
the basin of Lake Kerr and up Juniper (Sweetwater) valley. The
extent of the sea in northern Lake County is fairly well marked by a
change in soil and drainage conditions. Referring to the soil map, the
"Portsmouth fine sand" seems to have been covered almost entirely by
the sea, while the areas of "Lakewood fine sand" and "St. Lucie sand"
west of it were mainly above its limits. This places the shore from
1 to 4 miles west of the St. Johns River from the northern end of the
county as far south as the Wekiva River. There seem to have been
narrow bays extending up Blackwater Creek as far at least as Lake
Norris, and up the Wekiva River as far as Wekiva Springs in Seminole








PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


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FIGURE~ 1. Topographic map of part of the Interlachen quadrangle, U. S. Geol.
N:Survey, showing the Pensacola shore-line running about north and south near

11 -the center, (Putnam County.)


11






12 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

County, and Rock Springs in Orange County, with an extension north
from Rock Springs into southern Lake County.
In Seminole County the shore had rather large bays between which
were prominent extensions. These perhaps are old stream meanqrs
antedating the Pensacola Sea. There was a bay around Lake Jessup
with an extension of about 8 miles south from the St. Johns River and a
width of similar amount. West of it at a distance of only about two miles
from the St. Johns River was a prominence extending from Sanford
to the Wekiva River, while east of it was a cape-like projection termi-
nating at Lake Harney and the St. Johns River near Osceola. South of
this cape was a long narrow bay now drained by the Econlockhatchee
River (locally known as Econ River) which extended fully 30 miles
up the Econlockhatchee valley across southeastern Seminole County,
and at least 15 miles into Orange County. A branch from it extended
southwestward up the Little Econlockhatchee River into the edge of
Orange County.
In eastern Orange County the Pensacola sea extended 6 to 10 miles
or more west of the St. Johns River. There are what seem to be small
bars, classed as "Orlando fine sand" on the Orange County soil map,
immediately west of the wet plain of "Bladen fine sand" bordering the
river. But the sea appears to have extended beyond these bars some
distance into the level area of "St. Johns fine sand." The water there
was probably too shallow for effective wave action, or the development
of a distinct scarp.
The extent of the Pensacola sea west of the headwater portion of
the St. Johns River is fairly well indicated on an unpublished map
by the U. S. Army Engineers of the part above Lake Monroe, based on
a survey made in 1903 under the direction of Capt. Francis R. Shunk,
and supplemented by maps of the U. S. Land Survey and chart of the
U. S. Coast Survey.4 The border of the Pensacola sea appears to have
been very near the line where the map shows a change from wet land
to drier land. The line runs into Osceola County 7 or 8 miles west of
Lake Poinsett and takes a south-southeast course for about 20 miles,
coming near the line of Osceola and Brevard counties directly east of
Deer Park. It then runs southward near this county line for 10 miles,
and passes east of south across the southwest township of Brevard
County. Its course is then southward through the middle of the two'
westernmost townships of Indian River County into Okeechobee
County. It passes near the southwest corner of Indian River County
north of Fort Drum. From there its course is south-southeast through
eastern Okeechobee, and southwestern St. Lucie County nearly to
4This map was prepared to accompany a report of June 22, 1904, to the Chief
Engineers, U. S. Army. With it are several profiles across this part of the river basin.






PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


Indiantown in Martin County. In the last 20 miles it forms the east
border of a narrow peninsula that lay east of the north part of the
Lake Okeechobee basin. Before continuing the description of its
course across from the Atlantic to the Gulf coast, the islands east of
the St. Johns River will be taken up.


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IIGURE 2. Part of the Palm Valley quadrangle U S Geol Survey showing an
island in the Pensocala sea near Durbin, and neighboring Pensacola bars.
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13





14 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN
ISLANDS AND OFF-SHORE BARS ON THE ATLANTIC COAST.
There are a number of places shown on the topographic maps of the
St. Marys, Jacksonville, Mayport, Palm Valley, and Orange Park
quadrangles where slender ridges about parallel with the present
coast rise above the 40-foot contour, while the swales separating then
are usually below that contour. These are interpreted to be off-shore
bars on shoals of the Pensacola sea, formed by its waves. There are
in these quadrangles small areas that rise above 50 feet and one near
Durbin in the Palm Valley quadrangle shown in Figure 2 reaches 70
feet. Some of those which reach 50 feet are dunes, or sand ridges
formed by wind action, as is evident from their form as well as struc-
ture, but they are probably on bars of the Pensacola sea. There are
other areas with plain or smooth surface which appear to have been
islands that were not covered by the Pensacola waters. The most
conspicuous within the quadrangle mentioned is the area around
Durbin, which embraces 3 or 4 square miles of which about 3 square
miles stand above 50 feet.
Directly east of Jacksonville, on the east side of the St. Johns River,
is an area of several square miles with points rising above 50 feet,
which appears to have been an island. Its surface does not have pro-
nounced dune topography and it may have been slightly raised by
wind deposit. A long narrow strip, a part of which is shown in Figure
3, runs north and south through the southeast part of the Jacksonville
and northeast part of the Orange Park quadrangles. This is generally
above 50 feet and at one place reaches 80 feet. This has the topog-
raphy of a strip of dunes, but as the base of the sand ridges is generally
above 50 feet, this strip appears to have been a slender island standing
above the Pensacola sea. East of it are several bars standing near the
40-foot contour, as shown in Figure 3, which appear referable to the
Pensacola Sea.
There is a small area of old dunes near Jacksonville of still greater
prominence. It is located east of the Prison Farm north of the St.
Johns River and has points above 100 feet. This may have been
heaped up after the withdrawal of the Pensacola waters, and perhaps
there was no island there in Pensacola time. The same is the case
with old dunes near Riverview in the western part of the Jacksonville
quadrangle and of some old dunes forming "St. Johns Bluff" near the
mouth of the St. Johns River in the Jacksonville and Mayport quad-
rangles, also of old and modern dunes near Fernandina. A small strip
of land near Evergreen School in northern Nassau County in the north-
west part of the St. Marys quadrangle, which has points above 60 feet,
may have been an island whose altitude has been increased somewhat
by sand deposits due to wind action.






PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


FICURE 3. Part of the Jacksonville quadrangle, U. S. Geol. Survey, showing a dune-
covered island in the Pensacola sea, and neighboring Pensacola bars.


15





16 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

Aside from the island near Durbin St. Johns County seems to have
been below the Pensacola sea except perhaps an off-shore bar which at
Hurds, on the Florida East Coast Railway southwest from St. Augus-
tine, has an altitude of 44 feet. It is probable that this altitude is
maintained for some distance north and south from Hurds, perhaps
southward past Gopher Ridge into Flagler County, but data as to alti
tude are not available. The degree of continuity as well as the alti-
tude of the bar in these counties has not been determined. The soil
map of Flagler County shows only scattered patches of dry sandy land
there.
In Putnam and Volusia counties there are large areas with the lake
region topography and suitable conditions for orchards of citrus fruits
which had been cut off from the main district probably by fluvial
action prior to the invasion of the surrounding lower areas by this Pen-
sacola sea. They rise to a moderate elevation of 30 to 40 feet above the
level reached by the sea. One of these extends from Satsuma Heights to
Barberville, a distance of 30 miles, with a width of 3 to 5 miles or more,
and height up to 80 feet or about 40 feet above the Pensacola sea.
There appears to have been a gap of 4 or 5 miles between this island
and one setting in at De Leon Springs and running south and east as
far as Osteen, a distance of fully 25 miles, with a width ranging from 2
miles or less up to about 8 miles. Much of this land stood scarcely 20
feet above the Pensacola sea. These lands are indicated on the State
soil map, 17th Ann. Rept. Florida Geol. Survey, 1925. In Volusia
County, as in Flagler and St. Johns counties, an off-shore bar was
formed some miles east of the large island strips just noted. The
altitude appears to be about 40 feet above present sea-level where well
developed. The degree of continuity has not been ascertained. It
lies within 5 or 6 miles of the present shore in much of its course.
In northern Brevard County a sandy ridge of old dunes 35 feet or
more in height lies only 1 to 3 miles back from Indian River, but bears
farther inland near Cocoa. Its course and degree of continuity have
not been determined farther south. The highway leading west from
Melbourne crosses a summit about midway between Melbourne and
the St. Johns River at a place where ridging is not so pronounced as
farther north. There is a sandy dune ridge near the present sea-coast
for much of the way from Oslo, in southeastern Indian River County,
across St. Lucie and Martin counties to the vicinity of West Palm
Beach, whose height ranges from 35 to 40 feet up to about 70 feet, the
latter height being attained in dunes near Olympia. To what degree
this sandy ridge was developed as an off-shore bar in Pensacola time,
and to what degree in later times has not been determined. The wind
evidently has been an important agent in places where the dune topog.





PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


raphy has been developed, but where the ridge takes the form of a
regular even-crested bar it may prove to be largely the product of
waves at the Pensacola stage.

SOUTHERN LIMIT OF THE FLORIDA PENINSULA IN PENSACOLA TIME.
As already indicated, a narrow strip of land extends southeastward
from near Okeechobee City nearly to Indiantown, on the east side of
the northern part of the Lake Okeechobee Basin. Its western shore
runs westward from a little north of Okeechobee City to the Kissimmee
River opposite Fort Bassenger. There may have been a narrow bay
extending some miles up the river, but the main shore had a westward
continuation to near the south end of Lake Istokpoga. It there turned
abruptly southward and passed through the eastern part of townships
37, 38, 39 and 40 S., R. 30 E. to Fisheating Creek near Palmdale, the land
to the east being flat and wet while that to the west has fairly well
drained slopes. From a map by the U. S. Army Engineers of a district
bordering the Caloosahatchee River5 it appears that the land has a
rather rapid slope from 40 down to 30 feet in a strip running southwest
from Hall City nearly to La Belle, from which place the contours bear
north of west and are more widely spaced. The shore thus seems to pass
about 2 to 21/2 miles north of La Belle. The slopes are so gentle in
southern Charlotte County that there were very unfavorable conditions
for the development of a definite scarp, but the limits of the sea were
probably 4 to 6 miles north of the south line of Charlotte County across
Ranges 24, 25, 26, and 27 E., T. 42 S. There probably was a bay extend-
ing up Prairie Creek into southern De Soto County, north of which the
shore ran westward to the valley of Peace River near Fort Ogden. A
narrow bay extended many miles up this river probably into Hardee
County. Surveys by the Army Engineers, and by D. G. Copeland,
Engineer of the Florida Development Company, show that two sandy
ridges rise above 40 feet in the district south of the Caloosahatchee
River, and these probably were built by the Pensacola sea and raised
slightly by wind action.

POSITION ON THE GULF COAST OF FLORIDA.
The description of the Pensacola shore on the Gulf coast naturally
starts at the Peace River valley, for this is where it begins to run about
parallel with the present coast. The shore seems to bear away from the
Peace River bay about west of Fort Ogden. Here as in the district east
of Peace River the slope is very gentle and conditions unfavorable for
development of a definite scarp. The profile of the Atlantic Coast
Line Railroad shows scarcely 5 feet variation in altitude in a distance
5House Doe. 215, 70th Congress 1st Session, Sheet No. 2, April, 1928.






18 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

of 15 miles, across southern Manatee and eastern Sarasota counties,
and for several miles it is at about 42 feet. This is slightly higher
than the Pensacola sea, whose altitude in this longitude appears to
have been about 35 feet; so the limits of the sea are theoretically placed
2 or 3 miles southwest of the railroad. The county line east of Honore
is 37 feet while Honore station is 30 feet, so the railroad seems to pass
to the Pensacola terrace near the line of Manatee and Sarasota counties.
It crosses sandy bars between there and Sarasota, but the limits off-he
sea appear to be north of the railroad. A bar near Utopia is 39 feet
and one near East Sarasota 33.6 feet. There is also a bar at Bee Ridge
south of East Sarasota at 36 feet. The bars at East Sarasota and Bee
Ridge are surrounded by lower land and do not connect with the old
shore-line.
The shore-line appears to bear northwestward from northern Sara-
sota County about to the Seaboard Air Line Railway in Manatee
County, which it crosses near the township corners of townships 34
and 35 S., ranges 18 and 19 E. From there a narrow bay extended east-
ward up the Manatee River valley for many miles, perhaps well toward
the east side of Manatee County. North of the river the shore-line
runs northwest and crosses the Seaboard Air Line about 3 miles west
of Parrish station. Its course is then northeastward to the Little
Manatee River in southern Hillsborough County, about 11/ miles
below Willow station. There was an embayment up the valley of this
stream for several miles. From the Little Manatee valley the coast
line had a northward course to Riverview on the Alafia River, running
near the line between ranges 19 and 20 E. across townships 32 and 31 S.
There was a bay north of the Alafia River extending into the northeast
part of T. 30 S., R. 20 E. The water also extended some miles up the
Alafia valley as a narrow bay. The features near Tampa are repre-
sented in Figure 4, as they are exceptionally complex.
The shore-line followed the east and north sides of the drainage
basin of Six Mile Creek (Palm River) around a large swamp lying
east of Harney. West of this drainage basin and south of the Hills-
borough River there was a large island covering the northern part of
Tampa, known as "Tampa Heights," and the district between Tampa
and Harney as indicated in 'Figure 4. There was a narrow bay less
than a mile wide along the Hillsborough River above Florida Avenue
and about 11/2 miles wide below Florida Avenue in Tampa, the east
border being near Florida Avenue and the west near Armenia Avenue.
In Temple Terrace, above Harney, the Hillsborough River has a very
narrow valley which opens into a swamp above Temple Terrace whose
level is slightly lower than that of the Pensacola sea and which extends
up Cypress Creek as well as the Hillsborough River. It is likely to



























LEGEND.
PCMSACOLA SHORL LINF.
CITY ODJUN1RIES x .rXXX3)1,
LAKES AND PONDS
RAILROADS
HIGHWAYS A AVLMUES


FIGURE 4. Map of the Pensacola shore-line in the vicinity of Tampa.






20 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

have been submerged in Pensacola time and the sea may have extended
into it through the narrow passage occupied by the Hillsborough River
in Temple Terrace.
There was a small island west of the Hillsborough River extending
from near Tampa Bay Boulevard southward about to Cypress Street
in Tampa and covering an area of about 3 square miles. This was
separated from the mainland on the north by a passage less than a
mile wide. This island rose less than 10 feet above the level of the
Pensacola sea, its highest point being about 40 feet above present
sea-level.
The mainland had a narrow peninsula along and west of Armenia
Avenue, terminating on the south in Sections 2 and 3, T. 29 S., R. 18 E.
From the end of this peninsula the shore-line bore northwestward into
the northwest corner of Hillsborough County, passing about a mile
south of Citrus Park and coming to the west line of the county about
2 miles south of its northwest corner. It there turned to the northeast
into Pasco County and crossed the Atlantic Coast Line Railroad about
a mile west of Odessa. In the absence of roads in this part of Pasco
County, north of Odessa, the course of the shore-line has not been
traced, but it comes westward to the state highway near Port Richey
and probably turns from a northward to a westward course near the
Anclote River in the central part of T. 26 S., R. 17 E.
Before outlining the course of the shore-line farther north, some
important islands in Pinellas County will be taken up. The southern-
most island is largely within the limits of St. Petersburg and covers
about 20 square miles. Its highest points stood 20 to 25 feet above the
level of the Pensacola sea, but the rise to them is so gentle as to be
scarcely perceptible. The St. Petersburg island was separated by a
space of several miles from a much larger island in the western part
of Pinellas County whose length was nearly 20 miles and general width
about 3 miles. Its southern terminus is in Sections 33 and 34, T. 30 S.,
R. 15 E. and northern in Section 36, T. 27 S., R. 15 E. Its west border
is close to the present coast line from near Indian Rocks to Clearwater,
and less than 2 miles east of the present coast from there northward.
This island reaches an altitude of nearly 100 feet above present sea
level directly east of Dunedin, but its general altitude is from 60 to 75
feet. On its east side in Safety Harbor there were a couple of small
islands separated from it by narrow passages, which gives diversity
to the topography of that village. Another island in northern Pinellas
County covered 4 or 5 square miles on the east side of Lake Butler.
Its easternmost point is less than 3 miles from the main coast line in
northwestern Hillsborough County.
From near Tarpon Springs a chain of bars extends northward along





PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA 21

or near the present paved highway to connect with the shore-line near
Port Richey. One of these bars from Elfers southward causes the
Anclote River to be deflected from a westward to a southward course
along its east side. One north of the Pithlachascotee River passes just
east of New Port Richey and connects with the old shore-line a short
distance northeast of Port Richey. These bars are undulating strips
of sandy land that have had considerable modification by wind action.
There are dunes at various heights in southwestern Pasco and north-
ern Pinellas counties, some of which derive material from the present
coast. It becomes difficult to separate some of them from the sandy
bars that rise above the level of the Pensacola sea and which may date
from Pensacola time. There is an exceptionally regular shore-line
from near Port Richey northward across Pasco, Hernando and Citrus
counties. It is marked by a change from wet land to drier land standing
well above the level of the Pensacola sea. In Pasco County the shore-
line was scarcely 3 miles back from the present coast, and in Hernando
County only 4 to 5 miles. In Citrus County the border lies near the
Atlantic Coast Line Railroad from Homosassa Springs northward to
the Withlacoochee River. There was a very narrow embayment up
the valley of this stream past Dunnellon. Tide-water of Pensacola
time may have extended up this valley about to the Tsala Apopka
Lakes and had some influence in their development. The level of the
lakes, as determined by the U. S. Geological Survey, is 38 to 39 feet,
and the 30-foot contour crosses the river about 11 miles below the
lake outlet. A narrow bay may also have extended up to Blue Springs
north of Dunnellon.
The Pensacola shore-line is well defined for only a few miles north
from the Withlacoochee valley, as there is a wide exposure of flat land
in Levy County on which the slope is so gentle as to prevent strong
wave action. There is some undulating land south of Lebanon station
which it is thought may have been an island in Pensacola time. The
station is in a plain about 30 feet above sea-level, and 10 to 15 feet
lower than this undulating land. The shore-line is run theoretically
across the plain a short distance north of the Atlantic Coast Line Rail-
road from Lebanon to Otter Creek. The profile of the highway from
Bronson past Otter Creek shows the plain to drop below 30 feet about
3,miles northeast of Otter Creek, thus indicating submergence as far
as that point in Pensacola time. The level at the crossing of the
Atlantic Coast Line Railroad in Otter Creek is only 3 feet lower, thus
showing a remarkably slight slope in the plain.
In the district west from Otter Creek as far south as the vicinity of
Ellzey there is more undulation than to the east, and the altitude
seems to range from 30 feet or less up to over 40 feet in passing from






22 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

basins to bordering higher land. The shore-line may have been 2 to 4
miles west of the Atlantic Coast Line Railroad from near Otter Creek
to Chiefland. From Chiefland to the Suwannee River near Oldtown
there is an undulating surface ranging from 42 feet down to 24 feet,
thus indicating that small bays extended east to this line. The Suwan-
nee River bluff is 25 feet. Between Oldtown and Cross City the sur-
face is below 30 feet for about 7 miles, and but one ridge rises above
40 feet between there and the eastern limits of Cross City. The surface
however in this interval appears to have been slightly above the Pen
sacola sea, so the shore-line is given a theoretical course 1 to 2 miles
south of the railroad and highway from near Eugene to Cross City.
It probably holds a similar distance south of the highway nearly to
the Steinhatchee River, but extends to the highway and railroad at
this stream, for it is below 30 feet at this crossing. In the vicinity of
Carbur and Athena the surface is a few feet higher and the land drier;
so the Pensacola shore-line probably departs somewhat farther from
the railroad there.
From near the meridian of Perry westward about to the meridian
of Tallahassee lines of levels for a proposed ship canal across Florida
run by the U. S. Army Engineers about 1879 under the direction of
Lieut. Colonel Q. A. Gillmore traverse a district so near the level
reached by the Pensacola sea that they can be used in determining
somewhat closely the extent of the sea in that section. The level of the
sea there being about 30 feet above present sea-level, a line connecting
points at or near this altitude will show its extent. This line crosses the
Fenholloway River near the bend 5 miles south of Perry, where it turns
northwest, and follows the river to Pershing. The river there turns
southwest while the old shore-line continues northwestward across the
southwest part of T. 4 S., R. 7 E. and the east and north parts of T. 4 S.,
R. 6 E. to the northeast corner of T. 4 S., R. 5 E. near which it turns
northward across Econfina River. It then runs northwest to the border
of the Aucilla valley about 2 miles below Covington. A narrow bay
extended up this valley about to the southwest corner of Madison Coun-
ty. West of the Aucilla River the old shore-line seems to run near the
Seaboard Air Line Railway as far as Wacissa and is but 1 to 2 miles
south of it from Wacissa westward to the St. Marks River in southeast-
ern Leon County. It appears to run near the west bank of the river in
a southwest course across T. 2 S., R. 2 E. and then bear westward to
Woodville, about 9 miles south of Tallahassee. There is a solution
basin 2 to 3 miles north of Woodville that is below 30 feet, thus bring-
ing possible submergence to within 6 miles of Tallahassee, but it is
not certain that it opened into the Pensacola sea. There are likely
also to be small areas south of the shore-line, as here given, which stood





PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


as islands in that sea. The village of Fanlew in Jefferson County
stands on one of these islands at 10 to 12 feet above the surrounding
lower plain.
In Wakulla County and also in southeastern Leon County the shore-
line appears to have been more irregular than in the district to the
east, because of prominences and depressions in the surface of the
underlying Tampa limestone, there being recesses at some of the
depressions and salients at the prominences. Where the surface of
the limestone stands near 30 feet and at lower levels it has been ex-
tensively laid bare by the waves of the Pensacola sea, but at a higher
altitude than 30 feet it generally carries a covering of sand several
feet thick. This change from bare rock to sand-covered rock at about
30 feet thus gives an indication of the altitude as well as extent of the
sea. In places there are sandy bars up to about 35 feet which are
likely to have been formed to some degree by wave action at the shore.
These are numerous both east and south of Crawfordville and between
Medart and Sopchoppy. The sand near Crawfordville and Medart is
exceptional in that it carries very coarse quartz and feldspar grains or
fragments in some cases 1/2 inch in diameter. These are not usually
very well rounded, but in bars west of Medart standing about 30 to 35
feet the largest ones, 1/ to 1/ inch in diameter, are well rounded as if
worked over by waves on the Pensacola shore.
The shore-line, which has a general southwest course from Wood-
ville to Crawfordville, seems to round a cape-like projection near
Medart, on which an altitude of 40 to 45 feet is shown by the highway
profile crossing it. Near Medart the shore-line turns from a course
east of south to a westward course which it maintains to Sopchoppy.
From such data as are available the shore-line has a westward course
from Sopchoppy to the Ocklocknee River and also westward across
the entire width of Liberty County, probably within the southern tier
of townships. The Apalachicola Northern Railway from the Gulf
coast northward to about 2 miles beyond the Franklin and Liberty
county line is below 30 feet.
There was a notable extension as a narrow bay up the valley of the
Apalachicola River on the border of Liberty and Calhoun counties,
but the shore-line on the west side swings westward in southern Calhoun
County to the Chipola valley and follows the west side of the Dead
Lakes southward into Gulf County. From near Wewahitchka it runs
westward to Panama City with a somewhat irregular border on the
north side of East Bay. It has considerable extension northward from
North Bay into the Econfina valley and its tributaries in northeastern
Bay County. Farther west it lies only a short distance back from the
north shore of St. Andrews Bay. There was an embayment extending






24 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN
far up the valley of the Choctawhatchee River, but the Pensacola
shore-line lies but a short distance north of Choctawhatchee Bay and
the lower west-flowing part of the Choctawhatchee River. It runs
through the southern par of the Choctawhatchee National Forest to
Pensacola Bay.
There were narrow embayments up Yellow River and Blackwattr
River and its tributaries from the head of Pensacola Bay. The position
of the shore on the borders of Pensacola and Escambia Bays is clearly
shown on the Fire Control maps of the U. S. Army Engineers, th coast
line being near the 30-foot contour. Directly west of Pensacola there
is a fine display of bars standing between the 20 and 30-foot contours,
with an occasional point above 30 feet. The Pensacola sea appears to
have stood at about 25 feet above present sea-level in the vicinity of
that city. The city of Pensacola stands partly on a prominent part of
the old shore-line with points 50 feet or more above it. Northeast of
Pensacola the west bluff of Escambia Bay attains an altitude of nearly
100 feet, and points within a mile back 110 to 120 feet above present
sea-level.

OFF-SHORE BARS OF THE PENSACOLA SEA IN WESTERN FLORIDA.
St. James Island in eastern Franklin County, bordered by the Ock-
locknee River and its distributary channel, Crooked Creek, is the east-
ernmost strip in middle northern Florida that seems likely to have
been developed as an off-shore feature of the Pensacola sea. Most of
this island is less than 20 feet above sea-level, but parts of it have a
nearly level crest at about 30 feet, while dunes on it reach 50 feet or
more. Such is the case directly northwest of Lanark station, while a
smooth ridge east from there is about 30 feet.
The strip of sandy land bordering St. George's Sound from Carra-
belle to East Point may have started as an off-shore bar in Pensacola
time and been given additions by wind action later. The same is true
of the strip bordering St. Vincent Sound from Apalachicola west-
ward to Indian Pass, and along the present coast northwestward past
St. Andrews and Choctawhatchee Bays and between East River and
Santa Rosa Sound, and between Pensacola Bay and this Sound. The
topographic map of the strip between Santa Rosa Sound and Pensa-
cola Bay shows dune ridges up to 40 feet above present sea-level. A
ridge over 30 feet high lies along the south side of East River in south-
eastern Santa Rosa County, as shown by the profile of a highway lead-
ing westward from the Okaloosa-Santa Rosa County line. The western
part of Escambia County south of the latitude of Pensacola is made
up of diverging bars extending from the high land in Pensacola west-
ward to Perdido Bay. The majority of them have a height consistent





PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


with the level of the Pensacola sea. Some of the lower ones farthest
south, which are at or below 20 feet, may have been developed later.
The bars leading west from the Navy Yard past Fort Barrancas are
largely below 20 feet, and where higher tht sand seems to have been
heaped up by wind action.
Although the bluffs at Pensacola are composed largely of the pebbly
Gitronelle formation the bars that trail away from them are composed
of rather fine sand, carrying scarcely any pebbly material. This is the
common condition of all the strips along the present mainland coast
to the eastward that seem likely to have been formed as off-shore bars
of the Pensacola sea. It is also a matter worthy of note that in places
where limestone has been washed by the Pensacola sea the bars contain
very few limestone pebbles, and not many flakes or broken bits of lime-
stone. The material is usually quartz sand brought in from the Pied-
mont region to the north.

BURIED PEAT NEAR MILTON
It is a matter of some interest to determine whether the sea rose
continuously to the level of the Pensacola shore-line from some lower
stage or had halts at certain levels as it rose. On the northern outskirts
of Milton, a peat bed about 3 feet thick is exposed for a distance of
50 to 60 yards in the west bank of Blackwater River at 13 to 16 feet
above present sea-level.* It rests on a fine sandy gravel and is overlain
by about 10 feet of sand carrying minute pebbles. This sand forms a
terrace 26 to 28 feet A. T. which is in harmony with the level of the
Pensacola sea. The peat seems to have been covered up in the course
of stream aggradation of the Pensacola stage and to antedate that
aggradation. That this relation is a certain indication of a rise in sea-
level is not fully established. It is a very exceptional feature not noted
generally in the sections of valley deposits connected with the Pensa-
cola sea, and hence one that needs to -be carefully considered before
drawing a conclusion as to a halt in the rise of the sea. Tests should
be made to determine whether the peat is in situ where the vegetation
grew or has been washed in from some higher level and buried beneath
the valley deposits. There are also cases where peat has formed as a
growth of floating vegetation on the border of a water body. If this
is encroached upon by the advance of a delta deposit it would be
pressed down to the bed of the water-body and thus be given the
appearance of having been formed at the lower level. The significance
of this buried peat at Milton thus remains to be determined.
An independent set of features suggesting a similar rise of sea-level
*For descriptions of this locqlity tee J. Kopt,,First Report of the Geological
Survey of Florida, p. 28, 1887; R. MI.-Harper, 3rd Ann. fRept. Florida Geol. Survey,
pp. 295-297, 1910.






26 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

following a halt is found in the somewhat discordant altitudes of the
base of scarps and the upper limit of the Pensacola sea, as shown by
bars and other coastal features in northeastern Florida and northward
on the borders of the Atlantic. The base of the scarp is down to about
25 feet for long distances, but the bars of the Pensacola sea are high
enough to take the 40-foot contour, while the youthful condition of
drainage, such as is represented in Figure 1, extends up to the same
contour. These differences may have come as the result of a rise of
the Pensacola sea from about 25 feet up to 40 feet. This would corre-
spond to the rise at Milton from the base of the peat at 13 feet to the
top of the Pensacola terrace at 26 to 28 feet.

TILTING OF THE PENSACOLA SHORELINE.
One of the main objects of the present study has been to determine
whether the Pensacola shore-line shows evidence of tilting, or instead
maintains the same altitude through its course through the region
examined. It was aimed to test out an assumption by C. Wythe Cooke
in his recent papers, previously cited, that the Gulf Coast as well as
the Atlantic Coast lacks evidence of deformation of Pleistocene shore-
lines.
This study has shown that the altitude of the Pensacola shore-line
has a somewhat steady decrease from east to west, but whether there
is a north to south change in altitude has not been determined. It is
found that the altitude of the Pensacola shore on the east side of
Florida is between 40 and 45 feet above present sea-level. As noted
above and shown in Figs. 2 and 3, the bars near Jacksonville in north-
eastern Florida stand above 40 feet, while the swales between the bars
are in places below that contour. The topographic maps of quad-
rangles in northeastern Florida show a general change at about 40
feet from a lower rather flat surface to a higher more steeply inclined
surface. Topographic maps are not available for the east part of
Florida farthest south, but the profile of a highway running west from
Melbourne into Osceola County shows the change from flat to more
steeply inclined surface near Deer Park to be at 43 feet above present
sea-level. It seems to be at about 45 feet east of Lake Okeechobee in
Martin County, but exact figures are not available. The Pensacola
shore-line is here at its easternmost position in Florida. In about the
same latitude on the west coast, on the borders of Tampa Bay, the
altitude is found to be 10 feet lower than on the east coast, or about
33 feet above the present sea-level, while at intermediate points it
appears to be between 33 and 43 feet, the altitude near La Belle being
just about the 35-foot cont6hi' On'n turning westward on the borders
of the Gulf the altitude ldecli-es to about 00 feet on the meridian of





PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


Tallahassee, while at the western end of Florida around Pensacola, it
is about 25 feet. Farther west, on the border of Mobile Bay, it is
about 22 feet, and in the vicinity of Baton Rouge, on the east side of
the Mississippi, the base of a scarp which seems referable to the Pen-
sacola sea is down to about 15 feet. The valleys of small streams in
that part of Louisiana fall below 20 feet as they approach this scarp.
They are broadly excavated down to this low level, thus indicating a
corresponding sea-level datum of considerable duration or sufficient to
equal the time required to develop the Pensacola shore-line.
The decline in altitude of the Pensacola shore in passing toward the
delta of the Mississippi River seems to strongly favor the interpretation
that the weight of the sediments of the delta may have had influence
in producing the downward westward slope of the shore-line. The
effect may be more pronounced near the Mississippi than farther east.
This is suggested by certain drainage features of a small stream near
the east border of the delta. As these features possess exceptional
interest they will be described in some detail. Reference may be made
to Figure 5, taken from the topographic map of the Baton Rouge quad-
rangle, for the location of the places mentioned. Dawson Creek, which
heads near the southern limits of the city of Baton Rouge, has a rather
broad, swampy valley below the 20-foot contour from near its head
down about to Trajers Bridge. Below this bridge there is, for a couple
of miles, to the junction with Ward Creek, a broad valley bottom
standing about 20 feet, into which a very narrow valley has been cut
below that contour. This seems to indicate that the swampy part
above the bridge has been depressed, or instead that the higher part
of the valley bottom below the bridge has been uplifted since the
stream had formed the broad valley. That the former has been the
case seems favored by the features of the neighboring part of Ward's
Creek valley in which there is no evidence of a bulge. Although
Ward's Creek is a larger stream its broad bottom remains above 20
feet about down to the mouth of Dawson Creek and shows a steady
decline down stream. It thus appears that the headwater part of
Dawson Creek, being nearer the border of the Mississippi delta, is
reflecting more clearly the effect of the weighting down or depression
occasioned by the delta accumulation. Inasmuch as the headwater
part of Dawson Creek is closely adjacent to the Mississippi valley it
may be thought that the waters of part of the river were turned through
it temporarily and scoured it to an exceptionally low gradient. Were
this the case the creek valley should show a deepening below that of
its tributaries which did not carry such a flow, but it will be seen that
the northern tributaries of this creek are down to a level to correspond
to that of the broad bottom of the creek, and their lower courses are




















I 6





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FIGURE 5. Map of part of the Baton Rouge, Louisiana, quadrangle, showing some features apparently referable to

the weight of the Mississippi delta. (See text.)


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PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


swampy. It thus appears probable that the low altitude is due to a
downward movement of land that is adjacent to the heavy load of
the Mississippi delta.
Delta growth in much of southern Louisiana and in eastern Texas
seems to have been rapid enough in Pensacola time, as well as in earlier
times, to obscure or obliterate the effect of shore currents and wave
attack, in consequence of which distinct scarps are not traceable
through that region. It is at present a matter of uncertainty whether
the Pensacola sea stood above the present level of the Gulf on that
part of the coast. But farther south in the vicinity of Corpus Christi,
Texas, topographic maps show clearly a shore-line and attendant off-
shore bar at about 20 feet above sea-level. These may have been
formed in Pensacola time. Recent papers by Dr. Donald C. Barton,
previously cited, have shown that in eastern Texas the deltas of such
rivers as the Trinity and Brazos have had a dominance over wave
attack on that part of the Gulf coast, thus making it difficult to deter-
mine the level of the sea there in Pensacola time, or at any of the
Pleistocene stages of the sea.
The determination that the Pensacola shore-line is tilted in the
region examined by the writer, from the Mississippi valley eastward
across Florida, naturally raises the question whether the interpreta-
tion by C. Wythe Cooke that it owes its altitude above present sea-level
on the Atlantic coast entirely to a lowering of the sea-level is likely to
be sustained. The fact that the shore holds a uniform level there
while departing from horizontality in this region does not make certain
that there has been no uplift of that part of the Atlantic coast. It is
conceivable that a shore-line may run for a long distance along an
isobase of uplift, and thus exhibit marked horizontality. The trend of
this part of the Atlantic coast is so nearly parallel with that of the neigh-
boring Appalachian mountain system as to lead one to expect any
uplift of the mountain system to carry isobases on its slope that will
trend in harmony with the trend of the mountain axis. There is clear
evidence from the comparatively recent deep trenching of the valleys
of the western slope of the Appalachians from Pennsylvania south-
ward that the mountains have become more elevated in late Tertiary
and early Quaternary time. On that slope there is no complication
involving fluctuations of sea-level to consider, such as affects the east-
ern slope. An established uplift of the mountain axis, however, carries
with it the natural inference that the eastern slope has been elevated,
unless some such factor as faulting can be demonstrated to have had
influence on the eastern slope to offset the effect of the rise of the
mountains.
The degree to which the ice sheets on the Antarctic continent and






30 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

Greenland were melted in interglacial stages, is not known, nor is the
amount of water locked up in the present ice-sheets. The latter ques-
tion may be settled in the near future by soundings of the thickness
of the ice. It will then be feasible to calculate whether, as suggested
by Cooke, a complete disappearance of the ice-sheets in interglacial
stages would have given a sea-level approximating that of the highest
of the Pleistocene shore-lines.
The reference by Cooke of the Pensacola stage to mid-Wisconsin
time seems to carry with it the assumption that there was less water
locked up in ice-sheets at that time, so that the sea-level stood higher
than at present. But there really was very little reduction of the
extent of the ice-sheets between the time of forming of the Early Wis-
consin and the Middle Wisconsin series of moraines, or between the
Middle Wisconsin and Late Wisconsin series. So the sea-level of mid-
Wisconsin time is likely to have been considerably below the present
level, instead of being up to the level of the Pensacola sea.

PROBABLE AGE OF THE PENSACOLA SHORE-LINE.
There are several ways in which the age of such a feature as the
Pensacola shore-line may be estimated. One of these is the degree of
weathering and toning down by rain wash which it has experienced
since the sea ceased operating on it. Another and more widespread
basis for estimate is found in the degree of erosion of the plain terrace,
standing just below the shore-line, which became exposed to the action
of streams on the withdrawal of the sea. A third means of determining
the age, only applicable if the shore-line under consideration is the
latest one standing above the present sea-level, is the estimate of time
required to form the present shore-line. In case the sea shrank to a
lower level than the present and then came up to the present, the time
involved in this stage would need to be estimated. Some paleontolo-
gists have used the extinction of certain species of animals as a time
measure, it being inferred that their extinction was widely effective
at a given time.
It is evident that the duration of faint scarps or notches cut in sand
or clay, as is the case with those of the Pensacola sea, must be rather
brief as expressed in geological reckonings. Every heavy rain in this
region of high precipitation may have a perceptible modifying influ-
ence on them. For this reason it is not surprising that shore-lines older
than the Pensacola have become so obscure that connected tracing
seems scarcely feasible. The fact that the Pensacola shore-line ex-
hibits a distinct scarp easily traceable for long distances is interpreted
to indicate a very moderate age. The notch made in the slope by the
waves, and the bank back of it, are generally still preserved in places





PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


where conditions for effective wave action were present. Where they
are not present it is doubtful if they ever were formed, as conditions
generally may have been such as to prevent effective wave action.
On the Pensacola terrace the development of drainage lines has
been so slight that much of the rainfall over a large part of its surface
is disposed of in slowly moving widespread currents rather than defi-
nitely confined in stream channels. The main streams, however, cut
across this terrace from the higher lands in sharply outlined valleys.
These are usually cut to considerable depth below present sea-level,
thus indicating a lower stand of the sea than the present, and conse-
quently better condition for drainage development. But in spite of
this the Pensacola terrace does not show a good development of tribu-
tary channels, and there are very few small independent streams run-
ning directly to the coast. The lower stage of the sea thus appears
to have been of brief duration. The rise to present sea-level tends
of course to slacken the fall and to cause the lower courses of the rivers
to become estuaries. It also has submerged the lowest part of the
Pensacola terrace producing an extension of the sea coast and enlarge-
ment of the bays. While it has no measurable effect on the slope of
the part of the terrace standing above present sea-level, the rise of the
sea probably is partly responsible for the slow escape of the water.
But there are large areas still poorly drained in which the slope of the
terrace is rapid enough to lead one to anticipate that in time there
will be a better development of definite drainage channels. This
feature is well illustrated in Fig. 1. Slopes fully as gentle on the bed
of a late Pleistocene glacial lake in northwestern Ohio have reached
such a state of drainage development, thus indicating a greater age
than that of the Pensacola terrace. It is estimated from Niagara Falls
history that the lake bed there is not over 25,000 years old.
The size of the system of bars along the present coast is such as to
seem to require a considerable period of time for its development.
Those on the Atlantic coast are especially bulky. Those on the Gulf
coast of the peninsula are more slender. Those on the northern Gulf
coast are so largely combined with the off-shore bars of Pensacola
time as to be difficult to evaluate. Studies of the rate of growth of the
modern coastal bars appear to be entirely inadequate for basing an
estimate. The rate of development of the shore features bordering
the Great Lakes has been given some attention, enough to show that
features of great strength may be produced in a few thousand years.
It is found by connecting the Glacial Lake stages with the succession
of events shown in the Niagara gorge that a period of less than 25,000
years is embraced in the Algonquin, Nipissing, and present stages of
lakes in the Huron, Michigan and Superior basins. The Algonquin





32 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

and Nipissing stages probably cover at least 80 percent of this time.
There thus remains only 4,000 to 5,000 years for the work of these lakes
at about their present stage. But in that time it is estimated from a
study of the Lake Survey charts that the shore of Lake Michigan has
been cut back over a mile on much of its west coast and probably still
more around the islands of the northern part and the adjoining main-
land. Such being the case the great coastal bars on the east side of
Florida, the largest being those east of the Indian River in Brevard
County, may prove to have been developed in a much shorter period
than 25,000 years. Shore currents, as well as wave work, seem to have
contributed to the growth of the broad system of bars in Brevard
County.
It thus appears probable that the period of exposure of the Pen-
sacola terrace may be not more than 15,000 to 20,000 years. This would
make the Pensacola shore-line a near correlative of the shore of the
glacial Lake Algonquin. It appears to be fully as well preserved as
the Algonquin beach, and may prove to be somewhat younger. The
amount of deformation it has suffered is very slight compared with
that of the Algonquin beach. The Algonquin beach has suffered a
deformation of about 410 feet in the interval of 340 miles between
Port Huron, Michigan, and Sault Ste. Marie, or a distance similar to
that between Pensacola and Jacksonville, Florida, where the tilting
amounts to only 15 feet. Of the deformation in Michigan about 100
feet appears to have taken place within the last 4,000 years, that being
the estimated time since the drainage of the upper Great Lakes was
turned to the Erie Basin and the enlarged flow over Niagara Falls has
formed the upper Great Gorge.






FOSSIL MAN AND PLEISTOCENE VERTEBRATES ON THE
PENSACOLA TERRACE
For the past 15 years there has been much interest in scientific
circles in the occurrence of human remains in close association with
those of vertebrates and other fossils, partly of extinct species, near
the Florida coast, on the lower part of the Pensacola terrace. An early
locality to attract notice is near Vero (now called Vero Beach). Sub-
sequently important finds were made near Melbourne, both places
being on the Atlantic coast. Remains of extinct vertebrates have been
found at several other places, especially near St. Petersburg, Braden-
ton and Sarasota on the Gulf coast. The literature is quite volum-
inous, as will appear from the subjoined list of papers, embracing and
supplementing the list published by Dr. Sellards in 1919.

BIBLIOGRAPHY
1916
E. H. Sellards. On the discovery of fossil human remains in Florida in asso-
ciation with extinct vertebrates. Am. Jour. Sci. vol. 42, pp. 1-18, July, 1916.
Human remains from the Pleistocene of Florida. Science, n. s.
vol. 44, pp. 615-617, October 27, 1916.
Human remains and associated fossils from the Pleistocene of
Florida. Florida Geol. Survey, Eighth Ann. Rept., pp. 121.160, pls. 15-31, figs. 1-15,
October, 1916.
1917
E. H. Sellards. On the association of human remains and extinct vertebrates at
Vero, Florida. Jour. Geol. vol. 25, pp. 4-24, January-February, 1917.
Rollin T. Chamberlin. Interpretation of the formations containing human
bones at Vero, Florida. Jour. Geol. vol. 25, pp. 25-39, January-February, 1917.
Thomas Wayland Vaughan. On reported Pleistocene human remains at Vero,
Florida. Jour. Geol. vol. 25, pp. 4042, January-February, 1917.
Ales Hrdlicka. Report of finds of supposedly ancient human remains at Vero,
Florida. Jour. Geol. vol. 25, pp. 43-51, January-February, 1917.
Oliver P. Hay. Quarternary deposits at Vero, Florida, and the vertebrate re-
mains contained therein. Jour. Geol. vol. 25, pp. 52-55, January-February, 1917.
George Grant MacCurdy. Archaeological evidences of man's antiquity at Vero,
Florida Jour. Geol. vol. 25, pp. 56-62, January-February, 1917.
E. H. Sellards. Further notes on human remains from Vero, Florida. Amer.
Anthropologist, n. s. vol. 19, no. 2, pp. 239-251, April-June, 1917.
George Grant MacCurdy. The problems of man's antiquity at Vero, Florida.
Amer. Anthropologist, n. s. vol. 19, no. 2, pp. 252-261, April-June, 1917.
Oliver P. Hay. On the finding of supposed Pleistocene human remains at
Vero. Florida. Jour. Washington Acad. Sci., vol. 7, pp. 258-260, June 4, 1917.
E. H. Sellards. Note on the deposits containing human remains and artifacts at
Vero, Florida. Jour. Geol. vol. 25, pp. 659-660, October-November, 1917.
Edward W. Berry. The fossil plants from Vero, Florida. Jour. Geol. vol. 25,
pp. 661-666. October-November, 1917.
Rollin T. Chamberlin. Further studies at Vero, Florida. Jour. Geol. vol. 25,
pp. 667-683, October-November, 1917.
1918
Oliver P. Hay. A review of some papers on fossil man at Vero, Florida, Science
n. s. vol. 47, pp. 370-371, April 12, 1918.
W. H. Holmes. Discussion and correspondence on the antiquity of man in
America. Science n. s. vol. 47, pp. 561-562, June 7, 1918.
F. H. Sterns. The Pleistocene man at Vero, Florida, Scientific American Sup.
plement, no. 2214, pp. 354-355, June 8, 1918.
(33)






34 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

G. R. Wieland. The Vero man and the sabre tooth tiger. Science n. s. vol. 48,
pp. 93-94, July 26, 1918.
Ales Hrdlicka. Recent discoveries attributed to early man in America. (In-
cluding a report on artifacts by Dr. W. H. Holmes). Bureau of American Ethnology,
Bull. 66, 1918.
O. P. Hay. Doctor Ales Hrdlicka and the Vero man, Science n. s. vol. 48, p. 462,
1918.
N. C. Nelson. Review of the Ninth Annual Report of the Florida Geological
Survey, Science n. s. vol. 47, pp. 394-395, 1918.
Chronology in Florida. Anthropological Papers of the American
Museum of Natural History, vol. 22, pt. 2, 1918.
1919
F. H. Sterns. The Pleistocene Man of Vero, Florida. A review of the latest
evidence and theories. Scientific American Supplement, February 22, 1919.
E. H. Sellards. Literature relating to human remains and artifacts at Vero,
Florida. Am. Jour. Sci., 4th ser., vol. 47, pp. 358-360, May, 1919. Florida Geol.
Survey, Twelfth Ann. Rept., pp. 1-4, 1919.
H. F. Wickham. Fossil beetles from Vero, Florida. Am. Jour. Sci. 4th ser.,
voL 47, pp. 355-357, May, 1919. Florida Geol. Survey, Twelfth Ann. Rept., pp. 5-7,
1919.
T. C. Chamberlin. Investigation versus propagandism. Jour. Geol. vol. 27,
no. 5, pp. 305-338, July-August, 1919.
Oliver P. Hay. Mammalian and fish remains from Florida of probably Pleis-
tocene age. Proc. U. S. Nat. Mus, vol. 56, pp. 103-112, 1919.
1923
Oliver P. Hay. The Pleistocene of North America and its vertebrated animals
from the States east of the Mississippi River and from the Canadian provinces east
of longitude 95. Carnegie Inst. Washington, Pub. no. 322, 499 pp. February, 1923.
Florida vertebrates discussed on pp. 20, 37, 121, 145, 157, 162, 179, 194, 206, 211, 222,
224, 232, 243, 262, 372.
1924
Frederic B. Loomis. Artifacts associated with the remains of a Columbian
elephant at Melbourne, Florida. Am. Jour. Sci., 5th ser., vol. 8, pp. 503-508, De-
cember, 1924.
1926
James W. Gidley. Fossil man in Florida (abstract): Bull. Geol. Soc. America,
vol. 37, no. 1, pp. 239-240, March 30, 1926.
Oliver P. Hay. On the geological age of Pleistocene vertebrates found at Vero
and Melbourne, Florida. Jour. Washington Acad. Sci., vol. 16, no. 14, pp. 387-392,
August 19, 1926.
James W. Gidley and Frederic B. Loomis. Fossil man in Florida. Am. Jour.
Sci., 5th ser., vol. 12, pp. 254-264, September, 1926.
C. Wythe Cooke. Fossil man and Pleistocene vertebrates in Florida. Am. Jour.
Sci., 5th ser., vol. 12, pp. 441-452, November, 1926.

1927
Oliver P. Hay. A review of recent reports on investigations made in Florida
on Pleistocene geology and paleontology. Jour. Washington Acad. Sci., vol. 17, no.
11, pp. 277-283, June 4, 1927.
1928
Oliver P. Hay. Again on Pleistocene man at Vero, Florida. Jour. Washing-
ton Acad. Sci, vol. 18, no. 9, pp. 233-241, May 4, 1928.
C. Wythe Cooke. The stratigraphy and age of the Pleistocene deposits in
Florida from which human bones have been reported. Jour. Washington Acad.
Sci., vol. 18, no. 15, pp. 414-421, September 19, 1928.

1929
James W. Gidley. Ancient man in Florida: Further investigations. Bull. Geol.
Soc. America, vol. 40, pp. 491.502, June 30, 1929.
C. Wythe Cooke and Stuart Mossom. Melbourne bone bed. Florida Geol.
Survey, Twentieth Ann. Rept., pp. 218-226, 1429.





PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


George G. Simpson. Pleistocene mammalian fauna of the Seminole Field,
Pinellas County, Florida. Bull. Am. Mus. Nat. Hist., vol. 56, pp. 561-599, 1929. The
extinct land mammals of Florida. Florida Geol. Survey, Twentieth Ann. Rept.,
pp. 229-280, 1929.
1930
George G. Simpson. Additions to the Pleistocene of Florida. Am. Mus. Novi-
tates, no. 406, pp. 1-14, March 17, 1930.
SOliver P. Hay. Remarks on Dr. George G. Simpson's work on the Pleistocene
paleontology of Florida. Jour. Washington Acad. Sci., vol. 20, no. 14, pp. 331-340,
August 19, 1930.
SOn the fossil Mammalia of the first interglacial Stage of the
Pleistocene of the United States. Jour. Washington Acad. Sci. vol. 20, No. 21, pp.
501-509, December 19, 1930.
1931
George G. Simpson. Origin of mammalian faunas as illustrated by that of
Florida. American Naturalist, vol. 65, No. 698, pp. 258-276, May-June, 1931.

There is wide diversity of opinion expressed in these papers as to
the presence of man as far back as the time when certain extinct species
of vertebrates, such as the mastodon, camel, and giant sloths were living
in this region.* There is, however, general agreement that these
remains are in the valley bottoms of small streams that had opened
shallow trenches in the Pensacola terrace, and which extend across
the littoral formation that borders the present coast.
The fragmentary and scattered condition of the human remains
has led nearly all the persons who have had opportunity to excavate
them to conclude that they were washed into the valley along with the
remains of the extinct species of vertebrates. But Hrdlicka maintains
it is more probable that they have been buried at a much later time,
and urges the importance of more definite evidence of the time rela-
tions in forming judgments on so far-reaching a question as the an-
tiquity of man in America.
The present writer has had no opportunity to study these remains
in place, but he has examined into the topographic and drainage rela-
tions of the burial sites and will accordingly deal only with this phase
of the question.
The remains at Vero and Melbourne are found in shallow valleys
that come to the coast across the Pensacola terrace. The floor of these
valleys is the Anastasia formation, described by Cooke as "a coarse
sandy coquina composed of rather firmly cemented broken shells and
sand." This occupies a narrow strip along the coast and is found in
the interstream spaces as well as in the floors of the shallow valleys.
It thus appears to antedate the cutting of these valleys or at least of
their lower ends. This would naturally be inferred, since it is a marine
deposit. But in the valleys there are deposits of fluvial character,
which have caused a slight aggradation, or filling. The lower part is
*Papers by Hay, Simpson, Berry and Wickham, noted in the Bibliography, list
these fossils.






36 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

generally largely of sand with but little associated muck, but the upper
part has mucky beds associated with pockets and strips of sandy
material. The remains of man in the Vero locality, as well as those of
the fossil vertebrates, were found in the lower, more sandy, part of
the filling. There is shown a confidence in the minds of those who
have given the deposits the most careful attention that the remains
were found beneath an undisturbed overlying deposit of mucky char-
acter. It also appears that Dr. Sellards and Mr. Gunter, who have
done most of the work of excavation and sifting, have found that the
human bones were frequently widely scattered, as indicated in Fig. 6.


7
L 3t
X 9
X



3 x x




ALE INCH EET


FIGURE 6. Ground plan showing the location of human bones found in the canal
bank at Vero, in April and June, 1916. Reproduced from an illustration in a paper
by Dr. Sellards, published in Journal of Geology, vol. 25, p. 12, 1917; and in Ninth
Annual Report, Fla. Geol. Survey, p. 73.

The manner of occurrence of the skull fragments is peculiarly sig-
nificant. Scarcely one-half of the skull was obtained, and the pieces
that were secured were distributed over an area of about seven by
three feet. This condition, as well as the widely separated parts of
the femur, can be explained on the basis of distribution by a stream,
but seems inconsistent with the hypothesis of an intrusive burial in a
grave. Combined with this evidence against an intrusive burial is
the unbroken continuity of the overlying deposit.
The human remains as well as those of the fossil vertebrates appear
to have been washed in from the land adjacent to the stream that
flowed in this valley. This border district, upstream from this locality,
is part of the Pensacola terrace. Whether the human remains on that
terrace are as ancient as those of the extinct species of vertebrates
remains unsettled, for any surface material of whatever age may have






PENSACOLA TERRACE, BEACHES AND BARS IN FLORIDA


been washed in. But the time of deposition of these remains in the
valley seems to have been within a limited range. It is likely also to
have been considerably later than the time when the sea withdrew
from the Pensacola terrace. This statement is applicable to the Mel-
bourne deposits as well as those at Vero. The Melbourne deposits are
in the bed of Crane Creek. The filling with sand and muck lacks
several feet of reaching the level of the bordering part of the Pensacola
terrace.
The question of the relation of the coming of man to that of the
disappearance of the extinct species of vertebrates seems to resolve
itself into a matter of probabilities. If the sea withdrew from the
Pensacola terrace within the past 25,000 years, as seems probable from
the slight change effected in the shore-line, and the very youthful
state of drainage lines across the terrace, the time of occupancy of the
terrace by these vertebrates appears not unlikely to have overlapped
the peopling of the region by man. The abundance of game in this
southern region would seem likely to have led to its early peopling by
tribes fond of the chase. As finds increase the relation may be more
fully cleared up.
At my request Dr. Roland M. Harper, of the Florida Geological
Survey, who has been in all the counties involved, and has published
reports on their natural features, has kindly prepared the discussion
of some economic features of the Pensacola terrace in Florida, and the
statistical comparisons with other parts of the State which follow.






SOME ECONOMIC FEATURES OF THE PENSACOLA TERRACE
IN FLORIDA.
By ROLAND M. HARPER.

GEOGRAPHY
The Pensacola terrace, as described by Dr. Leverett in the foregoing
pages, together with some coastal beaches and dunes which rise above
its level, and the Florida Keys which have had a different history,
corresponds approximately with that part of Florida mapped by Dr.
Eugene A. Smith in his geological and agricultural description of
Florida, nearly fifty years ago, as the "pitch pine, treeless and alluvial
region."* It covers approximately 44% of the land area of the state.
The greater part of it is sandy, but the Everglades and other muck
lands constitute about one-fourth of the terrace area, and there are
also several hundred square miles where limestone lies at or near the
surface.
On account of its low elevation, the ground-water is within a few
feet of the surface everywhere, which makes the soil rather damp and
sour, so that not much farming is possible without drainage or ferti-
lization, or both.t The original vegetation was about half slash pine
forest (long-leaf pine being scarce near sea-level), with an under-
growth of saw-palmetto and various other low shrubs and herbs, and
the rest mostly swamp, marsh and prairie.
All the seaports of the State are of course on this terrace, though
it is so narrow at places on the Gulf coast that the residential sections
of Tampa, St. Petersburg and Pensacola lie partly or mostly above it.
The early settlers, finding little in the back country to encourage agri-
cultural developments, congregated mostly around the seaports and
engaged in commerce, fishing, and other activities characteristic of
coast settlements. The pine forests near by became important sources
of lumber and turpentine, and many cattle and hogs were raised at
slight expense on free range in the pine woods and prairies, though
much of the area was too marshy or rocky for grazing. The shipment
of beef on the hoof from the lowlands of Florida to Cuba was an
important industry 30 or 40 years ago, and perhaps has not entirely
ceased yet.
When Florida became connected with the North by railroads, and
the prosperity of the nation enabled many people to take long winter
vacations, these same seaports became important winter resorts, on
account of their proximity to ocean beaches, their climate a little
*E. A. Smith, Tenth Census U. S., vol. 6, pp. 205-208, 240.243, 1884. (Map
opposite p. 187.)
tThere is, however, much poor soil on the uplands as well. See Florida Geol.
Survey Seventeenth Ann. Rep., pp. 33-34, 40. -
(38)





PENSACOLA TERRACE IN FLORIDA


milder than in the interior, and their hotel facilities. Many coast
towns that are not seaports have also been developed by the tourist
business.
Many tourists became permanent residents, and from the beginning
of the winter resort business to the present, the Pensacola terrace has
had a very progressive and cosmopolitan population, contrasting in
many ways with the agricultural population on the fertile uplands of
the state. Of course there are many delightful resorts on the uplands
too, especially in the lake region, but farming is the principal business
there, and that makes a difference in the population, as will be shown
by several kinds of statistics farther on.
In the last fifty years or so large quantities of fertilizers from the
world's potash, phosphate* and nitrate mines have been put on the
market, and at the same time machinery for digging drainage ditches
has been gradually developed, and all this has greatly stimulated agri-
culture in the formerly unappreciated sandy and marshy lowlands.t
Farming on the terrace has long been more intensive and specialized
than on the more fertile uplands, as will be shown farther on by the
expenditures and receipts per acre. Throughout the country truck
farming is chiefly concentrated on level lands, probably because the
water supply can be more closely controlled there than on slopes.
And in this respect the Pensacola terrace is ideal, for its average slope
is only a few feet to the mile.
Florida's peninsular position gives it almost a monopoly of the
winter vegetable business of the United States, and these crops are
marketed at a time when they command a high price on account of
their scarcity. In this respect the southern third of the state, which
is nearly all on the Pensacola terrace, has an advantage over the rest,
and the value of crops per acre is decidedly greater there than on the
more northerly portions of the same terrace; though these local differ-
ences are not here brought out in the statistics. The mere fact that suc-
cessful farming on the terrace requires more knowledge of engineering
and chemistry and greater expenditures per unit area than on the
fertile uplands, calls for a more intelligent and hence more prosperous
class of farmers than the average.
STATISTICAL COMPARISONS.
The following comparisons have been made by picking out on a
state map the counties and parts of counties included in the Pensacola
terrace, and fitting the statistics of population, agriculture, etc., to
them.
*Much of the phosphate is mined in Florida, but not on the Pensacola terrace.
tFor a study of the influence of commercial fertilizers on the agricultural devel-
opment of the coastal plain see Journal of Geography, vol. 15, pp. 42-48, Oct., 1916.
Also Geog. Review, vol. 2, pp. 366-367, Nov., 1916. Some statistics of drainage in
different parts of Florida are given farther on.






40 FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN

Some statistics of 1880 have been used, to show the great changes in
the last fifty years, but most of them are the latest available. The 1930
figures available for single counties at this writing are rather few, so
some for 1920 or 1925 have been used instead for certain features.
Most of the statistics have been taken from United States census reports,
but some additional ones have been obtained from the state census of
1925, and from John M. Hager's "Commercial Survey of the Southeast,"
published by the U. S. Department of Commerce early in 1928. The
statistics of families and radio sets in 1930 are taken from a press
bulletin of the U. S. Census Bureau, dated March 23, 1931, and those
of gasoline consumption from a report of the inspection division of
the state agricultural department covering 1929 and the first half of
1930.
POPULATION
In 1880, which is perhaps as far back as it is worth while to carry
the comparisons, the Pensacola terrace had only about one-fourth of
the population of the state; but by 1930 it had almost exactly half, so
that it is now more thickly settled than the rest of the state. It has
always had most of the state's urban population (using the arbitrary
census definition of urban population, as that in incorporated places
with 2500 inhabitants or more). In 1880 there were only four "census
cities" in Florida, namely, Key West, Jacksonville, Pensacola and
Fernandina; and all of those are below the Pensacola shore line except
that Pensacola is partly above it.
People from other states and countries seem to have always been
more numerous on the terrace than on the uplands, but that is probably
not so much on account of the topography as on account of the seaports.
In 1880 about 30% and in 1925 about 60% of the natives of other states
living in Florida were on the terrace; and the difference is still greater
when foreigners are considered. Both in 1880 and in 1925 over 80% of
the foreigners in the state were on the terrace and other lowlands. And
even if we leave out the Keys (Monroe County), which had over half
the foreigners in the state in 1880 (but much fewer in 1925), there
were over twice as many on the terrace proper as on the uplands.
In ante-bellum days the large plantations with their many slaves
were on the fertile uplands, and some of the upland counties had more
negroes than whites, which has never been true of any of the terrace
counties. This condition continued to within the present century, but
now there is very little difference between uplands and lowlands in
the racial composition of the population.
The terrace, with about half the total population of the state, has
about 60% of the adult population, and this has an important bearing
on education and wealth, as will be shown farther on.





PENSACOLA TERRACE IN FLORIDA


There are naturally some marked differences in occupations in
the two areas, but the census figures on this point for single counties
are rather meager, dividing all occupations into only nine groups (with
distinction of sex but not of race or age).* And in these forestry and
fishing are combined with farming, thus obscuring what might other-
wise be some significant contrasts. The terrace has a larger proportion
of manufacturers and merchants than the uplands, and fewer miners
and farmers; but some of this difference is of course due to the pro-
portion of urban population, and not directly to the topography.
FARMING.
In 1880, when drainage ditches and commercial fertilizers were
almost unknown, the terrace had less than half of one percent of its
area cultivated, as compared with over four percent in the rest of the
State. At present it is about two percent cultivated, and the rest of
the State ten percent. Only about one-fourth of the farms, one-fifth
of the farm population, and one-eighth of the cultivated land in the
State are on the terrace, but these farms produce about one-third of
the State's crop values.
Over half the farmers reporting drainage ditches, and two-thirds
of the mileage of such ditches, in Florida in 1920 were on the terrace.
The farms on the terrace average only about half as large as on
the uplands, and this permits (or may be a result of) more intensive
cultivation. The expenditure for fertilizer per improved acre was
over four times as much on the terrace as on the uplands in 1880, and
in 1920 over six times as much. The relative value of crops per acre
was not quite 2 to 1 in 1880, and nearly 4 to 1 in 1920. In value of
crops per farm the terrace was a little below the uplands in 1880, but
nearly double it in 1920.
This intensive farming seems to set too fast a pace for the average
negro, and although the racial composition of the aggregate population
is now about the same on terrace and upland, the ratio of white to
negro farmers is about 10 to 1 on the terrace as compared with 21/2
to 1 in the rest of the state. The terrace has more foreign white than
negro farmers, and nearly half the State's foreign-born farmers. There
is doubtless some correlation between this and the fact that farming
is much more intensive in most European countries than in the United
States.
WEALTH AND EDUCATION.
There seems to be no satisfactory direct measure of wealth for
single counties, on account of variations in the rate of assessed to true
valuations, and the amount of property that escapes taxation, rightly
*There are no statistics of occupations by counties in any U. S. census report
between 1840 and 1930, but some previously unpublished data of this sort from the
census of 1920 are included in Hager's Commercial Survey.






42 FLORIDA GEOLOGICAL SURVEY--BULLETIN SEVEN

or wrongly, in different counties; but some indirect indications of dif-
ferences of wealth are available. One of the simplest is the proportion
of adults in the population; for most adults are producers of wealth
and most children are not. The ratio of adults to children is now
about 3 to 2 on the terrace, and this makes possible better public school
facilities than on the uplands, where the number of adults and children
was nearly equal in 1920. (Corresponding figures for counties in 1930
are not yet available.) And this makes the percentage of illiteracy,
among both races, much less on the terrace than inland.
Another indication of wealth is the number of income-tax-payers,
which is available by counties for 1924 (in Hager's Commercial Survey
previously referred to). At that time over 75% of such tax-payers in
the State, and a still larger proportion of those with incomes above
$10,000, lived on the terrace. The statistics of radio sets and gasoline
consumption show differences of the same sort.

EXPLANATION OF TABLE.
The following table shows some of the contrasts between those
parts of Florida above and below the Pensacola shore-line, by means
of percentages and other ratios, in parallel columns. Some of the
figures include some fractional parts of counties, while some are based
on whole counties.* Many other kinds of statistics could have been
used for the same purpose, if space had been unlimited.
A third column of figures, for State averages, is added, for the
benefit of any one who may wish to make comparisons between Florida
and other states. Florida has long ranked ahead of other southern
states in various measures of wealth and culture, and it is the first and
only southeastern state to have more than half its population urban.
*The area below the shore-line can be estimated with reasonable accuracy, but
there is more uncertainty about the population and farms, which are very unevenly
distributed in some of the counties that lie partly above and partly below the line
as mapped by Dr. Leverett. Generally the densest population is on the coastward
side of the line, but this relation is reversed in some of the counties bordering the
Gulf between Tampa and Apalachicola, where the coast is rather marshy. The fact
that the line passes through several large cities complicates matters still further,
for there it would be necessary to know the population of single blocks to apportion
it accurately.
The statistics of density of population, urban population, racial composition,
improved land, and farm expenditures and receipts have been adjusted as closely
as possible to the terrace area,, making allowance for known inequalities of distri-
bution in the divided counties. But that is a rather tedious undertaking, and the
other statistics are based on whole counties (13 in 1880, 24 at the beginning of
1925), some of which lie partly above the Pensacola shore-line. And while accuracy
cannot be guaranteed in either case, the percentage of error may be no greater than
in the original census data, which can never be perfect. At any rate, wherever the
figures show a great contrast it is certain that a real difference exists; and even
where the difference is small it may be significant.






PENSACOLA TERRACE IN FLORIDA


STATISTICAL COMPARISONS OF PENSACOLA TERRACE WITH
REST OF FLORIDA.

POPULATION STATISTICS Terrace Rest of Whole
State State

Inhabitants per square mile, 1880................ 3.0 6.4 4.9
1920................ 17.2 17.8 17.6
1930................ 30.6 23.7 26.6
Percent urban, 1880 ............................ 33.8 1.4 10.0
1920 ............................. 58.3 20.5 37.8
1930............. ............... 68.0 35.8 51.7
Percent white, 1880 ............................. 62.5 49.5 53.0
1920............................. 63.5 68.0 66.0
1925............................. 69.0 67.0 67.8
Percent native of other states, 1880............... 35.8 31.8 32.0
1925, white......... 51.6 39.7 46.2
Snegro ....... 40.4 27.8 33.9
Percent foreign-born, 1880....................... 10.9 0.7 3.68
1925, white................. 8.5 2.1 5.55
negro ................ 6.9 0.4 3.36
Percent of adults, 1880 (male) ................... 50.5 43.0 45.2
1920 (white) ................... 59.5 52.2 54.9
(negro) ................... 61.1 50.9 53.3
Persons per family, 1920......................... 3.95 4.30 4.14
1930 ........................ 3.73 4.10 3.89
Percent of persons over 10 illiterate, 1920 (white).. 1.95 4.41 3.22
(negro).. 13.3 27.5 21.7
Occupations, 1920:
Percent of workers engaged in
M ining ................................. 0.3 1.2 0.8
Agriculture, etc. ......................... 16.9 45.9 32.2
Manufacturing, etc. ..................... 33.1 19.9 26.1
Transportation, etc. ...................... 9.6 5.9 7.6
Trade .................................. 12.3 6.5 9.2
Professional service ..................... 5.4 3.8 4.5
Percent of population paying income tax, 1924-5.... 7.9 2.1 5.1
Percent of families having radio sets, 1930......... 19.8 9.7 15.5
Per capital consumption of gasoline, first half of
1930 (gals.) .... ........................... 98.9 62.3 82.4


AGRICULTURAL STATISTICS

Percent of land improved, 1880.................. 0.5 4.4 2.7
1920.................. 1.8 10.2 6.5
Improved acres per farm, 1880.................... 20.4 44.1 40.5
1920................... 24.5 47.1 42.5
Percent of farmers in 1920: Native white.......... 81.4 69.6 71.9
Foreign white......... 10.2 2.6 4.1
Negro ................ 8.4 27.8 24.0
Percent of population on farms, 1925............. 9.2 33.8 20.8
Percent of farm population, white ................ 81.6 69.1 72.0
Percent of farms reporting drainage ditches, 1920.. 27.0 4.0 8.5
Percent of farm area drained..................... 7.9 1.4 2.4
Expenditure for fertilizers, per improved acre,
1879-80 ($) ............................... 0.26 0.06 0.08
1919-20 ($) ............................... 17.90 2.70 4.50
Value of products, 1879 ($) Per farm........... 262 327 318
Per improved acre.. 12.90 7.40 7.85
Value of crops, 1920 ($) Per farm............... 2390 1240 1490
Per improved acre...... 97 26 35





FLORIDA GEOLOGICAL SURVEY-BULLETIN SEVEN.


Whether or not the principle that areas lying below the latest
Pleistocene shore-line are always more prosperous than those farther
inland is of nation-wide application cannot be asserted until similar
studies have been made in other states. But it is quite probable that
some such relation exists, for large cities tend to grow up along the
coast, and farming in the lowlands of other states is rather intensive,
for much the same reasons as in Florida.
General Francis A. Walker, who directed the 1880 census, investi-
gated the distribution of the population of the United States according
to altitude, and found 18.3% of the total population, 28.3% of the
foreign born population and 22.3% of the colored population in that
year living within 100 feet of sea-level. But in the absence of any
indication of the areas of the different altitudinal belts, it is impossible
to say just how much the lowlands differed from the highlands in
density of population. And no statistics of the composition of the
population, except as to color and nativity, in the different belts were
given in that census.
In a special report of the U. S. Census Bureau, "Supplementary
Analysis and Derivative Tables," published in 1906, Dr. Henry Gannett
divided the country into 19 physiographic divisions, one of which, the
"coast lowlands," includes the Pensacola terrace and a little additional
area in Florida (following county lines). It was found to contain
2.8% of the area and 2.4% of the population of the United States in
1900, and had 22.5 inhabitants per square mile, as compared with a
national average of 25.6. Its population increased 28.1% between
1890 and 1900, as compared with 20.7% in the whole United States.




BULETIN 7, PLATE 1.


FLORIDA STATE GEOLOGICAL SURVEY


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