The peat deposits of Florida, their occurrence, development and uses

BULLETIN THIRTY-FRONTISPIECE

(Courtesy Miami Herald)
Fire in the Everglades burning peat, April 1944. Such fires occur frequently during the dry season and destroy
some of the dry, surface peat. If the Everglades were more generously flooded such fires could be reduced and the peat
saved.

FiLORIDA GEOLOGICAL SURVEY

STATE OF FLORIDA
DEPARTMENT OF CONSERVATION
J. T. HURST, Supervisor of Conservation
Florida Geological Survey
HERMAN GUNTER, Director, Geological Survey

GEOLOGICAL BULLETIN NO. 30

THE PEAT DEPOSITS OF FLORIDA
Their Occurrence, Development, and Uses

By
JOHN H. DAVIS, JR., Ph.D
Research Assistant
Florida Geological Survey

Published for
THE FLORIDA GEOLOGICAL SURVEY
Tallahassee, 1946

Published December 1, 1946

THE E. O. PAINTER PRINTING COMPANY
DELAND. FLORIDA

LETTER OF TRANSMITTAL

Honorable J. T. Hurst, Supervisor
Florida State Board of Conservation
Sir:
I have the honor to transmit a report of one of our investigations
entitled "THE PEAT DEPOSITS OF FLORIDA, their occurrence, de-
velopment, and uses" by Dr. John H. Davis, Jr., Research Assistant,
Florida Geological Survey, and recommend that it be published as Geo-
logical Bulletin No. 30.
This bulletin describes and discusses most of the larger peat
deposits of Florida and many of the smaller deposits, and estimates are
given of the area and depth of many of these. From prospecting data
the quantity in tons of peat in many deposits is given. The nature,
origin, kinds, and composition of peats are described. Many analyses
of Florida peats are presented. The geology of both surface and buried
peats is described, and some possible correlations of peat and lignite
layers with glacial and interglacial ages are considered.
The present and possible future ways of utilizing Florida's large
peat resources are considered in detail. Some experiments to determine
the practicality of using peat for fuel, and in making plastics were
conducted, and even though these did not give favorable results they
show what difficulties must be overcome if large scale utilization of
peat is attempted in the future.
The present use of peat is mainly for soil improvement, as a humus,
and as a fertilizer filler. Production of this horticultural peat in Florida
is increasing and the industry may be further expanded as the good
quality of some Florida peats become better advertised.
Respectfully submitted,
Herman Gunter, Director
Florida Geological Survey
Tallahassee, Florida
July 16, 1946

FOREWORD

The Florida Geological Survey has received many inquiries
concerning the location, quantity, quality, and uses of peat
that occurs in numerous deposits in the State because Florida
is known to have the third largest amount of peat in the
United States. Some of the larger of these deposits have
been drained and the peat and muck soils used for agriculture,
particularly in the Everglades. Such peat lands are a great
agricultural resource and their use will be expanded and
more nearly perfected by those persons and public agencies
interested in agriculture, particularly winter vegetables,
sugar cane, and cattle.
Another use of peat is as a material in horticulture, flori-
culture, fertilizers, as fuel, and for some industrial purposes.
Thus used peat is mined and handled similar to minerals and
coal and its occurrence, processing, and use are of import-
ance to this Geological Survey and the United States Bureau
of Mines. To learn more about these an investigation of the
peat resources of Florida was undertaken and this paper
prepared to give the extent and quantity of the peat deposits,
the nature, kinds, and composition of peat, some of the
geologic significance of the peat deposits, and the uses of
peat.

J. H. D., 1946
Florida Geological Survey
Tallahassee, Florida.

VI

ACKNOWLEDGEMENTS

The United States Bureau of Mines and the University of
Florida's Engineering and Industrial Experiment Station
were the main organizations cooperating with the Florida
Geological Survey in this investigation. The former con-
ducted most of the analyses of samples of peat from various
deposits and aided in the test of using peat as a fuel. Mr. R.
C. Specht of the Engineering and Industrial Experiment Sta-
tion carried out experiments to test the use of peat in making
plastics, and tested some of its distillation products. The
results of this research indicate some possible industrial uses
of peat.
Most of the peat producers and many interested persons
have kindly assisted the writer in numerous ways. Dr.
Herman Gunter and other members of the staff of the
Florida Geological Survey aided in the field and laboratory
work, and in the preparation of the manuscript.

VII

CONTENTS
Page
Foreword ......................................................................................... V
Acknowledgem ents .................................................................................. VI
Introduction ............................................................................. .. ................... 1
Brief Preliminary Outline ................................................................. 2
Some processes and products of peat utilization .................. 4
Best present use .................. ................... 5
Ultimate large scale utilization .............................................. 6
Scientific interest of peat ........................................................ 6
Brief History of Utilization and Interest in Peat in Florida ...... 7
Peat for humus and fertilizer .................................................... 10
Sum m ary ................................................................ .................. 11
World Uses of Peat ............................................... ........................... 13
PART I. NATURE, ORIGIN, KINDS, AND COMPOSITION OF
PEATS IN GENERAL ............................................................................... 15
Nature and Origin .......................... ................... 15
Vegetation, prelim inary ............................................................ 16
Environmental conditions ............................................................... 17
Peat stratification and plant succession ................... 19
Sedimentary peats of lakes and lake development ........... 22
Lake develop ent .............................................................. 23
Lake deposits .................................................................... 24
Kinds of Peats and their Classification ......................................... 25
A general scientific classification of peats .............................. 26
M uck and hum us ................................. .................................... 28
Diatomaceous earths or mucks ............................................... 29
Types of peat m material ................................................................ 30
Sedimentary, plastic, and pulpy peat .............................. 31
Fibrous peat ....................................................................... 31
W oody peat ....................................................... ................. 33
Kinds of peats based on utilization .......................................... 33
Peat soils ................................................................................. 34
Florida peats, preliminary ............ ................. 36
Characteristics and Composition of Peats .................................... 36
Physical-mechanical and colloidal characteristics ........... 38
Water content and absorbing capacity .................................. 41
Uses based on water-holding capacity .................................. 45
Drying characteristics ........................................................... 46
Weight, density, and specific gravity .................... 50
Volume and weight estimates .................................................. 51
Atmospheric and gas content .......................... 53
Color ........................................................................ .................... 54
Tem perature relations ................................................................ 54
Reaction or Hydrogen-ion concentration (pH) .................... 55
Summary of pH conditions of Florida peats .................. 57
Heat values .................................. ...... ..................... 60
Chemical Composition .......... .......................... 61
Inorganic constituents ............................................................ 62
Inorganic analyses .................................. ..................-... 64
Organic constituents ......................................... ...............---- 68
N itrogen .............................................. ......... .............. 70
Organic analyses ...... ......... .................. 71
Rate of Peat Form ation .................................................................... 72
M icrobiological N ature .................................................................. 75
PART II. FLORIDA PEATS AND PEAT DEPOSITS .................... 78
Methods of sampling, tests, and analyses of peats ........................ 78
Kinds of peats, and some mucks ...................................................... 81
Buried peats, preliminary ............................................................. 86
Vegetation of peat areas ...................................... ......................... 86
vTiii

CONTENTS- (Continued)
Page
Vegetation of peat areas (continued)
Marsh vegetation ............................---------------- ----------------..... 87
Saw-grass marshes .....................------------------------------ 88
Rush marshes and wet prairies .............................--------------------89
Flag pond m arshes ............................................................. 90
Salt-m arshes .......................................................................... 91
Other m arsh plants ............................................................. 92
Bog-like marshes ..............---------- ----------------------..-- 92
Swamp Forests ..........................----------- ---- ----------------. 93
Bay-tree swamps ...................------------------------- ----- 93
Other swamps .......................------------------------------ 94
Mangrove swamps .............................----------- ------------------ 95
Plants of open water habitats ..................------------------------ 96
Harper's descriptions ....................-------------------------------- 97
Analyses of Florida Peats .................................................................. 98
Use of tables ..---------------........................------------------------99
Harper's analyses of samples ....-----------............ ---------------111
Occurrence and Description of Deposits ...................--...........---.-------........ 114
Regions and Areas, Quantity ....................----------- --------------115
The Everglades region ............--------------------------.-. 117
The Lake Istokpoga area ................................................. 129
The Kissimmee River Valley ............................................ 132
The Upper St. Johns River Valley, and Fellsmere
Drainage District ................------------------------------- 133
The Peace Creek Drainage District and other deposits
of Polk County ...................................................................... 135
The Lake Apopka marsh ........................-------------------------. 138
Lake County deposits ...................--------------------------- 140
The Clerm ont m arsh .................................................. 141
Other deposits, Lake County ............------..------------ 141
Putnam County deposits ...............------------------------ 142
Other Peninsular Florida deposits ..................-----------.............-----.--.. 143
Northwestern Florida deposits .............--------------------.. 146
Summary .......................--------------------------- ---------- 147
Deposits of Lakes and other bodies of water ................................ 147
Diatomaceous Deposits and their Use .....................----........---------........----. 152
Occurrence and tests ..---.....--...-- ------- --------- 153
M ining and processing ................................................................ 159
Diatoms and their significance .................................................. 161
Marls associated with peat deposits ....................----.....----------------.......-..... 162
PART III. GEOLOGY OF PEAT DEPOSITS, AND SOME
OF THE BURIED DERIVATIVES OF PEAT ........................------------------............. 165
Surface D eposits ............................................................... ................... 165
Effects of sea level changes of the Quaternary ....................166
Relations to sea level changes ......................------.....-----....--.....-..--------..-. 167
Postglacial and Recent coastal changes ................-......... -------------172
Pleistocene and Recent chronology ..........................................173
Sink areas ...................................................................................... 174
Recent filling of basins by peat formation .............................. 175
Significance of lake peats ......................................................... 176
Reversed deposits in lakes ............------------------------- 177
Regional rise in w ater ................................................................ 180
Evidences of sea level changes ..................-------------------.. 180
Evidences of water rise inland .......................................... 181
Reduced underground drainage ........................................181
Buried Peats and Derivatives of Peat ..............................................182
Buried Quaternary peats ............................................................ 183
Peat derivatives in Tertiary formations ............----------------- 189
Peat Deposits and Past Climates .................................................... 193
Pollen analyses ...........................................-- ... .... ............ 195
IX

CONTENTS- (Continued)
Page
PART IV. UTILIZATION OF FLORIDA PEATS ............................ 198
P ast P reduction .................................................................................... 200
Recent and Present Production ........-...................---------------........--------..........-....-. 202
Methods of Excavation and Preparation ..................-------........-....-....-. 207
Excavating method ............................................------------------------------............---...-. 208
Cultivating method .................................................---------------------------------................. 212
Some elaborate methods of processing ................-------......---....--...... 213
Shipping and sales ..............................----------------------......................-.......... ----------214
Methods of Use for Soils and Plant Growth ..-----------------............................ 214
Fertilizers made from peat .....................................------------------------.......----..--........ 217
Possible Utilization and Tests ...................................--------------------.........-........--. 218
Peat for heat and power ......................................-------------------------.............-..-. 221
Test of preparation for use as a solid fuel ..............-........--------........ 224
Charcoal .............................................................---------------------------------------................. 227
Peat gas for fuel and power ............................-------------..--------........--...... 227
By-products .........................................---------------------------.........-....---.-----.. 230
Carbonization and by-products .........--------.....-....-------................-----. 230
Tests of Florida peats ..................................-------------------......------.......-....---....--. 232
Summary and significance of tests ..................................------ 234
Montan wax ....................----------------------...................................--------..................-------- 236
Use in making plastics ...--..-............--------------................----------.........-.......----. 236
Methods and results of tests ....................-----...........--....-----------.. 237
Difficulties encountered .......................--------------------................---. 239
INDEX .......................................................... ............................--------------------------------------------------................. 241

X

ILLUSTRATIONS

Frontispiece-Fire in the Everglades burning peat, April 1944. Such
fires occur frequently during the dry season and destroy
some of the dry, surface peat. If the Everglades were
more generously flooded such fires could be reduced and
the peat saved.
Figures Page
1 Map of Florida showing peat deposits ..............................opposite 2
2 Seasonal rains flood many marshes where peat occurs. Here
the Istokpoga marsh near Brighton is deeply flooded during
September, 1945 .........................--------------------- ----.....-----------. 18
3 Profile of peat deposit and underlying sediments from a tree
island in the Everglades showing peat stratification. These
layers developed in a sequence due to the water conditions and
kind of vegetation which slowly changed as peat filled in the
basin ....................-......................................................------------------------------------....................--------.---. 20
4 Profile section across Mud Lake, Marion County, showing the
deep deposit of this lake, with sedimentary, sapropel peat over
fibrous, lowmoor, saw-grass peat. After E. C. Roe .................... 24
5 Peat forms soils, called muck, after cultivation, and large
areas in the Everglades produce fine crops. Here at Canal
Point are sugar cane fields .............................-----.......-----------------......................... ----------28
6 Recently excavated, fibrous saw-grass peat, and machete used
to cut samples. Note most fibers are vertical and coarse in
this peat ....................-----------------------------........----...------------32
7 Volume sample of peat (left) taken by use of brass cylinder
(right). Such volume samples were used as the basis for
calculating quantity of peat in the deposits .................................. ------------------47
8 Showing shrinkage of peat. Sample of Loxahatchee peat on
left was size of brass cylinder before drying and shrinking........ 47
9 Hiler peat auger which was used to take most samples below
the w ater table ...................................................................................... 79
10 Saw-grass vegetation of the central Everglades. The saw-grass
forms a dense cover over the marsh and fibrous peat is de-
veloped from its undergrowth parts and debris is formed when
parts above ground die .......................-------............----------..-..............--------------......--.....-. 88
11 Peat develops in mangrove swamps which are flooded by the
tide. In this red mangrove, Rhizophora mangle, swamp on
Key Largo the raw fibrous peat is 4 feet thick ............................ 95
12 Aquatic plants of many kinds form sedimentary and some
fibrous peat. Here the air boat floats on 1 foot of water over a
deep, 10 feet, deposit of Loxahatchee peat ...................................... --------------------96
13 Isopach map of the Everglades region showing thickness of
peat and some muck areas .....................-..........----------....---..---..-..................... -----------122
14 Profile across the Everglades showing layers of peat and some
marl, rock, and sand sediments .............................................. ..... 123
15 Pit showing profile of sediments and peat in the Everglades
near the northern part of the Hillsborough Canal. A. Saw-
grass peat, 4 feet thick. B. Lake Flirt marl, 20 inches thick.
C. Fort Thompson formation limestone ..... .................................... 125
16 Isopach map of the Lake Istokpoga marsh and swamp area
showing thickness of Brighton peat formed in marshes, and
area of Istokpoga peat and muck of swamps and bay-gall
forests ............... ................................................................................. 130
17 Inspecting and sampling peat along canal bank in the Istok-
poga m arshes ........................................................................................ 131
18 Map of a part of the Peace Creek Drainage District, Polk
County, showing marsh and prairie areas that have some peat
and some diatomaceous muck, and a few bay-tree swamp areas
w ith peat .... .........-........................................... ..... ..................... 13
XI

ILLUSTRATIONS-(Continued)
Figures Page
19 Peat area of the Lake Apopka marshes and some peat areas of
Lake County .............................................---------------------------............................................. 139
20 Excavating peat at Florahome with a long-handled spade. The
blocks thus dug are piled loosely and dry quickly. This hand
labor method has now been replaced by a dragline as demand
has made increased production profitable .........-...-....................--------------...... 143
21 Sedimentary peat, sapropel, in dipper at Mud Lake, showing
the soupy consistency. Courtesy of E. C. Roe .............................. 149
22 Diatom shells, frustules, of a few species from a deposit 15
miles south of Clermont, Lake County. Note typical markings
on the shells, 1. Surirella oblonga Ehrenberg. X 929; 2,
General view of diatomite material showing a number of
species, X 100; Pinnularia major (Kiitzing). X 488; Pinnu-
laria gibba Ehrenberg. X 592 (from McLeon Basin, Santa Rosa
County; (5) Pinnularia virides (Nitzsch). X 1200 ........................ 158
23 Tamiami canal bank in the Everglades, showing a layer of
marl interbedded in the peat. Photo by Robert B. Campbell .... 163
24 Mangrove peat uncovered by a hurricane which washed away
the beach sand that covered the peat, at Naples beach .............. 173
25 Geological cross-section at Silver Springs Lock Site showing
series of core holes with layers of buried peat .............................. 185
26 Geological cross-section at the Eureka Dam Site showing series
of core holes with layers of buried peat .......................................... 188
27 This sign shows that deposits of peat being excavated are
considered mines .............................................................------------------------------------..................... 198
28 Concrete drying area and peat processing plant of the Florida
Humus Company, Zellwood, Orange County, in July 1932.
Elaborate methods of drying and processing the peat were
used at this plant .................................................................................. ---------------------------------201
29 Partly excavated peat deposit of Daetwyler Nurseries near
Pinecastle showing peat excavator and board runway for
trucks. From about 20 acres of this deposit approximately
350,000 cubic yards of wet peat have been obtained. Excavating
9 feet deep usually produces about 15,000 loosely piled cubic
yards per acre ..-................--...........................--------------------.....------.........---..-............. 205
30 Pulverized Florahome peat in bags loaded on tram car for
m ovem ent to shed or truck ..................................... ........................... 206
31 Bank of fibrous pond-prairie peat in deposit of the Florida
Nursery and Landscape Company, at Leesburg. This peat
rests directly on sand. Water is removed from deposit by
pumping, and most of the excavating was by hand labor .......... 207
32 Peat excavator, constructed by M. J. Daetwyler, loading truck
on deposit near Pinecastle, Orange County. This excavator
digs about a cubic yard per minute .................................................. 209
33 Peat and muck pulverizer used by J. C. Canfield near Fort
Lauderdale. D.D.T. is added to the peat in this operation,
which insecticide seems to reduce insects on lawns to which
this prepared peat is added ....................................... ....... ............. 211
34 Peat shredder in operation, shredding a cubic yard per minute
at Daetwyler Nursery ..................................................--------------------------------..................... 211
35 Excavating peat with a dragline near a road in the Everglades.
With water two feet below the surface the dump trucks could
back onto the peat marsh without much difficulty ........................ 225
36 Everglades peat piled to dry in the open. Thus piled it lost
moisture in spite of heavy rains but failed to become, dry
enough for use as a fuel ................................................... ............. 225
XII

Tables Page
1 Field water-content of some Florida peats ...................---------........-..... ---------43
2 Specific gravity of some Florida peats .......................-------------..--...........--.. 51
3 Reaction (pH values) of some Florida peats .......................--------......... 58
4 Partial analyses of some peat and muck soils in Florida, from
R. E. Rose ............--- ---.---------.--. -------------63
5 Chemical composition of some Florida peats ................................ 66
6 Ratio of carbon to nitrogen, and total nitrogen, moisture free
basis .........-------------------------------------------------- 70
7 Organic composition of the saw-grass plant and saw-grass peat 71
8 Condensed analyses of organic composition of Mud Lake peats.. 72
9 Occurrence of microorganisms in a lowmoor peat profile .......... 76
10 Outline of kinds of Florida peats and mucks ..............-----------..........--........ ----81
11 United States Bureau of Mines, Coal-Analysis Report.......-.......-- 98
12 County list of Florida peat analyses by United States Bureau
of Mines ..---....--.....---.------------------------ 101
13 Location of places where samples were taken for analyses
given in table 12 ...----- --------------------- ------------108
14 Proportions of some chemical constituents and moisture of
peat of important Florida deposits ...........--..............----------------...................... -------109
15 Analyses of Florida peat for Harper by United States Geo-
logical Survey --.........-------------------------- -------------- 112
16 Approximate quantity of peat in the Everglades .---........-.........--........ 115
17 Approximate quantity of peat in most Florida deposits outside
the Everglades ..-----------------------------------------116
18 Quantity, ash, and B. t. u. values of peat of the Istokpoga
marshes .----------------------------------------------132
19 Location of some diatomaceous deposits in Florida ....................----- 154
20 Tests of diatomaceous material, weights and per cent of
diatomite --........................------ ......... ................---------------... 156
21 Characteristics of Florida diatomite ................................------------..............-. 157
22 List of some Florida wells having carbonaceous material .---........ 192
23 Florida peat production by periods from 1917 to 1941, and
main producers .-----------------------..------------------ 202
24 Florida peat production 1941 to June 1946, and main
producers .----------------------------------------------204
25 Uses of peat lands and peat material ............................................------------ 219
26 Results obtained from the dry distillation of Florahome and
Everglades peats ---.................................. ------.................................----------- 233
27 Summary of averages of results of dry distillation ...................-----. 234

XIII

THE PEAT DEPOSITS OF FLORIDA
Their Occurrence, Development, and Uses

JOHN H. DAVIS, JR.

INTRODUCTION

For a number of reasons the large and small deposits of
peat in Florida have been neglected except as regards their
agricultural development as soils for crops, some pasturage,
and in a few places their use for horticultural peat material.
The Florida deposits are the third most extensive in the United
States and the Everglades region probably contains more peat
than any other similar size area.
Harper' made a preliminary report about these peat de-
posits but it has been nearly forty years since his investiga-
tion was made and some conditions of the deposits have
changed. Moreover, no over-all, nearly complete survey of
the many deposits had been made and such an investigation
was needed to get a comprehensive view of the peat resources
of the State. The large and many of the small peat deposits
were studied to learn the various kinds of peat, depth and
character of the deposits, and to get estimates of quantity and
weight of the peat in these deposits.
The utilization of peat as a material was particularly
considered because very few uses have been made of it to date.
Some experiments to determine whether or not Everglades
peat, and other peats of large deposits, could be economically
used for fuel for generating heat and power, or for making
plastics, were undertaken. The present uses for soil con-
ditioning, as a humus, and as a fertilizer filler were investi-
gated to see if new or improved methods for handling the peat
could be devised.
To correlate the peat deposits and some buried peats, or
peat derivatives, with numerous, known geologic conditions
an investigation of the geologic significance of some peats was
undertaken.

1Harper, R. M., Preliminary report on the peat deposits of Florida.
Florida Geol. Survey 3d Ann. Rept., pp. 197-375, 1910.

2 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

The following report of this peat investigation is for con-
venience presented in four main parts so as to clearly deal
with the different conditions, kinds, and significance of the
peat deposits of Florida as pointed out above. The four are:
Part I. Nature, Origin, Kinds, and Composition of Peats in
General; Part II. Florida Peats and Peat Deposits; Part III.
Geology of the Peat Deposits; and Part IV. Utilization of
Peat.
To set the stage for these descriptions and discussions a
Brief Preliminary Outline, stressing the utilization and scien-
tific interests of peat, is presented, followed by a Brief
History of the Utilization and Interest in Peat in Florida, and
a short outline of World Uses of Peat.

BRIEF PRELIMINARY OUTLINE
Distribution and Quantity: In Florida peat occurs in the
Everglades region, the Lake Istokpoga marshes, the upper St.
Johns River marshes, Fellsmere Drainage District areas, the
Oklawaha River valley, the Lake Apopka marsh, many Lake
County marshes, the Florahome wet prairie area, the Peace
Creek Drainage District area, and many scattered smaller
marsh or swamp areas in many counties. This survey esti-
mated that there are in Florida peat areas totaling about 3,500
square miles and containing over 1,750,000,000 tons of peat on
an air dry basis. In the United States, occurring principally in
Minnesota, Wisconsin, Florida, Michigan, Maine, New Jersey,
New York, and a few other states, there are about 11,000
square miles of peat deposits and over 12,000,000,000 air dry
tons of peat. The Florida deposits are shallower than most
and contain less peat per square mile.
Values: As agricultural lands there are many peat soil
areas in Florida which are very productive of winter vegeta-
bles, sugar cane, and other crops and these are usually more
valuable for their soils than for excavated peat. Such lands
when improved are valued at from $50 to $500 an acre of
which there are over $50,000,000 worth in Florida. In general,
excavated, partly dried, and processed peats have had in some
states an average value of about $3 to $5 per ton. Florida's
non-agricultural peat deposits covering some 1,500,000 acres
if valued at only $1 per ton represent a potential value of over

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THE PEAT DEPOSITS OF FLORIDA

$1,500,000,000. The total value of peat and peat lands in the
United States has been estimated at about $38,000,000,000;
which is no mean resource.
Utilization: That this great natural resource should be
more extensively utilized is obvious. Uses other than agri-
cultural need to be developed and expanded. At present some
Florida peats are used on a small scale for horticulture, soil
conditioning and with fertilizers. In the United States the
greatest quantity of domestic peat used was 107,261 tons in
1918 when some of it was used for fuel. In 1942 only 71,500
tons of domestic peat was produced and 49,232 tons of peat
moss was imported, whereas in Europe during this year
probably 35,000,000 tons of peat were produced. Some
countries and totals used during 1941 are; Russia over 30,-
000,000 tons, about 6,000,000 tons in Denmark, and 7,000,000
tons in Ireland, to cite a few of the largest users. During 1911
successful commercial operations of a large electric power
station in Germany which used only peat for fuel was estab-
lished near Osnabruk producing 428,870 kilowatt hours of
electric current a month. Since then larger plants than this
one have been put in operation in Russia and in other countries
where transportation of coal and petroleum are difficult.
Recently, 1946, power plants using peat for fuel are being
built in Ireland on a large scale.
The present uses of peat in the United States are best
summarized by the sales reports of the United States Bureau
of Mines, most of which are given in the Minerals Yearbook,
for four recent years.

Litter
Production Soil Mixed for Barns,
Year (Short Tons) Improvement Fertilizers Poultry, Etc.
1940 70,097 93% 2% 5%
1941 86,503 75% 20% 5%
1942 71,500 61% 30% 9%
1943 60,002 66% 27% 7%

The most profitable but not all the possible uses and
products of peat are briefly outlined below to give some idea
of the many methods of utilization. Each of these uses will
be considered in more detail in Part IV.

3

4 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

SOME PROCESSES AND PRODUCTS OF PEAT UTILIZATION
1. Peat for humus, soil improvement, and fertilizer filler.
Excavated, partly dried by air, and usually shredded or pulver-
ized. This is the principal use of peat in Florida, of which an
average of about 7,000 tons valued at nearly $25,000 have
been produced yearly since 1917, mostly in small operations.
During 1945 nearly 30,000 tons worth about $150,000 was
produced in Florida.
2. Machine peat. Dug by hand labor or diggers of the
chain bucket type or power shovels and draglines, macerated
in a pug mill similar to those used in grinding clay for brick
and then forced through an orifice and cut into bricks and air
dried. Two tons of this machined peat usually equal one ton
of good soft coal in heat value, British thermal units or
calories.
3. Powdered peat for fuel. Dug by a number of means or
plowed and harrowed on the bog or marsh, then air dried and
collected as it is, or pulverized to a dust or powder. In this
form peat has been used as a fuel under boilers by employing
various stokers.
4. Peat briquets. Peat dried to about 15 per cent mois-
ture is pulverized and then mechanically molded in a press
into briquets. This process involves capital and skill but
yields a product that is easy to ship and stands weathering.
It is a clean, easily handled, domestic fuel.
5. Dry distillation and carbonization. The main products
yielded are: (1) coke, useful in refinishing metals, hardening
of steel, purifying water, making gunpowder; the quality is
good and B. t. u. value about 12,000 units per pound; (2) gas,
8,000 to 10,000 cubic feet per ton, having 300 to 400 B. t. u. per
cubic foot can be produced, the gas is useful for illumination
being burned in mantles, and it is a serviceable furnace fuel,
or for power in gas engine; (3) tar, upon distillation yielding
light and heavy oils, paraffin wax, creosote and resin com-
pounds, and pitch; and (4) tar water, from which methyl
alcohol, acetic acid, and ammonia can be derived, but the
ammonia is less in quantity than that derived from the pro-
ducer gas process.
6. Producer gas. Peat is excellent for this purpose the
gas derived from this process being approximately the same

THE PEAT DEPOSITS OF FLORIDA

as that from coal, and the volume is large. More power can be
developed from a ton of peat converted into producer gas and
used in a gas engine than is usually developed from a ton of
soft coal used under a boiler to generate steam. Furthermore,
it is frequently not necessary to remove so large a percentage
of moisture from peat when used in this way as compared to
using it as powdered peat or machined peat. By-products
from this process are mainly tars and ammonia compounds.
The Mond process used extensively in England is notable be-
cause this process produces large quantities of ammonium
sulphate. Other processes recently developed may prove even
better for obtaining ammonium sulphate which is a valuable
product for agriculture. Utilization of peat for power gas is
one of the most promising of its uses.
The development of uses under 3, 5, and 6 are in the nature
of large investments and complex industries and large reserves
of peat, assured markets, and development of efficient methods
will be necessary to make these processes profitable.
Many other products such as millboard materials, insula-
tion materials, and perhaps plastics may be developed from
peat, and some of these products would also support new
industries if they could be efficiently developed.
7. Material for plastics. Some kinds of peat have been
used recently in mixtures with resinous plastics and pressed
and heated to form a good product.

BEST PRESENT USE
Peat used in landscaping and horticulture for plant nurse-
ries, lawns, and ornamental shrub plantings has at present the
greatest sale which will probably increase because of the
great increase in construction of homes. Florida peat, par-
ticularly the acid pond-prairie peat, is proving to be in in-
creasing demand since the close of World War II. Production
in 1946 will probably exceed that produced in 1943 and 1944
combined, or for any previous year. Nurserymen and other
large users are recognizing the good quality of shredded
Florida peat and orders for it are exceeding rate of production
at the present time.
It is possible that with more advertising, better methods of
excavating and processing, and a lower price the demand for

5

6 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

horticultural peat will continue particularly in the southeast-
ern United States. This industry may, therefore, expand. But
even if expanded to 150,000 tons per year it will be small com-
pared to the possible production that can be obtained from
the numerous Florida deposits if other uses of peat could be
made profitable.

ULTIMATE LARGE SCALE UTILIZATION
Final development of large scale mining and uses of peat
will depend upon: (1) the application of engineering skills to
adapt processes now measurably successful abroad to the con-
ditions of the United States, and Florida in particular; (2) a
careful study of the market to ascertain which of the products
should be in demand in various sections of the country.
Florida needs more and cheaper power and fuel, fertilizer
materials, and construction materials such as millboards, in-
sulation materials, and plastics. Some products of peat useful
in small industries might be profitably developed even though
some large scale industries might prove impractical.
With the results of this survey of peat resources giving
analyses, estimates of quantity and quality, and characteris-
tics of peat material some methods of utilization and expan-
sion of the uses of Florida's peat deposits may be developed.
Final promotion of large scale utilization will depend upon the
initiative of private industries which can take advantage of
the facts given here and develop the industrial and economic
aspects of peat utilization.
The chief difficulty to overcome is the removal of water
from the peat in a manner that is not costly or too time con-
suming. Until good methods for doing this are developed the
use of peat material will remain a hazardous financial venture.

SCIENTIFIC INTEREST OF PEAT
Peat is of great scientific interest and investigations con-
cerning peat deposits, peat soils, and peat material are amply
justified as additions to the sum total of knowledge about our
natural features and potential resources, even if all this infor-
mation cannot be directly applied to utilization.
Geologists are interested in peat because the deposits, as
part of the earth's crust, often reflect past conditions to topog-
raphy and climate, and peat has played an important role in

THE PEAT DEPOSITS OF FLORIDA

the origin of coal. In Florida some of the peat deposits, par-
ticularly those that are buried, are helpful in interpreting the
correlation of geologic formations of the Quaternary. More-
over, the mining engineers and bureaus of mines are inter-
ested in peat because it can be handled as a mined product.
Part III considers some of the geologic and climatic signifi-
cance of peat.
Botanists, plant ecologists particularly, are interested in
the plants forming peat deposits, the changes in the kinds of
plants with the development of these deposits, and the topo-
graphic, water, climatic, and other environmental relations
that affect peat formation in marshes, bogs, swamps, and
lakes.
The chemists and physicists are attempting to unravel the
complex nature of the peat material and soils derived from
peat. Although most of their work has been connected with
inorganic constituents, water conditions, and the soil reaction
(pH), particularly as these apply to agriculture, recently
some of them are beginning to investigate the complex or-
ganic substances. Industrial chemists and engineers are con-
sidering the fuel values, gas, and by-products of distillation
that can be obtained from peat.
Agriculturists are well informed about the nature and
management of peat soils and have made thorough investiga-
tions of peat lands.
Because all of these fields of science are contributing to
the knowledge of peat an extensive literature has developed on
the subject and it is difficult for one investigator to compre-
hend the many aspects of peat and its utilization. For this
reason the following treatment of peat does not pretend to be
exhaustive.

BRIEF HISTORY OF UTILIZATION AND INTEREST IN
PEAT IN FLORIDA
The many areas of peat and muck widely distributed in
Florida, particularly in the peninsula, led to an early develop-
ment of these lands for agricultural purposes because when
such lands were drained they often produce fine crops. Some
small areas of muck and peat were drained before 1900 but
most of the organized large drainage projects were begun

8 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

during this century, and some of the finest crop areas are now
on formerly flooded peat or muck lands.
This agricultural development was, and will probably re-
main, the most important use of our peat and muck lands.
But there have been other uses of peat and these uses may be
more widely developed. The history' of attempts to develop
these other, non-agricultural uses of peat is well illustrated by
the following description.2, 3

"In September, 1905, the Orlando Water and Light Company, of
Orlando, Fla., completed the installation of a plant for the treatment
and briquetting of peat, which occurs abundantly in the low-lying lands
of Florida. The plant is located about 3 miles from Orlando, on the
border of a peat bog from which its supply is drawn. As originally
installed, this plant consisted of a macerating machine or pug mill, in
which the fiber of the peat is entirely destroyed, and a brick press. The
briquettes as they came from the press were about the size of an ordi-
nary building brick, but when dried in the sun shrunk to about one-fourth
their former bulk and lost from 75 to 85 per cent in weight. The
briquetting feature of the plant was abandoned in the summer of 1906,
as it was found that this part of the work represented 75 per cent of
the total cost, and that a satisfactory fuel could be made without
briquetting. The method of treatment at the present consists simply of
"machining" the peat in the pug mill and dumping it in masses of
several hundred tons. As the peat dries it shrinks and cracks into
large, irregularly rectangular blocks, which a1re broken off from the
heap and stored. When thoroughly dried, these blocks make a good hard
fuel, which it is stated may be used for both locomotive and stationary
boilers, for household purposes, and for the manufacture of gas. Tests
of the machined peat for producer gas at the Geological Survey fuel-
testing plant gave excellent results.
"The machine used at the Orlando plant was built by the Moore and
Wyman Elevator and Machine Works, South Boston, Mass., under
patents issued to the late T. H. Leavitt, of Boston.
"The work of the Orlando Water and Light Company, of Orlando,
Fla., may perhaps be considered typical. There is a popular impression
that peat bogs are largely if not wholly confined to northern countries,
but this is not correct, since Florida has some of the finest deposits in
this country. The Orlando Company is working on a deposit filling a
small lake basin. The company has installed a Leavitt machine with a
belt conveyor for transporting the peat to the mill, where it is disinte-
grated and molded into bricks without pressure. The bricks are tien
laid out, and in the hot Florida sun soon lose a large percentage of
their moisture. As the peat comes from the bog it carries about 85 per
cent of water, but in' a few days after the bricks have been manufac-
tured this is reduced to 30 per cent and finally to about 15 per cent
without artificial drying. When the bricks have reached this stage they
have shrunk to about one-half their original dimensions, and then they
2 Excerpt from Bulletin No. 316, Department .of the Interior, United
States Geological Survey, George Otis Smith, Director; Contributions to
Economic Geology, 1906, Part II-Coal, Lignite, and Peat, Marius R.
Campbell, Geologist in Charge, Washington, Government Printing
Office, 1906.
3 Campbell, M. R., Peat: Mineral Resources U. S., 1905.. pp. 1319-20,
1 9 0 6 ... ..... .

THE PEAT DEPOSITS OF FLORIDA

may be stacked out in the weather without reabsorbing an appreciable
amount of water.
"The business is hampered by the excessive rains which prevail in
Florida during the wet season from June to November, and some means
of artificial drying or protection must be resorted to before the work can
be kept in continuous operation.
"Although the plant has not passed the experimental stage, several
hundred tons of the machine peat have been produced and used under
the boilers of the electric light plant. It is confidently believed by the
owners that peat fuel produced in this way can successfully stand in
competition with hard-pine wood at $3 per cord and Alabama coal at $7
per ton."

But according to the May 1924 issue of "Sunshine, Flor-
ida's Magazine" the first use of peat for fuel was by Mr. J. M.
Cheney in his power and light plant at Orlando in 1907. How-
ever, both these references probably are about the same plant
even though the dates given are different. Cheney was owner
of the Orlando Water and Light Company.
In this same article a sketch of the activities of the most
enthusiastic exponent of various uses of Florida's peat is
given. This person was Mr. Robert Ranson, a Civil Engineer,
from Ipswich, England, who soon after coming to Florida in
1884 began experiments and projects in the use of peat. For
over 35 years he industriously promoted a number of peat
using projects and led in state and national conferences and
societies concerned with peat.
Some of his first mining operations were at Julington
Creek, Crescent Lake, and near Pablo Beach. In 1906-1907 he
attempted to introduce the idea of using peat for making
producer gas for light, heat, and power, but when this aspect
of the project failed, he dried and pulverized the dredged peat
and sold it as a fertilizer filler. In 1908 he excavated 5,000
tons of peat at Julington Creek most of which was used for
fertilizer or soil conditioning purposes.
After a trip to England, during which Mr. Ranson obtained
more ideas about uses of peat, he continued to experiment
-with the production of producer gas but had little success in
'selling the idea although he satisfactorily demonstrated that
such gas could be produced in quantity. His experimental
plant near Canal Point in the Everglades during 1924 pro-
duced power gas, ammonia, tars, oils, methyl alcohol, and
some other by-products, but the expense of operating the test
plant was so great that his backers and promoters discon-
tinued further development of the project.

9

10 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

Big ideas prevailed during the 1920's in Florida and Robert
Ranson's ideas about peat used for fuel and power were ad-
vanced in the most glowing terms. One article about peat was
titled "Acres of Diamonds in the Everglades" in which the
conversion of millions of tons of Everglades peat into fuel for
electrical and other power projects was envisioned. Ranson's
idea was to use the large non-agricultural areas of peat in the
Everglades which would be excavated of their peat layer and
the peat used in large retorts to produce gas for power and
fuel, with recovery of valuable by-products for fertilizer and
industrial uses. Because a similar method, particularly well
developed as the Mond Process of making producer gas, was
common practice in many European countries, it was con-
sidered as probably applicable to Florida. The promotion of
this idea failed, however, and it has not since been tried in
Florida.
Among many of Ranson's estimates of the fuel value of
Florida peat, one for the Everglades peat deposits states, "five
hundred thousand acres there are, and they average ten feet
in depth. Every such acre of deposits contains the equivalent
heat of six thousand barrels of fuel oil. Each ton of Ever-
glade peat, excavated and dried by my process, would cost one
dollar to produce and deliver to power plants within a radius
of five miles; and it would give six times more heat than the
present dollar's worth of fuel oil. Furthermore, the by-
products that can be obtained from peat will more than pay
for the cost of production."
However right Robert Ranson may have been his projects
did not materialize and after his death in 1934 little has been
said or done about the uses of peat for other than crop lands
and fertilizer purposes.
Peat for Humus and Fertilizer
Peat for humus, soil conditioning, and as a fertilizer filler
has been moderately useful. Some producers have made
profits whereas others have failed. Considering these projects
we find that those which failed financially usually had opera-
tions of excavating, drying, processing, and selling on a too
elaborate and costly scale. The Florida Humus Company of
Zellwood was one such concern. Their dredging operation,
drying platform, driers, and other processing machinery were

THE PEAT DEPOSITS OF FLORIDA

too costly to allow a profit on the small scales of prepared
peat.
Other concerns, however, as the West Florida Humus
Company at Panama City, are producing dried peat for humus
at a profit. Nurseries, as the Southern States Nursery, Daet-
wyler Nursery, and Florida Nursery and Landscape Company
are excavating peat for their own use and disposing of some
commercially. The total amount of peat that was processed,
used locally, or sold during 1944 in Florida probably exceeded
40,000 tons of 50 per cent air dry peat.
The total quantity and value of peat produced in Florida
by these and similar companies preparing peat for soil humus
and fertilizer material has been about 200,000 tons of 50 per
cent air dry peat sold or valued at nearly $1,200,000 for the
years 1917 through 1945, as shown in tables 23 and 24. This
is an average of less than 7,000 tons and about $40,000 per
year for the peat industry in Florida and there has not been
a progressive expansion of the industry. These figures indi-
cate that some better methods of mining, processing, and
using or selling the peat need to be developed to expand this
industry.
Summary
From this brief review we see that the utilization of peat
in Florida has been an unorganized industry with many
failures and only a few successes. However, there remains
the great possibility of a large scale use of peat if proper low
cost production can be developed. This prospect is recognized
in an article in the "Manufacturers Record" for January 21,
1926, which, in a discussion of "Florida's Greatest Industrial
Opportunity," states, "with low-priced power from its peat
deposits, Florida has a basic resource for expansion that
should place it in the front rank of the industrial states of the
Union." Our purpose in this investigation was to estimate
the power and fuel potentialities of Florida's peat deposits
and, if practical, promote their development. The present
uses of peat lands for crops, and some peat for humus and
fertilizer will expand, and the agricultural and commercial
enterprises associated with them will probably continue to be
most profitable, but no one knows or has thoroughly under-
taken to estimate the possibilities of other profitable uses of
peat and that was the purpose of this investigation.

11

12 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

There have been a few former investigations of Florida's
peat resources, and many reports by the United States Bureau
of Mines concerning the resources and utilization of peat in
the United States, all of which show that there has been a long
continued interest in the possible expansion of our present
small scale utilization of peat. The Florida Geological Survey
published a "Preliminary report on the peat deposits of
Florida" in 1910 which was the result of a survey of types, dis-
tribution, formation, and some uses of peat by Roland M.
Harper.4 This report contains principally descriptions of the
types of peat and the vegetation of peat areas in the different
natural divisions of the State. It gives a few analyses of
Florida peat and discusses briefly the utilization of Florida
peats.
The United States Bureau of Mines and the United States
Geological Survey have also investigated some of the peat
resources of Florida and four of their publications give some
details about Florida peats.5 Moreover, these publications
discuss many possible uses and are good references.
Some interest in the utilization of Florida peat for fuel and
industrial purposes was manifest in 1923 when efforts were
made by Senator D. U. Fletcher to have the United States
Bureau of Mines carry out an investigation of Florida peat
deposits and their utilization, but nothing came of this pro-
posal. Since that time no organized effort has been made to
bring the possibilities of utilization of Florida peat resources
to the attention of the public.
On the other hand, peat lands used for their soil value in
the growing of crops have been and will probably continue to
be extensively developed by drainage. As agriculture becomes
more and more intensified and the methods of handling peat
or muck soils are better developed, even larger areas of bogs,

4 Harper, R. M., Preliminary report on the peat deposits of Florida.
Florida Geol. Survey, 3d Ann. Rept., pp. 197-375, 1910.
5 Davis, C. A., Peat resources of the United States, exclusive of
Alaska. U. S. Geol. Survey Bull. 394, pp. 62-69, 1909.
5 Davis, C. A., The uses of peat for fuel and other purposes. U. S.
Bur. Mines Bull. 16, pp. 7-203, 1911.
5 Soper, E. K., and Osbon, C. C., The occurrence and use of peat in
the United States. U. S. Geol. Survey Bull. 728, 1922.
5 Odell, W. W., and Hood, 0. P., Possibilities of the commercial utili-
zation of peat. U. S. Bur. Mines Bull. 253, 1936.

THE PEAT DEPOSITS OF FLORIDA

marshes, moors, and swamps will be reclaimed. The greatest
difficulties in handling these highly organic soils have been
the control of water in these soils by many methods of drain-
age and irrigation, and the addition of proper minerals to
these soils to supplement the lack of materials in the peat.
Alteration and control of the soil reaction, acidity particu-
larly, and a better understanding and use of soil bacteria and
other soil organisms are also leading to a more proficient use
of peat lands for many different crops.
The gradual loss of some of these peat soils of drained
areas, however, has caused a condition difficult to overcome.
Oxidation of the organic materials, compacting, fires, other
forms of deterioration, and subsidence of the surface level of
cultivated peat lands are all very difficult to control. In
general, many peat soils are being lost or deteriorating at
such a rate that their agricultural utilization is impaired. In
fact, some large areas of good peat soils are becoming rapidly
destroyed by cultivation, as in the Florida Everglades, and
once destroyed these slowly accumulated deposits cannot be
restored. In this respect, therefore, peat lands for agricul-
ture are being "mined" because the soils are being used up
even if not transported away. Conservation of peat lands, if
they are to be of continued use, is a very important aspect of
the proper utilization of peat.

WORLD USES OF PEAT
Evidences of the utilization of peat dates back to antiquity
because it is known to have been used in early Egypt and
Palestine for fuel. Among a few accounts of its use Waks-
man 6 cites a quotation from the Natural History of Pliny
(XVI, 1 Chauci), concerning various peoples who "mould mud
with their hands and dry the mud in wind rather than in the
sun; this earth they burn to cook their food and warm their
bodies benumbed by cold."
Where coal supplies are limited, as in Ireland, Russia,
Sweden, Denmark, Holland, and Germany peat has long been
used for domestic fuel. Recently, during the First World War
and more recently during the Second World War, especially in

6 Waksman, S. A., The peats of New Jersey. New Jersey Dept. Cons.
and Devel., Geol. series, Bull. 55, p. 13, 1942.

13

14 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

Russia, the use of peat for fuel on a large scale has increased
greatly with advances in methods of burning peat under boil-
ers. Russia in 1938 used 26,460,700 tons and probably has
used much more since then.
The application of peat on farmsteads has been its most
widespread use as a material. Purcell 7 pointed out that one-
seventh of Ireland was covered by peat deposits and that
during the decade 1910-1920 the total consumption was six to
eight million tons of air dry peat per year, most of which was
for farmstead fuel purposes.
This local consumption of peat for fuel in homes will
probably continue in Europe as long as coal and other compet-
ing fuels are more costly. But in North America with wood,
coal, and petroleum abundant and transportation well de-
veloped peat has not become an important domestic fuel. In
Canada and some of the northern parts of the United States
some domestic uses of peat were developed but never on a large
scale. Moreover, it is probable that very few farmsteads and
homes will ever depend upon peat for fuel in America because
our fuel and power economy is becoming more and more de-
pendent upon coal, petroleum, and electricity.

7 Purcell, P. F., The peat resources of Ireland. Dept. of Sci. Ind.
Research, Fuel Research Board, Sp. Rept. 2. pp. 1-26, 1920.

THE PEAT DEPOSITS OF FLORIDA

Part I
NATURE, ORIGIN, KINDS, AND
COMPOSITION OF PEATS IN GENERAL

NATURE AND ORIGIN
Peat is an accumulation of partly decomposed and disinte-
grated organic materials, derived mainly from the parts of
plants, which material has usually accumulated where water
abounds. The peat varies in consistency from a fibrous,
matted, turf-like material to a mud-like plastic, slime or ooze.
The different kinds of peats are most frequently classified on
the basis of the plants which formed most of the material,
and to a less extent on the basis of the texture and composi-
tion of the peat. The mode of origin of the peat deposits is
also important in any classification of kinds of peat.
On the basis of origin two main kinds of peat have been
distinguished: (1) autochthonous; and (2) allochthonous.
Autochthonous peats are those that are formed in situ, little or
none of the organic constituents having been transported.
These are the fibrous peats of marshes, bogs, moors, some
swamps, and other places where vegetation, composed of
mosses, ferns, many grasses, sedges, rushes, reeds, some
shrubs, and trees, grows and dies and the remains of the
plants accumulate. Allochthonous peats are those that are
mainly of sedimentary origin the materials forming them hav-
ing been largely transported to the place of their deposition.
These are the peats of lake bottoms and other bodies of water.
Such peats are usually non-fibrous, plastic, colloidal, and
macerated.
The development of peat in deposits is a process now often
referred to as paludification. This process is controlled by a
number of interrelated factors each of which should be partly
understood so as to understand the true nature of peat. These
factors are: (1) the water conditions of the particular area
where the deposit accumulated; (2) the vegetation that
formed most of the peat; and (3) the climate of the region
where the deposit was formed.
Many persons have been interested in the conditions of
formation of peat and in the kinds of peat and their utiliza-

15

16 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

tion. Recently the persons most interested have been soil
chemists and biologists, such as S. A. Waksman, and A. P.
Dachnowski-Stokes,8 who is publishing the most recent book
about peat. C. A. Davis, and Vaino Auer are two men who
wrote much of the past literature on peat in the United States
and Canada respectively. Their writings should be referred
to for more information than can be given here.

VEGETATION
Many generations of plants, which are usually special
kinds adapted to certain definite water conditions and which
formed one or several kinds of vegetation, have contributed to
the layers of peat found in most deposits. The plants vary
from those that are woody shrubs and trees of swamps and
bogs to those that are herbaceous and live entirely in water.
Mosses, particularly species of Sphagnum, numerous trees and
shrubs of swamps, many sedges, reeds, some grasses, and a
variety of other aquatic or semi-aquatic marsh plants con-
tribute most to peat deposits. These peat forming plants
frequently grow in fairly definite communities which are some
of our most commonly recognized types of vegetation. To
these types of vegetation a number of names have been ap-
plied, such as; marsh, swamp, bog, moor, fen, meadow, and
wet savanna or wet prairie. These terms are in some cases
designations of areas as well as types of vegetation, and in
both cases terminology has become very confusing. The
systems of classifying peats are now usually based on the
terms moor, bog, marsh, swamp, plus some habitat designa-
tions such as high or low, limnic, terrestrial, aquatic (fresh
water) or marine. Such classifications will be considered in
more detail later.
In the past many botanists, geologists, and other students
of peat have been concerned mainly with the plants growing
on the surface of the peat deposit and failed to discover the
evidences of changes in vegetation with development of the
peat. Recently, however, there have been many studies of the
different layers of peat and from these studies there have
come estimates of the age of the deposits and of the kinds of
plants associated with them in the paludification process. In
8 Dachnowski-Stokes, A. P., Peat. Chronic Botanica, 1946.

THE PEAT DEPOSITS OF FLORIDA

general, during the development of a deposit the different
generations of plants forming the peat change slowly from
one dominant kind of vegetation to another-from a marsh to
a swamp-and as a consequence of this process the deposit
will have distinct layers of peat.
A particular peat deposit may be the product of a number
of different kinds of vegetation, and of a number of slightly
different water conditions, and in some instances of different
climates. Therefore, from the nature of the layers of peat in
the deposit information regarding the conditions of its forma-
tion, and in some cases the age of each layer, may be de-
termined. Within recent years the science of plant ecology
has done much to interpret the way the vegetation changes as
peat deposits develop, and the science of micropaleontology
(study of small fossils) has by the study of plant pollen grains
and other spores made some interpretations as to the past
climate of the region when a particular layer of peat was
formed. The findings of both of these sciences will be con-
sidered later.

ENVIRONMENTAL CONDITIONS
In the process of peat formation the water conditions and
climate are most obviously important. Topography and past
changes in sea level, surface and ground water all affect the
water conditions. Climate, rainfall particularly, affects the
water conditions. But by climate we here mean the changes
in past, regional climates that cause changes in vegetation;
such as changes from warm to cold climates during inter-
glacial and glacial ages respectively.
Geologic changes are therefore important in interpreting
the older, usually deeper, and buried peat deposits. These
geologic conditions will be considered in Part III.
The present climate, topography, and water conditions
work together in peat formation. Peat may be formed under
very varied temperature conditions, from arctic to tropical,
but the present day formation is mainly in cool temperature
areas. It must not be supposed, however, as some writers
have maintained, that peat formation is limited to cool
climates because the mangrove swamps are definitely tropical
or sub-tropical and they form peat. The great peat deposits

17

18 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

of the Florida Everglade ve developed ii ejenme when
the temperature of the region most of the time has been warm
temperate to sub-tropical.

Figure 2.-Seasonal rains flood many marshes where peat occurs.
Here the Istokpoga marsh near Brighton is deeply flooded during Sep-
tember, 1945.
It is not, therefore, so much temperature as precipitation
and surface- or ground-water conditions which promote peat
formation. In general, depressions containing quiet water in
them most of the year, or large areas of low relief covered
by slowly moving or still water part of the year, are the best
conditions for the formation of the lowmoor or lowland peats
and many of the forest or swamp peats. The upland or high-
moor peats on the other hand are formed independently of
flooded conditions in some instances, but they do depend upon
high rainfall and high humidity for their development. Conse-
quently the most important initiating causes of peat formation
are the proper combination of air- and surface- and ground-
water conditions which not only definitely promote the growth
of peat forming plants but consistently influence the gradual
accumulation of only partly decomposed organic materials.
These water conditions should be continually kept in mind in
all considerations of peat deposits.

THE PEAT DEPOSITS OF FLORIDA

The Florida peats are mostly of the lowmoor type and
frequently are referred to as marsh peat. Their development
is usually a consequence of poor drainage, seasonally heavy
rainfall, and ground water rich in mineral salts. At present
most of this Florida peat is formed in marshes and to a less
extent in some swamps swamps here being considered
flooded areas where trees and shrubs predominate. There are
also seasonally wet prairies in Florida which have accumu-
lated some peat and which become flooded but do not remain
so continually.

PEAT STRATIFICATION AND PLANT SUCCESSION
The gradual changes in types of vegetation in the moors,
bogs, swamps, marshes, lakes, ponds, lagoons, and some
rivers developing peat deposits have been described by a num-
ber of plant ecologists, and soil or peat scientists, of which a
few are by Warming,9 Dachnowski,10 Clements," Soper,12 and
Waksman.13
The description of successional stages in Minnesota
swamps by Soper gives a primary sere (succession) in the
filling in of a lake to form a pine forest in the following
stages: (1) stonewort-waterweed stage; (2) pondweed-
water-lily stage; (3) rush-wild rice stage; (4) bog-meadow
stage; (5) bog-heath stage; (6) tamarack-spruce stage;
(7) pine association.
Waksman 14 has ably pointed out that:
"The concepts relating to peat layers and horizons, to profile types
of peat deposits, and to factors of peat accumulation- (furnish) a corre-
lation-with reference to the profile structure of both American and
European peat lands.-knowledge of the profile section of peat deposits
constitutes a distinct step forward for-ecology, geography, economics,
paleontology, and even archeology."

9 Warming, Eugene, Ecology of plants. Oxford Univ. Press., Trans.
by Vohl., Groom and Balfour, pp. 358-363, London, 1925.
10 Dachnowski, A. P., Peat deposits of Ohio their origin, formation,
and uses. Geol. Survey Ohio Bull. 16, 1922.
11 Clements, F. E., Plant Succession. Carnegie Inst. Washington Pub.
242, 1916.
12 Soper, E. K., The peat deposits of Minnesota. Minnesota Geol.
Survey Bull. 16, pp. 63-70, 1919.
13 Waksman, S. A., The peats of New Jersey and their utilization.
New Jersey Dept. Cons. and Devel., Geol. Ser., Bull. 55, pp. 30-37, 1942.
14 Waksman, S. A., The stratigraphic study of peat deposits. Soil
Sci., Vol. 17, pp. 107-134, 1924.

19

20 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

GANDy PEAT

/.' ..

SAW RASS PEAT

4.5' -

LOXANATCHEE PEAT

8.5' -

LAKE FLIRT MAIt

FT THOMPSON FM.

(6esQ)A-

Figure 3.-Profile of peat deposit and underlying sediments from a
tree island in the Everglades showing peat stratification. These layers
developed in a sequence due to the water conditions and kind of vegeta-
tion which slowly changed as peat filled in the basin.

THE PEAT DEPOSITS OF FLORIDA

Moreover, he states:
"The principle method of differentiating peat deposits into series and
type-profiles is based upon the number of peat layers and horizons, and
upon the combination of characteristics,-to identify units of layers it is
necessary to have a certain amount of botanical information regarding
the plant remains which constitute peat."
When the layers of peat are considered in connection with
the kinds of vegetation and other conditions forming them a
fairly accurate history of the sequence of types of vegetation
may be interpreted. This sequence of different kinds of vege-
tation usually occurs in a fairly definite and often progressive
fashion and the change from one kind of vegetation to another
is known as a plant succession or sere.
In Florida some peat stratification and plant successions
start on underlying floor materials of sand, marl, or even lime-
stone and develop through lake, marsh and swamp stages into
a south temperate or sub-tropical, non-flooded forest stage
which is generally known as a hammock forest of evergreen
and deciduous hardwood trees with palms frequently present.
One example of a Florida sequence of stages is the general oc-
currence of successional vegetation stages in the Everglades.
The peats formed during each stage of vegetation are shown
in the following outline, in order from the bottom up: (but not
all of this sequence occurs at any one place)
TYPE OF PEAT
VEGETATION 15 OR MUCK 16
Everglades hammock forest (association) 17 Hammock muck
Bay tree forest (associes) Gandy peat
Custard-apple swamp (associes) Okeechobee muck
Mixed herb-shrub marsh (associes) Okeelanta peaty muck
Saw-grass marsh (associes) Everglades peat
Open-water, Aquatic marsh (associes) Loxahatchee peat
Another succession of vegetation resulting in fairly
definite layers of peat occurs in the coastal mangrove swamps
in those localities where deep peat, muck, and shell marl de-
posits have formed. The stages in this vegetational succes-
sion and types of peat or muck formed are as follows: 18

15 Davis, J. H., Jr., Natural features of southern Florida. Fla. Geol.
Survey Bull. 25, 1943.
16 Classification mostly by Henderson, Gallatin, and U. S. Soil Con-
servation service.
17 Ecological names for the rank of each type of vegetation in paren-
thesis.
18 Davis, J. H., Jr., The ecology and geologic role of Mangroves in
Florida. Carnegie Inst. Washington Pub. 517, pp. 322-339 and 387-394,
1940.

21

22 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

TYPE OF PEAT OR
VEGETATION OTHER DEPOSIT
Coastal hammock forest or Hardwood Hammock muck or peat
and palm forest (associations)
Conocarpus transition or Buttonwood Buttonwood muck or peat
zone (associes)
Avicennia and salt-marsh or Black Black mangrove peat or peaty
mangrove and salt-marsh zone (as- muck
socies)
Mature Rhizophora or Red Mangrove Red mangrove peat or peaty
swamp zone (consocies) marl
Pioneer Rhizophora (family) Off- Marl and muck
shore pioneer mangroves
These relations between types of peat and vegetation will
be considered further under Vegetation of Peat Areas and in
the description of Kinds of Florida Peats, Part II.

SEDIMENTARY PEATS OF LAKES AND LAKE DEVELOPMENT
The stratification of peat in many deposits indicates the
gradual change of some lakes and other bodies of water into
herbaceous marshes, then forest swamps, and in some cases
finally into hammock forests. This sequence is mainly the
resulting of filling up of the lake basins by the gradual ac-
cumulation of deposits in the form of numerous sediments, or
fibrous, or woody peats. The sediments are either predomi-
nantly of organic origin or of inorganic materials. The former
types of sediments are frequently known as peats, organic
muds, and mucks. They are classified as allochthonous, sedi-
mentary, or aquatic peats. They can be distinguished from
marsh and swamp peats because they are usually without
fibers, mud-like, frequently macerated, colloidal, and plastic.
The term allochthonous is usually applied to them because
they are a type of deposit formed by the gradual accumulation
of floated, drifted and wind-blown vegetable material accumu-
lated in more or less quiet bodies of open water.
Studies of these lake peats by Forsaith 19 and in this in-
vestigation indicate that many lakes, ponds and some rivers
in Florida have great deposits of organic sediments which
occur in the open water parts of these bodies of water, or in
some cases below, above, or even between layers of fibrous
and woody peats formed in marshes or swamps respectively.

19 Forsaith, Carl C., A report on some allochthonous peat deposits of
Florida. Botanical Gazette 62: 32-52, 1916.

THE PEAT DEPOSITS OF FLORIDA

The present marshes and some swamps were in many in-
stances formerly lakes or ponds, or parts of these, which have
changed to marshes or swamps. Such changes take place so
frequently in Florida that we should briefly consider lake de-
velopment and aquatic or sedimentary peats in some detail.

Lake Development
The usual sequence of lake development is a gradual to rapid filling
in of the basin until the whole deposit reaches the surface and no free
open water exists, or until the bottom is entirely covered by large,
attached aquatic plants and the lake becomes a pond, marsh, moor, bog,
or swamp. The sequence of development of lakes or, in ecological terms,
the successional stages in lake development, are fairly well known from
studies of many lakes of the northern United States and Europe. There-
fore, to better understand peat formation some pertinent aspects of
limnology, science of lakes, should be considered.
Welch 20 and other limnologists recognized three main types of lakes,
as follows: (1) Oligotrophic, which are usually deep and have few or no
deposits; (2) Eutrophic, which are usually shallow and have large quan-
tities of organic deposits that are rapidly filling them up and most of
the organic deposits of such lakes are peats of the type that are fibrous
and formed in place, autochthonous; and (3) Dystrophic, lakes deep to
shallow with organic bottom deposits of the aquatic peat type, alloch-
thonous, and usually macerated.
The oligotrophic lakes may gradually become filled with inorganic
sediments and as they get shallower they may change to eutrophic or
dystrophic lakes. There are few oligotrophic lakes in Florida.
Both the eutrophic and dystrophic lakes form peat and in some cases
these lakes become so completely filled up with organic deposits that
they change to shallow ponds, meadow-like moors, marshes, bogs, or
swamps. The eutrophic lakes are most apt to form marshes and moors
and the dystrophic lakes bogs. The latter occur particularly in the
north temperate region.
The distinction between eutrophic and dystrophic lakes is in some
ways arbitrary because one part of the lake, usually the central deep
water part, may be dystrophic and the bordering shallow water part
eutrophic as concerns organic deposits. In general, however, the
dystrophic lakes are without much plant life around their border or in
the shallow, littoral parts of the lake. The organic bottom deposits of
the dystrophic lakes are predominantly macerated aquatic peats of the
gyttja and sapropel types. Dystrophic lakes and deposits of this type
of peat occur in Florida in such lakes as Newnan, Minnehaha and
Weir, but over the State as a whole the eutrophic lakes and eutrophic
peat deposits are more frequent.
The eutrophic lakes are characterized by broad margins, littoral
zones, usually covered by a marsh or swamp vegetation with an
abundance of plankton and other aquatic plants. In these lakes the peat
deposits are of the lowmoor, fibrous type. The peats and mucks ac-
cumulate in the marsh and swamp zones of the shallow parts of the
lakes, and as the gradual filling in of the lake progresses these zones
become broader and the peat deeper until in some cases all open water
areas are obliterated and the whole lake becomes a marsh, lowmoor, or
swamp.
20 Welch, J, S., Limnology. McGraw-Hill, New York, pp. 310-315 and
318-321, 1933.

23

24 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

The natural process of maturing of a lake by the development of
peat deposits that fill up the basin may be termed eutrophication.
Towards the last stage of this process the changes become proportion-
ately very rapid with filling in possible within a short time. This filling
in process varies a great deal from lake to lake and even parts of the
same lake so that the rate must be estimated for each locality. In
Florida it seems fairly certain that some of the eutrophic lakes are filling
with peat very rapidly, but others are doing so slowly. One condition
that accelerates this process is a lowering of water levels, which has
occurred in many lake basins, so that marginal vegetation more rapidly
spreads over the lake causing more peat to form.
The rate of filling in of dystrophic lakes in Florida seems, in general,
to be slower than that 6f eutrophic lakes but further study is needed to
determine these relative rates.

Lake Deposits
The sedimentary, macerated and colloidal organic deposits
of many Florida lakes are in places over five feet deep. They
occur in numerous lakes which have no attached, submerged
aquatic plants, but they are also present in some lakes, Lake
Apopka, where these aquatic plants are common. A con-
siderable quantity of these organic sediments cover the floor
of so many ponds, lakes, and rivers in Florida that extensive
surveys and studies of them should be made before definite
conclusions about the deposits can be drawn.

,II I I I I I I I I I I

./H H,,oneos o r vMr, os.

E SAPROPEL
FIBROUS SAWA.FASS PEAT

Figure 4.-Profile section across Mud Lake, Marion County, show-
ing the deep deposit of this lake, with sedimentary, sapropel peat over
fibrous, lowmoor, saw-grass peat. After E. C. Roe.

Florida lake basins usually have accumulated peat deposits
in the bordering marshes and a few swamps. These are
fibrous or woody autochthonous peats, formed in situ, and
may be underlain by sedimentary allochthonous peats
formed before the marshes and swamps developed. In the
open water parts of the lakes the sedimentary, allochthonous
peats partially or completely cover the floor of the lake. But

THE PEAT DEPOSITS OF FLORIDA

in some cases, as described later (see Part III, Significance of
Lake Peats) the peat layers in a lake basin may be reversed
from their usual order with fibrous autochthonous peats below
sedimentary allochthonous peats indicating that the water in
the basin increased in depth after the fibrous peat was formed
in shallow water marshes.
Lake deposits in central Florida were studied by Forsaith 21
who concluded that: "It is evident that those (peats) of
lacustrine character (allochthonous) are of vastly greater
numerical and quantitative importance than those of an auto-
chthonous nature." But he was mistaken if all the peat de-
posits of lake basins, marshes, swamps, wet prairies and
coastal marshes and swamps are considered because the
marshes, particularly the Everglades, contain much more peat
than in sedimentary deposits of lakes.
The kinds of sedimentary peats have been variously de-
scribed as: (1) macerated, sapropel and gyttja; (2) colloidal,
liver mud and dy; (3) and doppleritic, calcareous types. All
these are generally known as aquatic, sedimentary or
allochthonous peats and will be considered later.
KINDS OF PEAT AND THEIR CLASSIFICATION
Peats are such complex and varied substances and have
been used for such a variety of purposes that a classification
of the different kinds is very difficult. Physical, chemical, and
physico-chemical characteristics and properties such as tex-
ture, structure, organic and mineral components, water con-
tent, and fuel values may be used for some classifications.
The soil-like nature of peat, especially after drainage and
cultivation in many cases forming muck, also leads to a
variety of classifications. The origin of the peat, mainly
from various peat-forming types of vegetation, and the con-
ditions of formation of the peat deposits lead to still another
group of classifications. And, finally, the various uses of peat
as a material for fuel, chemical products, manufactured
products, and some agriculture have led to still another
method of classification.
For practical purposes, which are usually the uses of peat ,
as a soil and as a material, classifications may be as numerous
as the variety of uses to which it is put and the mode of origin
21 Forsaith, Carl C., op. cit.

25

26 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

or conditions of the formative processes may be entirely ig-
nored. In some cases even composition, texture, structure,
and color may be disregarded in the classifications of peat for
utilization; viz. in the use of peat for fuel where British
thermal units or calories are the chief property under con-
sideration.
A GENERAL SCIENTIFIC CLASSIFICATION OF PEATS
There are enough combinations of easily identifiable charac-
teristics of peat with those features of peat attributable to
mode of origin and field conditions of the deposits to afford a
reasonably uniform and universal classification. This classi-
fication is based essentially on the origin and nature of the
peat, particularly the vegetation forming it, and on some of
the environmental conditions, such as topographic features
and water conditions, and it is more generally applicable than
strictly industrial or agricultural classifications. The ques-
tion is: should the emphasis in classification be based upon
the nature of the product or upon the formative processes?
Also, are the water conditions which control the accumulation
of peat or the botanical composition and sequence of vegeta-
tion units forming peat most important in a classification on
the basis of formative processes? Furthermore, are the
chemical composition, structure, texture, color, pH values and
heat values (calories or British thermal units), and water-
holding capacity more important than the above in dis-
tinguishing kinds?
Certainly the physical, chemical, and physico-chemical
characteristics of peat are most important for agriculture and
industrial or commercial purposes, but classifications based on
these alone, as will be shown, fail to give any idea of origin
and field conditions. Therefore, and because of many former
scientifically useful classifications, the classifications based on
(1) botanical features; (2) controlling, basic environmental
conditions; and (3) the general mode of origin of the deposit,
or layers in deposits, are considered most universally applica-
ble.
Dachnowski,22 who has classified peats on a scientific basis,
also has stated that:
22 Dachnowski, A. P., Quality and value of important types of peat
material. U. S. Dept. of Agr., Bur. Plant Ind., Bull 802, pp. 1-40, 1919,
or, Jour. Amer. Peat Soc. Vol. 13, pp. 219-261, 1921.

THE PEAT DEPOSITS OF FLORIDA

. types of peat material, their difference in botanical composi-
tion, in disintegrating capacity, and in related physical and chemical
characteristics have been established in Europe-. They form an
adequate basis in problems which deal with methods to be practiced in
the development and cultural preparation of a peat deposit, such as the
well-known 'Veenkultur,' the Rimpan cultural method, the German high-
moor method, and others or in operations where the removal of peat for
technical uses and centralized power plants is practicable. Data such
as those just mentioned, regarding the nature and behavior of the
various types of disintegrating plant remains making up a peat deposit,
are considered of special importance in drainage projects intended to be
practicable from an engineering and agricultural standpoint; they are
essential for an adequate method of dewatering peat materials that are
found to be of value for manufacturing purposes. It is rather in the
knowledge of the different kinds of peat material, the factors in the
field which brought about their accumulation and determined their
character, that a satisfactory basis has been found for the improve-
ment of peat by means of suitable crops or by specific operations in the
technical industries."

One of the simplest and most generally useful classifica-
tions of peat is proposed by Waksman,23 which has nearly uni-
versal application. The European terms hochmoor and flach-
moor which he uses are now becoming generally accepted. The
four main kinds are: (1) upland or highmoor; (2) lowland or
lowmoor; (3) swamp or forest; and (4) sedimentary or
aquatic; mostly macerated, colloidal, and mud peats. To
these may be added another group; (5) muck and humus,
which may be developed from peat by disintegration and de-
composition. But since both terms are frequently applied to
other soil-like materials not definitely associated with peats,
they do not constitute a definite type of peat.

In one of the most recent scientific classifications of peat, Powers 24,
gives four types based on the materials forming the deposits, which are:
(1) Limnetic or lacustrine materials, which include various oozes and
peat materials of sedimentary or allochthonous origin. (2) Telmatic
materials, the marsh vegetation which is present as one of the bottom
layers of almost all peat bogs. In North America, Carex or sedge forms
most of the telmatic peat, which occurs widely in bogs of the marshy or
lowmoor type. (3) Semiterrestrial peat materials, typified by Sphagnum
peat, which is widely distributed and constitutes most of the highmoor
bogs of the northern part of North America. (4) Terrestrial materials,
as, for example, in the grass-herb-forest peat. Most of the peat bogs
which have been studied are located in cool northerly regions, and their
plant assemblages differ markedly from those in bogs of the same type
in warmer lattitudes."

23 Waksman, S. A., The peats of New Jersey and their utilization.
New Jersey Dept. Cons. and Devel., Geol. Ser., Bull. 55, pp. 26-30, 1942.
24 Powers, W. E., Recent advances in the study of peat. Bulletin
National Research Council, Report Committee on Sedimentation 1930-32,
1932.

27

28 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

Because Florida peats are of the warmer latitudes their
classification does not entirely fit those developed for the peats
of more northern regions. In Part II a classification of Florida
peats is given that is not entirely based on any of the above
systems.
MUCK AND HUMUS
These soil-like materials may be derived from peats. Many
disintegrated top layers of peat, especially after the peat lands
have been drained and cultivated, are known as muck. In
such cases the peat which may have been fibrous, woody, or
even sedimentary or plastic becomes disintegrated into
smaller fragments brought about mainly by changes in mois-
ture content, cultivation, and by the growing roots of crop
plants. Such muck is usually granular to powdery and much

(Courtesy U. S. Sugar Corporation)
Figure 5.-Peat forms soils, called muck, after cultivation, and large
areas in the Everglades produce fine crops. Here at Canal Point are
sugar cane fields.

THE PEAT DEPOSITS OF FLORIDA

darker in color than the peat from which it was derived.
Many of the Everglades farmlands are surfaced by this type
of muck formed mainly from peat.
Another meaning of the term muck refers to soils that are
composed of more mineral than organic matter and that are
frequently of a mud or plastic character. These soil mucks a
distinguished from peat muck are of less than 50 per cen>
organic composition, but they are so similar to peats in may
instances that distinctions can only be made after analysis.
One of these soil mucks is the Okeechobee or custard-apple
muck of the Everglades region near Lake Okeechobee.
Throughout Florida there are many of these soil mucks
frequently bordering the deeper peat areas. In Florida the
soil mucks and peat mucks are not always distinguished in
farming practice or soil classification.
Humus is used as a term to designate decomposition
products of peat as well as the organic constituents of some
soils. Humus ordinarily is considered a decomposition
product of organic matter that becomes the organic portion of
a soil. It may be derived directly from peat principally by the
action of microorganisms and biochemical processes. Because
humus products are frequently soluble they become trans-
ported and incorporated into many materials, such as the dy
type of aquatic peat. Another type is some of the hardpans
where the dark brown humus materials act as a cementing
material mostly in sands. But these hardpan soils should not
be considered peats, they are ground water podzol soils.

DIATOMACEOUS EARTHS OR MUCKS
Some peats and mucks contain such an abundance of the
microscopic diatom plants that have tests of silica that these
form a material generally known as diatomaceous earth.
When this diatomaceous earth is burned, calcined, a nearly
pure silica residue is obtained that is generally called diato-
mite. This diatomite is of commercial value being used for a
number of purposes, such as a filtration medium, for the ab-
sorption of moisture, in making concrete and plaster, in ther-
mal insulation, and some polishes.
The Florida diatomaceous earths usually contain so much
carbonaceous organic matter that when wet and not com-
pacted they are dark brown or black and similar in appearance

29

30 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

to peat or muck. In general diatomaceous earths have an
unctuous, greasy feel which distinguishes them from the
fibrous peats that have a rougher firmer feel. Muck, peats and
diatomaceous earths are frequently associated in the same
deposit and in some instances it is difficult to distinguish
diatomaceous earth from the more plastic peats or mucks.
Some mucks have a similar greasy feel and black color. How-
ever, upon drying the diatomaceous earths usually become
lighter in color approaching a tan or cream color, whereas the
mucks and peats usually become darker in color. Upon burn-
ing or even slow oxidation in deposits the diatomaceous layers
may be distinguished by their lighter cream to white color and
eventually by their powdery texture.
7 Most of Florida's diatomaceous earths are mucks and not
white in color and is generally known as diatomaceous
earth. The diatomaceous muck may change to diatomaceous
earth with oxidation of the organic materials. In wet deposits
the dark colored muck form is the rule and in dry deposits the
light colored earth form is common. In our prospecting of
diatomaceous deposits and in the descriptions to follow (see
Diatomaceous Deposits and their Use) the term diatomace-
ous earth is used to designate both forms of diatomaceous
materials.
Proportions of diatomaceous earth, peat, and muck, and
the layers in which they occur vary some from place to place
but, in general, the diatomaceous earth is in the upper layers
of the deposits.
Many peat deposits in Florida contain diatomaceous earth
and for this reason the diatomaceous deposits are considered
in the description of Florida peats given in Part II.

TYPES OF PEAT MATERIAL
The four types of peats considered above may be more
generally and probably more practically described as three
types of peat material in the manner suggested by Dachnow-
ski,25 which are: (1) sedimentary or pulpy peat; (2) fibrous
peat and (3) woody peat. The sedimentary or pulpy peats are
mainly aquatic peats, the fibrous peats are both the lowmoor
25 Dachnowski, A. P., The stratigraphic study of peat deposits. Soil
Sci., vol. 17, pp. 107-134, 1924.

THE PEAT DEPOSITS OF FLORIDA

and highmoor peats, and the woody peats are the swamp or
forest peats. These may be described simply in terms of com-
position, texture, structure, color, and some other characteris-
tics and properties.

Sedimentary, Plastic, and Pulpy Peat
The texture varies from very finely divided particles of
organic debris to coarse but seldom fibrous material frequently
mixed with inorganic and mud-like sediments. When wet it is
often a sticky, gel-like, amorphous mass. When dry it is
usually dense and compact and may be heavy, stiff, and im-
pervious. There are seldom any planes of bedding in the de-
posit. Under pressure it frequently yields to plastic flow and
when excavated it does not readily stand in vertical walls.
The color is usually dark brown, black, gray, or olive green
becoming darker when dried.
Upon drying it usually shrinks to a remarkable degree
often becoming hard and horn-like. When dry some kinds
break into angular fragments because of a conchoidal frac-
ture.
Because disintegrated surface layers of other peats are
likely to resemble sedimentary peat caution should be used in
assigning peats of drained and cultivated areas to this type.

Fibrous Peat
The texture and structure is an interwoven network of only
partly altered plant remains varying from very coarse to
finely fibered materials with, in many cases, finely divided
non-fibrous particles of organic and inorganic matter inter-
spersed between the fibers. A large portion of this fibrous
mass is pore space both between the fibers and intra- or inter-
cellular space in the plant tissues. Being mainly derived from
roots, rootlets, rhizomes, and in some cases as the high-moor
peats from mosses, its structure often reflects the growth form
of parts of the plants. Whole root systems and leaves often
remain well preserved in this peat.
The color is very variable depending upon the color of the
plant remains, the degree of decomposition, and the mineral
salts associated. Red and yellow browns are common, but
grey, dark brown, and nearly black are more frequent. Upon

31

32 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

drying and oxidation many fibrous peats become darker often
becoming black.
Upon drying some finely fibrous peats with large propor-
tions of sedimentary materials may shrink greatly, but other
coarser and more matted fibrous peats may retain nearly

Figure 6.-Recently excavated, fibrous saw-grass peat, and ma-
chete used to cut samples. Note most fibers are vertical and coarse in
this peat.
their original wet dimensions. Some of these peats are very
friable and many of them break by normal fracture when
dried, others shatter into a powder when crushed. If they
contain a large proportion of fine plastic material they may
remain firm and compact when dry. Upon excavation the
vertical walls stand up well in most fibrous peat.
The high degree of porosity of fibrous peat is a characteris-
tic that influences the water-holding capacity, absorbing ca,-
pacity when once dried, air content, temperature, weight, and
volume to such an extent that porosity must nearly always be
considered in handling or classifying this kind of peat.
Types of fibrous peats derived from different dominant
plants of the vegetation that formed them may be dis-
tinguished; viz., moss peat, reed peat, sedge peat, saw-grass

THE PEAT DEPOSITS OF FLORIDA

peat, and others that were noted under the marsh group above
and will be described later in the detailed consideration of
Florida peats.
Woody Peat
The texture and structure of this peat is much more varied
than either the fibrous or sedimentary peats. Woody material
of various sizes and shapes and in different stages of decompo-
sition are its most outstanding characteristic. With these
woody fragments both fibrous and plastic peat materials may
be associated to form a very hetrogenous mass of material.
In general, partly granular debris and irregular shaped woody
fragments are the most common materials. In some instances
this peat may vary so much that layers of woody peat may
have separate horizons of a banded and bedded appearance,
their distinctive characters depending upon the relative pro-
portions of the woody materials and the fibrous or plastic ma-
terials.
The types of woody peats may be distinguished on the
basis of the woody plants, trees, and shrubs which contributed
to the peat. Some of these are heath, bay, cypress, willow,
alder, and other deciduous, and conifer trees and shrubs. The
woody particles, and in some cases whole limbs or trunks, may
be so well preserved that the tree or shrub may be identified.

KINDS OF PEATS BASED ON UTILIZATION
Industrial and agricultural peats, other than peat soils,
have been variously classified, and with the expansion of the
uses of peat many other classifications will be developed. The
bases of some of these classifications are the water-absorbing
capacity, degree of fineness, type of fibrous condition, color,
reaction expressed in terms of pH, mineral content especially
nitrogen compounds, and chemical components.
The United States Treasury 26 recognizes three types of
peat: (1) moss peat; (2) reed muck or sedge muck; and (3)
reed peat or sedge peat. These mucks are in reality peats
having about 10 to 15 per cent ash and differing mainly from
the similar reed or sedge peats in having more finely divided
plant debris due to a more advanced state of decomposition.
Therefore, these two categories may be considered only one.
26 U. S. Treasury Department, Procurement Division, Specifications
for peat. No. 563, May 19, 1942.

33

34 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

The moss peat or peat moss as it is known in the trade, is
poorly decomposed, fibrous to porous, and derived in large
part from Sphagnum moss, with acidity of 3.5 to 5.5 pH
values, and capable of absorbing 1100 to 2000 per cent water.
The reed or sedge peats have water-absorbing capacities
varying from 100 to 800 per cent and a pH range of 5.00 to 7.5.
These types are further divided into classes, peat moss
with: (a) horticultural grade, fine shreds; (b) poultry litter,
medium shreds; and (c) stable bedding, coarse shreds. The
reed or sedge peats have two classes; (a) acid grade, pH 4.5
to 5.5; and (b) nearly neutral grade, pH 5.5 to 7.5.
Waksman 27 gives four types of peat material for practical
purposes, namely:
1. Moss peat, yellowish brown, fibrous, pH 3.5 to 5.0, low
in nitrogen and ash, absorbing 600 to 1500 per cent water, and
marketed in various degrees of fineness for horticulture,
bedding, and litter.
2. Sedge and reed peat, dark brown to black, pH 4.5 to 6.5
high in nitrogen and ash, absorbing 300 to 600 per cent water,
and marketed for composts and other soil improvement pur-
poses.
3. Forest peat, brown or reddish brown, and fluffy with
fine to coarse particles of wood, pH 3.8 to 5.5, medium in
nitrogen and ash, absorbing 400 to 800 per cent water, and
marketed for mulching.
4. Peat loam, alluvial or sedimentary peat, often:known
as muck, with less organic matter, 10 to 50 per cent, thani.nost
peats and plastic, colloidal, or granular.
These simple classifications of marketed peats reflect the
few prevalent uses and do not include many other classifica-
tions based on utilization in Europe or possible future utiliza-
tion. Chemical analyses and heat values will probably de-
termine some of the future classifications of peat used for in-
dustrial and fuel purposes. A classification of peats based on
utilization will be considered later in Part IV.
PEAT SOILS
Peat or muck soils are very diversely classified because
the bases for "recognition of types and the names given are
often without reference to origin or a world wide system of
27 Waksman, S. A., The peats of New Jersey and their utilization.
New Jersey Dept. Cons. and Devel., Geol. Ser., Bull. 55, pp. 25-30, 1942.

THE PEAT DEPOSITS OF FLORIDA

classification. Soil scientists and farmers in general use only
local names, such as Everglades peat, Okeechobee muck, and
Loxahatchee peat, to designate kinds, and the characteristics
of each must be kept in mind when comparisons or identifica-
tions are made.
Most peat soils are only the surface layers of peat deposits
and, as pointed out above, these drained and cultivated layers
frequently become fine particled, granular, dark in color, a>
more plastic than they were originally. For this reason they
are often referred to as muck soils even though they may be
of greater organic than mineral content. Some regional
classification and mapping of peat deposits as soil types is
done, and in some cases the profile of the whole deposit is con-
sidered in the designation of the soil. But, in most cases only
surface layers are considered.
Present classifications of peat lands as soils are based
mainly on water conditions, mineral content, color and soil
reaction. Some of these soil classifications now also recog-
nize the importance of the structure, texture, conditions that
influence water content, transmissibility, drying and wetting
characteristics, conditions of ditch and dike banks, and the
series of peat strata that may be present. The mud, marl
sand, or rock, that may underlie the deposit or in some in-
stances be interbedded with the peat, are also considered.
From the agricultural point of view it is important to know
more than just the conditions of the top or soil layer of peat
deposits because if the stratification, mode of formation, the
probable rate of formation, and best method of retaining good
water conditions are known, the lands can be better handled
for crops and pasturage.
Besides the peat and muck soils other partly organic soils
may develop in poorly drained areas which are known as the:
(1) ground-water podzols; and (2) the half-bog soils. Some
planosols and some Tundra and Alpine Meadow soils may also
have organic matter in large proportions.
Henderson 28 in his description of Florida soils character-
izes the marsh and swamp soils as bog soils and lists five
general kinds, namely:
28 Henderson, J. R., The Soils of Florida. Univ. of Florida Agr. Exper.
Sta. Bull. 334, 1939.

35

36 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

"(1) Muck, dark brown to black, highly decomposed or-
ganic matter containing 35 to 75 per cent mineral material,
mainly fine sand and silt.
"(2) Peat, dark brown to black partially decomposed or-
ganic matter containing 0 to 35 per cent mineral matter.
"(3) Peaty muck,-gradation between peat and muck-
agricultural use-more valuable than peat and less valuable
than muck.
"(4) Swamp, miscellaneous unclassified (soils of) swamp
areas.
"(5) Tidal-marsh, (soils of) marshy areas along the coast
which are subject to tidal inundation."
This classification of "bog soils" has been further ex-
panded in Florida by the naming and description of certain
soil types under some of these five categories by Henderson
and others 29 who have done their most intensive work on
organic soils of some areas of southern Florida, particularly
the Everglades.
FLORIDA PEATS
The many kinds of Florida peats may be classified accord-
ing to any one, or a combination of, those systems outlined
above. They are, in general, mainly lowmoor, fibrous peats in
the extensive marshes and some wet prairies, some forest or
woody peats in the swamps, and allochthonous, aquatic, sedi-
mentary peats in the lakes.
These will be classified in Part II when the kinds and
quantities of peat in the deposits are considered in detail.
The names of some of the Florida peats and a few of their
characteristics will be used in the following descriptions of
the characteristics and composition of peats and the reader
will need to refer to the descriptions of these peats in Part II
to become familiar with these names used.

CHARACTERISTICS AND COMPOSITION OF PEATS
Most of the characteristics, properties, and composition of
peat materials and peat soils are based on the fact that peats
are essentially a mixture of water and partly decomposed
29 Notably soil scientists of the U. S. Soil Conservation Service
working in the Everglades Drainage District.

THE PEAT DEPOSITS OF FLORIDA

plant matter. The physical and physico-chemical characteris-
tics and properties such as texture and structure, soil reac-
tion, and heat values of peats vary a great deal because of the
different types of vegetation from which they are derived and
the different environmental conditions under which they de-
velop. These characteristics and properties are many, of
which the following are among the most important, namely:
(1) water-holding, water-absorbing, and drying characteris-
tics; (2) texture and structure; (3) weight, density, and
specific gravity; (4) atmosphere and gas content; (5) col-
loidal conditions; (6) temperature relations; (7) soil reac-
tion (pH values) ; and (8) heat values (B. t. u. or calory).
The chemical composition is related to many of these
properties and characteristics and is also directly determined
by the peat forming plants and environmental conditions.
The organic compounds, particularly lignins, proteins, cellu-
loses, hemicelluloses, and tars, are important but are not well
known. The inorganic minerals and substances vary a great
deal and are well known, particularly in peat soils that are
used for agriculture.
Although it is impossible in many cases to distinguish be-
tween the chemical composition and some of the physical or
physico-chemical properties the chemical composition will be
considered separately here because the analyses made in this
investigation were mostly chemical.
Some of the characteristics and composition of the Florida
peats are considered in the following descriptions, but most of
the analyses of these peats are given in Part II. The general
classification of peats and their distinctive characteristics
need to be understood before the Florida peats can be ade-
quately described and appraised.
Many of the particular characteristics of Florida peats,
such as drying, weight, organic composition, and microbio-
logical nature need considerably more investigation before
these peats can be sufficiently well understood to make the
best use of them.
Some of the useful characteristics and properties of peats
are pointed out below but a fuller discussion of uses is pre-
sented in Part IV.

37

38 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

PHYSICAL-MECHANICAL AND COLLOIDAL CHARACTERISTICS

Texture and structure are the most readily recognized
physical-mechanical properties, and these have been partly
considered in the description of kinds of peats. The four
usually recognized variations in texture and structure are:
(1) fibrous; (2) sedimentary, macerated, and plastic, often
colloidal; (3) granular; and (4) woody with pieces of wood
or stems abundant in the peat.
The fibrous peats, figure 6, vary a great deal in com-
pactness or looseness of structure, and in the fineness or
coarseness of texture of the fibers, and these differences ac-
count for many of the various conditions of water, weight,
volume, air content, and temperature relations in the deposits
or of the excavated material. Great porosity is a chief
characteristic of nearly all fibrous peats.
The sedimentary, macerated, and plastic peats have less
definite structure and texture than fibrous peats and they are
more difficult to correlate with such properties as water-
holding capacity, drying, and volume and weight measure-
ments. They are apt to have some collodial properties such
as flocculation, buffering properties, and high absorption of
and coagulation with bases and salts. They often form stable
emulsions with water. These properties are important but
their chief characteristics are that they are mud-like, very
wet, and shrink and harden more than fibrous peats upon dry-
ing. Some sedimentary peats occur with fibrous, granular, or
woody peats, but most often they are distinct deposits in
bodies of water.
The granular peats are mainly peat soils becoming granu-
lar after drainage and cultivation. They can be developed
from fibrous, sedimentary and woody peats. Disintegration
in the case of fibrous peat and coagulation, flocculation, and
other granulation processes in the case of sedimentary peats
are mainly responsible for their formation.
Woody peats are a mixture of fibers or plastic peat ma-
terial with fragments of stems or large roots, and in some
cases leaves, together forming a very heterogeneous mass.
Upon drying the woody particles shrink less than the other
materials. In some deposits parts of logs and stumps are well

THE PEAT DEPOSITS OF FLORIDA

preserved and in many cases the trees or shrubs can be identi-
fied.
Variability in texture and structure are due mainly to the
kinds of plants, a few animals, and inorganic sediments from
which the peats were formed, plus the degree of disintegra-
tion and decomposition in the deposits. Layering or stratifi-
cation in a deposit is generally best recognized by differences
in texture and structure at different levels in the deposits.
The fibrous condition of peats varies from very fine fibers
matted into a felt-like mass, the fibers running in nearly all
directions through the mass, to coarse fibers usually oriented
vertically, figure 6, to mixtures of fine and coarse fibers
with orientation of fibers in general vertical. Another condi-
tion is the matted and fibrous, in which case leaves and other
flat parts of plants form plate-like mats, laminae, with fibers
usually vertical so that the mass pulls apart along horizontal
and vertical cleavage planes. And still another fibrous con-
dition is the mixture of fibers, fine to coarse with granular or
flaky pieces of wood or large chunks or even limbs of wood.
Between the matrix of fibers there may be small or large
quantities of granular or very fine particled materials form-
ing a structural mass that may when wet appear and feel
almost non-fibrous or plastic. In general, this finely divided
material between the fibers constitutes the greater bulk of the
mass in heavy peats, as the saw-grass peat of the Everglades.
Plastic organic materials and inorganic sands, silts, and clays
are common constituents of all but the most fibrous peats.
The top layers of raw peat with live roots, rhizomes, and
other under-water parts of plants are more coarsely fibrous
and matted. Usually in the lower part of a peat deposit the
fibrous material decreases and the more finely divided ma-
terials of sedimentary peats increase.
The sedimentary, macerated, and plastic peats vary from
those that have a few small, partly disintegrated parts of
plants and animals to a mass of very fine particled, mud-like,
organic material that can not be identified as to its source.
The colloidal, jelly-like, mud peats are of such consistency that
they can be fashioned into various shapes much like putty
when they become partly dried. When wet some of these

39

40 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

macerated or plastic peats flow and nearly all are amorphous.
Many plastic peats are sticky or soapy to the touch.
A peat that has fine fibers and a large percentage of fine
particled materials may be termed fibro-plastic, especially
upon drying when the few fibers no longer hold the mass in a
definite shape. This is the case with some of the semi-aquatic
peats such as the Loxahatchee peat of the Everglades region.
Granular peats are predominantly dried or partly dried,
aereated, and pulverized such as commonly occur in the upper
layers of drained and cultivated peat lands. Plastic or fibrous
peats that have finely divided materials between the fibers
form this granular peat. Coarsely fibrous peats sometime re-
tain their fibrous nature even after drying. Mud-like peats
often become lumpy, in cakes, or hard layers when dried.
Some woody peats, especially with leaf materials, usually be-
come flaky and chaffy or crumbly when dried.
Waksman 30 in his discussion of the colloidal nature of peat
pointed out that strongly acid peats do not form emulsions in
water but high calcium peats do. Neutral and acid salts as
well as acids coagulate the hydrosol formed in peat. In sedge
reed peats, as the Everglades peat where there is a high con-
tent of calcium, the potassium and ammonium cations are
absorbed to a greater extent than in acid peats such as
Sphagnum peats. The absorption of different bases by acid
peats varies with the kind of base; thus CaCO is acted on
least rapidly and CaO, Na2CO3 and NaOH more rapidly, in
ascending order. The rate of neutralization of peat with
CaCO3 increases with an increase in the initial pH value of the
peat.
Other physical and physico-chemical properties such as
the heat values, the color, temperatures, and hydrogen-ion
concentration are important, but they will be considered
later after a consideration of water content and drying of peat,
which are more definitely related to the above properties.
The porosity of some peats is a characteristic of value in many
other ways than water-holding capacity. One of these is use
in briquets of magnesium oxide in the process of conversion
to magnesium chloride.
30 Waksman, S. A., The peats of New Jersey and their utilization.
New Jersey Dept. Cons. and Devel., Geol. Ser., Bull. 55, 1942.

THE PEAT DEPOSITS OF FLORIDA

WATER CONTENT AND ABSORBING CAPACITY
The high water content of recently excavated and field
peat, and the high water-absorbing capacity of peat that has
been dried are among the most significant practical properties
of peat. Different peats vary considerably in these respects
depending on their origin, degree of decomposition, and
chemical composition. On an oven-dry basis some of the
Florida peats have as much as 934 per cent water, as in the
Lake Apopka marsh peats, and as little as 349 per cent water
in the shallow saw-grass peats of parts of the Everglades
when the water-table is below the peat layer. Waksman 31
pointed out that some Sphagnum peats are able to hold as
much as 1,500 per cent water. He 32 also showed that Florida
Everglades peats varied from 432 to 805 per cent moisture.
The "water holding capacity" of various commerical peats
is considered so important that the "Specifications for Peat"
of the Procurement Division, U. S. Treasury Department clas-
sifies three types of peat on this basis: (1) moss peat (or peat
moss, as it is designated by the trade) 1100 to 2000 per cent;
(2) reed muck or sedge muck 100 to 350 per cent; and (3)
reed peat or sedge peat 350 to 800 per cent. On this basis the
Florida peats are mostly reed and sedge peats with, in a few
instances, more water-holding capacity than 800 per cent and
some less than 350 per cent.
Laboratory tests for this "water-holding capacity" are
usually made by the following procedure,33 or slight variations
as follows:
"Place an unweighed sample of 25 to 50 grams taken from the center
of the composite sample, in a tarred, covered container having a wire
screen bottom of approximately 25 meshes to the linear inch. Immerse
in water at room temperature (200 to 300 C) for 18 to 24 hours. Remove
the container with sample from the water and allow to drain for one
hour while supported on glass rods under a bell jar. Carefully wipe the
excess water from the outside of the container and weigh. Heat in an
oven at 1050 to 110 C. to constant weight, before weighing, cool the
container and contents in a desiccator. The per cent of water absorbed
may be computed from the difference in weight between the saturated
sample and the oven-dry sample, based on the oven-dry weight."
"(Caution: It is important that the sample shall not have been sub-
jected to partial preliminary drying, as dried or partially dried peat or
muck may not reabsorb water to its original absorbing capacity.)"
31 Waksman, S. A., Op. cit., pp. 83-86.
32 Waksman, S. A., Op. cit., pp. 80-81.
33 U. S. Treasury Department, Procurement Division, Specifications
for peat. No. 563, May 19, 1942.

41

42 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

The water-holding capacity of peat in laboratory tests is
not the same as the water content of peat before removal from
deposits. This latter is the field-water-content and it is diffi-
cult if not impossible to measure accurately. It was approxi-
mated in this investigation by weighing uniform size samples
at or near the deposits then drying these to a nearly constant
weight in the laboratory. Later, after drying in ovens with
thermal control at about 105 C. to nearly constant weight,
the percentage of loss of weight for both the air-dry and oven-
dry conditions were then calculated based on the field weight
of the sample. Some of the results of such tests are given in
table 1. These percentages of water in the peat show approxi-
mately the field-water-content conditions. Most of the tables
presented here that give per cent of water, either oven-dry or
air-dry, are similarly based on field volumes of the samples.
The air dried samples were all dried to nearly constant weight
in the laboratory at Tallahassee.
These field-water-content data show that Florida peats in
the deposits below the water table have an average of 5.2 per
cent more water than the peats above the water table. Even
in the cases where the water table is 3 feet below the surface
the top 3 feet has only from 5.3 to 7.2 per cent less water than
the underlying peat below the water table. This means that
very little water in peat permeates downward by gravity most
of it being held in the peat by absorption and capillarity.
In table 14, Part II, the percentage of water in the peat in
some of the important Florida deposits is given in terms of
the air-drying loss. This air-drying loss is less than the field-
water-content because in the latter case the per cent of loss
after drying in an oven is added to the per cent lost upon
drying only in the laboratory. Drying in the laboratory is
not as uniform as drying in an oven, therefore, the data in
table 1, express more accurately the amount of water in peats
of various deposits. But data on only air-dried peat are more
useful for purposes of handling the peat as a material.
Clayton et al.,34 in their study of Everglades peat found
the per cent of moisture oven dried for muck soils in the areas
where these soils are cultivated. The water content is as ow
34 Clayton, B. S., Neller, J. R. and Allison, R. V., Water control in the
peat and muck soils of the Florida Everglades. Univ. of Florida, Agr.
Exper. Sta. Bull. 378, 1942.

TABLE 1
FIELD-WATER-CONTENT OF SOME FLORIDA PEATS

Oven-dry
Depth in Conditions Per cent
Location Kind of Peat deposit, in Inches Water Table, etc Water
Everglades ....................................saw-grass, shallow ..................................top 36..........moist, above water table .................. 79.7
Everglades ....................................saw-grass, deep ........................................top 36............moist, above water table .................. 79.1
Everglades ....................................saw-grass, deep .........................................36 64-..... wet, below water table ...................... 83.4
Everglades ....................................Loxahatchee, deep ..................................top 12............moist, above water table .................. 89.7
Everglades ....................................Loxahatchee, deep .................................----------------36 110-............wet, below water table ...................... 94.6
Istokpoga marsh ..........................Brighton, deep ..........................................top 24............moist, above water table .................. 82.4
c Istokpoga marsh ..........................Brighton, deep ..........................................24 124............wet, below water table ...................... 87.6
Fellsmere marsh ..........................saw-grass, shallow ..................................top 36............moist, above water level .................. 75.9
Fellsmere marsh ..........................saw-grass, deep ........................................24 110..........wet, below water table ..-----------.................... 83.6
Lake Apopka marsh ....................saw-grass, deep ........................................top 12............moist, above water table .................. 85.4
Lake Apopka marsh ....................saw-grass, deep ........................................24 120 ..........wet, below water table ...................... 91.7
Clermont marsh ..........................Pond-prairie, deep ....................................top 12............moist, above water table .................. 84.7
Clermont marsh ..........................Pond-prairie, deep ......................................24 96............wet, below water table ...................... 92.1
Florahome ....................................Prairie, medium deep ................. ............top 24............dry, drained .......................--------------------................. 63.2
Florahome ....................................Prairie, medium deep ................................24 60....... wet, near water table .....--.....--.............- 84.8
Miscellaneous ................................Miscellaneous ...........................................top 24............dry, drained ....-...........----......................... 68.7
Miscellaneous ................................Miscellaneous ................................ 24 40............24- 40............moist, above water table .................. 76.5
Miscellaneous ................................Miscellaneous .-................--------............-..............----48 120............ wet, below water table .......--.--.............. 85.4

44 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

as 29 per cent in Okeechobee muck and 62 per cent in a saw-
grass peat from the top to a depth of six inches. The average
condition in cultivated or nearly constantly drained peat or
muck areas in the northern part of the Everglades is 67 per
cent in the upper 2 feet of soil, and 79 per cent water in the
peat or muck below this 2 feet. In fact, most of the samples
of peat soils below 2 feet contained over 82 per cent water.
These data from cultivated peat or muck soils of the Ever-
glades where conditions are much drier than most marshes,
bogs, or swamps, are cited to show that even under cultivation
and compaction the peat above the water table continues to
hold most of its water.
This water-retaining capacity of peat is a very important
physical and physico-chemical property. Among other things
it means that; (1) peat both drained and undrained has a
high percentage of water when undisturbed; (2) peat is
difficult to dry by gravity drainage; (3) lateral transmission of
water through peat, seepage of water through peat, drainage
of peat soils by canals, and drying of peat after excavation are
all slow because they are affected by these water-holding
characteristics of peat.
If peat areas are to be used as soils for agriculture* a
knowledge of the water-holding capacities is very important,
and moreover, no general rule can be applied to any one area or
any type of peat because the fibrous or plastic nature of the
peat, the looseness or compactness, depth, and degree of de-
composition all are important factors.
Clayton, et al.,35 showed that rates of seepage vertically
downward through Everglades peat vary greatly from a rate
of 0.3 foot per day through the top 18 inches to a rate of 27.3
feet per day through the layer from 18 to 36 inches below the
surface. Horizontal transmission of water was at a rate of
0.25 foot per day at a depth of 3 feet. Their observations
showed that the top soil had been much changed by cultiva-
tion and weathering causing it to be less capable of trans-
mitting water downward than the lower undisturbed peat
layers.
Such slow transfer of water through peat affects the
methods of drying after excavation of peat and piling it for
35 Clayton, B. S. et al., op. cit.

THE PEAT DEPOSITS OF FLORIDA

drying, or by harrowing it in the field to dry. Once the sur-
face is macerated, pulverized and then dried it is difficult to
wet the peat rapidly to depths very far below the surface.
These characteristics of peat, therefore, are important in
all operations concerning peat either as a soil or as a material.
As a material for use with mixed fertilizers, or for drying
sufficiently to burn, or for drying for use in processing to
make manufactured products the water content and rate and
conditions of drying are very important and these will be
considered in more detail later.

USES BASED ON WATER-HOLDING CAPACITY
Because of the great water-holding capacity of peat it has
found wide application, chief among which are its uses in the
improvement of the physical condition of soil, as a litter in
stables and poultry houses, and as a surgical absorbent
dressing, which was the use made of Sphagnum or Sphagnum
peat in large quantities during World War I.
Some agricultural and horticultural uses that are conse-
quences and corollaries of these water-holding and water-
absorbing characteristics of peat are: 36
(1) Despite the fact that peat increases the water content
of mineral soils, it holds the water so tight that plants may
not be able to use it. Therefore, caution is advised in using
peat humus as soil dressing to increase soil moisture, especially
in sandy soils where added peat may actually withdraw water
from the sand doing more harm than good. This water-
absorbing power is related to the fact that soils treated with
peat frequently develop a higher wilting point than the origi-
nal soils, therefore, making moisture more unavailable to
plants than before treatment.
(2) Some peats, particularly sedge and reed peats, become
granular when partly dried and have poor capillarity so that
such peats tend to have a damming effect on soil moisture im-
mediately below the surface. As a precaution most peats
should be thoroughly shredded if they are to be used as
horticultural peat and mixed with the soil.
(3) These above characteristics frequently offset any ad-
vantages which might be gained from using peat as a soil con-
36 Some of these conclusions from Waksman op. cit.

45

46 FLORIDA GEOLOGICAL S URVEY-BULLETIN THIRTY

ditioner and a careful selection of soil type, water conditions,
type and condition of the peat and quantity used should be
exercised before applying peat to soils for their improvement.
Peat once air dried, usually below 40 per cent moisture, is
not readily wetted by water and, as Waksman 37 pointed out,
when wetted a heat of wetting develops which his test gave as
13.7 calories per gram. This heat developed is the heat of
compression due to the strong attraction of peat for water as
absorption and adsorption take place. Waksman also states
that wetting resistance is due to the strongly adsorbed air film
and that peat may be considered, therefore, an "aerophilic"
material.
This property of poor re-absorption of water by dried peat
is important in handling this material because if a certain
water content is desired it would be difficult to re-establish the
desired water content once the peat becomes too dry. Once
dried for some purposes, as for fuel, or in preparing horticul-
tural peat, it becomes difficult to wet. In the former case re-
maining dry is a good characteristic, but in the latter case it is
bad. For this reason the "Specification for Peat" of the Pro-
curement Division, U. S. Treasury Department tries to ap-
proximate this water-absorbing capacity by a measurement of
the "water-holding capacity." This measurement, however,
fails to give the exact re-absorbing power.

DRYING CHARACTERISTICS
When peats, which are nearly always wet in the deposits,
are dried the structure, some of the texture, and other quali-
ties are often radically modified. The loss of water from a
mass of peat is not as simple a response to temperature, pres-
sure, humidity, and other atmospheric conditions as might
seem the case because the texture, structure, organic nature,
and biological conditions of the peat affect this loss of water.
Shrinkage of the mass, aeration, oxidation, temperature
changes, and disintegration or decomposition are some of the
usual results of drying. Loss of weight is the most uniform
result of drying.
Loss of weight is principally a loss of water, but this de-
hydration is usually also accompanied by loss of volatile mat-
37 Waksman, S. A. op. Cit., p. 82.

THE PEAT DEPOSITS OF FLORIDA

Figure 7.-Volume sample of peat (left) taken by use of brass
cylinder (right). Such volume samples were used as the basis for
calculating quantity of peat in the deposits.

Figure 8.-Showing shrinkage of peat. Sample of Loxahatchee peat
on left was size of brass cylinder before drying and shrinking.

47

48 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

ter of various kinds such as carbon dioxide, ammonia, and
hydrogen sulphide. The loss of weight upon drying is, how-
ever, usually considered only as water loss and is expressed as
air-drying loss or oven-drying loss in the analyses. Many of
the Florida peats from the parts of a deposit above water
table lose an average of 78 per cent weight when oven dried,
and 86 per cent weight is the average lost from peats below
the water table. The loss of weight when only air dried is less,
averaging 75 per cent above the water table and 82 per cent
below the water level.
Shrinkage in size of the peat mass upon drying varies a
great deal with different types of peat. In general, the moss
peats and most fibrous, matted sedge peats shrink least and
the sedimentary plastic peats shrink most. Test of some
Florida peats, figures 7 and 8, showed that: (1) Everglades
saw-grass peat shrank to about 20-25 per cent of its original
volume when air dried, Loxahatchee semi-aquatic peat to
10-15 per cent, and woody Gandy peat to about 30-50 per
cent; (2) the lake bottom sedimentary peats to about 10 per
cent; (3) fibrous mangrove peat to about 40-50 per cent, and
(4) the matted strongly fibrous Florahome peat only to about
45-60 per cent.
The correlation between shrinkage, loss in volume, and
loss of weight upon drying can be roughly estimated by com-
paring specific gravities of the wet unshrunken peat and the
dry shrunken peat. In general, the peats after drying are of
less specific gravity than when saturated with water. For
example, wet saw-grass Everglades peat averages 1.09 specific
gravity, but this peat when air dried to 15 per cent moisture
and usually shrunken to 25 per cent its wet size becomes about
0.69 specific gravity. Similarly, Loxahatchee peat when dried
shrinks from an average wet specific gravity of about 1.05 to
a dry condition of about 0.75. Florahome peat shrinks less
than most Florida peats, changing from a wet specific gravity
of 1.06 to specific gravity 0.29 upon drying, also losing 83 per
cent in weight, and decreasing 52 per cent in volume.
The size and shape of the fibers and small fragments of
plants or other organic debris held together in a loose struc-
ture peat may be greatly altered upon drying. Once so altered
the original texture and structure usually cannot be completely

THE PEAT DEPOSITS OF FLORIDA

restored by rewetting the peat. For this reason peat once
dried usually cannot be made to take up again as much mois-
ture as was lost in drying, or return to its original size and
shape.
Rate of Loss of Weight on Drying
The rate of loss of weight of peat during drying is not a
steady decline as might be expected if only loss of water was
involved. In most samples tested the rate of loss of weight
increased during the first few days until a peak rate of loss
was reached, then the rate declined rapidly. If the loss of
weight had been only a loss of water due to evaporation from
the peat the rate of loss of weight would probably have been
greatest during the first few days declining in a regular man-
ner to a slow rate of loss until the rate became negligible.
But since this is not the case other explanations are due.
The loss of weight when peat dries, therefore, seems to be
due, at least partly, to the biological activities of organisms
in the peat. When first extracted the wet peat sample slowly
begins to dry, the bacteria and other organisms, particularly
those dependent upon oxygen, begin to multiply rapidly as
atmospheric oxygen is more and more incorporated in the
mass of peat. Consequently the rate of loss increases due to
the increased activity of these organisms until finally the peak
of their activity is reached and the rate of loss and their ac-
tivity both decrease. Carbon dioxide and other gases are
liberated by the action of these organisms.
No experiments were conducted to prove the presence or
activity of these organisms but it is well known that aerobic
bacteria increase in peat when air is admitted to it, and in the
case of some peats the Actinomycetes become very numerous.
Oxidation of the organic matter in the peat results as has been
shown by measurements of the increase in CO2. Moreover,
the nitrogen, sulphur, and carbohydrate compounds in the
peat are also affected by the activity of these organisms. In
piles of excavated peat the rate of loss of weight on drying is
not due just to water loss or physical and chemical activity.
The tests made of drying excavated Everglades saw-grass peat
in the open at Twenty Mile Bend on State Highway No. 26 west
of Fort Lauderdale indicated that the rate of drying was not
similar to the rate of drying of sand or clay that had little
organic matter and less organisms.

49

50 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

In general, however, peat loses weight when drying so
slowly that difference in rate of loss during different intervals
of the drying process are not of particular importance in
handling the material.

WEIGHT, DENSITY, AND SPECIFIC GRAVITY
The differences in structure and composition of peats cause
them to vary a great deal in weight, density, and specific
gravity. Most of the living plant tissues which contribute to
the formation of peat have a specific gravity less than water.
The fibers and other tissues, celluloses, lignins, and other
substances in the peat are heavier than water-lignin sub-
stances averaging 1.4 specific gravity and celluloses about 1.5
specific gravity-but these are usually retained structurally
and so arranged that the great porosity makes the peat when
dry much lighter than water in all but a few cases. Davis 38
notes the specific gravity of some types of peat: turfyy peat
0.11 to 0.26; fibrous peat 0.24 to 0.67; earthy peat 0.41 to 0.90;
and pitchy peat 0.62 to 1.03." Table 2 gives the specific gravity
of some of the Florida peats.
Inorganic content, usually given as the ash content, and
the weight of the materials composing this ash are factors af-
fecting weight and volume. Silica sand, particularly, adds
weight to many peats in Florida.
The swelling and shrinking of peats make volume and
weight determination very difficult because of their usually
great porosity and colloidal nature. The pore volume in
peat, which varies a great deal, can be approximated by the
air content of peat in a fresh condition, but at best the volume,
weight, and specific gravity measurements are nearly always
approximations. Even in the marsh or bog there are seasonal
variations in volume and weight related to the air and water
content of the peat.
Clayton 39 found that the Everglades peat near the Ever-
glades Experiment Station, Belle Glade, varied from 17.5
pounds per cubic foot oven-dry at the top 6 inches, to 7.7
38 Davis, C. A., The uses of peat for fuel and other purposes. U. S.
Bur. Mines Bull. 16, p. 45, 1911.
39 Clayton, B. S., et al., op. cit. p. 11. Water control in the peat and
muck soils of the Florida Everglades. Univ. of Florida. Agr. Exper. Sta.
Bull. 378, 1942.

THE PEAT DEPOSITS OF FLORIDA

TABLE 2
SPECIFIC GRAVITY OF SOME FLORIDA PEATS

Field Lab.
Region or Area Station Depth Wet Pounds Air Dry Pounds
Inches Sp. Gr. Cu. Ft. Sp. Gr. Cu. Ft.
EVERGLADES
Central part .... E 2 Top 6 1.09 68 0.74 46
E 2 12-18 1.09 68 0.64 40
E 2 24-30 1.02 63 0.55 34
E 3 Top- 6 0.82 51 8.80 50
E 3 12-18 1.02 63 0.76 48
E 3 24-30 1.13 70 0.68 43
E 3 36-40 1.17 72 0.56 35
Southwestern
part ............... NT 1 Top 6 0.76 47 0.55 34
NT 1 20-26 0.86 54 0.78 49
NT 1 33-39 0.96 60 0.75 47
NT 3 Top 6 1.00 63 0.73 45
NT 3 20-26 1.00 63 0.94 59
ISTOKPOGA
MARSH .............. I 5 Top 6 0.88 55 0.75 47
I 5 12-18 0.81 50 0.70 44
I 5 24-30 0.84 52 0.70 44
I 5 36-40 0.88 54 0.78 49
T 8 Top -12 0.70 44 0.65 41
T 8 14-20 0.84 53 0.72 45

pounds at 43-48 inches, and Waksman 40 found the specific
gravity 0.63 to 0.50 for oven-dry peat from saw-grass areas of
the Everglades. These figures, show a marked dissimilarity
in weight because the weights given by Clayton would indicate
a specific gravity range of 0.28 to 0.12, which are much less
than those determined by Waksman. Similar attempts to de-
termine oven-dry or air-dry specific gravity in this investiga-
tion led to similar inconsistent results, mainly because of
shrinking or other changes in volume caused by handling.
Therefore, specific gravity determinations are not as useful as
volume-weight estimates of peat under field conditions.

VOLUME AND WEIGHT ESTIMATES
The determinations of volume and weight were made by
using cylinders of 76.3 cubic inches, or about 1230 cc. The
sample thus obtained with the cylinder, figure 7, was first
weighed in or near the deposit and then after air drying, the
peat in the laboratory, which usually left a moisture content
between 10 and 15 per cent, the samples were again weighed.

40 Waksman, S. A., op cit. The peats of New Jersey and their
utilization. New Jersey Dept. Cons. and Devel. Geol. Ser. Bull. 55, 1942.

3A-

51

52 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

From these data the pounds per cubic foot, tons per acre for
a depth of one foot of both the air-dry and field condition of
the peat were calculated. This method of estimating weight
per unit volume gave good results some of which are given in
Part II. The average Florida peats with not over 20 per cent
ash varied from about 10 to 5 pounds per cubic foot, or from
about 220 tons per acre foot for the Everglades saw-grass peat
to about 100 tons per acre foot for the Lake Apopka marsh
peat. All of these volumes and weights estimates were calcu-
lated on the basis of air-dry weight and field volume. The wet
field weight, which is usually a saturated condition of the
peats, was for the Everglades saw-grass peat about 59 pounds
per cubic foot or about 1,275 tons per acre foot. These data
show that excavating some wet peats involves the handling of
about 50 pounds of water in every cubic foot.
Air drying peat reduces not only the weight but also the
volume because shrinkage is usually great. The amount of
shrinkage varies from about one-third to one-twelfth the
original volume. Some of the sedimentary mucks and some of
the loose texture fibrous peats shrink least. For instance,
samples of Everglades and Loxahatchee peats shrank from a
volume of 1230 c.c. to 230 c.c. and 180 c.c. respectively when
air dried to nearly constant weight. Other peats with a firmer
fibrous composition, such as the Florahome peat, shrank to
only 410 c.c. from 1230 c.c. The peats with a high ash content
lose even more volume than some of the fibrous peats, but
there seems to be no general rule about extent of shrinkage
for the different types of peat. Other results of shrinkage
were previously considered in the discussion of Drying
Characteristics.
Wet peat in the Everglades saw-grass areas averages be-
tween 1400 and 1600 pounds per cubic yard, which when air-
dried to about 15 per cent moisture and shrunk to about one-
fourth its original size weighs between 600 and 675 pounds per
cubic yard. All these estimates of air dry weights and
volumes are only approximations. Therefore, for handling
the peat the weight per volume under the wet and air-dry
conditions should be determined for the peats of each deposit
that is to be mined.
In general, the more fibrous, light-colored, and poorly de-
composed peats are lighter in weight than more compact,
plastic, granular, darker, more thoroughly decomposed peats.

THE PEAT DEPOSITS OF FLORIDA

The light weight peats make more bulk and require more
storage and transportation space and are, therefore, usually
more costly to handle. But for some purposes the light
weight peats are more useful.

ATMOSPHERIC AND GAS CONTENT
In marshes or bogs covered by water there is very little
air in the peat because pore spaces are taken up by water, but
as peat dries, particularly if there is much shrinkage or com-
pacting, the air content greatly increases. For this reason
alternate flooding and drying of marshes causes air to be
drawn into and out of the upper layers of peat. This aeration
aids in the decomposition processes by promoting the activity
of bacteria and by oxidation of the organic materials.
Gases are dissolved in the water of peat marshes and bogs.
Wet bogs frequently contain besides gases of the atmosphere
also some methane and carbon dioxide. There is a little or
no oxygen in flooded peat and this oxygen deficiency is
probably an important factor inhibiting both the growth
of non-marsh or non-bog plants, and the growth of decomposi-
tion bacteria.
Aeration of the peat by drainage or the occurrence of a
natural seasonally low water table causes the air and gas
content to change and result in the following: (1) more rapid
oxidation and loss of organic compounds; (2) hastening of
decomposition; and (3) plants foreign to the wet marsh or
bog become established. These conditions are very noticeable
in the Everglades and other drained peat areas of Florida.
Neller41 found that a carbon dioxide concentration of 8 to
15 per cent was characteristic of Everglades peat soils above
the water table. At various depths below the surface he found
this concentration less near the surface than near the water
table level. The amount of carbon dioxide found was generally
balanced by a correspondingly decreased amount of oxygen
indicating that respiration of roots and decomposition of peat
above the water table was usual. The relative amounts of
carbon dioxide and oxygen are also probably influenced by the
solubility of carbon dioxide in the soil waters and by the ab-
sorption of oxygen in the formation of nitrates.
41 Neller, J. R., Significance of the composition of soil air in Ever-
glades peat land. Soil Sci. Soc. America Proc., Vol. 8, pp. 341-344, 1944.

53

54 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

COLOR
Peats range from light-yellowish or straw tints through
various shades of yellowish-brown, reddish-brown, and dark
brown to jet black. Most of the light colored peats become
darker when wet and, in general, excavated wet peats change
to dark brown or black when disturbed and exposed to air.
Where peat soils and peat deposits have been drained and the
upper layers have had access to air these layers usually be-
come darkened. This darkening is generally due to oxidation
of the organic compounds causing an increase in the carbon of
the plant debris.
Identification or description of peats on the basis of color
are common. In some cases, as in the Everglades, the Loxa-
hatchee peat is yellowish, the Gandy peat is reddish-brown,
and the saw-grass peat is dark brown to nearly black.
Color may affect temperature to a slight extent, but its
effect is negligible compared to the effect of water content or
temperature. Black peats are considered cold soils but this
is mainly because they are usually near the surface and are
frequently loose and dry.
Rarely if ever can color be used as an index to mineral
content, but color is used to determine the origin of peat from
certain plants. For instance, in some deposits the reddish
peats are formed from the roots of the red root plant, Gyro-
theca, and the predominantly brown color of some peats is due
to one of the sedges of the sedge genus Rynchospora, known as
the beak rushes. Similarly, some woody peats of bay-tree
swamps are reddish because the bark and wood of bay trees,
Persea colors the peat.
TEMPERATURE RELATIONS
Peat bogs and marshes frequently occur in depressions
where the air temperature becomes colder than the surround-
ing territory, and peat soils are cold soils because peat soils
do not give up heat to the atmosphere as rapidly as mineral
soils. For these reasons, low temperatures tend to occur in
the layers of atmosphere next to the surface of peat deposits.
A wet or moist peat soil allows the movement of heat to take
place more rapidly than a dry, loose peat. Therefore, the
looser and drier the surface layer the greater is the danger
from frosts.

THE PEAT DEPOSITS OF FLORIDA

These temperature conditions often result in costly frosts
in cultivated peat soils when the water table lies well below
the surface. In the Everglades some recent minimum temp-
erature records by Clayton 42 have been very low for this
section with one cold spell as low as 90 F. for March 14, 1932.
In general, lower temperatures occur more frequently now
than before drainage of the Everglades.
Another condition of importance is that the drained but
virgin, uncultivated, marsh lands have lower surface tempera-
tures than cultivated lands. This is due to the fact that the
looser top peat and mulch of leaves and trash on the virgin
land act as an insulating cover that retards the transfer of
heat from the lower wet peat to the air above, whereas, air
over cleared lands obtain more heat from the soils. Also, the
more decomposed a peat soil becomes the less is the probability
of frost. Consequently, older reclaimed peat areas are less
subject to frost than recently reclaimed areas.
REACTION OR HYDROGEN-ION CONCENTRATION (pH)
Most of the measurements of acidity, alkalinity, and neu-
trality of peats and peat soils are now calculated in terms of
the hydrogen-ion concentration and expressed by the symbol
pH. These conditions of peat are also known as the peat
reaction or soil reaction.
Most peats have an acid reaction which is in part de-
veloped in the deposits because of the type of vegetation
forming the peat, the humic acids formed in the peat, and the
water and oxygen conditions. The most acid peats are
usually those formed from some swamp and heath plants,
Sphagnum moss, and sedges like Rhynchospora or Eriophorum.
The least acid, neutral, and slightly alkaline peats in Florida
are the saw-grass peats of the Everglades and some other
deposits where marl occurs. Some organic sediments of lakes,
such as those of lakes Apopka and Harris are also calcareous
and have an alkaline reaction. The salt-marsh and mangrove
swamp peats range from acid to alkaline, the latter depending
upon the amount of marl occurring in the deposit. The hard-
ness of the water and the associated marls of peat deposits are
the main cause of alkalinity in peats.
42 Clayton, B. S., Meteorologist at the Everglades Experiment Sta-
tion, Belle Glade, Florida.

55

56 FLORIDA GEOLOGICAL SURVEY---BULLETIN THIRTY

Kurz 4 considered the role of mosses in causing acidity in
peat that it is probable the peat on which the mosses grew was
made more acid by the growth of the mosses. The chemical
nature of the plant tissues forming the peat, the humic acids
in the peat, and some other conditions in the deposits tend to
make the peat material acid. However, the free water in peat
marshes or swamps particularly in parts of the Everglades
and in mangrove swamps or salt-water marshes may be alka-
line even though the peat material is acid. Frequently the
wet peat material of alkaline water situations is alkaline but
the dry peat of the same situation is acid. The reaction of
the peats in each deposit should be determined before use is
made of them, especially for azaleas and other acid soil plants.
Waksman 4 gave four types of peats and peat soils based
on pH values, which are: (1) oxidizing peats which are those
having a pH of less than 3.8, the heath plants being the domi-
nant type of vegetation forming this peat; (2) reducing peats
with an approximate pH of 5.5 to 4.4, the peats formed from a
mixed vegetation; (3) feebly oxidizing peats having an ap-
proximate pH of 4.4 to 3.4 with vegetation of the highmoor
type; and (4) peats feebly oxidizing at times with a pH below
3.4 and the vegetation mainly Eriophorum. But most of these
kinds of peats are not common in Florida.
The Procurement Division of the United States Treasury
classes lowmoor sedge and reed peats into two grades; (1)
horticultural, with pH values of 4.5 to 5.5; and (2) poultry
litter, with pH values of 5.5 to 7.5. No doubt other com-
mercial classifications of peats based on pH values will be de-
veloped as peat is more abundantly utilized. The horticultural
class is now mainly used with plants prefering acid soils such
as azaleas and camellias.
From tests made of pH values of most Florida peats table
3 was prepared to show not only the difference in these values
of different kinds of peats at different places, but also the
difference in pH values at different levels in some deposits.
These data show that in most deposits acidity usually de-

43 Kurz, Herman, Influence of Sphagnum and other mosses on bog
reactions. Ecology, vol. 9, pp. 56-69, 1928.
44 Waksman, S. A., The peats of New Jersey and their utilization.
New Jersey Dept. of Conservation and Development. Geological series
Bull. 55, p. 87, 1942.

THE PEAT DEPOSITS OF FLORIDA

creases from the surface downward in regular fashion in the
peat deposits of Florida. In some cases the change from
acidity toward alkalinity is rapid near the bottom of the
deposit especially if the peat is underlain by marl or lime-
stone. For instance, a very wide range of pH was determined
by Volk and Bell 45 for a profile of the Brighton peat of the
Istokpoga marshes, which was pH 3.8 near the surface and
pH 7.0 near the bottom. Also very important is the fact that
different peat reactions may occur in different parts of the
same marsh area, as is the case in the Clermont marsh. In
general, the drained aerated, cultivated peat and muck soils
are more acid than the similar undisturbed peats.

Summary of PH Conditions of Florida Peats
The Everglades peats of three types average; (1) saw-
grass peats pH 6.04 to 6.59, (2) Loxahatchee peats pH 5.61-
6.15 and (3) Gandy peats 4.43-4.90. The table shows that:
(1) Lowmoor, saw-grass peats are less acid, average pH 5.96,
than the lowmoor wet prairie or pond type peats, average pH
4.45; (2) the forest peats are most acid, average pH 4.34; and
(3) the sedimentary peats average pH 6.14.
When peat soils used for agriculture are more completely
classified in Florida it is probable that the reaction charac-
teristics, pH values, will determine certain types not yet dis-
tinguished. The pH values will affect cultural and fertilizer
practice in handling such peat soils. The present distinction
between the Everglades saw-grass peat and the Brighton saw-
grass peat is based mainly upon the pH values, the Brighton
peat being the most acid.
The pH values of peats may be determined in the field by
the use of some portable apparatus but this method is not very
accurate and the results can not be compared to most of the
pH data already assembled because most of the past pH
measurements have been based on air dried samples and
measured with standard laboratory equipment. All the
samples in this investigation were air dried and the pH de-
terminations made by the Department of soils of the Uni-
versity of Florida, Gainesville.
45 Volk, G. M., and Bell, C. E., Soil Reaction (pH), some critical
factors in its determination, control and significance. Univ. of Florida
Agr. Exper. Sta. Tech. Bull. 400, 1944.

57

58 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

TABLE 3
REACTION (pH VALUES) OF SOME FLORIDA PEATS

Depth in
Location and Kind of Peat Deposit, Average Range of
In Inches pH pH
Everglades
Saw-grass peat ........................... Top 24 6.04 5.07 6.71
24 60 6.41 6.08- 6.77
60 96 6.59 6.11-7.16

Loxahatchee peat ....................... Top 24 5.61 5.45 5.61
24 60 6.03 5.70-6.23
60 120 6.14 5.90 6.38

Gandy peat ................................. Top 24 4.43 4.17 4.70
24 36 4.90 4.88 4.93
Istokpoga marshes and swamps
Brighton peat ................................ Top 24 4.15 3.80 4.50
24 60 4.86 4.70-4.98
60 132 5.65 4.85- 7.00

Istokpoga peat ........................... Top 24 4.40 4.30 4.50
24 36 4.85 4.80-4.90
48 86 4.98 4.75 5.35
86 144 5.67 5.15 6.65
Fellsmere area and
St. Johns River marshes
Saw-grass peats ......................... Top 24 5.55 5.07 6.12
24 60 5.67 5.30- 6.12
60 120 6.01 5.59 6.22
Lake Apopka marsh
Saw-grass peats ......................... Top 24 5.78 ................
24 60 5.79 ................
60 180 6.14 ................
Oklawaha River marshes
Saw-grass peats ......................... Top 24 4.95 ................
24 60 5.65 ................
60 108 6.05 ................
Emeraldo marsh, Lake County
Saw-grass peat ........................... Top 24 5.03 ................
24 40 5.13 ................
Clermont marsh, Lake County
Saw-grass peat ........................... Top 24 5.85 ................
24 60 6.15 ................

Pond-prairie peat .................. Top 24 4.15 ................
36 84 4.78 ................
Jumper Creek, Sumter County
Saw-grass peat ... .................. Top 48 5.93 ................
60 72 7.21 ................
Florahome, Putnam County
Prairie peat ............................. Top 24 4.40 3.91 4.90
24 60 5.44 5.38-5.50
Pinecastle, Orange County
Pond-prairie peat ....................... Top 24 4.60 4.40 4.80
24 60 4.85 4.75 4.95
60 228 4.90 4.75-5.08

THE PEAT DEPOSITS OF FLORIDA 59

TABLE 3-(Continued)
REACTION (pH VALUES) OF SOME FLORIDA PEATS

Depth in
Location and Kind of Peat Deposit, Average Range of
In Inches pH pH
Leesburg
Pond-prairie peat .......................... Top 24 3.64 3.50 3.80
24 60 4.52 4.26 4.78
60 132 4.88 4.78- 5.01
Eustis Meadow
Pond-prairie peat ...................... Top 24 4.31 ................
24 60 4.51 ................
Panama City
Pond-prairie peat ....................... Top 24 3.69 3.59 3.79
24 60 3.96 3.84- 3.99
60 120 4.42 3.99 4.86
Bayport, Hernando County
Salt-marsh peat ......................... Top 36 5.58 ................
36 60 4.33 ................
Barron River, Collier County
Salt-marsh peat ......................... Top 36 5.55 ................

South of Mayo, Lafayette County
Bay forest peat ........................... Top 24 3.95 3.81 4.14
24 60 4.11 4.09-4.14
60 84 4.26 4.09 4.44
North of Astatula, Lake County
Bay forest peat ........................... Top 24 3.92 3.80 4.15
24 60 4.16 4.06 4.26
60 84 4.48 4.26 4.71
Near Carrabelle, Franklin County
Tyty-forest peat ......................... Top 24 3.97

Feather-bed Bay, Jefferson County
Tyty-forest peat ......................... Top 24 3.77 ................

Mangrove swamp near Miami
Red mangrove peat ................... Top 24 5.50 ................
24 60 5.00 ................
Mangrove swamp, Key Largo
Black mangrove peat ............... Top 24 7.12 ................
24 60 6.98 ................
Lake Apopka
Sedimentary peat ....................... Top 48 5.71 |

Lake Harris I
Sedimentary peat ....................... Top 48 7.48 |

Lake Minnehaha
Sedimentary peat ....................... Top 36 5.66

Lake Eustis
Sedimentary peat ...................Top 36 5.63

Mud Lake, Marion County

- -

1 7.31

Sedimentary peat -........ -......-..........

Top 48

60 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

Heat Values
Peat is extensively used for fuel in Europe and its heat
values are well known. These heat values, as with most other
substances, are usually measured in terms of gram calories
(metric system) or British thermal units (English system).
To raise the temperature of water from the freezing to the
boiling point requires 100 calories for a gram and 180 B. t. u.
for a pound, one B. t. u. being equivalent to 252 gram calories.
After the boiling point is reached 965 B. t. u. are required to
convert one pound of water to steam and 536 calories to simi-
larly convert one gram. Most heat values in the United States
are expressed in terms of the British thermal units per pound
of oven-dry fuel, or of moisetor wet fuel with the percentage of
water in the fuel designated. Davis 46 also gives the fuel
values in terms of pounds of water evaporated at 212F. per
pound of fuel. Using evaporation or steaming test data and
B. t. u. the comparisons between the average fuel values of a
number of common fuels, ash and water content, are as fol-
lows, according to Davis.47

One Pound British Pounds of water
thermal units evaporated
W ood ...............................-----------------------....... 5,700 ................ 3.4
Peat .....................................------------------------....... 7,165 ................ 4.4
Lignite.................................----------------------....... 7.500 ................ 4.8
Bituminous coal ...................... 11,000 ................ 6.8
Anthracite coal ...................... 14,000 ................ 8.6

This rough comparison shows that peat has heat value
comparable with lignite and usually over half as much as
anthracite. Florida peats vary a great deal in B. t. u. values
because of a wide range of ash content. Averages of 100
samples of Florida peats taken from most deposits of the state
are as follows:

One Pound Moisture Moisture free Moisture and
15 per cent with ash Ash free
B. t. u. Range .......... 3,860 9,150 5,830 10,750 9,440 11,650
B. t. u. Average ...... 6,767 8,454 10,494
46 Davis, C. A., The uses of peat for fuel and other purposes. U. S.
Bur. of Mines Bull. 16, pp. 61-62.
47 Davis, C. A. ibid. pp. 58-64.

THE PEAT DEPOSITS OF FLORIDA

These averages and ranges in heat values of Florida peats
include some of the poorest peat deposits as well as the best.
A more detailed set of data is presented in other tables (see
particularly tables 11, 14 and 15).
Although peat fuel may not be extensively produced in the
United States as long as there is an abundant supply of coal
and petroleum, it has great potential value as a source of heat
and power and may be utilized to conserve other fuels. The
utilization of peat for heat and power will be considered in
detail in Part IV.

CHEMICAL COMPOSITION
Peats, lignites, and many types of coal are complex mix-
tures of more or less decomposed residues of plants, and to a
lesser degree of animals and their excreta, with inorganic
materials that are usually less than the organic materials.
The plants contributing to peat formation are mostly herbace-
ous, but some are woody, and all of these are composed of a
great variety of chemical substances. Some of these numer-
ous constituents of living plants are subjected to microbiologi-
cal decomposition almost immediately after death and some
parts do not become a part of peat, but most of the con-
stituents of these plants do remain in the peat. Some of the
plant tissues that contribute to peat formation are the rela-
tively hard mechanical and conductive tissues that are gen-
erally known as the fibrous or woody parts. The lignins are
usually the most important of the carbohydrate substances
retained in the peat; other substances are celluloses, hemi-
celluloses, proteins, fats, waxes, and gums.
The lack of oxygen, due to the abundance of water, the
fermentation, oxidation, and reduction of the organic com-
pounds, frequently due to bacteria and other decay organisms,
and the other processes of decay and decomposition, all bring
about changes in the organic constituents as peat is being
formed from plant remains. A typical common product of
decomposition in peat is humus and humic acids which are not
homogenous chemical compounds and whose chemical struc-
tures are not well known. A common characteristic of humus
and humic acids is their color, brown or brownish-black.
These colors are typical of most peats and waters from peat

61

62 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

marshes, bogs, and swamps. The peat humus usually turns
darker on exposure to air and may become black.
Lignins are generally considered the precursors of humic
acids. During the course of humus formation in peat de-
posits a process of oxidation (or dehydrogenation) of lignins,
and perhaps other substances, forms humic acids which are
similar in some respects to the familiar hydroxyquinones of
photography. The colloidal nature of humic acid, as well as
its characteristic brown color, is important in peat.
The fats, waxes, gums, resins, and proteins of plants all
contribute to the organic constituents of peats. The relative
proportions of these and the carbohydrate substances vary in
different layers of the same deposit of peat as well as in
different peat deposits. Some of these proportions of organic
materials will be discussed later. We will consider the in-
organic constituents first.

INORGANIC CONSTITUENTS
The inorganic constituents of peats are mainly minerals.
Some of these minerals were incorporated in the plant tissues,
but most of them, especially in peats of high inorganic con-
tent, were brought into the deposit in free water and incorpo-
rated with organic materials to form the peat mass. These
inorganic substances are usually considered the ash content of
the peat and the organic substances the combustible portion
that is lost upon burning.
The usual analysis shows the inorganic content as ash
expressed in per cent by weight of the air-dried or oven-dried
peat. These ash components are well known but the organic
constituents are not well known.
Forsee 48 reported that the typical saw-grass Everglades
peats, average 10 per cent ash on an oven-dry weight basis. His
analyses of these peats gave an average of 3% N., 3% CaO,
0.6% MgO, 0.1% P205, 0.1% K20, 0.1% Na2O, 0.6% A1203,
1.0% Fe20O, 0.003% Mn., and 0.001% copper. The manganese
and copper are in such small quantities that they are known
as micro or trace elements. Besides these, other trace ele-
ments in the Everglades peat and Okeechobee muck are zinc,
48 Forsee, W. T., Recent plant responses to some of the micro ele-
ments on Everglades peats. Soil Sci. Soc. of Florida, vol. 2 pp. 53-58,
1940.

THE PEAT DEPOSITS OF FLORIDA

boron, cobalt, titanium, zirconium, strontium, barium, vana-
dium, chromium, nickel, silver, molybdenum, and lead. As
shown by Allison and Gaddum 49 some of these trace elements
are fairly constant in quantity whereas others are very eratic.
The quantities of most of these elements are so low that in
many cases they are insignificant except as they concern the
proper fertilization of crops raised on peat soils. Copper,
manganese, zinc, and boron are the four trace elements now
most generally used in connection with the fertility of peat or
muck soils.
Other analyses of the ash content and many elements rep-
resented in peat have been less detailed than those of the
Everglades region. Some few of these can be found in the
literature although most analyses of minerals are made for
farmers and for local purposes and the records of these are
buried in the files of numerous laboratories.

TABLE 4
PARTIAL ANALYSES OF SOME PEAT AND MUCK SOILS IN
FLORIDA, FROM R. E. ROSE
Location, Samples Ammonia Phosphoric Potash Lime Iron and
Average and Range Acid Alumina
Everglades
Av. 34 samples 3.10 0.18 0.08 ...... ......
Maximum 4.41 0.53 0.18 ......
Range
Minimum 0.44 0.04 0.03 -
Fellsmere
Av. 7 samples 2.59 0.091 0.046 1.77 1.54
Maximum 3.39 0.180 0.073 2.95 2.80
Range
Minimum 1.76 0.024 0.028 0.83 0.71
Lake Apopka Marsh
Av. 3 samples 2.66 0.223 0.069 1.96 3.46
Maximum 2.85 0.280 0.078 2.09 5.70
Range
Minimum 2.28 0.181 0.060 1.83 1.65

A few of the muck and peat soil analyses, given by Rose 50
are reproduced in table 4 to show mainly the phosphorus,
potash, and nitrogen value, and calcium, iron, and alumina

49 Allison, R. V., and Gaddum, L. W., The trace element content of
some important soils-a comparison. Soil Sci. Soc. of Florida, vol. 2, pp.
68-91, 1940.
50o Rose, R. E., Analyses of Florida muck soils. Ann. Rept., State
Chemist, Tallahassee, Florida, 1917.
Rose, R. E., Florida soil analyses. Ann. Rept., State Chemist, Talla-
hassee, Florida, 1914, 1919, and 1921.

63

64 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

values are given in a few cases. These elements were con-
sidered the main important soil nutrients until some of the
trace or micro quantity elements were discovered to be im-
portant in crop nutrition.
In general, the plants forming peat are richer in phos-
phoric acid and potassium than the peat itself and these easily
soluble salts when not in organic combination are rapidly
leached out as peat is formed or ages. In the deposits calcium
usually increases and nitrogen, potassium, and phosphoric
acid decrease with depth.
INORGANIC ANALYSES
Some detailed analyses of peat and in a few instances of
the plants which form it, especially the saw-grass plant,
Mariscus jamaicensis (Crantz) Britton, of the Everglades,
have been made by a number of workers.5- Most of these
analyses are of the mineral constituents but there are a few of
the organic materials, the latter mainly by Waksman and
Stevens. Besides these the United States Bureau of Mines
analyses of peat samples taken by Harper and in this investi-
gation give the percentages of ash, carbon, hydrogen, oxygen,
nitrogen, and sulphur, together with the percentages of mois-
ture volatile matter, fixed carbon, and heat values expressed
in British thermal units. From the analyses of peats col-
lected during this investigation table 12 was prepared to show
the proportions of ash, carbon, hydrogen, oxygen, nitrogen,
and sulphur on a moisture free basis.
From these data and many other analyses given in Part III
a few general conclusions may be drawn: (1) the ash contents

51 Waksman, S. A., and Stevens, J. R., Contributions to the chemical
composition of peat, I-IV. Soil Sci., vol. 26, pp. 113-137 and 239-252, 1928,
vol. 27, pp. 271-281 and 389-398, 1929.
Waksman, S. A., The peats of New Jersey and their utilization. New
Jersey Dept. Cons. and Devel., Geol. Ser., Bull. 55, p. 67, 1942.
Miller, C. F., Inorganic composition of a peat and of the plant from
which it was formed. Jour. Agr. Research, vol. 13, pp. 605-609, 1918.
Hammer, H. E., The Chemical composition of Florida Everglades
peat soils, with special reference to their inorganic constituents. Soil
Sci., vol. 28, pp. 1-14, 1929.
Dachnowski, A. P., The chemical examination of various materials
by means of food-stuff analysis. Jour. Agr. Research, vol. 29, pp. 69-83,
1924.
Clayton, B. S., Neller, J. R., and Allison, R. V., Water control in the
peat and muck soils of the Florida Everglades. Univ. of Florida Agr.
Exper. Sta. Bull. 378, 1942.
Harper, R. M., Preliminary report on the peat deposits of Florida.
Florida Geol. Survey, 3d Ann. Rept., pp. 197-375, 1910.

THE PEAT DEPOSITS OF FLORIDA

of different types of peats vary greatly from place to place in
the same deposit as well as in different deposits; (2) in the
Everglades the peats with low ash content are the woody
Gandy peats of tree islands that developed on deep saw-grass
and Loxahatchee peats. Loxahatchee peats have intermediate
amounts of ash, and saw-grass peats have the greatest ash
content; (3) saw-grass marsh peats in general throughout
the State have a relatively high ash content because these
marshes are characteristically in areas where surface water
with sediments frequently flood over the marshes; (4) the
fibrous, matted, rush type peats, especially where developed in
small ponds or peat prairies, have in many instances the
lowest ash content but in some localities their ash content is
high; (5) the woody or swamp peats in general have the high-
est ash content, especially where the swamps are near rivers
or streams and alluvial sediments become incorporated in the
peat; (6) sedimentary peats of the sapropel and livermud
types contain a high percentage of ash which in many in-
stances are over 50 per cent, in which case they are considered
mucks and muds.
In any deposit, particularly if it is small or shallow, the
ash content varies considerably and sampling of different
parts and at different depths is advised. If used on a large
scale, or for purposes where ash content is important, are
planned analyses of ash content should be made of many parts
of the deposit.
Peats formed from sedge, rush, and grass vegetation are
rich in ash because the plants which form them assimilate
large quantities of minerals which remain in the plants and
thus contribute to the ash content of the peat. The lower
parts, rhizomes, and roots of saw-grass have 3.57 per cent
ash and these parts contribute most to the formation of saw-
grass peat. A few analyses 54 of the saw-grass plants show
that on a moisture free basis the ash content varies from 2.7
to 3.7 per cent, whereas the peat in the same area from saw-
grass plants varies from 7.8 to 11.2 per cent. These data indi-
cate that saw grass peat during its development concentrates
the amount of ash. Later we will consider this concentration
as an index to rate of peat formation.
54 Analyses number 120 and 121 of this investigation.

65

TABLE 5
CHEMICAL COMPOSITION OF SOME FLORIDA PEATS

Everglades Percentage of Dry Material
Saw-grass peat Iron
Oxide
Silica and Lime Magnesia Soda Potash Phosphoric Nitrogen Total
Alumina Acid Ash

Miller's 52 analyses 2.25 0.83 3.42 0.50 0.19 0.08 0.50 3.18 8.37

Percentage-6rhe Ash Content
Feustel and Byers 53 analysesI I I I
SiOF2 FeO, CaO MgO NaO P20. Al O TiO KO SO, MnO CO,

Saw-grass peat 14.49 2.16 41.21 6.03 0.56 0.94 2.29 0.46 0.39 6.29 0.08 25.25

Sedimentary peat 33.25 8.18 21.52 6.47 0.43 1.02 7.09 0.81 0.35 16.25 0.03 4.34

52 Miller, C. F., Inorganic composition of a peat and of the plant from which it was formed: Jour. Agr. Research, vol. 13,
pp. 605-609, 1918.
53 Feustel, I. C., and Byers, H. G., The physical and chemical characteristics of certain American peat profiles: U. S. Dept. of
Agr. Tech. Bull. 214, 1930.

THE PEAT DEPOSITS OF FLORIDA

Miller .5 made the most detailed comparison of inorganic
constituents of all parts of saw-grass plants and of four
typical samples of saw-grass peat. The transformation from
living plant tissues, to peat he concluded, involved no change
in silicon dioxide but the other constituents were leached to
the following extent:
Iron oxide and alumina, 12.2 per cent; lime 24 per cent;
soda, 84.6 per cent; phosphoric acid, 70 per cent; and nitrogen
33 per cent.
The diatomaceous earths of Florida are mainly peats and
mucks and many of these have a high silica content which in
some cases is over 50 per cent of the oven-dry weight, or 10
per cent of the wet weight. Similarly some sedimentary peats
have a high percentage of silica derived from both diatoms
and sponge spicules.
Terrestrial waters brought into the peat deposits are
frequently rich in minerals which add to the ash content.
Highmoor peats of the Sphagnum bogs and heath type may
rely partly upon atmospheric water but lowmoor marsh,
forest swamp, and aquatic or sedimentary peat deposits de-
pend a great deal upon surface water draining into the de-
pressions. Therefore, the minerals of the deposits are fre-
quently derived from the surrounding territory.
Accumulations of marl, calcium carbonate, silicate sands,
and some iron and aluminum in clays are common in the
lower layers of many peat deposits, especially the lowmoor
and sedimentary aquatic peats.
Sulphur in peat deposits is derived from a number of
sources and may be present in various forms. A considerable
quantity of sulphur may be due to the fact that the water fed
into the peat deposits contain hydrogen sulphide. Hydrogen
sulphide fermentation occurs in some lake and marsh deposits
because of bacterial organisms. These sources of hydrogen
sulphide cause such an abundance of this evil smelling gas in
many peats that this odor is frequently associated with peat.
Some sapropel, sedimentary peats, the mangrove and salt-
marsh peats, and peats near some springs, as on the Itchtuck-
nee River near Blue Hole Spring, have an abundance of sul-
phur.
55 Miller, C. F., op. cit.

67

68 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

ORGANIC CONSTITUENTS
In the formation of peat the main changes are in the
organic composition of the plant materials that form the peat.
Only an approximate idea of these organic changes has been
obtained from analyses because the rate and degree of de-
composition are not well known. In general the disintegration
is so slow that the chemically active elements, such as
nitrogen, oxygen, and hydrogen, are released more rapidly
than carbon which remains in higher concentration in the
peat than in the original plant tissues. In the formation of
peat (which may be given the formula C62H72024) the cellulose
(which may be considered C72H120060) is broken down rapidly
producing oxygen and hydrogen combines as water (H20)
and carbon, hydrogen, and oxygen combined as various gasses
such as carbon dioxide (CO2) and marsh gas or methane
(CHJ). The following chemical reaction of cellulose de-
composition to peat shows these changes.
C72H120060 C6272024 + H20 + CO2 + CH4
(Cellulose) (Peat) (Water) (Carbon (Methane)
dioxide)

The organic composition of Florida peats are not well
known but a few general conditions have been studied. The
proportional amounts of carbon, hydrogen, and oxygen do not
vary a great deal. When expressed in terms of ratio to
hydrogen taken as unity the following ratios of carbon and
oxygen for some of the types of Florida peats are:

Hydrogen Carbon Oxygen
Saw-grass peats 1 10.9 5.3
Swamp or woody peats 1 11.3 6.1
Pond-prairie peats 1 10.4 4.6
Sedimentary peats 1 8.7 4.3
Average 1 10.3 5.0

If the atomic weights of these elements are considered an
empirical formula (C8.6H1oO3.3)X can be derived which indi-
cates a higher proportion of carbon and less oxygen than in
such organic compounds as cellulose (C6Hio005)X. This greater
proportion of carbon is to be expected in peats because carbon-
ization takes place during the formation of peat. Slow de-
composition during the forming of peat causes the celluloses,

THE PEAT DEPOSITS OF FLORIDA

lignins, and other organic compounds to lose hydrogen and
oxygen more rapidly than carbon. This change is indicated
in the deep layers of peat deposits. By comparing the ratios
of carbon, hydrogen, and oxygen at different depths in the
ten peat deposits representing all the Florida types of peats
the following ratios to hydrogen were obtained:

Hydrogen Carbon Oxygen
Top to 36 inches 1 9.9 4.8
36 to 72 inches 1 10.3 4.5
72 to 108 inches 1 10.9 4.2

Since the amount of hydrogen decreases very slightly, less
than two per cent from the top to 10 feet, hydrogen is the best
element with which to compare the others.
During the formation of peat from plant tissues some of
the organic constituents, especially the celluloses, decrease
rapidly in proportionate quantities, whereas other constitu-
ents the waxy substances, lignins and proteins, increase pro-
portionately. These latter substances have a higher percent-
age of carbon than the celluloses and undergo less decomposi-
tion.
One set of analyses of Everglades saw-grass plants, both
the leaves and shoots above ground and the shoots, rhizomes,
and roots underground, indicate some changes from the saw-
grass plant to the saw-grass type of peat. In the plant the
ratios are:
Hydrogen Carbon Oxygen
1 9.2 7.1
In the peat the ratios are:
Hydrogen Carbon Oxygen
1 10.9 5.3
These ratios indicate only a slight change from the saw-
grass plant to the saw-grass peat, especially the upper, raw
layers of peat. In general, hydrogen content decreases very
slowly when peat is formed but oxygen content decreases
rapidly and carbon content increases slowly.
As peat continues to age and become lignite and eventually
coal the carbon, hydrogen, and oxygen ratios change. In gen-
eral, the lignites have less carbon but more hydrogen and
oxygen than the peats. The bituminous coals have more

69

70 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

carbon, about the same amount of hydrogen and much less
oxygen than peats.
Nitrogen
Nitrogen is an important constituent of peat when it is
used as a soil for crops or distilled to obtain ammonium sul-
phate. The proteins of the plants forming peat probably con-
tribute most of the nitrogen. The proteins hydrolize into
various amino acids as peat is formed and some ammonia
may eventually be formed, but this ammonia nitrogen does
not seem to accumulate. In lowmoor peats, viz., saw-grass
and Everglades peat, the nitrogen content more than doubles
when peat is formed, but in some highmoor peats, viz., bog
peat, the nitrogen content decreases with peat formation.
Everglades saw-grass plants average one per cent nitrogen
and the top layers of Everglades saw-grass peat average about
3.5 per cent nitrogen, both on a moisture free basis.
The use of peat to obtain ammonium sulphate has attrac-
tive economic possibilities but at present there is an abundant
supply and low price of this material because much of it is
from coke ovens.
Only a small part of the nitrogen in peat is in available
form for plant nutrition because most of it is in protein or
amino acid form and not in a free state or as nitrates. How-
ever, little or no nitrogen need be used in fertilizers applied to
peat soils because there is usually enough in available form
for plants.
TABLE 6
RATIO OF CARBON TO NITROGEN, AND TOTAL NITROGEN,
MOISTURE FREE BASIS
Per cent
Nitrogen Carbon Nitrogen
Everglades saw-grass peat
Top-6 inches ............................ 1 15.5 3.9
12-24 inches .............................. 1 16.3 3.78
24-26 inches ............................ 1 17.1 3.55
36-64 inches .....................----------------......... 1 20.4 3.0
Florahome peat
Top-6 inches ............................ 1 17.7 2.9
12-24 inches ............................ 1 18.0 3.0
25-120 inches .......................... 1 19.4 2.9
Miscellaneous types
Top-36 inches .......................... 1 18.0 3.35
36-84 inches ............................ 1 19.7 3.15
60-156 inches .......................... 1 20.2 3.02

THE PEAT DEPOSITS OF FLORIDA

In considering the organic compounds of peats the nitro-
gen content compared to the carbon content are a good indica-
tion of changes taking place in peat formation and aging of
peat. The preceding table 6, carbon-nitrogen ratios from
some Florida peats indicate the differences in proportions of
these two elements with differences in depth in the peat de-
posits.
These data indicate that the nitrogenous compounds in
peats which were originally proteins probably become more
rapidly decomposed than some of the high carbon carbohy-
drates, such as the lignins and the waxes or tars. In general,
there is a decrease of total nitrogen with depth in most
Florida peat deposits, but this rate of decrease in nitrogen is
not as rapid as the rate of increase in carbon in most deposits.
Organic Analyses
The analyses of the organic composition of saw-grass
plants and Everglades peat by Waksman and Stevens 56 are
probably the best of any available about Florida and table 7 re-
produces some of these. The ash content, alcohol soluble frac-
tion, and lignin fraction increase with depth, but the other
components decrease. There is about three times as much ash
in the peat as in the saw-grass plant, about four times as
much crude protein, and a definite increase in lignin. The
most striking difference between the plant and the peat is
the great decrease in cellulose and a sharp reduction in hemi-
cellulose when peat is formed. These few changes show that

TABLE 7
ORGANIC COMPOSITION OF THE SAW-GRASS PLANT AND
SAW-GRASS PEAT

Percentages of Dry Matter

Everglades Q l 8 .
Saw-grass peat P M O < U 0
Upper layers 9.85| 22.65 3.03 1.521 1.17 7.10 0.33 44.59
Lower layers 11.59| 20.81 2.39 1.141 1.31 5.96 0.21 48.03
Saw-grass plant 3.73 5.50j 1.04 6.041........ 21.10 29.521 29.98
56 Waksman, S. A., and Stevens, K. R., op. cit., 1928, 1929.

71

72 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

the cellulose and hemicellulose components of the living plant
are about 50 per cent, but there is such a rapid decomposition
of these when the plant tissues form the peat that deep layers
of peat contain only about six per cent. Lignin materials,
however, increase with peat formation and with depth in the
peat deposits.
The sapropel aquatic ooze, and the fibrous peats of Mud
Lake were similarly analyzed by Waksm.an and Stevens 57 who
found that the top sapropel peat had distinctly more hemicel-
lulose and less lignin than the underlying fibrous peat, as
shown in table 8.
TABLE 8
CONDENSED ANALYSES OF ORGANIC COMPOSITION OF
MUD LAKE PEATS

Percentages of Dry Matter

Depths from g
Surface in 3
centimeters 0 0 Uo 5 -

1 60 ......... 21.62 20.00 13.41 29.76 0.14 0.26
60 180 ..... 31.42 15.28 3.28 48.88 0.50 0.86
180 300 ... 12.26 16.34 3.67 57.39 0.73 I 1.25

RATE OF PEAT FORMATION
Chemical composition and observations on the rate of
formation in deposits are two means of estimating the rate of
peat formation. There have been so few observations of de-
posits over long periods of time that this method of estimating
rate of formation of peat can not yet be accurately used. We
must therefore turn to chemical composition to obtain some
estimates.
Peat formed mainly from saw-grass vegetation in the
Everglades probably developed at a fairly constant rate in the
deep peat areas because conditions of plant growth, surface
water, and other factors do not now vary a great deal. The
inorganic constituents of this peat were obtained mainly from
the minerals the saw-grass plants were able to incorporate in
their tissues.

57 Waksman, S. A., and Stevens, K. R., op. cit., p. 279.

THE PEAT DEPOSITS OF FLORIDA

The disintegrated and decomposed products of these
plants, because of the chemical changes considered above, be-
came of different proportions than those in the living plant
tissues. Among these inorganic constituents the one probably
least changed in this process is silicon dioxide and we may
use the percentages of this mineral to get some estimates of
the rate of peat formation.
Therefore, by comparing the amount of silicon dioxide in
the saw-grass plants and in the saw-grass peat a ratio indi-
cating the quantity of living plant material needed to form a
similar amount of saw-grass peat can be determined. This
was done by Miller.58 In his detailed analyses he found that
there was an average of 0.3 per cent silicon dioxide in the saw-
grass plant tissues and an average of 2.2 per cent in saw-grass
peat. These proportions indicated, according to Miller: "As-
suming that no silica was lost during the transformation,
about 7 parts of saw-grass was required to yield 1 part of
peat."
If from this data we assume 7 parts of saw-grass to form
1 part of peat then some estimate of the rate of forming of a
given quantity of peat may be obtained if the weight of saw-
grass cover and rate of its growth were determined. To esti-
mate these a number of observations and calculations were
made as follows.
Particular measured areas where saw-grass grew sparsely,
densely, and in medium abundance, and of short, medium and
tall size were chosen and the plants cut down and underground
parts excavated to include what seemed to be all living parts,
six areas of saw-grass growth were measured and they aver-
aged 4.4 tons of plant parts air dry weight per acre, tops and
underground parts included. The silicon dioxide of these
plant parts would weigh 270 pounds.
From many samples the weight of peat per acre one foot
deep in saw-grass peat areas of the Everglades was estimated
at 180 tons on an air dry basis. This peat would contain
approximately 7,520 pounds of silicon dioxide. Therefore
nearly 28 crops or generations of saw-grass plants would be
required to form the average acre of peat one foot thick.

58 Miller, C. F., Inorganic composition of peat and of the plant from
which it was formed. Jour. Agri. Research, 13: 605-609, 1918.

73

74 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

We have as yet not satisfactorily determined how much
saw-grass plants grow per year, how much they die back per
year and are replaced by new growth, and other data needed
to determine how many years per crop of 4.5 tons per acre.
From preliminary observations it seems probable however
that 6 to 10 years are required per crop, or 8 years average.
At this rate of plant growth approximately 225 years are re-
quired to form one foot of saw-grass peat.
This estimate by chemical ratios may give much too rapid
a rate of peat formation because it would indicate that the 10
feet thick peat of the northern part of the Everglades required
only about 2,250 years to develop. This peat, however, has
probably not developed continuously without interruption. In
fact layers of ash below some peat were found along the
Miami Canal when it was being dredged indicating fires.
These fires and other adverse conditions may have retarded
the rate of peat formation.
Geologically the Everglades peats seem to be younger than
the age of Wisconsin glaciation because most of them rest on
Lake Flirt marl which is considered of Recent origin. Also to
date no pollen of plants of a glacial age have been found in
these peats.
The estimate of 2,250 years for the formation of 10 feet of
peat is, however, probably the minimum time of formation, a
longer period of 5,000 years or even 10,000 years would be
more nearly in accord with estimates of the age of other de-
posits of similar thickness. Further investigations will be
needed to more accurately fix the time involved in peat forma-
tion. Other information regarding age of peat deposits is
given in Part IV.
Archaelogists 59 have found wooden artifacts of Indian
villages probably inhabited during the early Spanish explora-
tions which were buried under peat. Peat occurs over parts of
Indian Mounds in the Everglades and other places. The evi-
dences of the age of the mounds are not however conclusive
and the age of the peat can not be accurately determined.

59 Cushing, F. H. Preliminary report on the explorations of ancient
Key-dweller remains on the Gulf Coast of Florida, 1897. Reprinted Proc.
Amer. Philosophical Soc. 36: p. 36.

THE PEAT DEPOSITS OF FLORIDA

MICROBIOLOGICAL NATURE
Bacteria, other fungi, and various other microorganisms
inhabit peat deposits and have a great deal to do with the
formation, nature, and composition of peats. These bring
about: (1) the primary breakdown of the parts of plants, and
some animals and excreta transforming them into peat; (2)
the gradual changes that take place in the composition of the
peat with time causing differences in successive layers; and
(3) some rapid changes in peat after a deposit is drained and
exposed to more air, or the peat material is excavated and
dried. In general the organisms and effects are as follows.
Organisms concerned in (1) are mainly aerobic bacteria
which decompose cellulose and other organic compounds and
aid in the rapid changes that occur in plant and some animal
tissues when peat is being formed.
The organisms of (2) occur in layers of peat which have
little or no oxygen and are mostly anaerobic bacteria which
may be found in peat layers laid down many centuries ago.
These cause some of the changes pointed out above that take
place with increase in depth. As peats continue to age oxygen
content decreases most rapidly, the carbon content increases
slowly and the hydrogen content decreases only slightly and
some of these changes are caused by these anaerobic organ-
isms. There is, moreover, a fairly definite change in the ratio
of nitrogen to carbon the relative amount of the carbon in-
creasing with age and depth.
The organisms of (3) are numerous bacteria, mostly aero-
bic, Actinomycetes and other fungi, which in general cause
rapid decomposition which can be calculated by measuring the
rate of CO2 evolution, as Neller 60 did in the Everglades.
The relative abundance of these organisms in a lowmoor
peat deposit are shown in table 9, which was borrowed from
Waksman and Stevens.61

60 Neller, J. R., Significance of the composition of soil air in Ever-
glades peat land. Soil Sci. Soc. America, 8: 341-344, 1944.
61 Waksman, S. A., and Stevens, K. R., Contribution to the chemical
composition of peat: V. The role of microorganisms in peat formation
and decomposition. Soil Science 28: 315-340, 1929, 34: 95-113, 1932.

4-

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76 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

TABLE 9
OCCURRENCE OF MICROORGANISMS IN A LOWMOOR
PEAT PROFILE
On Basis of Fresh Peat Material

0 d
W. 0
o S oS

30 4......... 6.0 72.5 350,000 40 250 + ++ ++
45 .............. 6.2 82.3 450,000 25 175 ........ ++ ++
60 Suae.......... 6.3 87.5 40,000 20 150 ........ + + +
75 ........... 6.3 87.1 35,000 25 33 ........ + ++
90 ........... 6.4 80.8 20,000 15 ............ ........ .......... + +
120 ........... 6.7 83.6 100,000 2 ............ ........ .......... + + +
150 ........... 6.8 84.5 500,000 .... ............ ........ ....... ++++
165 ........... 8.0 64.8 200,000 .... ............ ........ .......... ++++
Clay bottom
+ designates a few; ++ a fair number; +++ abundance of organ-
isms; ++++ numerous (about 25,000 more colonies formed by 1 gram
of material.
Soil microbiological studies of many kinds have shown the
importance of these microorganisms in peat and muck soils as
well as in peat deposits. The microorganisms are now con-
sidered very important in handling peat either as a soil or as
a material. The study of bacteria of nitrification and denitri-
fication in peat soils is becoming more and more important.
The addition of bacteria, usually by adding stable manure,
frequently has a favorable effect upon decomposition and ni-
trification. The utilization of peat for preparation of com-
posts, for soil improvement and other agricultural purposes
will be benefitted by a better knowledge and use of the micro-
organisms. It is also entirely probable that bacteria and
some other organisms may be used to good advantage in the
preparation of some industrial products from peat. In fact
some recent work in Germany using peat with CaCN2 has
indicated that bacteria added to peat may help increase its
proportion of carbon and make it more useful as a fuel. The
origin of coal from peat is due in part to the action of anaero-
bic bacteria producing lignite then bituminous coal.

THE PEAT DEPOSITS OF FLORIDA 77

This very brief account of microorganisms in peat only
suggests their importance in any investigation of peat re-
sources and their use. For further information the reader is
referred to Waksman 62 and others who have outlined the
subject more thoroughly. Some of these uses will be con-
sidered briefly in Part III, especially as they concern the
preparation of peat for soil applications and in fertilizers.
62 Waksman, S. A., The peats of New Jersey and their utilization.
New Jersey Dept. of Cons. and Devel., Geological Series Bull. 55, 1942.

78 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

Part II
FLORIDA PEATS AND PEAT DEPOSITS
The peat resources of Florida had not been adequately
estimated when this investigation was undertaken although
Harper 63 had made a good preliminary report concerning
them, and Soper and Osbon 64 had included some statistics
about them, and Vernon 65 recently gave some figures concern-
ing the mining and uses of peat. This investigation undertook
to locate most of the large areas of peat of possible com-
mercial quantity, or peat lands for possible agricultural use
that are not now so used. The main purpose was to obtain some
estimates of the quantity of the peat in the deposits. In this
part of this report the kinds of peat will be described and we
will give analyses of samples, estimates of quantity, and de-
scribe the main deposits. Later in Part III the utilization of
the peats obtained from some of these deposits will be con-
sidered in more detail.
Analyses of samples of peat from these deposits were made
to furnish data for the estimates of quality, and as one means
of distinguishing the different kinds of peats. The analyses
will probably prove useful in any present and contemplated
uses of peat because they give data about chemical and water
conditions and heat values.

METHODS OF SAMPLING, TESTS, AND ANALYSES
OF PEAT
In the field observations were made of the structure, tex-
ture, color, water conditions in the deposit, depth and extent
of the deposit, and vegetation. Where the areas were drained
the condition of canal banks and top soil layers were studied
if they were present.
For the numerous tests and analyses many samples were
taken mainly by the use of three kinds of equipment: (1) a

63 Harper, R. M., Preliminary report on the peat deposits of Florida.
Florida Geol. Survey 3d Ann. Rept., pp. 197-375, 1910.
64 Soper, E. K. and Osbon, C. C., The Occurrence and Uses of Peat in
the United States. U. S. Geol. Survey, Bull. 728, 1922.
65 Vernon, R. 0., Florida Mineral Industry. Florida Geo. Survey,
Bull. 24, 1943.

THE PEAT DEPOSITS OF FLORIDA

shovel or spade; (2) a Hiler peat sampler; and (3) a brass
cylinder measuring about four inches by six inches, volume
.0422 cubic foot or about 1230 cubic centimeters. The Hiler or
Swedish peat sampler was the standard equipment for getting

Figure 9.-Hiler peat auger which was used to take most samples
below the water table,

79

80 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

samples at definite depths with very little or no mixing or
contamination. A Davis peat sampler was also used in some
instances for the same purpose, but it was not as satisfactory
an instrument. An Ekman dredge was used to get the surface
of lake and pond sediments.
The usual practice followed in the field was: (1) samples
were obtained with the brass cylinder at intervals of one foot
to as great a depth as water and work conditions would permit
so as to furnish data about volume-care was taken to keep
disturbance of the structure and water content at a minimum;
(2) excavation with the shovel or spade to visually examine
the structure, texture, color, stratification, and other easily
noticed characteristics; and (3) use of the Hiler peat sampler,
figure 9 to obtain samples at greater depths than the other
implements could be conveniently used. In deep water areas
an Ekman dredge was used to get the surface of the deposit,
and a Hiler sampler was used to get samples below the sur-
face.
In all cases observations as to the water level in the peat
deposit were made if the water was below the surface. If the
water was above the surface the depth of the water was
measured.
The volume samples of peat taken with the brass cylinder,
figure 7, were in most cases weighed on the spot or within
a few hours after being taken; thus very little water had
drained off or evaporated. These samples were later weighed
after they had been thoroughly air dried to a nearly constant
weight. From these data the water lost on drying, and air dry
tons per acre one foot thick were calculated.
Parts of the samples collected by all methods were used
for the analyses by the United States Bureau of Mines, Coal
Analysis Section, Pittsburg, Pennsylvania. Their Coal-
Analysis Report for each of these samples gave a Proximate
Analysis showing moisture, volatile matter, fixed carbon, and
ash in per cent all calculated under four conditions: (1) air
dry; (2) as received; (3) moisture free (oven dry); and (4)
moisture and ash free. Similarly an Ultimate Analysis gave
hydrogen, carbon, nitrogen, oxygen, sulphur, ash and also the
British thermal units. One of these reports of an analysis of
peat from the Triangle Area in the Everglades is given in

THE PEAT DEPOSITS OF FLORIDA

table 11 to illustrate the above, and in tables 12 and 13 a tabu-
lation of analyses of Florida peats is given and arranged ac-
cording to counties.

KINDS OF PEATS, AND SOME MUCKS

As a result of the field observations, inspection and tests of
samples, and the analyses, the kinds of peats in Florida were
classified. This classification is based upon the scientific
classification outlined in Part I. Three main types are recog-
nized: (1) Lowmoor, marsh peats; (2) Swamp forest, woody
peats; and (3) Aquatic, allochthonous, sedimentary peats
found mainly in open water parts of lakes.
The names of some of these peats and mucks are those
proposed by soil surveyors who have classified most of the
main types in the Everglades and adjacent regions of south-
ern Florida; especially the soil classification by the U. S. Soil
Conservation Service.66
Other names used here are given by the author and these
are entirely temporary names used for convenience in classi-
fication.
The following outline is not a complete classification or
description of these peats and mucks. A few of the main
characteristics of some of the most wide spread peats are
described below, and the sedimentary peats are considered in
some detail in description of lake deposits.

TABLE 10
OUTLINE OF KINDS OF FLORIDA PEATS AND MUCKS
I. MARSH OR LOWMOOR PEATS.
A. FIBROUS. Sedge, reed, and some moss types, varying from turfy
to nearly plastic; coarse to finely fibrous within which mass
usually is finely divided detritus forming a matrix material;
frequently occurring in layers. Mostly Autochthonous.
1. SAW-GRASS PEAT. Composed mainly of coarse fibers with
rhizomes and roots of saw-grass usually distinct; with matrix
material usually abundant; light-brown to nearly black, be-
coming dark rapidly upon drying; reaction neutral to medium
acid, pH range 7.0 to 4.0, very widely distributed in many
saw-grass marshes, especially the Everglades.
66 See particularly Gallatin, M. H. and Henderson, J. R., Progress re-
port on the soil survey of the Everglades. Soil Sci. Soc. of Florida, vol.
5-A, pp. 95-104, 1943. .

81

82 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

a. EVERGLADES PEAT. Coarsely fibrous with more matrix
material than most saw-grass peat; often with lenses or
layers of plastic peat or muck, or with marl layers; in some
areas finely fibrous; Loxahatchee peat interbedded or below
this peat; reaction pH 7.0 to 5.5. Name used for saw-grass
peat of the Everglades and adjacent regions.
b. BRIGHTON PEAT. Saw-grass peat with a high percentage of
other plants forming a coarsely fibrous peat that is in some
parts reddish-brown, and with some woody fragments; more
acid than Everglades peat, pH 7.0 to 3.8. Name used spe-
cifically for peat in Istokpoga marshes.
c. MARSH PEAT. General name for all other saw-grass marsh
peats; varying from coarsely to finely fibrous, and some
matted fibrous; light brown to dark, nearly black; occurring
in many marshes usually bordering hard water lakes.
2. PRAIRIE AND POND PEAT. A dark brown, matted, fibrous,
firm peat, developed in numerous small ponds and some broad
fcPt prairie-like areas, often in deep deposits, distinctly acid,
PpH range 3.5 to 5.5. One of the best horticultural peats be-
cause it is acid and usually easily handled.
a. FLORAHOME PEAT. Coarse and fine fibered, matted with
leaves of aquatic plants common, firm, and shrinks very little
upon drying, retaining brown color. Typical locality is de-
posit near Florahome, Putnam County.
b. POND PEAT. More finely fibrous and matted than Florahome
peat, light to dark brown, shrinks some upon drying, acid,
good for horticulture. Found in many seasonally flooded
ponds, deposits often deep. In some deposits a slick, greasy
diatomaceous peat is associated.
c. PRAIRIE PEAT. Turf-like to finely, matted fibrous. Deposits
usually shallow.
d. WOODY POND-PRAIRIE PEAT. Mixed matted fibrous pond
and prairie peat with woody fragments, development in bay-
tree swamps which developed over fibrous peat.
3. SALT-MARSH PEATS. Many kinds not yet distinguished.
Usually coarsely fibrous with roots and rhizomes of salt-
marsh plants common; with silts and clays in matrix, marls
and shells common; gray to nearly black; in some areas
mixed with mangrove peats; reaction usually alkaline.

B. FIBROUS AND PLASTIC. Fine fibrous, loose texture peats with
much plastic material in matrix; not firm, shrinking greatly
on drying and losing shape easily; straw colored to nearly
black. Occurring in many marshes below fibrous peats.
Partly allochthonous.
1. FIBRO-PLASTIC MARSH PEAT. Many kinds not named;
usually in beds below fibrous peat; few fibers and much sedi-
mentary material varying from sands to muds; color very
varied.
2. LOXAHATCHEE PEAT. Local name applied to nearly plastic,
matted, fine fibrous, loose texture peats of the Everglades
sloughs and ponds; also found below saw-grass Everglades
peat in some areas; straw-colored to brown; reaction pK
range 6.5 to 5.0^

THE PEAT DEPOSITS OF FLORIDA

II. FOREST SWAMP PEATS AND MUCKS.
A. WOODY. Varying from partly decomposed logs, stems, and woody
fragments to granular, pulpy, and flaky debris associated
with both plastic and fibrous materials; if much plastic ma-
terial known as a muck. Some deposits of banded and bedded
appearance; frequently developed on top of the Fibrous peats
or the Aquatic peats.
1. BAY PEATS AND MUCKS. Reddish woody pieces mixed with
fibrous to granular and some plastic materials; if very plastic
known as muck; often on top of fibrous marsh peats; but
frequently very shallow over sand, in which case often has
top with Sphagnum moss and fern tussocks. Occurring in
many widely scattered small bay-tree swamps of numerous
types. Reaction usually acid, pH range 5.0 to 3.6.
a. GANDY PEAT. Local name for fibrous, woody, duff-like mix-
ture occurring in the bay-tree islands of the Everglades
region. Material reddish-brown; pH range 5.0 to 4.0; often
developed on top of Everglades or Loxahatchee peats.
b. ISTOKPOGA PEAT AND MUCK. Local name for mucky peat
with many pulpy, wood fragments, reddish-brown to nearly
black, occurring in the bay-gall swamps near Lake Istokpoga;
pH range 5.0 to 4.0; some deposits deep.
c. TYTY-BAY PEATS AND MUCKS. Sandy, matted fibrous
peats and mucks; in some areas with Sphagnum moss peat
developed in thin layer on top. Seldom in deep deposits.
2. MANGROVE AND BUTTONWOOD PEATS AND MUCKS.
Marls usually associated. Many kinds of very fibrous to
plastic peats and mucks usually with shells, marl, and other
sediments associated; developed in coastal, saline, mangrove
swamps; three kinds partly distinguished.
a. RED MANGROVE PEAT AND MUCK. An interlocking net-
work of fibers of the roots of the red mangrove forming a firm
mass; between the fibers a matrix of mud, marls, shells etc.;
alkaline to slightly acid, pH range 7.2 to 5.0; usually in outer
zone of swamp, or below the black mangrove, or salt-marsh
peats.
b. BLACK MANGROVE PEAT AND MUCK. Less fibrous more
plastic than red mangrove peat; less reddish color and some
yellowish woody fragments; usually with marls, shells, sand
in places. Often developed on top of red mangrove peat.
c. BUTTONWOOD PEAT OR DUFF-HUMUS. A leafy, fibrous,
flaky, duff-like peat usually developed in buttonwood zone of
swamps or some coastal hammocks.
B. PLASTIC AND WOODY. Many kinds of swamp peats and mucks;
names given usually those of dominant trees of the deposits;
mostly muds with some woody fragments, very little fibrous
material.
1. RIVER SWAMP MUCKS, only a few peats. Many kinds not
differentiated. Alluvial materials, plastic and sandy, with
logs and other woody parts, finely divided organic materials;
usually dark gray to black.
2. CYPRESS AND GUM SWAMP MUCKS AND PEATS. Many
kinds not differentiated. Plastic and woody; often sandy,
some fibrous; seldom in deep deposits.

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84 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

3. OKEECHOBEE MUCK. Mostly plastic, sticky and greasy,
granular, dark-gray to black, but with some woody materials;
derived from custard-apple swamps and sediments from Lake
Okeechobee; forming a zone around much of region near Lake
Okeechobee, and a layer in saw-grass peat. A fine farming
soil of the northern Everglades.
4. OKEELANTA PEAT-MUCK. Plastic and Fibrous; mixture of
Okeechobee Muck and Everglades Peat; occurring in zone
between pure deposits of these two.
III. SEDIMENTARY, PLASTIC, AQUATIC PEATS AND
MUCKS.
Many organic sediments generally formed in lakes or other
quiet bodies of water. Usually fine particled, macerated,
plastic and often colloidal; mostly allochthonous. Variously
classified as many kinds of lake sediments; name bioliths now
applied.
A. ORGANIC. Organic sediments rich in ignitable carbonaceous ma-
terial; may be considered peats if over 50 percent loss on
ignition of oven dry material.
1. GYTTJA. Fine detritus, amorphous material usually more soup-
like than colloidal; black or gray-brown to greenish; no or
very little H S; some nitrogen, very little humic acid; many
kinds have been recognized; algal gyttja; marly gyttja; and
diatomaceous gyttja, Florida kinds not yet differentiated.
2. SAPROPEL. Slimy ooze-like, more colloidal than gyttja, more
decaying organic matter; usually with H9S. Algal sapropel
of Mud Lake typical.
2. DY. Humus type in some places partly fibrous, often colloidal,
amorphous.
4. LIVER MUD. Gel-like, very colloidal, similar to sapropel.
B. MOSTLY MINERAL. Non-ignitable Peats, Mucks, and Earths;
mainly marls and diatomaceous earths; usually distinctly
plastic. Marls gray to whitish; diatomaceous earths gray to
reddish.
1. MARLY-MUCKS. Mostly mucks not peats, plastic but some
with fibrous peat, dry to gray, granular.
2. DIATOMACEOUS EARTHS. Mostly peat like with some fibers,
usually with slick, greasy feel, drying to brown or gray color,
occurring as layers in fibrous peat deposits.

This outline is so sketchy that a few general conditions
and characteristics of peats and the vegetation of peat areas
need some consideration.
Many marsh lands, wet prairies, borders of many lakes,
borders and central portions of some ponds, deposits of some
swamps, and some layers of peat below forest peats are of
the lowmoor types. Most of the Everglades peat lands, the
Istokpoga marsh lands, the Fellsmere and upper St. John
River marshes, the Lake Apopka marsh, some of the Okla-
waha River marshes some parts of the Peace Valley Drainage

THE PEAT DEPOSITS OF FLORIDA

District, and the areas near Florahome, Putnam County, are
the largest of the lowmoor peat areas. They comprise over
three-fourths of Florida peat deposits.
Most inland forest peats do not occur in large areas because
they are usually developed in only a few non-alluvial swamps
being mainly developed in bay-tree, tyty, and some cypress ,
forests, most of which are of relatively small size. The larg-
est tyty and bay-tree forests of northern and western FloridaK
usually contain some peat but the deposits are only a few
inches deep, except in some small areas. The bay-gall swamps
of Lake Istokpoga, and near the marshes of the Peace Valley
Drainage District are among the largest of these inland forest
peat areas. The mangrove swamps along the southwest coast
of the peninsula contain deep forest peat in some places but
this peat is seldom pure being mixed with shells, marl, sand,
and other sediments.
The sedimentary, plastic, aquatic peats are organic de-
posits in some of the numerous lakes, but probably do not
occur in thick layers in the majority of the lakes. The depth
and area of these usually collodial, macerated, mud-like peats
are unknown except in a few lakes that have been studied. It
is possible that the total quantity of these peats may exceed
that of the forest peats. They should be distinguished from
the marsh or lowmoor peats common in marshy parts of many
lakes and ponds, or in some instances covering the small lakes
or ponds, but in numerous instances it is difficult to distinguish
between lowmoor and aquatic peats. For this reason some
peats, i. e., the Loxahatchee peat of the Everglades, is con-
sidered a semi-aquatic or semi-marsh peat, both fibrous and
plastic.
Typical highmoor peats formed in bogs from heath shrubs,
Sphagnum moss, ferns, and other plants are not now being
formed in large quantity in Florida. Both the Sphagnum moss
and some heath shrubs occur in quantity in some bay-tree and
tyty forests, or in parts of the pine flatwoods. The mats of
Sphagnum and peat are, however, seldom over a few inche
deep. A few of the bay-tree swamp peats and some pond or
prairie peats, especially where ferns are common, are, how-
ever, sold as moss peat because they are loose, fibrous, light
weight and strongly acid.

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86 FLORIDA GEOLOGICAL SURVEY-BULLETIN THIRTY

In general, the physical and physico-chemical characteris-
tics which are most useful in describing peats are; color, tex-
ture, homogeneity, water content, pH values, and the ash
content. The weight, compactness and other structural fea-
tures of peat are also used in distinguishing types. For a
detailed consideration of these characteristics the reader
should refer to Part I, and to the Analyses to follow later.

BURIED PEATS, PRELIMINARY
Nearly all the organic deposits classed as peat are on or
near the surface, or they occur as strata below only a few
feet of other materials, marls, sands, mucks, and clays. Some
shallow to deeply buried carbonaceous deposits do, however,
occur in Florida that are peats or derivatives of peats.
Since the recent increase in well drilling in Florida many of
these buried layers of carbonaceous material are being dis-
covered. Some layers are so little altered that they are still
raw, fibrous peats, but others are lignites, sapropelites, and
perhaps bituminous coal.
The samples of these buried carbonaceous materials come
from some sedimentary strata of fairly definite geologic age
and, therefore, are of importance in determining the geology
of Florida. The most significant of these are described in Part
IV. The kinds of such materials is of secondary importance.
In the U. S. Navy Cecil Field well (W-581), Duval County
the deposit is a lignite about 57 feet thick. In many wells,
however, there are only streaks, or even just stains, of car-
bonaceous materials in the limestone and dolomite. There are
a few definite layers of sapropelite probably derived from
sedimentary peats, but on the whole lignite is the most
common material.

VEGETATION OF PEAT AREAS
The marsh or lowmoor peats, swamp or woody peats, and
aquatic or sedimentary peats nearly all originated from dis-
tinctive kinds of vegetation composed of certain definite peat
forming plants. These plants vary from place to place and
usually the variations in the conditions of water level are
the most frequent cause of the differences in both the vegeta-
tion and the kind of peat. In many instances, the plants that

THE PEAT DEPOSITS OF FLORIDA

formed the peat have persisted as the vegetation of the
present peat deposits, but in some cases where drainage has
altered water conditions the plants growing on the deposits
have changed. Over the Florida deposits those plants that
are most abundant are usually definitely indicative of a certain
type of peat, at least the upper layers of the peat, and the type
of peat can frequently be identified by the kind of vegetation.
For this particular reason it is useful to know some of the
plants of the peat deposits.
In the following brief descriptions of the vegetation of
Florida peat areas we will consider only a few of the typical
and abundant plants because a full description of the botany
of each kind of peat deposit would occupy too much space.
The same general classification of peats as follows: (1) low-
moor peats and mucks of marshes and wet prairies; (2) forest
or woody peats of swamps; and (3) aquatic peats and organic
sediments of lakes, ponds, and some rivers, will be used to
describe the vegetation of: (1) marshes; (2) swamps; and
(3) open water habitats, each type of vegetation being re-
lated to the above three general types of peat respectively.

MARSH VEGETATION
The marsh and wet prairie plants forming lowmoor peats
are mainly sedges, rushes, grasses, a few reeds, a number of
other herbs, and some broad-leaved aquatic and semi-aquatic
pond and marsh plants such as water-lilies, pickerel-weeds,
arrow-heads, and arums. Nearly all these plants are provided
with rhizomes, fibrous roots, and frequently succulent under-
water or under-ground organs. These submerged parts form
a mass of matted and interlocking plant parts that contribute
most to the peat material. The above-water and above-soil
parts do not contribute very much to the peat that is forming.
In Florida there are four main types of vegetation which
cover the marsh and wet prairie areas whose plants form dis-
tinctly different peats, these are: (1) the saw-grass or sedge
marshes, of which the Everglades is an example; (2) the
rush marsh or wet prairie vegetation forming such peats as
the Florahome type; (3) the broad-leaved aquatic or flag
marshes and ponds usually forming a flag peat, or muck, or a
plastic peat; and (4) the salt-marsh vegetation composed of

87

	Frontispiece
	Title Page
	Front Matter
	Foreword
	Acknowledgement
	Table of Contents
	List of Illustrations
	Main
	Index

MILLISECOND	CLASS.METHOD	MESSAGE
0	sobekcm_page_globals.constructor
0	sobekcm_page_globals.constructor	Application State validated or built
0	sobekcm_database.verify_item_lookup_object
0	sobekcm_page_globals.constructor	Navigation Object created from URI query string
0	sobekcm_database.verify_item_lookup_object
0	sobekcm_page_globals.display_item	Retrieving item or group information
0	sobekcm_page_globals.get_entire_collection_hierarchy	Retrieving hierarchy information
0	sobekcm_assistant.get_entire_collection_hierarchy
0	cached_data_manager.retrieve_item_aggregation
0	cached_data_manager.retrieve_item_aggregation	Found item aggregation on local cache
0	item_aggregation_builder.get_item_aggregation	Found 'all' item aggregation in cache
0	system.web.ui.page.page_load (ufdc.page_load)
0	sobekcm_page_globals.constructor.on_page_load
0	html_echo_mainwriter.add_style_references	Adding style references to HTML
0	html_echo_mainwriter.add_text_to_page	Reading the text from the file and echoing back to the output stream
52	html_echo_mainwriter.add_text_to_page	Finished reading and writing the file