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THIRD ANNUAL REPORT
1909-1910
E. H. SELLARDS, Ph.D., STATE GEOLOGIST
PUBLISHED FOR
THE STATE GEOLOGICAL SURVEY
TALLAHASSEE, 1910
LETTER OF TRANSMITTAL.
To His Excellency, Hon. Albert W. Gilchrist, Governor of Florida.
Sir:-In accordance with the Survey Law I submit herewith a report of the progress of investigations made by the Geological Survey for the year ending June 30, i9io. The work of the Survey has progressed actively during the past year. This report contains papers on the phosphate deposits, the peat deposits, the lakes and the artesian water supply.
In connection with the report on water supply I would respectfully call attention to the evidence of the loss of flow in some of the artesian wells, and to the danger of a material reduction in the artesian supply in some localities, if the waste of water is not prohibited by law.
The generous interest you have taken in the work of the State Survey is appreciated.
Very respectfully,
E. H. SELLARDS,
State Geologist.
Tallahassee, Florida,
October i, 19IO.
CONTENTS.
PACE
Adm inistrative Report .................................................. 9
A Preliminary Paper on the Florida Phosphate Deposits.
By E. H. Sellards. (Plates I to 5)............................... 17
Some Florida Lakes and Lake Basins.
By E. H. Sellards. (Plates 6 to 9; text figures I to 5) ............... 43
The Artesian Water Supply of Eastern Florida.
By E. H. Sellards and Herman Gunter. (Plates io to 15; text figures
6 to i6 ) .. ..... ... .... ... ....... ............... .. ...... .... ..... 77
A Preliminary Report on the Florida Peat Deposits.
By Roland MW. Harper. (Plates I6 to 28; text figures J7 to 30)..........197
Index .............................. .......... ..................... 377
ILLUSTRATIONS.
PLATES.
PLATE No.k FOLLOWING PAGE
I. Fig. I. Phosphate washer..........................
Fig. 2. Drill used in prospecting f or hard rock phosphate ........
Fig. 3. View of incline to Pit .................................. 32
2. Fig. I. Pit of hard rock phosphate mine......................
Fig. 2. Top surface of Miami oolitic limestone .................
Fig. 3. View showing laminated structure of plate rock deposit..3:2
3. Fig. I. Pit of land pebble phosphate, Mulberry .................
Fig. 2. View showing indurated overburden in pebble phosphate..
Fig. 3. View of abrupt break in the phosphate stratum.......... 3
4. Fig. I. Irregular top surface of bed rock of land pebble .........
Fig. 2. Unconformity in the phosphate stratum ................
Fig. 3. Irregular line of contact between yellow and gray sand..... 32
5. Pit of plate rock phosphate mine showing very irregular top surface of limestone...................................... 32
6. Miccosukee Basin, Low Water Stage of i9g9......................... 64
7. Fig. I. Lake Jackson .......................................
Fig. 2. Alligator, Lake......................... 0.*0. ......... #64
8. Fig. I.- The Sink of Lake Lafayette..........................
Fig. 2. Paynes Prairie, Looking Out From the Sink ...............
Fig. 3. View of Paynes Prairie From Near the Sink................ 64
9. Spouting Well near Orlando ................................... 64
10. Fig. I. Exposure of hardpan at Black Bluff on Clark's Creek, eight miles from Fernandina ............................
Fig. 2. Artesian well used for power, Melbourne............... 88
I I. Palmetto flatwoods ........................................... 96
12. Fig. I. Scrub,' east side of Lake Kingsley, Clay County..........
Fig. 2. Sandy pineland, DeLeon Springs .......................
Fig. 3. Open flatwoods, three Miles east of DeLeon Springrs.. 13. Fig. I. Everglades west of Ft. Lauderdale .....................
Fig. 2. Small prairie, four miles west of Sebastian..............
Fig. 3. Turnbull Hammock, one mile west of Daytona ............. 96
14. Fig. I. Sand dune near Mayport ..............................
Fig. 2. Ancient sand dune, two miles west of Daytona ...........
Fig. 3.- Exposure at Saw Pit Landing, St. Marys River ............ 96
15. Map showing areas of artesian flow in Florida. .... .... 1 -o
16. Map showing geographical divisions of the State .................. 204
17. Salt marshes ................................................. 232
I8& Mangrove swamps (near head of Biscayne Bay)................... 232
19. Muddy swamps (of Apalachicola River)............ ....... 0..... 232
20. Calcareous streams........................................... 232
21. Suwannee River estuaries (Hog Island)..........................2'48
22. Estuarine swamps of Blackwater River (Santa Rosa Co.) ..........248
23. Cypress ponds and bays................... ..................... 248
24. Small lakes (south of Tavares, Lake CO.) ........................ 248
25. Borders of large lakes.......................................... 280
26. Saw-grass marshes (around Lake Harris) ........................280&
TEXT FIGURES.
PAGE
1. Sketch Map showing location of Lakes Iamonia, Jackson, Lafayette,
and M iccosukee .............................................. 54
2. Lake Jackson .................................................... 56
3. Lake Lafayette ................................................... 58
4. Lake Miccosukee......................................... 00
5. Sketch Map of Hogtown Prairie and surroundings ................. 66
6. A rtesian basin ................................................... 109
7. Artesian slope........................................ ...0Ho
8. Artesian flow from unconfined horizontal strata ....................III
9. Artesian flow from cavities in limestone ........................... III
io. Method of measuring artesian flow ................................ 119
II. Map of flowing area of Nassau and Duval Counties................135
12. Map of flowing area of St. Johns County .......................... 143
13. Map of flowing area of Clay and Putnam Counties .................. 155
14. Map of flowing area of Orange County ............................ 167
15. Flowing well on Lake Jessup, Orange County .................... 172
16. Map of flowing area of Volusia County......................... 175
17. Scene in estuarine swamp of Apalachicola River .................... 236
18. Interior of dense tyty swamp, Walton Co ........................... 253
I9. Interior of gun1 swamp, Leon Co ................................ 255
20, Slash-pine bog, Lake Co.................................... 256
21. Non-alluvial swamp, DeSoto Co................................... 259
22. Deep open tyty bay near Carrabelle, Franklin Co .................. 265
23. Lake Alfred, near Bartow Junction, Polk Co ....................... 269
24. Lake Butler, Bradford Co ........................................ 27z
25. Clear Lake, a fresh lagoon in Palm Beach Co ...................... 273
26. H elena Run, Lake Co ............................................. 281
27. 'Gator-hole near south end of Everglades .......................... 285
28. Scene in Everglades near head of Miami River...................286
29. Hardpan on shore of bay near Apalachicola ........................ 294
30. Fossil peat locality near M ilton ................................... 296
ERRATA.
Page 46, explanation of P1. 9, for "Two views of" read view of.
Page 48, footnote, for "plate Io" read plate 15.
Page 50, second line from bottom of page, for "340" read 840.
FLORIDA STATE GEOLOGICAL SURVEY.
E. H. SELLARDS, STATE GEOLOGIST
ADMINISTRATIVE REPORT.
The members of the State Survey during the past year have been, in addition to the State Geologist, Mr. Herman Gunter and Dr. R. M. Harper. The chemical analyses necessary to the work of the State Survey are made by the State Chemist.
Mr. Gunter has assisted in the preparation of the paper on the artesian water supply of Eastern Florida. In addition he has had charge of cataloging and recording the Survey collections.
Dr. Harper has prepared a preliminary paper on the peat resources of the State. The fuel tests of peat samples, in connection with this work, were made in the fuel testing laboratory of the United States Geological Survey.
In addition to the necessary correspondence and administrative work of the office, the State Geologist has prepared papers on the phosphate deposits, on certain variable lakes, and on the artesian water supply.
\PUBLICATIONS ISSUED.
The Second Annual Report covering the operations of the Surveyto June 30, i909, was issued during the year This report contains: (I) Administrative Report; (2) a preliminary report on the Geology of Florida with special reference to the stratigraphy including a tographic and geologic map cif Florida prepared in co-operation with the United States Geological Survey;
(3) the topography and geology of Southern Florida; (4) mineral industries; (5) the fullers earth deposits of Gadsden County with notes on similar deposits found elsewhere in the State.
DISTRIBUTION OF REPORTS.
The reports issued by the Survey are distributed upon request to citizens, and to city and other public libraries. The results of the survey thus become permanently available to those interested in the geology and mineral resources of the State.
10 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
PUBLICATION S AVAILABLE FOR DISTRIBUTION.
The following is'a list of the publications issued by the State Geological Survey and now available for distribution:
I First Annual Report, 1908.
This report contains: (I) Administrative Report; (2) a
sketch of the geology of Florida; (3) a chapter on mineral industries, including phosphate, kaolin or ball clay, brick making clays, fullers earl~h, pqat, lime and cement, and road making materials; (4~) a bibliography of publications on Florida, geology with a review of the more important papers published previous to the organization of the present Geological Survey.
2 Second Annual Report. (Contents given above.)
3 Third Annual Report. (This volume.)
4 Bulletin No. I. The Underground Water Supply of Central
Florida. 1908.
This Report contains: (I) Underground water,: general
discussion; (:2) the underground water of central Florida, deeR> and shallow wells, ,spring and artesian 'prospects; (3) effects of underground solution, cavities, sink-holes, disappearing streams, and solution basins; (4) drainage of lakes, ponds and swamp lands, and disposal of sewage by bored wells; (5) wateranalyses and tables giving general water resources, public water
supplies, spring and well records.
5 Circular No. I. An approximate mapping of the areas of artesian flow in Florida. 1908.
The reports of the State Survey may be obtained without cost by addressing, The State Geologist, Tallahassee, Fla.
THE PURPOSE AND DUTIES OF THE STATE GEOLOGICAL SURVEY.
Among the specific objects for which the Survey exists, as statedin the enactment, is that of making known information regarding the "minerals, water supply,- and other natural resources of the
,ADMINISTRATIVE REPORT. i
A distinctly educational function of the Survey is indicated by Section 4 Of the law, which makes it the duty of the State Geologist to make collections of specimens illustrating the geological and mineral features of the State, duplicate sets of which shall be deposited with each of the State colleges. The publication of annual reports is provided for as a means of disseminating the information obtained in the progress of the Survey.
The Survey is thus intended to serve on the one hand an economic, and on the other an educational purpose.
in its economic relations, a State Survey touches on very va Iried interests of the State's development. In its 'results it may be expected, judging from the experience of similar surveys in otherStates, to contribute not so much to, sensational or sudden development of great mineral deposits as to an intelligent development of the State's natural resources. Its educational value is of no less immediate concern to the State, both to the citizens within the State and-to prospective citizens without.
A knowledge of the soil and of the'available water supply is very necessary to successful agriculture, and the'Survey's investigations along these lines are of value to all landowners. A knowledge of the mineral deposits which may lie beneath the surface is likewise necessary to a correct valuation of land. The relation of the State Survey to the ownership of mineral lands is specifically defined. The Survey law provides that it shall be the duty of the State Geologist and his assistants, when they discover any mineral deposits or substances of value, to notify the owners of the land upon, which such deposits occur before disclosing their location to any other person or persons. Failure to do so is punishable by fine and imprisonment. It is not intended- by the law, however, that the State Geologist's time shall be devoted to examinations and reports upon the value of private mineral lands. Reports of this character are properly the province of commercial geologists, who may be employed by owner s of land for that purpose. To accomplish the best results, the work of the Survey must. be in accordance with definite plans by which the State' s resources are investigated in an orderly manner. Only such examinations of private lands can be made as constitute a part of the regularly planned operations of the Survey.
RELATION OF THE STATE SURVEY TO OTHER ORGANIZATIONS.
I T
12 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
voted chiefly to an investigation of the general geology and stratigraphy of the State and the underground water supply. Bulletin No. I published in 19o8 formed a part of the results of this cooperative work. A special report on the stratigraphy of the State forming a second part of this co-operative work was published in' the Second Annual Report in i9o9.
During the present year co-operation has been continued in the investigation of the peat deposits. Numerous peat samples in connection with this work, have been tested during the year in the peat testing plant of the National Survey. These tests form it -.rt of and are included in the report on peat deposits. Through this generous co-operation on the part of the National Survey the State Survey is able to publish at this time a much more complete report on the peat resources of the State than would otherwise have been possible. The constant co-operation and advice in connection with this work given by Professor Charles A. Davis, in charge of peat investigations for the National Geological Survey, is especially ap preciated.
The State Department of Agriculture: The Survey law provides that analytical work necessary to the investigations of the Survey shall be done by the State Chemist. The Survey is thus brought into co-operative relation with the Division of Chemistry of the Department of Agriculture and in so far as the work of the Survey contributes to agricultural interests, to the Department of Agriculture as a whole.
The State Agricultural Experiment Station:-In its study of the water supply in relation to agriculture, of soils in their geological relations, and in other ways, the work of the State Survey may be expected to supplement certain lines of work of the State Experiment Stations, the two organizations being of mutual aid to each other.
THE SURVEY LIBRARY.
A well-equipped reference library is essential to the best results and an effort is being made to bring together those publications which are necessary to the immediate and future work of the Survey. The Survey library now contains more than i,5oo volumes. These include the reports of the several State Geological Surveys; the Annual Reports, Bulletins, Monographs, Professional Papers, Water Supply and Irrigation Papers, and other publications of the National Geological Survey; the reports of the Canadian, and a few other foreign Geological Surveys; and many miscellaneous volumes and papers on geological subjects. Additions to the Survey. library will be appreciated.
ADMINISTRATIVE REPORT.i)
EXHIBITION OF GEOLOGICAL MATERIAL.
The Survey law provides for the exhibition of geological mat.erial. The space available foi- this purpose is unfortunately as yet very limited. A part of one room has, however, been used for this purpose. Three cases have been built, designed to serve the double purpose of storage and exhibition, the lower part of the case being adapted to the purpose of storing material.- In making the collections a systematic plan has been followed to secure a, representation of the rocks, minerals, and fossils of each formation in the State. The collections will be added to as opportunity peri-nits.
SAMPLES SENT TO THlE SURVEY FOR EXAMINATION.
Samples of rocks, minerals and fossils will be at all times gladly received, and reported upon. Attention to inquiries ar d general' correspondence are a part of the duties of the office, and afford a means through which the Survey may in many ways be useful to the citizens of the State.
The f ollowing suggestions are offered for the guidance of those submitting samples:
I. The exact location of all samples should be given. This should be carefully written out in. full and placed on the inside of the package.
2. The statement accompanying the' samples should give the conditions under which the specimen occurs, 'Whether an isolated fragment or part of a larger mass or deposit.
3., Each package should be addressed to the Florida State Geologrical Survey, Tallahassee. The name and address of the sender should be plainly written on the outside.
4. Transportation charges, whether by mail, express or f reight, should in all cases be prepaid.
THE COLLECTION OF STAkTISTICAL INFORMATION.
For many purposes the collection and publication of statistical information is helpful, both to the industries concerned and to the general- public. Such statistical information is desired from all tl'e mineral industries of the State. Such information will be recognized as strictly confidential in so far as it relates to the private business of any individual or company, and will be used only in making
14 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
FINANCIAL STATEMENT.
The total appropriation for the State Geological Survey is $7,500 per annum. With the exception of the salary of the State Geologist the amount of which is fixed by statute, all Survey accounts are paid upon warrants issued by the Comptroller as per itemized vouchers approved by the Governor. The following is a list of the expenses of the Survey for the year ending June 30. I9io. The original of all bills and the itemized statements of all expense accounts are on file in the office of the Comptroller. Duplicate copies of the same are on file in the office of the State Geologist:
LIST OF WARRANTS ISSUED.
July, I9o9.
Overcharge for preceding year ................................ $ 117.-.2
Herman Gunter, Assistant, salary July, 19097.................. o75.00
Engineering and Mining Journal, publications..................5. )J
August, 1909.
Herman Gunter, Assistant, salary, August, I9097............ 75.' 0
Andrus & Church, pamphlet cases......................... .9
September I909.
E. H'. Sellards, salady for quarter ending Sept. 30, 1909.............625.00
E. H. Sellards, expenses, July, August and September, i.o9 .... 46.
Herman Gunter, Asst., expenses ($13.05), salary ($Ioo.oo), October. 113.05 Child Bros., book case and repairs..........................26.oo
John McDougall, (ostage ....................................5o.oo
Maurice Joyce Engraving Co., engraving ....................... 26.o7
October, 1909.
E. H. Sellards, expenses, October, 1909............................48.41
Herman Gunter, expenses (30.20) salary (Ioo.oo) October .... 130.20 November I9o9.
E. H. Sellards, expenses, November, i9096...................... 60.71
Herman Gunter, Asst., expenses (79.69) salary (ioo.oo) Nov... 179.619 Yaeger-Bethel Hardware Company, camp supplies............... 54.42
December 19o9.
E. H. Sellards, salary for quarter ending Dec., 1909 ...............625.00
E. H. Sellards, expenses, December, 19o9.......................36.65
Herman Gunter, Asst., expenses ($8o.8o), salary ($ioo.oo), Dec ...i8o. 3o Nellie Mathes, stenographer, salary, one-half month ................ 30.00
H. & W. B. Drew Co., supplies......................... IO.6i
Academy Natural Sciences, publications......................20.00
Engineering and Mining Journal, subscription ................ 5.00
American Journal of Science, subscription ..................... 6.oo
Dan Allen, dreayage........................................381
Seaboard Air Line Railway, freight..........................33.95
January 1910.\E. H. Sellards, expenses January, 1910.............. .............. 79.45
Herman Gunter, Asst., expenses (86.35) salary (IOO.oo) Jan ......186.35 Nellie Mathes, stenographer, salary, one-half month....... .....30.00
The Record Com'pany, printing ............................ 678.35
ADMINISTRATIVE REPORT.
Andrew B. Graham Co., engraving .......................... 330.0
John McDougall, postage ...................... ............... 125.oo00
Dan Allen, drayage ...................................... 7.43
Southern Express Company ............ ................ 4.82
Ware Brothers, subscription .............. .............. 5.oo
February, 1910.
E. H. Sellards, expenses, February, 19Io ...................... 66.30
Herman Gunter, Asst., expenses (87.41) salary (Ioo.oo) Feb... 187.41 Nellie Mathes, stenographer, salary, two-thirds month........... 40.0oo
John McDougall, postage and envelopes .................... ioo.oo
H. & W. B. Drew Co., supplies ..........................1...I0.18
March, 1910.
E. H. Sellards, salary for the quarter ending March, Ig9io .... 625.oo00 E H. Sellards, expenses, March, 19Io ........................127.79
Herman Gunter, Asst., expenses ($123.60), salary ($Ioo.oo)...... .223.60
Nellie Mathes, stenographer, salary, two-thirds month ........ 40.00 Southern Express Company .............. ............ 3.89
D. R. Cox Furniture Co., supplies ............................19.oo
S. B. Hubbard & Co., supplies................ ............... 2.0
H. & W. B. Drew Co., supplies............................... 15.70
April, 19Io.
E. H. Sellards, expenses, April, I9o................. ......... 163.59
Herman Gunter, Asst., expenses ($112.20), salary ($Ioo.oo), April. 212.20 Nellie Mathes, stenographer, two-thirds month.................. 40.oo00
John McDougal, postage.............. .................... 30.00
Duval Harness Co., field supplies................ .......... 6.ou0
H. Dunod & Pinat, publications.. ....... .... .......... 4.
T. J. Appleyard, printing.................................... 7.00oo
May, 1910.
E. H. Sellards, expenses, May, Ig9Io................................ O.100.59
Herman Gunter, Asst., expenses (82.95), salary (loo.oo) ........... 182.95
R. M. Harper, Asst., expenses ($36.09), salary $ioo.oo) ............ 136.0o
Nellie Mathes, stenographer, salary, two-thirds month............ 4o.oJ
Knight Crockery and Furniture Co., supplies................... 10.20
June, 191o.
E. H. Sellards, salary for the quarter ending June 30, 1910o...... .625.00oo E. H. Sellards, expenses June, 191o.............. ........... 5.44
Herman Gunter, salary June, $Ioo.oo............................ Ioo00.0o
R. M. Harper, salary June, $100.00............................... 100.00C
Nellie Mathes, salary June 19Io..................... .......... 6.50
T. J. Appleyard, printing........................... .............. 12.80
Andrus & Church, pamphlet cases................. .......... iI.8o
Economic Publishing Co, publications....................... 3.00
University of Chicago Press, publications................... 3.00
T. B. Byrd & Co., sample jars............................... 3.60
H. & W. B. Drew Co., supplies............................. 5.46
Total expenditures....................... .. ......................$7,313.03
Balance available.................................... 186.97
$7,500.00
15
A PRELIMINARY PAPER ON THE FLORIDA PHOSPHATE DEPOSITS.
By E. H. SELLARDS.
CONTENTS.
PAGE.
The Hard Rock Phosphate-Dunnellon formation...................... 21
Lithologic description............................................ 21
Gray sands................................................2 2
Clays ........................ ............................. 22Flint boulders...............................................Limestone inclusions......................................... 22
Conglomerate............................................... 22
Vertebrate and invertebrate fossils........................... 2-3
Phosphate rock ............................................. 23
Materials lying above the phosphate formation ....................... 24
Relation to the underlying formations-Vicksburg limestones ...
Local details ...................................................23?
Suwannee, County........................................... 25
Columbia County ........................................... 23
Alachua County ............................................ 26
Marion County .............................................,!
Citrus County.......... .................................... 29
Hernando County ...........................................219
Thickness ..................................................... 30
Source of materials ..................... ........................ 30
Conditions of deposition ......................................... 31
Formation name ................. .............................. 32
The Land Pebble Phosphate-Bone Valley formation.................... 33
Lithologic description ........................................... 33
Materials lying above the phosphate formation ............ .......... .34
Relation to the underlying formation-Arcadia marl?................. 35
Local details ................................................... 33
Hillsboro County .................... ....................... 33
Polk County................................................ 36
Condition of deposition ........................................ 37
Change of conditions during deposition .......................... ')
State and Government lands in the phosphate section...................... 38
List of phosphate companies operating in Florida during i90................. 39
Production of phosphate during 1909.............................. ............. 40
Table of production and shipment of Florida phosphate, 1908 09............41I
ILLUSTRATION S.
PLATE NO.
1. Fig. .
Fig. 2.
Fig. 3. 2. Fig. i.
Fig. 2.
Fig. 3. 3. Fig. i.
Fig. 2.
Fig. 3.
4. Fig. i.
Fig. 2.
Fig. 3.
FOLLOWING XCAE.-
Phosphate washer .......................... P.......
Drill used in prospecting for hard rock phosphate... View of incline to pit................................
Pit of hard rock phosphate mine......................
Top surface of Miami oolitic limestone...............
View *showing laminated structure of plate rock deposit. Pit of land pebble phosphate, Mulberry.................
View showing indurated overburden in pebble phosphate. View of abrupt break in the phosphate stratum ......... Irregular top surface of bed rock of land pebble .......... Unconformity of the phosphate stratum...............
Irregular line of contact between yellow and gray sand....
5. Pit of plate rock phosphate mine showing very irregular top surface of limestone ......................................0
32
32 32 32
A PRELIMINARY PAPER ON THE FLORIDA
PHOSPHATE DEPOSITS
E. H. SELLARDS.
THE HARD ROCK PHOSPHATE.-DUNNELLON FORMATION.
The area of hard rock phosphate at present productive, lies in the western part of central peninsular Florida and extends as a narrow strip parallel with the gulf coast in a general north and south direction from southern Suwannee and Columbia Counties to Hernando County, a distance of one hundred miles. Mining has been carried on continuously in this section since 1888. Seventy-four plants under the ownership of twenty mining companies operated in this section during i909. These plants were distributed as follows: Suwannee County, one; Columbia County, three; Alachua County, twenty-two; Marion County, twelve; Citrus County, thirty-four; Hernando County, two. Owing to the depressed condition of the phosphate market a number of these plants closed either temporarily or permanently early in the year while many others closed before the end of the year. At the beginning of I9io, the number of plants in actual operation was thirty-seven. These plants were distributed as follows: Suwannee and Columbia Counties, one plant each; Alachua County, fourteen plants; Marion County, eight plants; Citrus County, twelve plants; Hernando County, one plant. Each phosphate plant operns up in the process of mining one to several pits offering exceptionally good exposures of the phosphate bearing formation. The following notes are based on observations of the exposures made at these and at the many other plants that have operated in this section during the past several years.
LITHOLOGIC DESCRIPTION.
The phosphate-bearing formation as developed in this section includes a mixture of materials from various sources and of the most diverse character, further complicated by pronounced
/
22 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
chemical activity within the formation itself. Although exceedingly variable from place to place the prevailing phase of the formation is feebly coherent, more or less phosphatic, light gray sands. Aside from these sands the principal materials, of the formation are clays, phosphate rock, flint boulders, limestone inclusions, pebble conglomerate, erratic and occasional water-worn flint pebbles, vertebrate and invertebrate fossils.
The gray sands may be observed in every pit that has been excavated in this section. Moreover, from drill and prospect holes it is known that these sands occur very generally over the intervening or barren area. The sands are of medium coarse texture, the grains being roughly angular. The amount of phosphate associated with the sands is variable. They are also more or less -calcareous in places. 'Upon prolonged exposure, as seen inl numerous abandoned pits, these sands oxidize at the surface assuming a pink or purple color. When affected by slow decay and by water carrying more or less iron in solution they become reddish or ochre-yellow in color.
The clays in this formation occur locally as clay lenses imbedded in the sand, or separating the sand from the phosphate rock, or overlying the phosphate rock. The clays are often of a light. buff, or blue color. When lying near the surface, however, they often oxidize to varying shades of red. The relative amount of clay in' the phosphate-bearing formation increases in a general way in passing to the south. The exposures in the southern part of the area show as a rule more clay than do similar exposures in the northern part of the area.
Flint boulders occur locally in this formation in some abundance, and occasionally phosphate pits which are otherwise workable are abandoned on account of the number of flint boulderS, encountered. The flint boulders are usually oval or somewhat flattened in shape and are of varying size, some weighing several tons. The exterior is usually of a light color. Some of the boulders are' hollowv and' are occasionally filled with water. Others are solid, compact and of a bluish color throughout. Fossils or casts of fossils occur frequently within the boulders. Limestone inclusions-, f rom the underlying f formations are f requent in this f orm-ation.
The pebble conglomerate feature is not of frequent occurrence but may occasionally be observed in the northern part of the
THE FLORIDA PHOSPHATE DEPOSITS.
worn, dark colored flint pebbles. This phase of the formation may be seen through a distance of ten or fifteen feet along the side of the pit. Water worn pebbles weighing one or more pounds occur occasionally in the northern part of the field.
The invertebrate fossils found are mostly contained in the limestone inclusions which come largely from the underlying Vicksburg limestones. The vertebrate remains occurring in the phosphate include among others, shark teeth, manatee, turtle and mastodon remains.
Phosphate rock, although the constituent of special economic interest, nevertheless makes up a relatively small part of the formation. The phosphate in this section occurs as fragmentary rock, boulder rock, plate rock or pebble. A certain portion of soft phosphate, unavoidably lost in mining, is also present. The relative amount of material that it is necessary to handle to obtain a definite amount of phosphate is always variable with each pit and with the different parts of any one pit. In general the phosphate rock obtained from the matrix of the grade demanded by the market will not exceed ten to twenty percent of the whole. The workable deposits of phosphate lying within this formation or representing locally a phase of this formation, occur very irregularly. While at one locality the phosphate may lie at the surface, elsewhere it may be so deep as not to be economically worked; while a deposit once located may cover more or less continuously a tract of land of some acres in extent, elsewhere a deposit appearing equally promising on the surface, may be found to be in reality of very limited extent. As to location, depth from the surface, extent into the ground, lateral extent, quantity and quality, the hard rock 1-hosphate deposits conform to no rule. The desired information regarding location, character and extent of deposits is to be obtaincd only by extensive prospecting and sampling.
The phosphate rock may lie beneath the gray sands, or above the gray sands or may be entirely surrounded by them. In some instances the phosphate is interbedded with the sands. Such interbedding of sand and phosphate was observed by the writer in the Central Phosphate Company pit No. 25 about three miles west of Clark. This phase of the relation of sand and phosphate occurs not infrequently and is confined to no particular part of the phosphate field. Gray sands surrounding the phosphate rock may be observed as previously stated in practically every pit throughout the phosphate section. As a rule the phosphate rock extends to and rests upon the underlying limestone. This relation, however, is by no means invariable as gray sands were observed underlying the phosphate rock at several localities. Gray sands above.
M3
24 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
the phosphate are ordinarily of frequent occurrence both in pits and in prospect holes.
MATERIALS LYING ABOVE THE PHOSPHATE.
A superficial deposit of pale yellow incoherent sand occurs generally throughout the phosphate section. The thickness of this sand varies exceedingly. Five to fifteen feet may be given as an average as seen in the pits, although a thickness of as much as thirty feet has been observed. The character and manner of occurrence of these sands leads the writer to the belief that they may be residual in origin.
These incoherent sands rest in some localities upon a red clayey sand stratum known to the miners as "hardpan." This
sand stratum contains sufficient clay to give it coherence and stands usually as a vertical wall in mining. This stratum is frequently absent, and when present varies greatly in thickness. The top surface. of this red sand stratum presents irregularities which might be taken to mark an unconformity between this formation and the incoherent sands above. Such irregularities as occur in the top surface, however, present rounded depression rather than sharp irregularities. Moreover the top surface of the red sands frequently conforms to the surface contour. Both the superficial sands and the red sands are, as far as the writer has observed, non-fossiliferous.
RELATION OF THE PHOSPHATE-BEARING FORMATION TO THE UNDERLYING FORMATIONS.
The phosphate-bearing formation rests in this section, wherever observed, upon the Vicksburg limestones. In the northern part of the section the pits are ordinarily worked out to the limestone. affording favorable opportunity for observing the contact. The top surface of the limestone is strikingly irregular, the rock projecting as rounded peaks. The numerous shells and other invertebrate fossils of which the limestone is largely made up are eroded off plane with the surface of the limestone. Passing to the south the limestone lies as a rule at a greater distance beneath the surface, and frequently is not reached by the ordinary processes of mining. It is occasionally reached, however, and wherever seen, throughout this entire section the relation between the phosphate formation and the limestone is the same, that is, the phosphate bearing formation lies upon and ,fills up irregularities in the top sur.face of the limestone. (P1. 2, Fig. I and P1. 5)
THE FLORIDA PHOSPHATE DEPOSITS.
LOCAL DETAILS.
;UWANNEE COUNTY.
The southern and southeastern part of Suwannee County has produced some phosphate although only one mine was in operation in this county during 19o9. A variable thickness of pale yellow sand occurs in the pits of this section. At the pits of plant No. IO of Dutton Phosphate Company, 2 miles north of Hildreth from two to twelve feet of this incoherent sand rests directly upon the phosphate bearing matrix. In one of the pits of this plant the phosphate matrix grades at the bottom into a yellow phosphatic clay overlying the limestone to a depth of 4 or 5 feet. In one of the pits at this plant are observed, as frequently seen elsewhere in the hard rock section, many large round elongate siliceous boulder.; interbedded in the phosphate matrix. The underlying formation here is the Ocala Limestone which occurs as peaks, and as "hog backs" of lime projecting into or even through the phosphate matrix.
COLUMBIA COUNTY.
The southern part of Columbia County adjacent to Suwannee County has produced considerable phosphate, although only one mine in this county was in actual operation at the close of I9o9.
At plant No. 2 of the Dutton Phosphate Company about onehalf mile west of Ichatucknee Springs the following section was obtained:
Pale incoherent sand ...................................10 to 20 feet
Phosphate-bearing matrix .............. ................ 20 to 25 feet
Buff yellow phosphatic clays ............................. 5 to 6 feet
Dark sandy phosphatic clays (exposed) .................. t feet
The incoherent sands in this pit, as at Dutton No. io, rest directly upon the phosphate stratum the top of which is exceedingly irregular. Clay lenses 6 to 12 inches thick are of frequent occurrence especially near the top. The underlying Ocala Limestone is reached in places. The buff yellow phosphatic clay observed in Dutton No. io is seen here also and is underlaid by 4 feet of dark sandy phosphatic clay.
The following section was made in one of the pits of the Schilman & Bene Phosphate plant about two miles northwest of Ft. White:
Pale yellow inc, hercnt sand........................... 3 to 5~ feet
Red clayey sands.................... ................. 5 to I0 feet
Phosphate matrix................................... 15 to 25 feet
Limestone at the bottom of the 'it.
25
26 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
This Section differs f rom the preceding chiefly in the presence of the red clayey sands which are sufficiently coherent to form a vertical wall in the pit. This clayey sand stratum when present is referred to by the miners as "hardpan."
The phosphate matrix in this exposure as in Dutton No. 10, grades belowv into yellow phosphatic clay. The overburden at this pit is not removed as it is f ound practicable to allow the entire overburden to be taken up with the phosphate \and to pass through the washer.
In the pit of the Fort White Hard Rock Company one-half' mile southeast of Ft. White, the foundation rock, as is usual in this section, is the Ocala. Limestone. The top of this limestone is exceedingly irregular, projecting as rounded peaks. Shells, sea urchins, and other fossils are partly eroded away, the limestone having a comparatively smooth surface. The phosphate rock consists chiefly of angular fragmental pieces, plates, pebbles and boulders imbedded in a sandy or clayey matrix. This matrix fills uip the irregularities in the underlying limestone. In several instances the phosphate matrix was seen to fill tip cavities and solution channels in the limestone. Slickensides occur due to the settling of the phosphate matrix as the underlying limestone dissolved away. Limestone inclusions and siliceous boulders occur in the phosphate stratum. The following section is seen in an abandoned pit of this plant.
Pale yellow incoherent sand............................ to 15 feet
Phosphate matrix.......... ........................... I to 20 f eet
Limestone top surface exceedingly irregular
The, phosphate producing area of southern Columbia and Snwannee Counties lies adjacent to and in the angle between the Snwannee and Santa Fe Rivers including the low ly ing and intensively eroded parts of each County. The limestone lies near the surface in this section and as a rule the phosphate is mined out by dry mmn ing, the limestone being exposed in the abandoned pits. Dredging which is applicable in the southern part of the phosphate area is not used in this section.
ALACHUA COUNTY.
THE FLORIDA PHOSPHATE DEPOSITS.
Pale yellow incoherent sands ............................ 5 to Io feet
Red clayey sands5................................... to io feet
Phosphate-bearing formation.........................10 to 25 feet
Limestone at bottom of pit.
The phosphate matrix consists of gray sands, yellow, buff and blue clays, and phosphate rock. At one place in this pit a stratum of gray sand !/ to 2 feet thick is seen interbedded with the phosphate rock.
The incline leading to a new pit being opened up by M. C. and T. A. Thompson near Neal gave the following section:
Pale yellow incoherent sands .............................. 5 to 10 feet
Red clayey sands................................... 7 to io feet
Gray phosphatic sands (exposed)........................ 15 feet
The gray-sands give place laterally to phosphate rock.
Pit No. 2 of the Cummer Lumber Company is perhaps the largest single pit in operation in the hard rock phosphate section. This pit is reported to include at the present time about thirteen acres. Pit No. of this Company, one mile west of Newberry, gives an exposure of the sandstone and flint pebble conglomerate already referred to as occurring occasionally in the hard rock de!Posits. The pebbles are round and more or less flattened. They vary in size from very small pebbles to pebbles weighing five to seven pounds.
In the pit of the Union Phosphate Company at Tioga a considerable number of rounded elongate siliceous boulders occur. These vary in size, the largest approximating a ton in weight. They are embedded in the phosphate-bearing matrix.
The many other pits which are now being worked, or which have recently been abandoned, although varying much even within a single pit in details are in general much the same as those described.
The limestone in this county as a rule, lies relatively near the surface. In most instances the limestone is encountered before or very soon after reaching the water level. The phosphate is thus largely worked out by dry mining and dredges are not in use. The limestone is encountered at varying depths. One pit may show a great deal of limestone projecting as peaks, while another pit of equal depth near by may scarcely reach the limestone. Some of the limestone peaks project 15 to 25 feet above the general level of the bottom of the pit. The ph sphate-bearing matrix here as elsewlhere fills up the irregularities in the limestone. The top surface of the limestone is as elsewhere entirely
27
28 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
irregular. In general clay lenses in the phosphate matrix are most frequent in the upper part of the formation.
The red clayey sand called "hardpan" by the miners may be present or lacking in the pits of this section. The loose pale yellow sand is practically always present varying in thickness from I to 25 feet.
MARION COUNTY.
The plate rock deposit found in the vicinity of Anthony and Sparr in the north central part of Marion County represents an eastward extension of the phosphate-bearing formation. The relation of the phosphate matrix to the underlying limestone is the same as previously described. The limestone projects into the phosphate matrix as rounded peaks. (P1. 5.) Circular depressions similar in appearance to pot holes or to "natural wells" are frequent in this section. These through subsidence are filled with the phosphate matrix. One of these depressions observed by the writer had been cut into, in the process of mining. This depression was about three and one-half feet in diameter at the top. fifteen feet deep and narrowed gradually to the bottom. Other depressions variable in diameter and in depth occur. The limestone lying below the line of the underground water level has usually a rough and jagged surface owing to solution by water in contact with the limestone. Above the water level the limestone has a smooth rounded surface. The shells and other fossils below water level are often removed by solution; above this level they are eroded off plane with the general rock surface. The plate rock beds show evidence of having been originally faintly stratified. Much of the stratification that originally existed, however, has been destroyed through repeated local subsidence as the underlying limestone was removed by solution. The stratification lines in the plate rock are frequently much curved and distorted owing to this irregular subsidence. (P1. 2, Fig. 3.)
The chief difference noted between the plate rock and the typical hard rock region is in the relatively large amount of fragmentary phosphate rock and small amount of boulder rock. In other words the mechanically transported rock in this section predominates over the rock formed chemically i situ. Flint and limestone boulders chemically formed are likewise absent or rare.
The deposits at Standard and at Juliette in the western part of Marion County are similar in general character to the hard rock deposits as previously described. The mines in this section are
THE FLORIDA PHOSPHATE DEPOSITS.
dry mines and usually reach to the bottom of the phosphate formation in places encountering the limestone.
In the southwestern part of Marion County and in Citrus County the hard rock phosphate-bearing formation reaches its maximum thickness. The underlying limestone dips in passing to the south, and is ordinarily encountered: at a considerable depth from the surface. Many of the phosphate pits in this section are worked as dry mines to the underground water level and afterwards as dredge mines to such depth as the dipper will reach. Some of the pits on higher lands are mined as dry mines only.
The pit at the Dunnellon Phosphate Company plant No. IO was one of the first pits regularly worked in the phosphate section and has been continuously in operation for the past twenty years. This mine is operated by a dredge. The bottom of the phosphate is not reached in this pit and the full thickness of the formation at this place has not been determined.
CITRUS COUNTY.
The conditions in Citrus County are in a general way similar to the conditions in the vicinity of Dunnellon in Marion County. The underlying limestone is only occasionally seen in the pits in this section. It is, however, frequently reached in the dredge operations below the water level. The surface of the limestone wherever seen projects as rounded peaks similar in character to the conditions further north. There is on an average more clay to be seen in the phosphate formation in this section than in the northern part of the field. In a few instances, notably that of the pit of the Istachatta Phosphate Company, the water level is within a few feet of the surface and the phosphate formation is entirely submerged. Only the pale sands of the overburden are here visible.
HERNANDO COUNTY.
Phosphate is being produced in Hernando County in the vicinity of Croom. The mine in operation here is a dredge mine. The relation of the phosphate formation to the underlying limestone as seen in an abandoned pit several miles west of Croom is the same as that in other parts of the phosphate section, the limestone projecting as rounded peaks. The material above the phosphate stratum consists largely of incoherent sands. The usual gray phosphatic sands weathering purple on exposure are seen sur-rounding the phosphate rock. In the mines near Groom a considerable amount of clay is associated with the phosphate.
30 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
THICKNESS.
The phosphate-bearing formation is exceedingly variable in thickness. In general it is of reduced thickness in the northern part of the area. In Suwannee, Columbia, Alachua and northern Marion Counties, the formation may reach a thickness of from 3o to 5o feet, although in places it is much reduced or even absent. The maximum thickness of the formation is probably found in southern Marion County and in Citrus County. Drillings made by the Dunnellon Phosphate Company along the Withlacoochee Rive t indicate a thickness of from 6o to 70 feet on the particular tract of land being prospected. Similar drillings by the J. Buttgenbac. Company gave in one instance for the phosphate formation along the river, a thickness of about 75 feet.
Extensive prospecting carried on by the Southern Phosphate Development Company near Inverness, indicated for the phosphate formation a thickness of 5o to IOO feet; 70 feet being a fair average for the particular deposits prospected. It is probable that the depth may in places approach 200 feet, although this maximum thickness is probably only local.
SOURCE OF MATERIALS.
The very complex and mixed character of the material making up the phosphate-bearing formation has already been mentioned. The determination of the source or sources of all this material is a problem of no little difficulty. A part of the material is of chemical origin formed in situ. This applies particularly, in die writers' opinion, to boulder phosphate rock and to flint boulders.
Of the limestone inclusions some constitute a part of the
mation as originally accumulated: others doubtless represent less soluble remnants left behind as the surrounding limestone dissolved permitting the phosphate stratum to subside and enclose them.
The gray sands find their closest resemblance lithologically to the sands of the Alum Bluff formation. Indeed as developed locally at many places one scarcely finds characters on which to distinguish the gray phosphatic sands of this formation from the similar gray phosphatic sands of the Alum Bluff formation, as seen at the type locality on the Apalachicola River. That these sands are residual from the Alum Bluff formation seems probable although the possibility of their origin from some of the later formations must be admitted. That they remain as residual from the Vicksburg Limestone the writer cannot believe.
THE FLORIDA PHOSPHATE DEPOSITS. 3
The source of the dark colored water worn flint Debbles and of the pebble conglomerate occasionally observed especially in the northern part of the field is at present scarcely more than conjectural. So far as the writer's observations hav e extended, materials of this character occur more 'frequently in the Miocene than in any other of the formations of the State.- 1 he presence of mastodon remains indicates admixture of Pliocene material from some source.
The origin of the phosphate is perhaps the most difficult problenm connected with these and, in fact, with phosphate deposits in general. In the case of the Florida deposits the writer is inclined to the view that the phosphoric acid has been very gradually concentrated from various formations in which it exists in only very small quantities. Enrichment by the addition of phosphoric acid is a well known process. Many. instances have come to light of shells originally calcareous now completely phosphatized, the phosphoric acid having replaced the carbonic acid. In many instances the shape and markings of the shell are retained. The bones imbedded in the phosphate also are more or less completely phosphatized. The formation of the phosphate boulders in situ seems evident. The plate an d fragumental. rock represent boulders formed during a preceding stage and subsequently broken, more or less transported and finally deposited in their present position. The pebble phosphate found among the rock phosphate is probably largely water worn detritus mechanically accumulated.
CONDITIONS OF DEPOSITION.
The variable and mixed character of the formation, the frequent clay lenses, the faint tendency to stratification, the occasional local accumulation of loose or conglomerate material indicate to the writer that the material accumulated in shallow water with conflicting currents. Much of the material may indeed have been. scarcely at all transported being residual from formations that have decayed in place. The local accumulation of pebble conglomerate, however, as well as the local occurrence of clay lenses implies conflicting currents in comparatively shallow water.- The faint tendency to st ratification leads to the same conclusions. Such stratification as existed, however, has been much distorted by the settling of the formation as the underlying limestone was removed by solution. The conditions of deposition do
31
.32 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
in this section include, aside from the Vicksburg limestones of Lower Oligocene age, Upper Oligocene formations of the Apalachicola group, Marine Miocene formations, and more or less of Pliocene or later materials since all of these formations occur in position in the adjacent and uneroded high-lands to the northeast. In the course of the decay and lowering of the general land surface there is naturally more or less shifting of material attended probably by the formation of temporary small lakes and streams. It is possible that the conditions thus arising may have been sufficient to account for the mixed condition of the materials, the tendency to stratification in places and other evidence of action by water without the necessity of assuming a complete resubmergence. On this point, however, the writer feels that evidence has not been accumulated to form a final opinion.
FORMATION NAME.
It is thus apparent that the formation contains a mixture of material largely residual from several formations from a early as the Lower Oligocene and as late at least as the Pliocene, fur-ther complicated by subsequent chemical action within the formation itself. The residual material moreover has been reworked and in places transported and redeposited. The term Dunnelhnil formation is suggested for these deposits since they were first found and are best developed in the vicinity of Dunnellon, Florida.
EXPLANATION OF PLATE I.
Fig. I. Phosphate washer for hard rock phosphate in use at pit No. 3, Cummer
Phosphate Company, Alachua County.
Fig. 2. Drill for prospection for hard rock phosphate, in use by the Southern
Phosphate Development Company. The prospect holes are drilled through the phosphate formation to the underlying formation, the Vicksburg Limestone, which is reached at this locality at a depth
of 75 to ioo feet.
Fig. 3. View of incline to pit, in the Croom mine of the Buttgenbach Phosphate
Company.
FLORIDA GEOLOGICAL SURVEY.
THIRD ANNUAL REPORT. PL. I.
EXPLANATION OF PLATE 2.
Fig. i.-View in ptt No. 25 of Central Phosphate Company in Alachua County, showing irregular top surface of the Vicksburg Limestone (Ocala formatior) after removal of the phosphate deposit. The limestone here as elsewhere in the phosphate section projects as peaks.
Fig. 2.-View showing the irregular top surface of the Miami oolitic limestone, Dade County, after the removal of the superficial sands. Photo by R. M' Harper.
Fig. 3.-View in the plate rock phosphate pit at Anthony, showing the laminated structure of the plate rock deposit. The solution of the underlying limestone has permitted subsidence of the phosphate deposit, the folding being due to irregular subsidence.
FLORIDA GEOLOGICAL SURVEY.
THIRD ANNUAL REPORT. PL. 2.
qi
EXPLANATION OF PLATE 3.
Fig. i.-View in pit No. 5, Prairie Pebble Phosphate Company, Mulberry, showing overburden of land pebble phosphate. The contact between the lightcolored incoherent sand and the somewhat indurated sand is well marked. The overburden in this pit is being removed by hydraulics.
Fig. 2.-View in pit of Florida Mining Company, showing a place where the overburden beneath the superficial sand is indurated, making it necessary to resort to blasting.
Fig. 3.--View in pit of the Pierce Phosphate Company, Pierce, Fla., showing an abrupt break in the pebble phosphate stratum. The break is seen near the right side of the picture, where slickensides have developed, as the overburden slid down past the phosphate stratum.
FLORIDA GEOLOGICAL SURVEY.
THIRD ANNUAL REPORT. PL.
EXPLANATION OF PLATE 4.
Fig. i.-View in pit of Pierce Phosphate Company, showing the irregular top surface of the bed rock (Arcadia marl) after the removal of the phosphate stratum. Phosphate plant in the background.
Fig. 2.-View in the pit of the Coronet Phosphate Company, Lakeland, Fla. Unconformity between the coarse phosphate above and the finer pebble phosphate below. This unconformity, although imperfectly shown in the photograph, is well marked at this locality. The material above is a coarse conglomerate, that beneath is fine pebble imbedded in clay.
Fig. 3.-View in pit of Standard Phosphate Company, showing irregular line of contact, apparent unconformity, between the loose surface sand and the more indurated sand beneath.
FLORIDA GEOLOGICAL SURVEY.
THIRD ANNUAL REPORT. PL.
THIRD ANNUAL REPORT. P[ 5.
Aft
VIEW IN THE PLATE ROCK PHOSPHATE MINE AT ANTHONY, SHOWING THE VERY IRREGULAR TOP
SURFACE OF THE LIMESTONE AFTER REMOVAL OF THE PHOSPHATE. PHOTOGRAPH SUPPLIED
EY P. JUMEAU.
FLORIDA GEOLOGICAL SURVEY.
THE FLORIDA PHOSPHATE DEPOSITS.
THE LAND PEBBLE PHOSPHATE-BONE, VALLEY FORMATION.
LITHOLOGIC DESCRIPTION.
The land pebble formation to which Matson and Clapp applied the term "Bone Valley Beds" was briefly described in the Second Annual Report. This formation includes a lower phosphate bearing member and an upper sand or sandstone membe-r. The lower member of the formation contains the workable phosphate deposits. The upper member forms the overburden-which must be removed in mining.
The phosphate bearing member of this formation is more or less definitely stratified, the stratification line being frequently continuous along the full length of the pit, a distance of a half mile or more. Elsewhere the stratification is irregular and cross bedding is evident.
Although variable from place to place this part of the formation has an average thickness of from 8 to 12 feet; its maximum thickness is possibly 18 or 20 feet. The matrix in which the phosphate pebble is imbetlded consists largely of clay, sand and soft/ phosphate. The pebble phosphate makes up in the workable deposits some ten to twenty-five per cent. of the whole. This member shows certain characteristics which are fairly persistent. The lower 2I2 to 3 feet is usually olive green in color, and contains pebble imbedded in clay. The next 3 to 5 feet is frequently dark blue in color although oxidizing on exposure to drab or yellow. The upper 2 to 4 feet of this member differs much particularly in the northern part of the area from that which lies below. This upper part contains coarser material and has a higher percentage of pebble phosphate in proportion to the matrix. The break between the coarser material at the top and the more clayey material beneath is particularly well marked as seen in the pit of the Coronet Phosphate Company in Hillsboro County (P1. 4, Fig 2.) The break is here so abrupt as to constitute a distinct unconformity. The line of contact is marked by the presence of water worn corals, bone fragments and very coarse conglomerate of phosphate pebbles. Passing to the south the contact line becomes less marked, the conglomerate character of the upper part largely disappearing at the south end of the phosphate area.
The indurated sand above the phosphate has an average thickness of from IO to 14 feet. Its maximum thickness, however, is mruch greater. On the other hand owing to decay and erosion these sands are in places much reduced and may be locally entirely
33
34 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT..
absent, the phosphate lying at the surface. Usually the sand contains sufficient admixture of clay to give it coherence. Under these conditions it oxidizes red near the surface. While this is the prevailing phase of the sand it is nevertheless subject to considerable variation from place to place. Not infrequently the sand is firmly cemented forming the so called "hardpan" which gives much trouble in prospecting and frequently necessitates blasting in mining. (Plate 3, Fig. 2.) In places the sand has a calcareous or phosphatic cement. Locally it varies also to an indurated rock with innumerable small cavities which gives a vesicular appearance to the mass. A sample of this rock was found to contain 15.56% phosphoric acid (equivalent to 33.97% tri-calcium phosphate).
The phosphate bearing member contains vertebrate remains including both marine and land animals. Most of the bones are more or less rolled and water worn although occasional whole skeletons are found. In the sands above the phosphate, fossils are rare. The writer has obtained, however, through the kindness of Mr. M. A. Waldo, Manager of the Dominion Phosphate Company a single tooth of the mastodon preserved as a cast in the phosphatic sands of the overburden. Aside from a few casts near the bottom of the phosphate bed invertebrates have not been found in this formation.
MATERIALS LYING ABOVE THE PHOSPHATE FORMATION.
As in the case of the hard rock section the surface material consists of incoherent pale yellow sand. The depth of this sand is variable, ranging from four to ten or more feet. A very definite and often irregular line separates these loose sands from the formation beneath. (P1. 3, Figs. I and 2, and P1. 4, Fig. 3.) This line Matson interprets as an evident unconformity.* This may be true although the fact must not be overlooked that seeming unconfoimities in materials lying near the surface may in reality represent only lines of decay. The writer is inclined to regard the loose surface sands in this section as residual, the irregular line representing the line of complete disintegration of the original sandy formation. A similar explanation has been offered previously by the writer for the surface sands of Gadsden Countyt as well as for the sands overlying the hard rock phosphate formation. (ante P. 24.)
*Florida Geol Survey. Second Annual Report, p. 139, 1909.
tFlorida Geol. Survey. Second Annual Report, p. 263, I9O9.
MHE FLORIDA PHOSPHATE DEPOSITS.
RELATION TO THE UNDERLYING FORMATION ARCADIA MARL?
The land pebble formation rests upon a pale yellow phosphatic marl, referred to by the miners as "bed rock". The relation is apparently as stated by Matson, that of unconformity. This is observed in the pit of the Pierce Phosphate Company, six miles south of Mulberry. The marl as exposed in this pit has a very roughly eroded surface. (P1. 4, Fig. I.) The phosphate
matrix fills these irregularities. The "bed rock" although varying in character is found to underlie the phosphate wherever observed in Hillsboro, Polk and DeSoto Counties. The marl beneath ihe phosphate is probably of Pliocene age.
In 1892 Dall applied the term Arcadia marl to a marl exposed on Mares Creek, six miles above Arcadia.* This marl Dall regarded as slightly older than the Caloosahatchee marl. Matson is of the opinion that the Arcadia marl may be only a phase of the Caloosahatchee marl. The exposure on Mares Creek examined by the writer occurs at and near the mouth of the creek. The marl as seen here has in lithologic character no very striking resemblance to the Caloosahatchee marl but is lithologically very similar to the marls seen at numerous places elsewhere on Peace Creek and underlying the Bone Valley formation. From the continuity of
exposures and similarity in character it seems probable that the "bed rock" of the land pebble phosphate is the Arcadia marl.
LOCAL DETAILS.
HILLSBORO COUNTY.
The northernmost plant in the land pebble section is that of the Coronet Phosphate Company located in Hillsboro County three miles southeast of Plant City. The following sections were observed in pits Nos. I and 2 of this plant.
SECTION IN PIT NO. I, CORONET PHOSPHATE COMPANY.
Pale yellow incoherent sand ............................... 4 feet
Gray indurated sand .................................... 4 feet
Conglomerate of phosphate pebble, bone fragments, water
worn flints and pebbles ............................... I to I2 feet
Buff yellow and olive green clay .......................... 2 to 5 feet
Yellow clay and marl, "bed rock" at bottom of pit.
SECTION IN PIT NO. 2, CORONET PHOSPHATE COMPANY.
Incoherent sand .......................................6 feet
Indurated sands grading at base into a conglomerate of phos*DaIl, Win. H., U. S. Geol. Survey. Bull. No, S4, 1892, pp. 131-132..
35
36 FLORIDA GEOLOGICAL SURVEY--THIRD ANNUAL REPORT.
phate pebble, bone fragments, water worn flints and coral..3 4 feet
Buff yellow and olive green clay matrix in which phosphate
pebble is embedded..................................5 feet
The superficial pale yellow sand is of fine texture and is nonfossiliferous. The indurated gray sand is also non-iossilife( us in the upper part. Towards the base, however, this sand grades into the conglomerate previously mentioned, the lower one. to ole and one-half feet being a very rich phosphate conglomerate.
The break between the phosphate pebble conglomerate and te underlying phosphate matrix is very abrupt representing a local unconformity. (P1. 4, Fig. 2.) Aside from the phosphate there is found in this conglomerate lying along the line of contact a considerable amount of coral occurring as water worn fragments, some of which weigh as much as 8 or io pounds. The larger corals u sually lie immediately upon the contact line. Water worn flint pebbles of one or two pounds in weight, also occur together with fragments of bone.
The phosphate stratum lying beneath this unconformity is chiefly of bluish color which upon exposure oxidizes to a light buff yellow. Occasional bones and flint pebbles are found also in this part of the formation. The water worn corals, however. were not observed below the unconformity. That part of the phosphate matrix below the unconformity contains also many rounded pieces of soft phosphate while that above the unconformity contains hard pebble rock only.
POLK COUNTY.
A pit operated by the Standard Phosphate Company near Medulla is notable for the extreme irregularity in the stratification of the phosphate bearing member. The strata here are observed to dip at an angle of as much as 45 degrees from the horizontal. The bed rock which consists of the usual yellow clay marl is likewise irregular and is observed to rise as much as fourteen feet in a horizontal distance of 50 feet.
In the pit of the Medulla Phosphate Company at Christina, the following section was observed:
Incoherent pale yellow sand .............................:2 to 5 feet
Gray sand, iron stained near surface........................8 feet
Phosphate hearing matrix .............................1I5 to 20 feet
Yellow clayey marl, "bed rock" (exposed) ..................4 feet
In Pit No. 3 of the Prairie Pebble Phosphate Company, near Mulberry the following section was observed:
THE FLORIDA PHOSPHATE DEPOSITS.
Incoherent sand.................................... 2 to 4 feet
Indurated gray sand grading below into phosphate matrix12 to I6 feet Workable phosphate stratum ........................... o10 to 12 feet
Yellow clay marl, "bed rock" (exposed).................. 5 feet
The upper 5 or 6 feet of the sand of this section contain some clay and are stained red by iron oxide. At the base the sands pass gradually into the pebble rock conglomerate. Beneath the pebble rock conglomerate the matrix is more clayey while near the base the clays 'of the matrix are olive green in color. The conglomerate as seen in this pit differs from that seen in the pit of the Coronet Phosphate Company in the absence of corals along the contact line.
The relation between the phosphate bearing formation and the underlying marl or limestone is well seen in the pit of the Pierce Phosphate Company, six miles south of Mulberry. The marl exposed in this pit, as previously stated, has a very roughly eroded surface. (P1. 4, Fig. I.) The phosphate matrix fills these irregularities. At this pit there is observed in places below the workable phosphate matrix one to three feet of material consisting of quartz sand intimately mixed with small black phosphatic pebbles. An old stream channel crosses this pit. In the bed of the stream is fine loose, more or less stratified dark colored sand. This stream where examined has cut (lown to the coarse part of the phosphate matrix and at one point almost cut out this coarse part of the matrix, that is it has cut through the sand and the
upper part of the phosphate formation. This stream occupies approximately the bed of an existing stream and probably indicates that conditions were such formerly as to permit the stream to cut its bed deeper than now, the channel subsequently having been aggraded. Near by in the same pit is a sudden dip in the sand overburden. (P1. 3, Fig. 3.) The point of break gives very much the character of a sink hole.
CONDITION OF DEPOSITION.
In attempting to determine the condition under \vhich the land pebble phosphate formation accumulated, the characteristics of the formation itself should be borne clearly in mind. The formation is more or less definitely stratified. The stratification, however, is irregular, and cross bedding and local sand deposits occur. The phosphate bearing part of the formation is highly fossiliferous containing both land and marine vertebrates. Most of these fossil bones are more or less eroded and water worn, indicatvIng that they have been rolled or washed before reaching their final resting place. Occasionally, however, a complete skeleton occurs. NWater worn bones o f both the land an(1 marine vertebrates could
37
38 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
have as suggested by Matson*, washed into this deposit from some pre-existing formation. This can not apply, however, to the occasional complete skeletons that are found in these deposits. it is probable that the formation accumulated in comparatively shallow water. That the water was not deep is evident from the irregularity of the stratification and from the occasional cross bedding. Also that the place of accumulation was not far removed from land is indicated by the comparatively coarse material and by the presence of numerous bones of land animals.
CHANGE OF CONDITIONS DURING DEPOSITION.
The land pebble phosphate formation, as previously stated, is not of uniform character throughout, indicating that the conditions varied from time to time during the accumulation of the material. The earliest phase of the formation observed consists of clear quartz grains and very small black pebble phos5phate f orming a stratum one to f our feet in thickness. This material occurs only locally and is non-workable, the phosphate pebble being too small to separate f rom the sand. This phase of the formation may be observed in the pit of the Pierce Phosphate Company, six miles south of Mulberry. The formation divides itself into the workable phosphate stratum and the indurated sands forming a part of the overburden previously described. Strati graphically the most pronounced break in the formation is that which occurs within the phosphate stratum itself, particularly in the northern part of the phosphate field, where the pebble -phosphate conglomerate rests upon the underlying clayey phosphate matrix. This conglomerate grades above very gradually into the overlying gray sands. A change in condition in deposition is clearly indicated. This change probably indicates elevation of the land to the north. Following this elevation there was brought in first the coarse phosphatic material accompanied by the flint and corals, and later the sands which make up the upper member of the formation.
STATE AND GOVERNMENT LANDS IN THE PHOSPHATE SECTION.
Both the State and the National Governments still own lands in the phosphate sections of the State. All State lands have been withdrawn from sale by order of the -Internal Improvement Board until properly classified.
THE FLORIDA PHOSPHATE DEPOSITS.
PHOSPHATE COMPANIES OPERATING IN FLORIDA DURING 1909
Thirty-six companies in all were engaged in mining phosphate in Florida during all or part of the year 19o9. Of these twenty companies operated in the hard rock section. Of this number, however, not more than fourteen were actually producing phosphate during any considerable part of the year, others being temporarily closed or preparing for subsequent operations. In the land pebble district sixteen companies were engaged in mining phosphate during all or a part of the year.
List of companies operating during all or part of 19o9:
NAMES. OFFICE. MINES.
I Armour Fertilizer Co.........Fort Meade........Pebble
2 Bradley, Peter B. and Robert S. Floral City..........Hard Rock.
3 Buttgenbach, J. & Co..........Dunnellon........Hard Rock.
4 Camp Phosphate Co.........".... Ocala............ Hard Rock.
5 Campagnie Generale des Pho5 phates de la Floride ............ Anthony ............. Plate Rock.
6 Charleston, S. C. Mining and Manufacturing Co ............ Charleston, S. C....Pebble.
7 Central Phosphate Co..........Newberry...........Hard Rock.
8 Coronet Phosphate Co.........Lakeland..........Pebble.
9 Cummer Lumber Co...........Jacksonville........Hard Rock.
io Dominion Phosphate Co.........Bartow.......... Pebble.
II Dennis & Blanton.............Gainesville .........Hard Rock.
12 Dunnellon Phosphate Co ........ Rockwell.........Hard Rock.
13 Dutton Phosphate Co..........Gainesville .........Hard Rock.
14 Florida Mining Co.............Mulberry..........Pebble.
15 Fla. Phosphate Mining Corpo'n.. Norfolk, Va........Pebble.
16 Franklin Phosphate Co.........Newberry.........Hard Rock.
I7 Ft. White Hard Rock Co.........Baltimore, Md-... Hard Rock.
18 Germofert Mining Co..........Charleston, S. C.... Pebble.
19 Holder Phosphate Co..........Ocala........ ..Hard Rock.
2o International Phosphate Co ..... Ft. Meade.........Pebble.
21 Istachatta Phosphate Co...'..... Istachatta ....... Hard Rock.
22 John McDowell ................ Newberry........ Hard Rock.
23 Medulla Phosphate Co ..........Christina........Pebble.
24 Mutual Mining Co .............Savannah, Ga ...... Hard Rock.
25 Palmetto Phosphate Co.......Baltimore, Md.. Pebble.
26 Phosphate Mining Co.........New York.........Pebble.
27 Pierce Phosphate Co ............ New York........ Pebble.
28 Prairie Pebble Phosphate Co.... Savannah Ga.... Pebble. 29 Schilman & Bene............... Ocala.............Hard Rock.
30 Southern Phosphate Development Co ...................... Ocala............. Hard Rock.
31 State Phosphate Co...........Bartow ...........Pebble.
32 Standard Phosphate Co.........Christina..........Pebble.
33 Thompson, M. C. & T. A ...Willeford .......... Hard Rock.
34 Tilghman Phosphate Co ........Bowling Green ...Pebble.
35 Union Phosphate Co ...........Tioga ............ Hard Rock.
36 Williams Phosphate Co ........Inverness ..........Hard Rock.
39
40 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
THE PRODUCTION OF PHOSPHATE DURING I9O9.
The total production of phosphate in Florida for the year 19o9 shows a slight decrease over that of the preceding year. The total production for I9O8, exclusive of river pebble, was 1,918,oi long tons. Including river pebble the total production for 19o8 was 1,95o,961 long tons, while for the year 19o9 the total production was 1,862,15i long tons. The decrease in production occurred entirely within the hard rock section, the output of land pebble having actually increased.
The shipment of phosphate for the year 19o9 practically equalled the production both of hard rock and of land pebble. Hard rock shipments amounting to 514,101 long tons have been reported as against the production of 527,582 long tons. For the pebble rock, shipments have been reported amounting to 1,329,102 long tons against the production of 1,334,569 lOng tons.
The phosphate market continued very much depressed during the year. Hard rock phosphate was reported to have been sold as low as from $5 to $6 per ton f. o. b. at mines, while land pebble was sold from $2.75 to $4.25 per ton f. o. b. at mines.
HARD ROCK PHOSPHATE.
The production of hard rock phosphate during 19o9 shows a decided falling off from that of the preceding year, the output having been curtailed by the operators on account of the Pw prices. The amount mined during 19o8 was 768,oi i long tons, while for the year 19o9 the total production reported is 527,582 long tons, a decrease of about 240,000 tons, or about 30 per cent.
As in former years practically all of the hard rock phosphate shipped, was consigned to foreign markets. The total amount of hard rock phosphate consigned for use in the United States during 1909 was 17,456 long tons. Of this amount 13,726 tons were used in Florida. The amount exported during 19o9 was 496,645 long tons.
PEBBLE PHOSPHATE.
While the production of hard rock phosphate was reduced during 19o9, the output of pebble was increased. The amount of pebble rock mined in 1908 was approximately I,I i o,ooo long tons. For the year 1909 the total production of pebble phosphate was 1,334,569 long tons, an increase of over 150,00o0 tons.
Shipments listed by the "American Fertilizer" showv that the total pebble rock exported during 1909 was 509,341 long tons.
THE FLORIDA PHOSPHATE DEPOSITS. 41
The amount consigned f or use within the United States as reported. by the operators was 819,761 long tons.
The mining of pebble rock on Peace River discontinued during the latter part of 19o8 was not resumed during 1909. A small shipment Of 3,215 tons of this rock during 1909, mined in 1908, is included in the total domestic shipmients of pebble rock as given. above.
SUMMARY OF PRODUCTION AND SHIPMENTS FOR THE YEAR 1909, Hard rock ... LONG TONS.
Total production ........... .................... 527,582
Consigned for use in U. S ........... .............. 17,456
Exported ............... ......................496,646
Total shipments .......... ....................... 514,10,
Pebble rock,.
Total production ...... ....... ........ ......... I,334,56c)
Consigned for use in U. S......................... 819,76j.
Exported .......... ...... ....................... 509,341
Total shipments....... .... .................... 1,329, 102
Total production of hard and pebble rock .............. ........ .....1, 862, 1 "
Total shipments of hard and pebble rock............................ 1,843,20"
COMPARATIVE TABLE OF PRODUCTION AND SHIPMENT OF
FLORIDA PHOSPHATE FOR THE YEARS 19o8 AND 1909.
(LONG TONS.)
PRODUCTION Consigned for Use EXPORTED Total Shipments in the U, S,
1908 1909 1908 1909 1908 1909 1908 1909 Hard Rock ......... 768,011 527,s8'2 9,900 17,456 631,001 496,645 631,001 514,101 Pebble Rock......1150000 1,334,569 421,781 819,701 470,270 509,341 900,519 1,329,102
Totals ............. 1,918,011 1,862,151 431,681 837,217 11,101,271 1,0-5,986 1,531,520 1,843,203
SOME FLORIDA LAKES AND LAKE BASINS
BY E. H. SELLARDS.
CONTENTS.
PAGE
Introduction ....................................................... 417
Location of the Lakes................................................ 48
Characteristics ..................................................... 48
Origin and History of Development ................................... 49
Relation of the Basins to the Level of Permanent Underground Water.. 52 Descriptions of Typical Lakes...................................... .5
Lake Jamonia, Leon County ..................................... 53
Lake Jackson, Leon County ................ .................... 5
Lake Lafayette, Leon County ..................................... 57
Lake Miccosukee, Jefferson County .............................. 5
Alligator Lake, Columbia County................................ 6
Alachua Lake, Alachua County ................................... 62
Ocheesee Lake, Jackson County ..................................67/
Methods of DrainageBy Surface Ditching............................................. 68
By Wells ...................................................... 68
Summary .......................................................... 74
ILLUSTRATIONS.
PLATE No. FOLLOWING
6. Miccosukee Basin, Low Water Stage of 19o9..............
7- Fig. i. Lake Jackson.....................................
Fig. 2. A lligator Lake ..........................................
8. Fig. i. The Sink of Lake Lafayette ..............................
Fig. 2. Paynes Prairie, Looking Out From the Sink............
Fig. 3. View of Paynes Prairie From Near the Sink...........
9. Two views of Spouting Well Near Orlando .......................
PA(r;,
64 64
-4
64
TEXT FIGURE No. PAGE
Sketch Map Showing Location of Lakes Iamonia, Jackson, Lafayette, and M iccosukee .......................................... 54
2. Lake Jackson ................................................... 56
3. L ake L afayette ................................................. 58
4- Lake M iccosukee ................................................ 6o
5. Sketch Map of Hogtown Prairie and Surroundings ................ 66
SOME FLORIDA LAKES AND LAKE BASINS.
E. H. SELLARDS.
INTRODUCTION.
Florida is Justly celebrated for the number and beauty of its. lakes. These lakes vary in size from the small ponds which scarcely exceed a few rods in circumference to the great Okeechobee, the surface area of which -exceeds 700 square miles. Okeechobee is in fact noteworthy as being, with the exception of Lake Michigan', the largest fresh water lake lying wholly within -the United States. In depth the Florida lakes, are likewise variable, and in fact the depth'is, frequently in inverse ratio to the size. Many of the large lakes are comparatively shallow, while some of the small lakes are deep. This is particularly true of the small sink-hole lakes, some of which, while not exceeding a few rods in circumference have a depth of one to two hundred or more feet. In origin and history of development the Florida lakes are as variable as in other characteristics.
The lakes described in this paper include only a few of the many Florida lakes and' represent a type peculiar in character and in manner of development. They are fresh water lakes, often of considerable size, although usually relatively shallow as compared to their areal extent. Moreover they are variable in character. Under normal conditions they are clear water lakes abounding in fish and the favorite haunt of the wild duck. They have as a rule no surface outlet, yet from many of them the water has at times disappeared in a manner seemingly inexplicable.. In most instances the lakes thus disappearing have refilled slowly. Some of them, however, have remained dry a number of years. A correct understanding of these lakes together with the origin and development of the basins which they occupy is necessarily based on a study of the geologic formations which underlie them.,
The fall of i909 offered an exceptionally favorable time for investigating lakes of this character. The prolonged dry, weather of the past few years had reduced these lakes to a low stage offering an opportunity of examining the soil and vegetation as well as the geologic structure of their basins. At the Tallahassee station in Leon County, near which several of these lakes are located,
48 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
below normal during the preceding four years and at the Lake City station the rainfall had been below normal for at least three years in succession and apparently, from some imperfect records, had not reached normal during the preceding seven years.
Under these circumstances it was deemed advisable to make use of the favorable opportunity during the fall of 19o9 for investigating the geology of these lake basins.
Attempts have been made to drain some of these lakes as the land is more or less valuable for agricultural purposes. In some instances drainage operations have been delayed owing to legal difficulties arising from the variable character of the lakes. The lake basins claimed by the State under the title of swamp and overflowed lands were likewise claimed by abutting property owners under the privilege of riparian rights. A recent decision of the State Supreme Court vests the title of the lands in question with the State, not, however, as swamp, and overflowed land but as navigable water.
LOCATION OF LAKES.
The lakes described in this paper occur in the upland section of the interior of Florida. In general they may be said to occur in a belt extending with interruptions from the Ocklocknee Rivei east and south paralleling the Gulf of Mexico to Hernando and Pasco 'Counties. The largest and best known examples are found in Leon, Jefferson, Columbia and Alachua Counties. Smaller but no less typical lakes of this type occur in Madison, Suwannee, Marion, Levy, Orange, Hernando and probably some other counties adjacent to those mentioned. West of the Apalachicola River small lakes of similar character occur in Jackson County and possibly also in Holmes County.* The lakes selected for description as illustrating this type include Lakes Iamonia, Jackson, and Lafayette, in Leon County; Lake Miiccosukee in Jefferson County: Alligator Lake in Columbia County; Alachua Lake in Alachua County; and Ocheesee Lake in Jackson County. The belt )f country through which these lakes occur, although now broken up through natural processes of erosion into, several more or less well defined sub-divisions, was probably at one 'time continuous.
CHARACTERISTICS.
The leading characteristics of these lakes have been mentioned. They do not occur along the coast nor in the level low lying parts
*For location of counties, see map plate I0, following page 121.
SOME FLORIDA LAKES AND LAKE BASINS.
of the state. On the contrary they are on the uplands, and occur in sections having a hilly or rolling topography. Sinks or openimgs occur through which the water escapes into the underlying formations. These sinks are located ordinarily at the foot of a steep bluff bordering the lake. Around the main sink one finds ordinarily other sinks of more recent formation indicating the manner and direction of enlargement of the basin. The sinks through which the water escapes are variable in depth but reach in all cases to underlying limestones. A channel as a rule leads back from this sink across the lake bottom representing the main channel of flow of %vater to the sink. Aside from this channel the bottom of the lake is relatively flat and level, although slight local depressions occur involving in some instances differences of level, of ten to fifteen feet. The soil in the lake basins varies considerably. In some of the lakes-those which seldom go dry-there is an accumulation of muck or peat formed largely from pond lilies and other aquatic vegetation. Local depressions in the lake often have an accumulation of this material amounting to several feet. Some of the other lakes which frequently go dry have little or no muck except in deIressions which hold water even in dry seasons. Beneath the v suck is usually found light colored sand washed and blown from the neighboring highlands. This sand may be several feet deep in places, elsewhere it is largely absent. Ordinarily a sandy clay occurs beneath the sand.
When these lakes dry up the Water is commonly reported as running out very suddenly. This, however, is usually not the case. As long as the lake has sufficient water to cover the entire basin' the lowering of the water surface proceeds very slowly. Subsequent-ly when the total surface area of the lake becomes much restricted the lowering of the water surface proceeds much more rapidly. This leads to the statement that the water of the lake disappeared suddenly while'as a matter of fact in many cases the water escapes through the sink no, faster and indeed hardly so fast during the dry season as it had been escaping when the lake was full during the season of normal rainfall. It is true, however, that new sinks, occasionally form in the bottom of the lake. In the case of 'the formation of new sinks the rate of escape of the water is increased.
ORIGIN AND HISTORY OF DEVELOPMENT.
The origin of these lake basins is a part of the history of development of the general topography of the region. In 'this development both mechanical erosion and erosion by solution have
49
50 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
had a part. The land surface when first elevated above sea was evidently much more nearly level than at present. Upon being lifted above sea level irregularities in topography rapidly develop.
A first step in. the process of erosion is the development of stream channels and valleys, largely through mechanical erosion. In addition to mechanical erosion, clusO n by solution due to underground water is likewise in process especially in sections underlaid by limestones.
As illustrating the efficiency of underground water as an eroding agent, the writer in a previous report computed the rate of erosion by solution in the sections of the state underlaid by limestones.* The estimate of the rate of solution given below is taken from that report.
Solution is the most apparent, and geologically the most important result of underground water circulation. Rain water, while passing through the air, takes into solution a small amount of C02 gas. To this is added organic and mineral acids taken up while passing through the soil. Increased pressure, as the water descends into the earth, enables the water to hold in solution greater quantities of gases, acids and salts, all of which greatly increase the dissolving power of the water.
That underground water is efficient as a solvent is evident from the analyses of well and spring waters. Rain water entering the earth with almost no solids in solution, returns to the surface through springs and wells with a load of mineral solids in solution determined by the length of time it has been in the ground, the distance traveled, and the character of the rocks and minerals with which it comes in contact.
The mineral matter thus taken into solution is carried along vith water, and, while some of it is re-deposited, a large amount is removed annually.
An estimate of the total mineral solids thus removed is difficult. A conception of the largeness of the amount removed is obtained from a consideration of some of the individual springs.
The water of Silver Springs contains, as shown by analysis, 274 parts solids per million parts water. Otherwise expressed, each m,1illion pounds of water is carrying with it 274 pounds of solids in solution. Silver Spring is estimated to flow a little more than three million pounds of water per minute (368,913 gallons). The interior of Florida is ,thus being carried into. the ocean through Silver Springs at the rate of more than 340 pounds per minute, or about six hundred tons: per day.
*Fla. Geol. Survey Bulletin No. I, pp. 46, 47, 48, 1908.
SOME FLORIDA LAKES AND LAKE BASINS.
The total solids removed in solution of central Florida, expressed in tabular results :*
Name of Spring County.
Blue ................... M arion
Blue ................... Levy
Ichetucknee............. Columbia
Newland..............Suwannee
Weekiwachee ........... Hernando
White Sulphur..........Hamilton Suwannee ..............Suwannee
through six other springs form, gives the following
Total solids Est. flow
(parts per (gals. per
million) min.)
112.1 349.166
196.8 25,000
211.6 i8o,ooo
233.5 75,000
227.8 100,000
166.6 32,400
332.7 19,747
Solids removed lbs. per day.
469,698 59,040 457,050 210,150
273,360
64,774 78,816
As the basis of an estimate of the total solids removed annually from the interior, let it be assumed, (i) that the average total solids in spring water amount to as much as 219 parts per million, this average being obtained from eight of the typical large springs of central Florida; (2) that the annual escape of the undergroun( water approximates the annual in-take, amounting, as previously estimated to 46o,536,689 gallons per square mile. Upon these estimates the mineral solids removed amount to a little more than four hundred tons annually per square mile.
Of the minerals thus removed, calcium carbonate or limestone greatly predominates, exceeding the combined weight of all other minerals. From the analyses it appears that magnesium carbonate, magnesium and calcium sulphates are present in variable, although usually limited, quantities. Chlorides are normally present in small amount, although occasionally, as in the case of Perrian Spring, they are exceptionally high. Silica is present in amounts varying from 5 to 25.5 parts per million. Traces of phosphoric acid and of iron and alumina are usually present.
The several undetermined factors which enter into the above estimates of mineral solids removed make it difficult to formulate a concrete statement of the rate of lowering of the general surface level. Nevertheless, such statements are desired and have a comparative value. Assuming for the rock removed, most of which is
*For 340 in the second line from the bottom on the preceding page read 84o.
tOrganic matter is deducted from the total solids as given for Suwannee Sulphur and White Sulphur Springs. The organic matter occurring in the other springs is of small amounts and was not separately determined. Analyses of the water of these springs were given in Bulletin No. I, pp. 72-75, 1908.
51
52 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
limestone, a vrg pcii rvt f2.5, a layer one foot thick over one square mile should weigh about two and one-sixth million tons. The calculated rate of removal of this rock is about four hundred tons per square mile per year. From these estimates it would appear that the surface level of the central peninsular section of Florida is being lowered by solution at the rate of a foot in five or six thousand years.
With due allowance for a wide niargin of, error in the above estimates* it is still evident that a very great amount of mineral solids is being removed annually in solution. The first effect of solution in limestone is to develop cavities through the rock along the line of ready flow of underground water. These cavities gradiilyenlarge until the overlying material, n longer ablhi supr its own weight, caves in, forming a sink.
The formation of a sink is a first step in the development of the many basins large and small occupied by these temporary lakes. A sink usually retains connection with the underlying limestone for some time after its formation and water entering the sink escapes into the limestone. Under these circumstances more or less of the material lying immediately around the sink is carried by surface wash through the sink. Moreover the large amount of water entering through the sink results in rapid solution in the limestone of that immediate vicinity. The result is frequently thIe formation of other sinks in close proximity to the first. As old sinks become clogged or partly filled, new sinks form by this process continually enlarging the basin.
Not infrequently a sink forms in or near the bed of a stlreatn When this occurs the lower course of the stream, or a part of1'it. may be reversed. Where many sinks form in succession or through a long period of time the valley of the stream is thereby enak .rgedi and is frequently carried to a level lower than the~ original 'dl Lakes jamonia and Lafayette in Leon County and Alachua Lake in Alachua County are illustrations of basins of this type.
RELATION OF THE LAKE BASINS TO THE LEVEL OF~
PERMANENT UNDERGROUND WATER.
SOME FLORIDA LAKES AND LAKE BASINS.
ground water goes on more rapidly above the level of permanent underground water than below this level. The term "belt of weathering" is commonly applied to that part of the earth's crust lying above the underground water level; while the term "belt of cementation" is applied to that part lying immediately below this level. According to Van Hise "the most characteristic reaction ot the belt of weathering is, solution. In contrast with this the most characteristic reaction in the belt of cementation is deposition in the openings of the rocks."* The rapid solution in the belt of weathering is due to a number of causes. First of all the water in this part of the earth's crust moves freely, while in the belt of cementation the water often moves very slowly. Moreover water is capable under given conditions of carrying a definite amount of mineral solids in solution and as the water from the surface enters the earth with little or no load, until it becomes saturated it takes materials into solution readily.
In accordance with this principle it is found that the largest of these basins are, as a rule, reduced practically to the level of un-derground water. Many of the smaller basins, it is true, have not r-ached the permanent water level, and stand at varying heights above that level. The relation of the basins to the underground water has a practical bearing and will be referred to again in connection with methods of drainage of the lakes.
DESCRIPTIONS OF TYPICAL LAKES.
LAKE IAMONIA.
Lake Iamonia lies near the north line of Leon County. The lake basin is irregular in outline, but has an average width of from one to one and one-half miles. The total length of the lake is from twelve to thirteen miles., At its west end the lake basin connects with the swamp of the Ocklocknee River. During flood seasons the river overflows into the lake. Similarly a high stage in the lake results in an overflow into the river. Small tributary streams enter the lake from both the north and the south side as well as from the east end. The tributaries are small flat-bottomed streams which are dry, except during the rainy season. The lake fluctuates much according to the rainfall. The lake basin when full covers an area of about 65oo acres. Except at the west end, where
*Treatise on Metamorphism Mon. U. S. Geol. Survey, XLVII, p. 165, I904.
53
54 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
it joins the Ocklocknee River, the Iake is largely surrounded by the red clay hills characteristic of this part of the State. These hills rise to an elevation of from 5o to 75 feet above the level of the lake.
Fig. I- Sketch map showing the location of lakes Jamonia, Jackson,
Lafayette and Miccosukee in Leon and Jefferson Counties.
The .sink through which the water escapes from this lake occurs along the north border. When visited May 7, 19IO, the sink was practically dry, having only a small amount of water in the bottom. Limestone rock, probably of Upper Oligocene age, is exposed near the bottom of the sink, the water escaping through or under these rocks. Above the limestone partly decayed sandy clays occur. These contain few fossils, although oyster shells were found in abundance at one locality. The total depth of the sink below the general level of the lake is not less than 50 feet. The sink occurs, as is usual in this type of lake, facing an abrupt bluff 30 feet or more in height. A considerable number of sinks occur around the border of the lake especially in the vicinity of the one large sink which receives ,the drainage of the lake. The formation of these sinks is doubtless due, as previously stated, to the fact that the water entering the drainage sink spreads laterally in the underlying limestone and dissolves the rock rapidly. The result is the formation by subsidence of numerous sinks adjacent to the drainage sink. The presence of these sinks also indicates the manner of enlargement o E the lake basin, and indicates in each case the direction of most rapid enlargement at the present time. At other times the enlarge-
SOME FLORJDA' LAKES AND LAKE BASINS.
ment by solution and subsidence may have been most active in some other locality or direction or part of the lake basin.
This lake only occasionally goes entirely dry and as a result a covering of muck or peat occurs over the greater part of the bottom of the lake. This deposit of muck reaches a considerable thickness in such natural depressions as occur over the lake bottom. Beneath the muck is usually found a deposit of light colored sand and beneath this is the red sandy clay.
The fact that the Ocklocknee River at flood stage flow into this lake makes any attempt at drainage doubtful of success. An effort Which proved unsuccessful was made at one time to prevent the river water from entering the lake by means of a dam. It seemed to be the views of the party constructing the dam that if the water of the Ocklocknee River could be kept out the sink would carry off the water from the lake. This, however, is not probable, since in the several other lakes to be described the sinks have not proved sufficient to carry off the water except in times of greatly reduced rainfall. Lake Iamonia basin represents apparently a stream valley lowered by solution and enlarged laterally by subsidence through the formation of sinks. Originally a small stream tributary to the Ocklocknee River flowed through this section. In this part of the county soluble limestones -occur at no great distance from the surface, and in the course of the natural processes of erosion the stream approached sufficiently near this limestone to permit of the formation of sinks and the escape of the water of the stream through the sinks. The enlargement of the valley to its present size has proceeded through the formation and partial filling of successive sinks. As each sink forms, it carries down to or below the lake level, a certain small area of land. Moreover the water passing through the bottom of the sink carries with it more or less detrital material so that the surrounding area is somewhat lowered by wash through the sink. In the course of time other sinks form, while the older sinks become clogged and usually partly fill up. The direction of active enlargement of each lake can be determined from the location of the recent sinks. As previously remarked this rapid enlargement is usually around the sink Which is at present actively receiving ,the drainage.
55
56 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
LAKE JACKSON.
Lake Jackson lies near the western border of Leon County within one and a half or two miles of the Ocklocknee River. This lake is irregular in shape, and has a total area of about 4,5oo acres. The bound. aries of the basin are sharply marked by the surrounding highlands d Ink which rise 75 to ioo feet
lake Jacsoz above the level of the
lake. Several sinks occur in the southern half of the lake. The largest of these, known locally as the "lime sink," is located Well out il the basin and in the angle between the north and east arms. (See map). An opening in the bottom of this sink Fig. 2.-Lake Jackson. in May, 1907, permitted
the water to run out, leaving the sink dry, and also draining the lake or such part of it as was connected with the sinks. An indefinitely defined broad depression or slough extends to the south-east from the lime sink. Several water holes representing old sinks occur along the line of this depression. A new sink occurred along the bottom of the depression about one mile southeast of the lime sink in June, 1907. A compact limestone showed in the bottom of this sink at a depth of about 25 feet from the surface. At the time this sink formed the lake was low, a part of the water having been carried off through (the opening which had formed in the lime sink a month earlier. All the water that could reach the new sink was carried off in the course of two or three days, leaving the lake dry except for occasional water holes. When examined in September, 1909, a small open sink was found in the slough which carried away all of the water that reached it froni the surrounding parts of the lake.
SOME FLORIDA LAKES AND LAKE BASINS.
The surface soil in the basin is quite generally a gray sand darkened by admixture of organic matter. In the lower parts of the lake, quite generally covered by water, more or less muck or peat occurs formed from 'the accumulation of aquatic vegetation. Sand lighter in color and lacking the organic matter occurs at a depth of I Y2 or 2 feet to3 or 4 feet. Beneath this sand is the usual red sandy clay.
This lake as already mentioned became dry, or nearly so, in the early spring of 1907. It was partly filled by the summer rains of the same year, but became dry or nearly so again during the summer of 19o9. The accompanying photograph of this lake was taken July 5, 1909 and shows an unusually low water stage of the lake for that season of the year. (P1. 7, Fig.I).
LAKE LAFAYETTE.
Lafayette Basin or Lake Lafayette lies in the eastern part of Leon County between Tallahassee and Chaires. The basin begins three and one half miles east of Tallahassee, and extends to within one mile of Chaires, having a total length of about five and one-half miles, and a width of one-half to one mile. An arm of the lake extends north from near the east end of the lake. The bottom of the basin is nearly level with the exception of occasional slight depressions. The tributaries to the lake are flat-bottomed streams with relatively broad valleys and no well defined channel. The soil in these stream valleys is a sandy loam, and the streams are ordinarily dry, carrying water only during the rainy season.
A drainage sink in this basin occurs near the west end of the lake along the northern border (See Fig. 3). The sink when measured in September, 19o9, was found to have a total depth of 75 feet. The sink is found, as is usual in this type of lake basin, facing a prominent bluff. A second sink is formed beyond the lake border, thus indicating the enlargement of the lake basin in that direction by subsidence, due to underground solution. This new sink is one hundred yards or more in circumference, and when formed carried down to the lake level, land which stood fifty feet or more above the lake and was being used previous to the subsidence as a cemetery.
That part of the lake basin which surrounds the sink lies at a slightly lower level than the more remote parts of the basin and is the first to be submerged at the approach of the rainy season. This area is entirely devoid of trees, and during the dry season becomes a praire. The greater part of the basin lying to the south of the railroad is thickly set with small cypress trees.
t;7'
58 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
The soil in the basoin is prevailingly a gray sand usually darkened by the presence of organic matter. At a depth of from one to two feet the amount of organic matter is reduced, the sand being lighter in color. Sandy clays are reached as a rule at a depth of from two and a half to three feet.
During a season of normal rainfall this basin is occupied by a lake having a -total area of approximately two thousand acres. Following a period of prolonged drought the basin becomes entirely dry, water remaining only at the sink. In times of excessive rainfall the lake overflows at the east end, the water discharged reaching streams tributary to the St. Marks River.
CAi
4 dt Chaires
Zdk.Arayette
Fig. 3.-Lake Lafayette.
This basin has much the character of an elongated valley. The general course of the streams of this part of the county, the shape of the basin and particularly the topography of the surrounding country indicate that (the drainage of this section was originally through these streams into the St. Marks River. The-formation of sinks diverted the drainage to a subterranean course, the west end of the basin having been reduced to a level somewhat lower than the east end. The further enlargement of the basin is being carried on through the formation of sinks along the border. The largest cf the newly formed sinks is found near the present drainage sink.
LAKE MICCOSUKEE
Miccosukee Basin or Lake Miccosukee lies between Leon and Jefferson Counties, the west border of the lake forming the county line. A small arm of the lake, however, near the north end reaches. into Leon County.
SOME FLORIDA LAKES AND LAKE BASINS.
Miccosukee Basin has a total area of about 5,oo00o acres. In its northern part the basin is bordered by sharply defined bluffs, which rise from 50 to 75 or 100oo feet above the lake bottom. Farther south these bluffs fall back and give place to a gradual rise of elevation from the lake border. At the south end bluffs are lacking. A drain known as Miccosukee drain enters irom the east side. This drain consists of a low, swampy area from one-fourth to three-fourths mile in width. This swamp land supports a thick growth of hardwood trees.
When full, Miccosukee Basin is covered with water to a depth of from 2 to 5 feet. Toward the south end around the border of the lake grass and button bushes project above the water even when the lake is full.
The sink of Lake Miccosukee is located near the north-west corner (see Fig. 4). The sink is bordered by a bluff having an elevation of from 75 to Ioo feet. Landslides along the border of the sink show recent enlargements of the basin. Numerous sinks occur along the border of the lake at this locality, showing enlargement of the lake basin through subsidence. The greatest depth of water found in the sink when examined September 7, 1909, was 38 feet. A .channel leads back from this sink across the prairie in a south-easterly direction. This channel has cut to a depth of from twenty to twenty-five feet. Followed back from the sink the channel is of gradually reduced depth finally at a distance of about two miles merging into the general level of the lake bottom. When examined September 8, 1909, this stream was carrying water into the sink at a rate estimated to be 2oo gallons per minute. Notwithstanding the inflow from the stream the water in the sink was being gradually lowered. Heavy rains oc-curred in this vicinity on September 21, 1909, and this stream when seen two days later was carrying approximately 7,00ooo gallons of water per minute. At this time the sink was being rapidly filled, having filled several feet during the two preceding days. From these observations it appears that the opening at the bottom of this sink permits the escape of water at a rate in excess of 2oo gallons per minute, but much less than 7,oo000 gallons per minute. From the behavior of the sink it is probable that not more than I,ooo gallons of water are escaping per minute, and the rate of escape may be much less.
The principal escape of water from Lake Miccosukee when the lake is full is through a drain which leads out from the south end of the lake and enters a sink about two and one-fourth miles from the south end of the lake. This sink is formed in a light colored limestone of Upper Oligocene age, probably representing the Chat-
59
60 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
Fig. 4.-Lake Miccosukee.
SOME FLORIDA LAKES AND LAKE BASINS.
tahoochee formation or the Tampa formation. The drain from the lake as it approaches the sink passes through a narrow gorge cut in this limestone.
About one-half mile farther south (Sec. 14) another sink is found. This third sink receives the flow from Mill Creek, a small stream draining considerable territory lying south of the Seaboard Air Line Railway and east of Lloyds.
During a season of excessive rains these sinks are unable to carry away the water. Under these conditions the overflow from Lake Miccosukee as well as from 'Mill Creek ultimately findL- its escape by flowing to the south-west past Lloyds to the St. Marks River.
The surface in Miccosukee Basin is covered with muck to a varying depth. Borings put down near the north end of the basin, out from the margin of the drain, indicated the presence of muck for a depth of from six inches to one foot. Beneath the muck in this part of the basin was found a gray sand. This sand is underlaid, at a variable depth, by the usual red sandy clay. At the south end of the lake the sand is largely absent, (the muck which is from one to three or more feet deep resting, so far as observed, directly upon the red clay.
Lake M,iccosukee probably represents a basin developed by solution near the headwaters of streams originally tributary to the St. Marks River. Previous to the formation of Miccosukee Basin the drainage of this part of the country doubtless passed through small streams, to the south past the present village of Lloyds, -thence to the Gulf through the St. Marks River. The lake basin since its formation has enlarged to the north-west, the lowest part of the basin now being found near the sink in the north-west corner.
Mill Creek which now enters from the south and disappears through a sink a few miles north of Lloyds illustrates the reversal of flow of a stream due to the formation of a sink- This stream, previous to the formation of the sink, flowed south-west to the St. Marks River. At the present time it flows north and enters the sink. At times of excessive rainfall the sink is unable to carry off the water and the stream under these conditions flows in its earlier course to the St. Marks River.
ALLIGATOR LAKE.
Alligator Lake lies in the central part of Columbia County, from one and a half to two miles southeast of Lake City. The lake basin has a total area of about I,OOO acres. Numerous smaller lakes occur to the west and north of this large lake. ,The stur-
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62 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
rounding country is in general level or rolling and lies at an elevation approximating 2oo feet above sea. The basin along its western side is bordered by a bluff which rises to an elevation of from 50 to 75 feet above the level of the lake. \ Voi the eastern and southeastern side the basin passes gradually into low lying swampy hammock land, or cypress swamp. The sink of Alligator Lake occurs along the southwestern border. The escape of water at the present time is through this sink. In the coun try bordering the lake around this sink numerous other sinks occur. The lake is said to overflow at high water stage to the south through a small stream known as Clay Hole Branch.
A soil boring put down fifty yards from the edge of the basin along its southwest border gave the following section:
Black muck With admixture of clay............................ft.
Yellow sand loam ............................................. 2 ft.
Fine light gray sandI....................................i2 ft.
A pit made by Mr. Greer in his garden near the border of the lake gave the following section:
Brownish colored imperfectly decayed vegetable matter (peat) .... I ft.
Black muck with admixture of sand and clay.................2 ft.
Red very sandy clay......................................I ft..
It is reported that at the time of the early settlements in Columbia County, 1835 or thereabouts, Alligator Basin was a prairie or savanna and was used at that time by the Indians as pasture land. The lake was dry in the-fall of 1801, and again in the fall of 1899 or 19oo. It was dry again during the winter and spring of 19o9, but was partly filled by rains during the following summer.
Approximately complete records of rainfall are available at the Lake City station for the year 1897 and succeeding years. The rainfall for the year 1899, at which time the lake became dry, was much below normal, amounting for the year to, only 30.49 inches. The next period of unusually low rainfall was the year 19o8. During this year the rainfall amounted to only 29.83. The rainfall during the year 1909 was likewise slightly below normal, amounting at Lake City to 49.68 inches.
ALACIIUA LAKE.
Alachna Lake or Paynes Prairie is the central and largest of the several lake basins of southeastern Alachua County. This basin is about eight miles long and varies in width from one and a half
SOME FLORIDA LAKES AND LAKE BASINS.
to four miles. It contains about twelve thousand-acres. Low divides scarcely exceeding ten feet in elevation separate this basini from Kanapaha and other prairies on the west and from Levy, Ledwith, and numerous smaller jakes on the south, and from Newnans Lake on the northeast. The total area embraced within these various basins is not less than fifty square miles. For a map of this section the reader may consult the Arredondo topographic sheet of the U. S. Geological Survey.
When dry or nearly so, this basin supports a dense growth of grasses and weeds. On the more elevated and dryer parts dogfennel prevails, growing to a height of eight or ten feet, while on the lower and wetter parts of the basin maiden cane abounds.
The principal stream entering this basin is a creek flowing from Newnans Lake. This creek enters at the east side of the basin and flows west and northwest to the sink.
The "sink." of Alachua Basin is located in the northeast border. Two sinks occur here. The waters from these sinks enter the Vicksburg Limestone. The sinks are partly surrounded by bluffs rising to an elevation of thirty or forty feet above the general level of the basin. Numerous sinks occur along the border of the lake showing enlargement of the lake basin in this direction. The stream entering the more westerly of the two sinks was carrying water when examined in October, 1907, at an estimated rate of 20,000 gallons per minute. At this time the water level in the sink was only 2.01 feet above the general level of water in the Vicksburg Limestone as shown by the Gainesville city well,* indicating that the sink was carrying water at its full capacity or nearly so.
In November, I9O9, the water in the sink stood approximately one and one-half feet above the level of the water in the surrounding limestone.
During seasons of heavy rainfall the stream draining from Newnans Lake and other smaller streams# carry water so rapidly that the water is unable to escape through the sink as rapidly as it flows in. Under these conditions the basin fills, becoming temporarily a lake. It is probable also that the drainage sink becomes more or less completely clogged at times retarding the escape of water, and in this case the prairie may continue as a lake through a succession of years.
Variation in this lake has been more or less perfectly recorded since the time of the earliest settlements in this section. When
*Bull No. I, Fla. Geol. Survey., p. 60, 1908.
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64 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
visited by Bart 'ram in 1776 this basin was known as "Alachna-savannah" and served as grazing ground for stock belonging to thc Indians.* 'The basin was visited by James Pierce in 1824 and was dry at that time. The water in the basin is said by W. W. Cameron who' lives near its margin to have been very low in 1861. When visited by Dr. E. A. Smith in i 88o the basin was comparatively full, forming a lake. The basin in fact is reported to have continued as a lake f rom 187 1 or 1873 to 189 1. In the f all of 189 t the basin became dry, and, with the exception of temporary overflows has been dry much of time since that date. It is possible that the higher water stage in the basin during the years from 1871 to 1891 was due to partial clogging of the -sink.. The records of rainfall during these years for this section is unfortunately lacking.
The following account of the disappearance of Alachua Lake appeared in the Providence journal for September 14, 189i. The account is given with some omissions as quoted by Dr. W. H. Dali in Bull, 84, U. S. Geol. S--urvey p. 94,192
"A curious spectacle was to be seen on the outskirts of Gainesville, Florida, recently. Alachua Lake** is no more. On its banks were lying thousands of dead 'fish* and the atmosphere wasI heavy with noxious gases. Men and boys were there in throngs with hoes and rakes, dragging to shore hundreds of fish which had sought the pools for refuge. The waters were fairly alive with their struggles for existence. Except for a small stream known as Payne's Creek flowing from Newnan's Lake into the Sink, the two main basins of the Sink, and a few stagnant pools, no water is now to be seen where a few years ago steamers were ploughing their way. This is tfle second time, since 1823 that a similar occurrence has taken, place. At that time the bed of the lake was a large prairie-Payne's Prairie-having in it a body of water called the Sink and a small creek. In 1868 heavy rains filled up the prairie, but the water disappeared after a short time and the prairie was again dry land. in 1873, after a series of heavy rains, the Sink overflowed and the creek swelled to the dimensions of a lake. During several years the waters increased till a larger lake was formed, and for fully fifteen years sufficient depth' of water gtood over the prairie to allow of small steamers. During tbe last two years, however, the waters have been gradually lowering, and about four weeks ago they commenced going down with surprising rapidity, tbe lake falling about eight feet in ten days, until now nothing is left of Alachua Lake but the memory of it. The Sink is considered the cause of this chang Ie. There is evidently an underground passage connected, and, for some reason not understood, this underground passage has been acting as, a drain until all the water in the lake has been drawn off.
THIRD ANNUAL REPORT. PI.. 6.
Miccosukee basin, low water stage, 19o9. This view is taken at the sink near the northwestern side of the lake.
FLORIDA GEOLOGICAL SURVEY.
EXPLANATION OF PLATE 7. Fig. I.-Lake Jackson. View taken from the north end of the lake. Photograph by R. M. Harper.
Fig. 2.-Alligator Lake. View taken from the bluff overlooking the lake. Photograph by A. M. Henry.
F( ORIDI)A (GEOLOGICAL SURVEY.
THIRD ANNUAL REPORT. PL. 7.
EXPLANATION OF PLATE 8. Fig. I.-The sink of Lake Lafayette.
Fig. 2.-Paynes Prairie at low water stage. View from the sink. Photograph by E. Peck Greene.
Fig. 3.- Paynes Prairie at low water stage. Photograph by R. M. Harper.
FLORIDA GEOLOGICAL SURVEY.
THIRD ANNUAL REPORT. PL. 8.
"FLORIDA GEOLOGICAL SURVEY.
Spouting well near Orlando. Photograph by T. P. Robinson.
THIRD ANNUAL REPORT. itL. 9
SOME FLORIDA LAKES AND LAKE BASINS.
with great rapidity. The rapid lowering of the surface is due, however, as previously stated, not to greater rapidity in the escape of the water, but to the fact that the total surface area of the lake became greatly restricted so that the escape of a given amount of water lowered the surface much more rapidly.
The following remarks regarding the lake appeared in the
Washington Evening Star of September i9, I89I. This quotation
is also from Dr. Dall's report.
"The Star recently printed an account of the disappearance of Alachua Lake in Florida, a lake that was so well established that a steamboat line was maintained on it. A U. S. Geological Survey party has been engaged at work in that region. A member of this party, Mr. Hersey Munroe, who is now in the city, gave an interesting account of the lake, or rather the ex-lake, to a Star reporter. "Alachua Lake," said Mr. Munroe, "is situated in north latitude 290 35' and west longitude 820 20' in Alachua County, Fla., and 2 miles so-,Nth of Gainesville, the county seat. The lake was formerly a prairie, known as Alachua prairie before the Seminole War during 1835-37. It has since been named Payne's Prairie, after King Payne, an old Seminole chief of an early day. The prairie was a great grazing spot for the Indians' cattle and later was used for a like purpose and for tillage by the whites, some fine crops of corn and cotton being grown. The prairie lands are immense meadows, covered by the finest grass, interspersed with clumps of beautiful oak trees and palmettoes. These lands are subject to inundation during the summer season. Hatchet Creek rises 3 miles north of Gainesville and flows in every direction of the compass for a distance of IO miles, emptying into Newnans Lake, a beautiful sheet of water covering io square miles.
rHOW THE LAKE WAS FORMED.
"The overflow from Newnans Lake forms a large creek named Pradirie Creek, which wended its way through Paynes Prairie to Alachua Sink, one of the curiosities of the State. There the waters found their way into a subterranean passage. Visitors, to have their curiosity gratified by seeing what the effect would be to have logs thrown into the sink, were the probable cause of the overflow of Paynes Prairie. The logs would float out to the center of the sink, whirl around in a circle and suddenly disappear. This choking of the outlet to the waters of Prairie Creek caused the overflow and made a sheet of water sufficient to float small steamers and other crafts.
"One steamer in particular had a splendid freight traffic, during the vegetable season carrying shipments of vegetables from its wharf on Chacala pond across Alachua Lake to the mouth of Sweetwater branch, the nearest point to Gainesville, the principal place for shipment north. After the overflow and the forming of a lake it was christened Alachua Lake. This name has beet' decided aon by the United States Board on Geographic Names. Alachua Lake is 8 miles long, east and west, and in one place 4. miles in width, north and south, covers 16,ooo acres, and the average depth is from 2 to 14 feet.
LOWERING FOR SEVERAL YEARS.
"For seve-ral years the lake has been gradually lowering. The elevation of the water above sea level as given by the Savannah, Florida and Western Rail-
66 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
road some years ago is 64 feet. By accurate levels run by one of the topographical parties cf the Geological Survey working in this section during the winter of 189o-91 the elevation of the water was found to be 58 feet, thus showing that the lake had been changing elevation; and about two weeks ago I was informed that Alachua Lake had disappeared entirely, that only small pools remained and the usual amount immediately around the sink."
The early geological history of that section of Alachua County now occupied by these larger basins and lakes was apparently as follows: Originally the surface runoff from southeastern Alachua County made its way through Orange Creek and the Ocklawaha River into the St. Johns River. These streams were then heading
Fig. 5.-Sketch map of Hogtown Prairie and surroundings, illustrating a stage in the development of a solution basis. From the Arredondo topographic sheet, U. S. Geol. Survey. The 6o-foot
contour line borders the prairie.
back in the plateau region of Alachua County, and were fed both by the surface runoff and by the numerous small springs issting" from the clays and sands of the Apalachicola group underlying th, e
SOME FLORIDA LAKES AND LAKE BASINS.
plateau. In the course of time the streams cut down to or nearly to the underlying Vicksburg Limestone. The result of the close approach to this limestone was the formation of sinks due to scltion in the limestone. After the formation of the sinks it became possible for the water to pass through the sinks and find its escape by subterranean drainage. This process of solution and subsidence continued through long intervals of time has resulted in the formation of these numerous basins. Some of these basins have beel carried to a level equal to or below their original outlet through Orange Creek.
Basins may be seen at the present time in varying stages of de-velopment. In the plateau itself no basins are found. Even here, however, are found occasional sinks, the first evident effect of the reduction by solution. An illustration of a partially developed basin may be found in Sanchez Prairie near Hague. The country surrounding this small basin stands at a level of about i8o feet. The basin itself occupying an area of a few hundred acres is reduced to an elevation of about ioo feet above sea. Hogtown Prairie near Gainesville (Text figure 5) represents a more advanced basin. Hogtown Creek probably originally flowed through Alachua Basin, thence to the St. Johns River through Orange Creek. The formation of the sink, however, permitted a subterranean escape and around this sink is formed Hogtown Prairie, now sepa rated from Paynes Prairie by elevations amounting to twenty or thirty feet.
OCHEESEE LAKE.
Of the few lakes occurring in Jackson County Ocheesee Lake is perhaps the largest. This lake lies in the southeastern part of the county extending from near Grand Ridge in a southeasterly direction to within three or four miles of the Apalachicola River. The total length of the lake is six or seven miles. In breadth it varies from a few rods to possibly three-fourths of a mile. At the northwest end the surrounding country rises very gradually. The southwest part of the lake, however, is surrounded by red sandy hills which rise from 75 to ioo feet above the bottom of the lake. The lake is perhaps best described in this instance as a swamp. the greater part of the lake bottom being occupied by a growth of cypress. Near the east end open water occurs over an area of about ioo acres. The water sinks into the Chattahoochee Limestone at the south-east end of the lake.
The history of the development of this lake is very clear. Originally the drainage from this part of the county passed by
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68 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
a surface stream to the Apalachicola River. At a distance of three or four miles from the river, this stream, after cutting its channel some depth, reached the Chattahoochee Limestone. When this formation was reached the water passed into the earth, the drainage becoming subterranean. Subsequent erosion carried the basin to its present level.
METHODS OF DRAINAGE.
Two methods of draining basins of this type may be considered.
(I) drainage by surface ditching to some stream or other outlet lying at a lower level: or (2) drainage into the underlying water bearing formation.
DRAINAGE BY SURFACE DITCHING.
Surface ditching usually suggests itself as the more natural method of drainage, and it is often inferred in the absence of definite information that the lakes lie at a higher level than near-by streams. This is not always the case, and such an assumption may lead to a very costly error. A lake or prairie of this type a few miles southeast of Citra was connected many years ago by canal at considerable expense with a tributary of the Ocklawaha River. Upon completion of the canal it was found that the lake basin was at a lower level than the stream bed. The peculiar method of formation of these lake basins by solution, as previously explained, carries them frequently to a lower level than the stream which served in earlier stages as an outlet. Lake Iamonia as previously stated lies practically on a level with the Ocklocknee River, and receives the overflow of that river during high water stages. Alachua Lake basin lies, as shown by the topographic map, at practically the same level as Orange Lake and the headwaters of Orange Creek which served formerly as the outlet.
DRAINAGE INTO THE UNDERLYING FORMATIONS BY WELLS.
Drainage into the underlying formations takes place naturally through the sinks already existing. Artificial drainage consists either in enlarging the sinks, or in making artificial openings in the form of dug or drilled wells through to the water bearing formation. In either case the principle is the same. The underlying limestone is porous and cavernous, and is filled with water to a definite although slightly variable line or level known as the permanent underground water level.
SOME FLORIDA LAKES AND LAKE BASINS.
Solution in the limestone occurs both above and below the water line, but chiefly above. As solution continues the overlying material is no longer able to support its own weight and caves in, forming a sink or natural opening from the surface to the limestone. As long as this sink remains open, water passes through and escapes readily into the limestone. Drilled or dug wells serve as artificial openings to the same formation. Wells drilled into this limestone will serve either as supply wells from which water may be pumped or as drainage wells into which water may be conducted. It is generally the case that a well entering this formation that can not be appreciably affected by pumping, will also conduct water readily. If the openings at the mouth of the well are sufficiently free to permit ready flow to the well when being pumped, they are, conversely, sufficiently open to allow the water to spread rapidly from the well when used as a drainage well. The amount of water held in the pores and cavities of the limestone is so great that the water level is not appreciably affected either by the water removed when a well is being pumped, or by the water added when a well or sink is used for drainage purposes.
Attempts to enlarge existing sinks or to re-open sinks that have become clogged have usually proved futile. It is doubtless true that the opening through sinks is a more or less winding channel and to re-open this when clogged with debris is difficult.
Better success has been obtained by dug or drilled wells. Where the underlying porous formation into which the well is to be drained lies near the surface, dug wells can be used to advantage and may be preferable. Dr. H. Bjystra has used this method in draining a small lake or "prairie" on his farm near Brooksville, Florida. At this locality the cavernous limestone lies near the surface and is reached by relatively shallow wells. The one difficulty experienced as reported by Dr. Bjystra is the fact that during the summer rainy season in one or two instances the rainfall has been so heavy within a short space of time that the wells were unable to carry away the water as fast as it fell, the result being temporary overflow of the farm and serious injury to growing crops. It is probable that this danger can be removed in this instance by digging additional wells.
Drilled or bored wells have been in some instances notably successful. An advantage in the drilled well is that it can be put down to any required depth. When properly cased and screened drilled wells are permanent. The effectiveness of the well is dependent upon the structure of the formation penetrated. If the water-conducting power of the formation reached by the well is
69
7{ FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
slight a limit is thereby placed on the effectiveness of the well. Unless the flow of water at the-bottom of the well is tree the in-take of water is necessarily limited.
Assuming free movement of the vater at the bottom of the well, the rapidity of in-take and hence the efficiency of the well is influenced by (a) size of well; (b) construction of well; (c) depth of water above the mouth of the pipe; (d) distance from the top of the pipe to the underground water level.*
(a) The capacity of a drain pipe increases rapidly with increased diameter. The area of the section of the pipe is proportionate to the square of the diameter. Thus the area of the cross section of a 12-inch well is nine times that of a 4-inch well. Moreover, for a given velocity the friction of movement is less in a large than in a small pipe.
(b) The construction of a well also affects its rapidity of intake. When the pipe is cut off squarely at the top according to the usual custom, the full capacity of the well is not realized. The rapidity of in-take may be appreciably increased by the use of a flared or bell-shaped mouth at the top of the pipe.
(c) If the underground water level lies some distance, from the surface and if there is free discharge at the bottom of the well, siphonage or draft-tube action increases the rate of flow. When the distance from the top of the pipe to the underground water level is 33 feet or over, the maximum possible draft-tube head of 32.8 feet may be available.
(d) The influence of the depth of water above the mouth of the pipe is as follows: Assuming that the water flows into the pipe as through an orifice, the in-take at the mouth of the pipe will be proportionate to the square root of the depth of the water above the mouth of the pipe.
The velocity of flow in the drainage well may be measured by means of Pitot's tube. This is a bent tube one arm of which is graduated, used to determine the velocity of running water. To make the measurement insert the tube vertically in the top of the pipe, the short end projecting upward and having its mouth a few inches below the top of the drain pipe. The velocity of flow in the pipe is expressed within close limits by the following formula in which h is the height in inches to which the water rises in the long arm above the surface of the lake.* v- V 64.321
12 23
*u.~ S. Geol. Surv. Water Supply Paper, I45, p. 36, 1905. R. E. IHortoni.
SOME FLORIDA LAKES AND LAKE BASINS.
The flow in cubic feet per second into the well will be
Q -0.0055 d2V 80 nearly
In this formula Q represents the flow in cubic feet per second; d" is the inside diameter of the pipe in inches, and h the height in inches to which the water rises in the long arm abnve the surface of the lake. V is the velocity of flow.
A notably successful instance of drainage by wells where the interests of a municipality were involved occurred at Orlando, Florida, and was given in Bulletin No. i, as follows:
"A very considerable land area south and east of Orlando, embracing possibly fourteen square miles, lies in an irregular basin with many lakes, marshes, and ponds. The overflow from this area originally drained to and disappeared through a natural sink about one mile east of the city. This sink became clogged in April. 1904. Unsuccessful efforts were made to re-open this sink, first by removing hyacinths accumulated around the opening, and later by the use of dynamite. In the meantime, heavy and continued rains formed a lake around the sink, overflowing the surrounding lands. In August, 1904, efforts were made to dispose of the water through drainage wells. The first well put down was a two-inch test well. The well reached a porous stratum and was thought to justify the expense of a larger and deeper well. Difficulty and delay were experienced in the drilling, but by August, 19o5, two wells, one eight-inch and one twelve-inch, put down at the side and near the original sink, had been completed. Two other wells were started and abandoned owing to the difficulties in drilling. The two successful wells were running at full capacity. It was thought probable that the two wells already put down would prove sufficient. Heavy rains followed, and by January, 19o6, a considerable area, including some cultivated ground, was flooded, practically all county roads leading into Orlando from the east were partly under water and impassable. The colored settlement known as Jonestown in the suburbs of Orlando was partly under water and uninhabitable; the water was approaching the city of Orlando itself and the situtation was becoming alarming. Levels taken by the county authorities indicated that drainage through surface canals was impossible or impracticable. Two additional twelve-inch wells werebored in November and December of 1906. The effect of thesewas evident at once, the lake beginning to fall. "By February a third twelve-inch well had been completed, making int all. one; eight-.
'72 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
inch well and f our twelve-inch wells running at this time. By the end of March the water had returned *practically to its normal level and has since been kept under control.
"Four of these drainage wells are located 'near the original sink and have a uniform depth of 140 feet, a cavity several feet in diameter having been reached at that depth. The fifth well is located one-half mile west of the sink, and terminates in a porous stratum at a depth of 340o feet."
Since the completion of these wells by the city a number of other drainage wells have been put down by individuals, used largely to reclaim trucking and farming lands.
One of these drainage wells near Orlando developed recently the unusual phenomenon of spouting. The well is located three miles north of Orlando on land belonging to Charles T. Myers. It was drilled in 1907 jointly by Mr. Myers and Messrs. McNeal and Davis, the latter gentlemen having the property leased for farming purposes. The well is twelve inches in diameter and has a total depth of 260 feet, and is cased 6o feet., It is located at the edge of a small lake. The level of permanent underground water at this locality is 33 feet from the surface. Trucking is carried on around the border of the lake and the well is intended, by carrying off the surplus water, to prevent the lake from rising above a given level, since to do so would flood the farming land. The well is similar in character to the other drainage wells of this locality and, as in the case of most of the other wells, terminates in a cavity in the limestone.
The well was first seen by the writer October 4, 1910. At this time the water of the lake stood a few inches above the level o f the pipe and the well was receiving water at much less than its full carrying capacity. At intervals of a few minutes the well would re.ve rse itself and spout, throwing a column of water into the air. The spouting comes on gradually. First the well ceases to receive water and begins bubbling; the column of water follows rising with considerable force to a height of twenty feet or more above the surface, the spout occurring with tolerable regularity at intervals of four minutes. Mr. R. D. Ijnis, who has charge of the farm, states, however, that the intervals between spouts vary from two to fifteen minutes, being probably influenced by varying conditions
SOME FLORIDA LAKES AND LAKE BASINS.
day. The well continued spouting without interruption for a little more than a week and until shut off by the owner.
Various fanciful theories have been advanced to account for the spouting, including supposed occurrence of gas and oil, and the supposed influence of recently formed sinks in the interior of the State. The true explanation is evidently much more simple. At the present stage of the lake the well is receiving water at less than its full carrying capacity and as the water enters the vertical pipe it forms a suction carrying a large amount of air into the well, which doubtless collects in a chamber or cavity along the side or at the bottom, of the well. As the well continues receiving water the air accumulates under pressure in this chamber until ultimately the pressure under which the air is confined is sufficient to overcome the weight of the overlying water and hence rushes out with considerable force carrying the column of water with it.
The fact that the well when first drilled did not spout and afterwards began spouting doubtless indicates that the essential conditions were subsequently developed either by caving or by other changes in the underground conditions.
The spouting of the well is therefore on the principle of the nirlift pump in which air under pressure is conveyed into the well through a special tube for that purpose and being liberated in the well lifts a column of water to the surface. In this spouting well, however, the air pressure is developed within the well. This well may, therefore, be classed as a self pumping well.
When partly shut off so that only a limited amount of water enters, the air taken into the well is able to return to the surface freely. Under these conditions spouting ceases. It is probable that if an elbow is placed on the well, allowing the water to enter laterally instead of vertically, the amount of air taken into the well will be so far reduced that the spouting will cease. Likewise when the lake rises so that the water stands several feet above the top of the pipe entering the well it is to be expected that the spouting will cease, since the pipe will then be carrying water at its full capacity, and little or no air under these conditions entering the well.*
The drainage wells are themselves remarkable and found in such perfection only under geological conditions similar to those existing in Florida. Of the many peculiarities of these wells,
*Since the above was written very heavy rains attending the storm of October 17, 19I0, caused the lake to rise 18 or 20 inches, and Mr. Unis writes that when the water rose in the lake the well ceased spotiting. A similar well at Albany, Georgia, is reported by McCallie. Science, XXIV, p. 694, 1906.
73
74 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
however, that of spouting is certainly the most striking and remarkable.
In considering the use of wells for drainage purposes the relation of the lake basin to the underground water level should first be definitely determined. The effectiveness of the well is reduced as the water level is approached, and it is of course obvious that the water in the lake can in no case be carried below the underground water level. Many of the larger lake basins are known to lie very close to the water level. If the lake basin lies as low as the permanent water level it is obvious that the water in the lake can not be drained by wells, moreover since the effectivness of the well is affected by the near approach to the water level, it is hardly practicable to reduce the water in the lake quite to the permanent underground water level. It must also be borne in mind that while the underground water is a permanent supply the water level or water line is not stationary, but varies with the seasons. The amount of variation for the locality concerned should be determined.
The fact that a lake basin stands somewhat above the water line at the close of a long dry season is not proof that it will be found to stand above the water line after a season of heavy, rainfall. In some sections of the state the range of variation of the water line has been found to be as much as ten feet, and may in some instances exceed that amount.
The relation between the level of the lake basin and the underground water has been determined for a few of the lakes. Measurements of Alachua Lake were made in 1907 and again in 1909. When measured in October, 1907, the water level in Alachua Lake was found to be 2.01 feet above the level of the underground water of the Vicksburg Limestone formation as determined from the Gainesville City well.* When measured in. November, I9O9. the water in the sink stood approximately 1.4 feet above the water level in the limestone as indicated by the city well. At the time these measurements were made the lake was at a low water stage. The underground water level was likewise at a low stage. From these measurements it appears that Alachua Lake during the dry seasons at least is lowered by natural drainage through the sink to or practically to the underground water level. During the rainy season the water in the lake doubtless rises above this level, alLhough it must be borne in mind that the water line also rises during the rainy season. It is evident, therefore, that the difference between the water level in the lake and the underground water line is great*For a record of this well, see Bull. No. I, pp. 30 and 88-89, i908.
SOME FLORIDA LAKES AND LAKE BASINS.7
est during the rainy season when the lake is receiving a large amount of surface drainage.
Approximate me asurements of the water level in Alligator Lake near Lake City have also been made., This is one of the smaller basins and the measurements indicate that the level of the water in the lake stands appreciably above the underground water level. In this instance the measurements of the water level and the lake level were made at different seasons of the year and the results can be only approximately compared. The data on this lake are as follows: Levels made by Professor N. H. Cox, on June i9, 1903. showed that the water in Alligator Lake stood 94.22. feet below theUnion Depot at Lake City.
The lake at the time the levels were made was at medium full stage. The water of the Lake City public well located near, and on about the same level as the depot was f ound at the time the well was completed in 1907 to stand 134 feet from the surface. Allowing for any correction that it might be necessary -to make owing to the fact that the measurements of lake level and ground water level were not made at the same time it would still seem that the lake basin in this instance stands somewhat -above the water level. The drainage of this lake by wells should be possible pro vided the underlying limestone at this locality proves to be sufficiently porous and cavernous to conduct water readily.
SUMMARY.
The basins of the temporary lakes have their origin in erosion by solution and by mechanical wash. Some of them appear to represent the enlarged valleys of what was originally a small stream. Sinks form along these streams diverting the course of the water into the underlying limestones. Other basins originate from sinks in no way connected with stream valleys. The origin of the sink was due primarily to solution in the limestone. After the sink is formed the general level of the surrounding area is lowered somewhat by mechanical wash, the material being carried into the sink. Subsequently other sinks form in the immediate vicinity. The formation of these new sinks is due also to solution. The large amount of water which entered the limestone from the first sink facilitates solution and results in the formation of additional sinks. The continuance of this process through a long period of time results in the development of the large basins occupied by these lakes. From their manner of development it follows that the'steepest bluffs
75
76 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
It is doubtless true that some of the lakes, especially the smaller ones, could be drained by surface ditching. Any attempt at drainage should be preceded, however, by the preparation of a carefully made topographic map of the region, or at least sufficient exact leveling should be made to determine definitely the relation of the lake basin to the proposed outlet, and to the intervening country.
While some of these lakes can be drained by bored 'Wells it is not to be assumed that all can be so drained. As has been shown some of these lake basins, especially the larger ones, have been'low ered by solution practically to the permanent underground water level. Before attempting drainage by wells definite data should be obtained as to the relation between the level of the lake basin and the underground water level of that locality. This information can often be obtained by running a line of levels f rom the lake to at near by deep well and comparing the level of water in the lake with the level at which the water stands in the well. If necessary, test wells may be drilled before undertaking large wells. Such lakes as have been lowered by natural drainage actually to the underground water level can of course be lowered no further by wells
THE ARTESIAN WATER SUPPLY OF EASTERN FLORIDA
BY E. H. SELLARDS AND HERMAN GUNTER.
CONTENTS.
PACE
Introduction ............................................. I .... ......... 85
T he area treated ....................................................... 86
G eology .................................................................. 86
O ligocene ............................................................ 86
V icksburg group .................................................. 86
A palachicola group .................................................. 88.
M iocene ............................................................. 89
P liocene .............................................................. 9()
P leistocene .......................................................... 91
Earth movements d1iring the Pleistocene ............................... 91
'Topography and Drainage ....................... 0 ...................... 92
E levations ....... I ................. .......... 92
R ivers ................................................................ 92
T he Lake R egion ..................................................... 93
C lim ate ........................................................ .......... 94
T em perature ......................... ................................ 94
P recipitation ......................................... ............... 95
Soils 96
General discussion Of underground waters ............................... 99
S ou rce .... ... ..... ........................................ ..........
A nnual rainfall ...................................................... 9.9
D isposition of rainfall ................................................. 100
Amount available for the underground supply ......................... io:2
Underground circulation of water ............. ........................ 102
Cause of m ovem ent ......... .......................................... io2
R ate of m ovem ent .................................................... 102
Depth of underground water .......................................... 102
Hydrogen sulphide' in underground water .............................. 104
Sulphur water not evidence of beds of sulphur .......................... io6
Sulphur deposits formed from hydrogen sulphide. io6
Absence of hydrogen sulphide from certain waters in Florida ........... 166
Amount of hydrogen sulphide influenced by pressure .................. 107
A rtesian w ater ......................................................... 107
A rtesian water defined ................................................. 107
Conditions necessary to retain artesian water ............................ io8
A rtesian basin ...................................................... 108
A rtesian slope ..................................................... 109
Artesian water from unconfined horizontal beds ...................... iio
Artesian water from* solution passages .................... 0 .......... III
Source of artesian water in Florida .................................... III
Formations supplying artesian water ................................... 112
D epth of artesian water ............................................... 112
C ost of w ells .............................................. ......... 112
Increased flow with increased depth ................................... 113
Increased head with increased depth .................................... 113
Increased temperature with increased depth ................... 0..* .. 0 0.. ILI
CONTENTS. (Conti nued.)
PAGE
Table showing loss of flow of artesian w ells ........'.......117
Waste of artesian wae.....................I8
Method of measuring flow of artesian wells. ........ ...... 118
Tables for determining yield of artesian wells ..............T2T
Area of artesian flow in Florida............................ 122
Discussion by counties.......................... 126
Nassau County .... ...... . . .. 126
Location and surface features ..................... ......126
Water-bearing formations............... ....... ....... 1 26
Area of artesian flow ....................... ....... 128
Local details ....................... ........... .......... 128
Callahan ...................................... T128
Crandall ..................................... ,....... r~o
Evergreen........................... .........
Fernandina ................... .................. 130
Hilliard ..............................13
Italia.................................... ....... 133
King's Ferry............................. ........ r 33
Lessie ...................... ..I .... .. :33
Lofton .................................. 133
Duval County .............. ......,...13z)
Location and surface features ......... ........135
Water-hearing formations................. ..36.
Area of artesian flo W..................., T137
Local details............................ T,48
Baldwin . . . .. . . .138
Bayard ............... .......... ...... 133
Jacksonville . .. . .. . .. .. I
Mandarin....................................... 141
Maxville..................................... ....... 141
St. Johns County................................... 141
Location and surface features .................... .. f4 [
Water-bearing formations....................... ......... 142
Area of artesian flow............................. ...... 14
Local details...................... ... ...................14
Anastasia Island ........................ .......... ,,...., 4
Armstrong...................................... _........ ...14
Dinnerland........................................ .......... 144
Dsinoe land.........................................._......1j45
Edlk Poit............................................. 145
Hsatngs....................................... ........... 146
Holyera onh ......................................... -......1T47
Hursns.....................................................T4
Molt re...................................................1 47
HRy. .................................................... 18
CONTENT' S.- (Continued.)
PAGE
Y elving ton ....................................................... 153
C lay C ounty ................................ ................ ......... 153
Location and surface features,....................................... 153
W ater-bearing formations..... .................................. 154
Area of artesian flow ...................................... ......... 154
L ocal details ........................................................ 156
D octors Inlet ..................................................... 156,
G reen Cove Springs ............................................... o6,
H ibernia ............... ............................... ......... 157
L en o .. ...... .. .. .... ... ... ... .. ..... .. .... .. . .. .. .... ... .. 1,-8
M agnolia Springs ....................................... ......... 159
M iddleburg ............................................. ... 59
Peoria ........... ................................... . 159
R ussell .......................................................... 16o '
W alkill ............. .................................... ....... i6o.
W est T ocoi ............................................. ......... 16
XVilliam s C rossing ................................................ '6G
Putnam County ...................................................... i6(
Location and surface features ...............................60.
W ater-bearing form ations ........................................... I6
A rea of artesian flow............................................... 161
Local details...........................................,.,.... )1
B ostw ick .... ................................................ 6
(;r,. cn,'cn C ty ........ ............................................. .5
Orange Mills ..............................It62
P ial ............................................... ......... 63
e r . . .. . .. . . . . . .. . .. . .. .. . . . . . .. . .. .. . .. .. .
R ce Creek ............. ........................................ 6
R on ................................. ............ 107
S 'al) M ateo ... ........................ .................... ...... to ;
Wats ba ...for ...... .............. ...................
Local dta.ls.............
W oodlur ....................................................... 16-1
g e C nt ...................... ............................ ... 107
Location and surface features ........................................ 17
Water-bearing formations........................................174
Area of artesian flow..............................
Local details ....................................................'75
Daytona ...................................... . . . 7
G en eva ..................... ........................ ........... 168
Enerprise.....................................................6
O i ed11 (o .............. ... ... ..... .............. ..... .... .... . 7
.af :r l . . . . . . . . . .. . . . . . .. .. ... . .. . .. . . . . .. 170
V o u i ou t .. . .. ............ ............. ......... I74C
A resa. o m iatesian.flow...................................... .. ... 174
L o cal t ai n ls ........... .... .......................... ........... 174
CONXTENT S.- (Continu cd.)
P A G IE
Lake Helen .................................................. 178
New Smyrna ................................................... 179
Oak Hill............................ .........................'179
Orange City ................................................18
Ormond...................... ...............................18
Pierson .. .. ......... . .... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. T81
Seville....................................................... IQ,
Brevard County ...................................................1T82
Location and surface features .......................... $.......... 182
Water-bearing formations........................................ 182
A rea of artesian flow . . . . . . .. . . . . . 182
Local details,................................................... 183
Chester Shoals.................................... ........... 183
City Point ................................................... 183
Cocoa..................................................... ... 184
Eau Gallie ..................................................
Frontenac ....................................................18
Grant........................................................ 186
Malabar ................................................... 18
Melbourne.................................................... 186
Merritts Island............................................... 188
Micco........................................................ 189
Rockledge I.......................................... ........ 189
Sharpes ...................................... .......Ig
Tillman.................................... ..... ......... 11
Titusville ....................................................'19'
Valkaria ........................................ I...... ....... 192
St. Lucie County .................................................. 192
Location and surface features..................................... 192
Water-bearing formations ....................................... 193
Area of artesian flow ........................................... 193
Local details................................... ............. 19
Eden ..................................................... 193
Ft. Pierce...................................................19
Narrows ..................................................... 194
Orchid.......................................................19
R oseland . . . . . . . . . . . . . . 9
Sebastian..............................................195
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