Citation
The geology and water resources of the upper Suwannee River Basin, Florida ( FGS: Report of investigation 87 )

Material Information

Title:
The geology and water resources of the upper Suwannee River Basin, Florida ( FGS: Report of investigation 87 )
Series Title:
( FGS: Report of investigation 87 )
Creator:
Ceryak, Ron
Knapp, Michael S
Burnson, Terry
Florida -- Bureau of Geology
Place of Publication:
Tallahassee
Publisher:
Florida Dept. of Natural Resources, Bureau of Geology
Publication Date:
Language:
English
Physical Description:
x, 165 p. : ill., maps ; 23 cm.

Subjects

Subjects / Keywords:
Geology -- Suwannee River Valley (Ga. and Fla.) ( lcsh )
Hydrology -- Suwannee River Valley (Ga. and Fla.) ( lcsh )
Suwannee River Water Management District (Fla.) ( lcsh )
Suwannee River, FL ( local )
Town of Suwannee ( local )
Alapaha River ( local )
City of Ocala ( local )
Osceola National Forest ( local )
Lake City ( local )
Aquifers ( jstor )
Groundwater ( jstor )
Limestones ( jstor )
Rivers ( jstor )
Groundwater level ( jstor )
Genre:
bibliography ( marcgt )
non-fiction ( marcgt )

Notes

Bibliography:
Bibliography: p. 116-120.
General Note:
Published for the Bureau of Geology, Division of Resource Management, Florida Department of Natural Resources in cooperation with Suwannee River Water Management District.
Statement of Responsibility:
by Ron Ceryak, Michael S. Knapp, and Terry Burnson.

Record Information

Source Institution:
University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier:
022375325 ( aleph )
16802159 ( oclc )
ACM3852 ( notis )

Full Text






UNIVERSITY OF FLORIDA LIBRARIES






P K YONGE
LIBRARY
OF
FLORIDA
HISTORY






STATE OF FLORIDA
DEPARTMENT OF NATURAL RESOURCES
Elton J. Gissendanner, Executive Director

DIVISION OF RESOURCE MANAGEMENT
Casey J. Gluckman, Director

BUREAU OF GEOLOGY Charles W Hendry, Jr., Chief








REPORT OF INVESTIGATION NO. 87

THE GEOLOGY AND WATER RESOURCES OF THE
UPPER SUWANNEE RIVER BASIN, FLORIDA

by
Ron Ceryak, Michael S. Knapp, and Terry Burnson


Published for the
BUREAU OF GEOLOGY
DIVISION OF RESOURCE MANAGEMENT
FLORIDA DEPARTMENT OF NATURAL RESOURCES
in cooperation with
SUWANNEE RIVER WATER MANAGEMENT DISTRICT


TALLAHASSEE
1983




F3.













DEPARTMENT
OF
NATURAL RESOURCES



BOB GRAHAM
Governor


GEORGE FIRESTONE
Secretary of State


BILL GUNTER
Treasurer


RALPH D. TURLINGTON Commissioner of Education


JIM SMITH
Attorney General


GERALD A. LEWIS Comptroller


DOYLE CONNER
Commissioner of Agriculture


ELTON J. GISSENDANNER
Executive Director








LETTER OF TRANSMITTAL


BUREAU OF GEOLOGY TALLAHASSEE
JULY 15, 1983

Governor Bob Graham, Chairman Florida Department of Natural Resources Tallahassee, Florida 32301

Dear Governor Graham:

The Bureau of Geology, Division of Resource Management, Department of Natural Resources, is publishing as its Report of Investigation No. 87, "The Geology and Water Resources of the Upper Suwannee River Basin, Florida." The Suwannee River is one of the major stream systems in Florida, as yet largely undeveloped. The information contained in this report is an important contribution towards understanding the geology and hydrology of this river, and its place in the region's environment.

Respectfully yours,


Charles W. Hendry, Jr., Chief Bureau of Geology


















































Printed for the
Florida Department of Natural Resources
Division of Resource Management
Bureau of Geology

Tallahassee
1983









iv







CONTENTS

Page
Pj)stract ........................................................................................................... 1
Acknowledgements ........................................................................................ 3
Introduction ................................................................................................... 4
Purpose ................................................................................................... 4
Location ................................................................................................. 4
Methodology ........................................................................................... 4
Climate ................................................................................................... 6
Metric Conversion Factors ......................................................................... 6
Geology-by Michael Knapp .................................................................................. 8
Geologic Overview ................................................................................. 8
Physiography ........................................................................................... 9
Geologic Structure .................................................................................. 11
Stratigraphy ........................................................................................... 14
Paleozoic Erathem ............................................................................ 14
Mesozoic Erathem ............................................................................ 18
Cretaceous System ..................................................................... 18
Cenozoic Erathem ............................................................................ 18
Paleocene Series ......................................................................... 18
Eocene Series ................................................................................ 18
Oligocene Series ......................................................................... 21
Miocene Series .............................................................................. 21
Plio-Pleistocene Series ................................................................. 27
Hydriogeology-by Ron Ceryak ......................................................................... 29
Hydrogeologic Overview ......................................................................... 29
Surficial Aquifer ..................................................................................... 32
Configuration and Extent ................................................................... 32
Water Level Relationships and Fluctuations ......................................... 34
Aquifer Properties ............................................................................ 35
Groundwater Development ................................................................ 35
Water Chemistry .................................................................................. 35
Secondary Artesian Aquifer ..................................................................... 39
Configuration and Extent ...... * ............................................................ 39
Water Level Relationships and Fluctuations ......................................... 39
Aquifer Properties ............................................................................ 43
Groundwater Development ............................................................... 43
Water Chemistry .................................................................................. 43
Fhridan Aquifer ........................................................................................... 44
Configuration and Extent ......................................................................... 44
Areas of Artesian and Nonartesian Conditions ........................................... 48
Potentiometric Surface Fluctuations .......................................................... 52
Water Level Relationships ....................................................................... 65
Aquifer Properties .................................................................................. 76
Groundwater Development ..................................................................... 84
Water Chemistry .................................................................................... 84







Hydrology-by Terry Burnson .......................................................................... 38
Hydrologic Overview .............................................................................. 38
Annual Peak Flow ...................................................................................... 97
Low Flows .......... * ................................................................................ 0
Surfacewater Chemistry ........................................................................... 106
Surfacewater Use, Impoundments, and Structures ....................................... 112
Conclusions ................................................................................................... 113
References .................................................................................................... 116
Appendix A - Geology .................................................................................... 121
A-1 Geologic Control Well Data ................................................................. 122
A-2 Measured Geologic Sections (Surface Outcrops) .................................... 126
A-3 Selected Florida Bureau of Geology Well Descriptions ............................ 130
Appendix B - Hydrogeology ............................................................................. 140
B-1 Water Level Well Control Data ............................................................. 141
B-2 Groundwater Quality Control Well Data ................................................ 150
B-3 Pearson Product Moment Correlation Coefficients for Water
Quality Parameters ............................................................................. 156
Appendix C - Hydrology .................................................................................. 157
C-1 Low Flow and Seepage Discharge Measurements on the Suwannee
R iver ................................................................................................ 158
C-2 Basic Statistical Analysis of Specific Water Quality Parameters at
Select Surfacewater Sites ................................................................... 162

































vi






ILLUSTRATIONS

Figure Page
1 Location of Study Area ................................................................. 5
2 Physiographic Features ............................................................... 10
3 Major Structural Features of North-Central Florida and
South Georgia ..................................................................... 12
4 Geologic Cross Section ............................................................... 16
5 Stratigraphic Data Points ............................................................. 17
6 Structural Top of Ocala Group .................................................... 20
7 Structural Top of Suwannee Limestone ......................................... 22
8 Location and Lithology of Surface Outcrops ...................................... 25
9 Structural Top of Hawthorn Formation ......................................... 26
10 Isopach of Combined Hawthorn Formation and
Plio-Pleistocene Deposits ...................................................... 28
11 General Hydrogeology ................................................................. 30
12 Cluster Analysis of Water Quality Parameters ................................ 31
13 Extent of Surficial Aquifer ............................................................ 33
14 Hydrographs of Wells that Tap the Surficial Aquifer in
Osceola National Forest .......................... ..... 34
1 5 Means and Ranges of Parameter Values ....................................... 36
16 Piper Trilinear Diagram - Groundwater ........................................... 38
17 Relationship of Secondary Artesian Water Levels to
Floridan Aquifer Water Levels at Osceola National
Forest ................................................................................. 4 1
18 Relationship of Secondary Artesian Water Levels to
Floridan Aquifer Water Levels at Occidental Chemical
Com pany ............................................................................ 42
19 Inferred Depth to Base of Potable Water in Floridan Aquifer ............ 45
20 Structural Top of Floridan Aquifer ................................................ 47
21 Artesian-Nonartesian Transition Zone Superimposed on
the Physiographic M ap ............................................................. 49
22 Artesian-Nonartesian Transition Zone Superimposed on
the Structural Top of the Floridan Aquifer ................................ 50
23 Artesian-Nonartesian Transition Zone Superimposed on
the Isopach of the Hawthorn Formation .................................. 51
24 River Basin and Climatological Region Boundaries for the
Suwannee River above the Withlacoochee, Alapaha,
and Withlacoochee River Subbasins ....................................... 53
25 Potentiometric Surface of Principal Artesian-Floridan
Aquifer in South-Central Georgia and North-Central
Florida .............................................................. ................. 54
26 Potentiometric Surface of the Floridan Aquifer in NorthCentral Florida, August 1977 ................................................ 55
27 Potentiometric Surface of the Floridan Aquifer in NorthCentral Florida, November 1977 ................................................ 57
28 Net Change in the Potentiometric Surface of the Floridan
Aquifer in North-Central Florida, August to November 1977 ......... 58








29 Potentiometric Surface of the Floridan Aquifer in NorthCentral Florida, February 1978 .............................................. 1
30 Net Change in the Potentiometric Surface of the Floridan
Aquifer in North-Central Florida, November 1977 to
February 1978 ........................................................................ 62
31 Potentiometric Surface of the Floridan Aquifer in NorthCentral Florida, May 1978 .................................................... 63
32 Net Change in the Potentiometric Surface of the Floridan
Aquifer in North-Central Florida, February to May 1978 ............... 64
33 Mean Monthly Rainfall for the South-Central Georgia
Climatological Region (30-Year Mean) ..................................... 66
34 Seasonal Relation of Mean Monthly Precipitation, Evaporation,
Streamflow, and Groundwater Level, Valdosta Area ................. 67
35 Long-Term Relation of Precipitation, Streamflow, and
Groundwater Level, Valdosta Area, 1957-1975 ....................... 68
36 Daily Groundwater Levels, Stream Discharge and Precipitation,
Valdosta Area, 1977 ........................................................... 69
37 Groundwater Level Fluctuation, Valdosta, Georgia, and
Jennings, Florida 1968-1977 ................................................ 70
38 Daily Groundwater Level Fluctuation, Valdosta, Georgia,
and Jasper, Florida, June 1976 through November
1977 .................................................................................. 72
39 Daily Groundwater Level Fluctuation at Jasper, Florida,
Compared with Daily Stage of Alapaha River near
Jennings, Florida, July 1976 through October 1977 ................ 73
40 Daily Groundwater Level Fluctuation at Valdosta, Georgia;
Fargo, Georgia; and Osceola National Forest,
Florida, 1977 .......................................................................... 74
41 Comparison of Stage of Suwannee River with Water
Levels in Three Wells Tapping the Floridan Aquifer
in Osceola National Forest .................................................... 77
42 Long-Term Groundwater Level Fluctuation, Lake City,
Florida, 1948-1979 ............................................................. 78
43 Generalized Geology, Well Construction, and Static
Water Levels at Aquifer Test Site ........................................... 80
44 Distance Versus Drawdown at Aquifer Test Site ............................ 81
45 Theis Composite Curve Matching Method ..................................... 32
46 Transmissivity Versus Specific Capacity in the Floridan
Aquifer in North-Central Florida .............................................. 33
47 Relation of Parameters with Depth, Test Well 1,
Valdosta, Georgia ................................................................. 36
48 Location Map, Study Area, Surfacewater and Rainfall Stations ............ 39
49 Location Map, Lakes, Ponds, and Springs ......................................... 10
50 Hydrographs for Alapaha River near Jennings, Florida,
and Alapaha Rise, Florida .......................................................... A
51 Monthly Means for Rainfall and Surfacewater Discharge
Stations .................................................................................. 16


Figure


Pat e








Fi, ure Page
52 Flood Frequency Curves for Select Surfacewater Stations ................. 99
53- Flow Duration Curves for Select Surfacewater Stations .................... 101
54 Seven-Day. Low Flow at Select Surfacewater Stations ...................... 102
55 Location Map, Seepage Run. Measurement Sites .................... 105
56 Piper Trilinear Diagram-Surfacewater ............................................ 108
57 Stage Versus Calcium Ion Concentration at Select
Stations on the Suwannee River .............................................. 110
58 Stage Versus Specific Conductivity at Select Stations
on the Suw annee River ........................................................... 111














TABLES

Table Page
1. Stratigraphic Nomenclature for Geologic Formations in the Upper Suw annee River Basin ............................................................................. 15
2. Relationship of Lithologic and Geologic Units in Osceola National Forest ............................................................................................... 24
3. Water Use in the Suwannee River above the Withlacoochee and Alapaha River Subbasins ..................................................................... 32
4. Generalized Description of Hydrogeologic Units in Osceola National Forest ............................................................................................... 40
5. Mean Monthly Rainfall in Inches-Georgia 1977-1978 .................................. 52
6. Lakes and Ponds in the Upper Suwannee River Basin, Florida .................. 91
7. Upper Suwannee River Basin Area Springs ............................................ 92
8. Monthly Mean Discharge for Select Surfacewater Stations ...................... 93
9. Mean Monthly Rainfall in Upper Suwannee River Basin ............................... 95
10. Annual Peaks Exceeding Flood Stage at White Springs and
Ellaville, Florida .................................................................................. 98
11. Extremes for Period of Record at Select Surfacewater Stations in Upper
Suwannee River Basin, Florida and Georgia .............................................. 100
12. Lowest Average Flow for Suwannee River at Fargo, Georgia, and
W hite Springs, Florida ........................................................................... 103
13. Lowest Average Flow for Suwannee River at Ellaville, Florida, and
Withlacoochee River near Pinetta, Florida ................................................. 104






THE GEOLOGY AND WATER RESOURCES OF THE
UPPER SUWANNEE RIVER BASIN, FLORIDA

by
Ron Ceryak1, Michael S. Knapp2, and Terry Burnson'

ABSTRACT
The Okefenokee Swamp contains the headwaters of the Suwannee River. The Upper Suwannee River Basin in Florida, excluding the major tributaries (Alapaha and Withlacoochee), is approximately 855 square miles. Upstream from White Springs, Florida, the Suwannee River is superimposed on as much as 300 feet of confining sediments overlying the Floridan Aquifer; and river flow is essentially dependent upon runoff. Peak flows characteristically occur in the spring. The mean annual discharge at Fargo, Georgia, is 1113 cubic feet per second (cfs); at White Springs, Florida, it is 1879 cfs; and at Ellaville, Florida, it is 6960 cfs. Since 1931 there have been at least 74 no-flow days recorded at Fargo, Georgia. At White Springs and elsewhere downstream, base flow is sustained by groundwater inflow. Stratigraphically segregated from the carbonate aquifer, surfacewater quality in the Suwannee River above White Springs reflects the influence of a poorly drained, heavily vegetated environment. Water quality is acidic with low specific conductance, low dissolved oxygen, and relatively low calcium and magnesium ion concentrations. At White Springs and continuing downstream, surfacewater quality is influenced both by runoff and groundwater inflow. Magnesium and calcium ion concentrations are relatively higher than those reported upstream as are specific conductivity, pH, and alkalinity values.
The Upper Suwannee River Basin is located within the eastern segment of the Gulf of Mexico sedimentary province (Pressler, 1947). It is within a transition zone between the North Gulf Coast sedimentary province and the Florida Peninsula sedimentary province (Chen, 1965). The Peninsular Arch is the dominant subsurface geologic structural feature in the area. The oldest stratum encountered in well samples is a black shale believed to be Silurian in age; however, the stratigraphic column consists chiefly of carbonate rocks ranging in age from Upper CrD3taceous through Tertiary.
Outcrops of the Suwannee Limestone, the St. Marks Formation, the HEwthorn Formation, and the Undifferentiated Terrace Deposits are de 3cribed. Structural contour maps were constructed for the tops of the 0 ala Group, Suwannee Limestone, Hawthorn Formation, and the Flh.ridan Aquifer hydrostratigraphic unit.
The major physiographic feature within the area is the Northern Hi hlands. The Northern HighlarTds is separated from the Gulf Coastal
,wannee River Water Management District, Route 3, Box 64, Live Oak, Fl 32060. 2 F rmerly with Florida Bureau of Geology; now with South Florida Water Management Dis rict, P.O. Box V, West Palm Beach, Fl 33402.





BUREAU OF GEOLOGY


Lowlands by the Cody Scarp, which crests at approximately 110 fe ,t above mean sea level (msl)
There are three aquifer systems in the study area. A perched, su~rficial aquifer mantles the Northern Highlands. This aquifer's water chemistry displays high relative values for sodium and chloride. A secondary artesian aquifer underlies the surficial aquifer and has high relative concentrations of fluoride and orthophosphate. The artesian portion of the Floridan Aquifer underlies the secondary artesian aquifer. Artesian and nonartesian areas within the Floridan Aquifer are separated by the Cody Scarp, a physical boundary that affects all of the hydrogeologic units in the basin. Water from the artesian portion of the Floridan Aquifer displays higher concentrations of all chemical constituents (except nitrate) than water from the nonartesian portion of the Floridan Aquifer. In artesian areas, water has been in contact with the rock longer and is more nearly in chemical equilibrium with it. All Floridan waters in the basin have high relative concentrations of calcium, magnesium, bicarbonate, alkalinity, sulfate, and high specific conductance.
The Valdosta, Georgia, region is the recharge area for the Floridan Aquifer in the Upper Suwannee Basin in Florida. This area is a potentiometric high with heads exceeding 100 feet above msl. Recharge areas have the highest groundwater level fluctuation (33 feet/year at Jennings, Florida), while groundwater levels under the confined highlands fluctuate as little as three feet per year.
An aquifer test at Occidental Chemical Company (OXY) in Hamilton County, Florida, indicates that the coefficient of transmissivity is about 190,000 ft2/day, and the coefficient of storage is about 0.001 for the confined, artesian portion of the Floridan Aquifer.









ACKNOWLEDGEMENTS
The authors wish to thank the many local residents who permitted us access to their property and use of their wells to examine the geology, measure water levels, and take water samples. Special thanks to Pete Deas and Stafford Scaff of Jasper, Ivey Prescott of Jennings, Santa Deas and H. T. Reid of Bellville, and Dorothy Nott of Live Oak for allowing us permission to install continuous recorders on their wells.
Thanks to the following well drillers who supplied invaluable information: Dayton Everetts, Lake Park, Georgia; George Knight and Leonard Bowers, Live Oak; and Pat and Buddy Lynch, Lake City.
Thanks to Occidental Chemical Company for the use of their facilities to collect water samples and to conduct an aquifer test.
Thanks to the U.S. Geological Survey, Tallahassee Subdistrict, for hydrologic and hydrogeologic data.
The authors are grateful to the following people for critical review of the manuscript: Charles Tibbals, Rick Krause, Jim Miller, Dick Johnston, Robert Hull, and Gilbert Hughes of the USGS; Sam Upchurch, University of South Florida; Dan Spangler, University of Florida, and the staffs of the SRWMD and Florida Bureau of Geology.
Thanks to Carolyn Mobley of the SRWMD for typing and editing the many drafts, PatsyBeauchamp, SRWMD, for the data assimilation, and Pat Batchelder, SRWMD for drafting the figures.






BUREAU OF GEOLOGY


INTRODUCTION

PURPOSE
This study was undertaken to define the geologic, hydrogeologic, and hydrologic characteristics of the Upper Suwannee River Basin in Florida. The study was undertaken by the Suwannee River Water Management District (SRWMD) in cooperation with the Florida Bureau of Geology (FBOG).

LOCATION
The Suwannee River originates in south Georgia's Okefenokee Swamp and flows south into Florida for 236 miles to the Gulf of Mexico. The Suwannee River Basin is divided into Upper and Lower Basins. The Lower Basin includes the Santa Fe River Subbasin and the Suwannee River below Withlacoochee River Subbasin. The Upper Basin includes the Alapaha River, Withlacoochee River, and Suwannee River above the Withlacoochee River subbasins (Vanlier, et al., 1975).
The Suwannee River above the Withlacoochee includes the Okefenokee Swamp and nearly 110 miles of river downstream to its confluence with the Withlacoochee River in Hamilton County, Florida (Figure 1). This subbasin has a 2770 square mile drainage of which 855 square miles are in Florida. The Alapaha River Subbasin has an 1840 square mile drainage of which 110 square miles are in Florida. The study area includes those parts of both subbasins that lie in Hamilton, Columbia, Suwannee, and Baker counties in Florida as well as an eastern portion of the Withlacoochee River Subbasin (70 square miles in Hamilton County). These and adjacent areas comprise an approximately 1450 square mile study area (Figure 1).

METHODOLOGY
Subsurface information was derived from existing FBOG well cuttings, cores, auger samples, geophysical logs, and drillers' logs (Appendix A-i). Twenty-four auger holes were drilled and 52 surface outcrops aloig the Suwannee, Alapaha, and Withlacoochee rivers were samples aid analyzed (Appendix A-2). Stratigraphic sections were measured ir, a number of sinkholes.
Groundwater level fluctuations in the Floridan Aquifer w(re monitored quarterly in 107 wells (Appendix B-1). Continuous water le' el records were obtained from five wells (Appendix B-i). An aquifer tt st was performed at Occidental Chemical Company (OXY) in Hamilt n County to determine hydraulic properties of the Floridan Aquifer.
Water chemistry of each aquifer was established by sampling 1 -2 wells. Samples were analyzed for chloride (Cl-), fluoride (F-), sulf te (SO4--), alkalinity, orthophosphate (o-P04--), nitrate (NO3-), calcil -n (Ca + +), magnesium (Mg + +), sodium (Na +), potassium (K +), pI, temperature, specific conductance, nitrite (NO-), and ammonia (NH4-').








REPORT OF INVESTIGATION NO. 87


r
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.___G EO0 R

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"LA AYM A T







s
" T A Y L 0 R .........

" ~L A F A Y ET T E ""






- UPPER SUWANNEE RIVER BASIN

STUDY AREA
E SUWANNEE RIVER ABOVE THE
WITHLACOOCHEE RIVER SUBBASIN


TO N










BAKER i


......... ......







10 0 10 20 30 Mlles

0 10 20 30 40 Kilometers


ALAPAHA RIVER SUBBASIN WITHLACOOCHEE RIVER SUBBASIN


Figure 1. Location of study area.


El






BUREAU OF GEOLOGY


Cluster diagrams, Piper Trilinear Diagrams, and means and ranges we -e used to evaluate the chemical data.
Streamflow data were obtained at five U.S. Geological Survey (USGS) continous recorder stations and one wire weight station in t~ie study area and were used to develop stage/discharge relations and surface water and groundwater relationships. Both low-flow and flood series distributions were defined using the Log-Pearson Type III method. Additional low-flow data were obtained from seepage runs made on the Suwannee River during drought periods. Surfacewater quality, sampled at eight stations, was tested for 14 selected parameters. Comparative analyses of water quality at the stations were rendered by application of basic statistical methods, graphical analysis, and a Piper Trilinear Diagram.

CLIMATE
Humid, subtropical climatic conditions prevail in the Upper Suwannee River Basin. The average year-round temperature is 670F. The warmest temperatures are generally recorded during the summer months of June through August. At this time maximum temperatures average near 900F. The coldest temperatures are usually recorded during the winter months of December and January. Minimum temperatures average in the mid-forties. Rainfall in the Upper Basin averages 54 inches per year. The highest rainfall rates usually occur in June through August in association with convectional activity. During the summer months and early fall, tropical storms and hurricanes can also bring inclement weather and heavy precipitation into the area. Rainfall during the winter, associated with frontal system activity, is usually of a longer duration and areally more uniform than convectional precipitation (Miller, et al., 1978b). The least amount of rainfall generally occurs in the fall during October and November. The average evapotranspiration rate estimated for the area is 42 inches per year (Fisk, 1977).

METRIC CONVERSION FACTORS
For the use of those readers who may prefer to use metric unts rather than the customary U.S. units, the conversion factors for terms used in this report are given here.

MULTIPLY BY TO OBTAIN
Acres 0.4047 Hectares
Acres 4047.0 Square Meters Cubic Feet/Second 28.3137 Liters/Second
Degrees Fahrenheit 5/9 (F-32) Degrees Centigrade
Feet 0.3048 Meters
Gallon/Minute 3.785 Liters/Minute
Horsepower 1.014 Horsepower (metric)






REPORT OF INVESTIGATION NO. 87


Inches Inches Miles Square Feet Square Miles


2.540 0.0254 1.609 0.0929 2.590


Centimeters Meters Kilometers Square Meters Square Kilometers






BUREAU OF GEOLOGY


GEOLOGY

GEOLOGIC OVERVIEW

The Upper Suwannee River Basin is located on the eastern margin of the huge depositional basin that has become known as the Gulf Coast Geosyncline. According to Murray (1961), this feature may have originated as early as pre-Cambrian time; but its present form is the result of tectonic movements associated with the Appalachian and Ouachita orogenies in late Paleozoic time. Pressler (1947) divided the sediments on the eastern flank of the Gulf of Mexico sedimentary basin into the North Florida Province and the South Florida Province by a general line running from Levy County northeast of Nassau County, Florida. The North Florida Province is composed predominantly of terrigenous, clastic sedimentary rocks; and the South Florida Province is dominated by carbonate sedimentary rocks. Puri and Vernon (1964) recognized these same two provinces but preferred the names North Gulf Coast Sedimentary Province and Florida Peninsular Sedimentary Province, respectively. Although the study area is located north of the boundary drawn by Pressler, the sediments are principally carbonates. Chen (1965) pointed out that the boundary between these two provinces has shifted geographically through geologic time. The region of Florida in which the study area is located is, therefore, considered to be within a transition zone between the two sedimentary provinces.
The Florida Peninsula has been divided into three district geomorphic zones by White (1970). These zones are the Southern or Distal Zone, the Central or Mid-peninsular Zone, and the Northern or Proximal Zone. The low-lying, flat lands of the Distal Zone are markedly different froni the undulatory surface of the Central and Northern Zones. Characteristically, the Central Zone is a series of ridges and valleys which run parallel to the peninsula coastline. The Northern Zone, in which the Upper Suwannee River Basin is located, is characterized by a continuous, broad upland that extends from the northern segment of the peninsula t ] western Florida. The major physiographic divisions within the Norther~i Zone are the Northern Highlands and the Gulf Coastal Lowlands.
The four major geologic structural elements within land borderin 1 the Upper Suwannee River Basin are the Peninsular Arch, the Ocaii Uplift, the Southeast Georgia Embayment, and the Suwannee Strait r Saddle. The Peninsular Arch is a totally subsurface structural feature I Florida, and it lies on the southwestern flank of the Peninsular Arch. T,, Southeast Georgia Embayment is a downwarped area lying to the nort 1 and east of the Peninsular Arch. The Suwannee Strait borders the Penir sular Arch on the north and was an effective barrier to clastic depositio. in both Mesozoic and Cenozioc time.







REPORT OF INVESTIGATION NO. 87


The stratigraphic units encountered in the study area range in age rom Paleozoic to Recent. The Paleozoic sediments are predominantly shale and quartzitic sandstones. The Mesozoic sediments are very sandy 3nd tend to be more calcareous toward the top. Cenozoic units are dominated by deposits of limestone and dolomite. Virtually all of the geologic units associated with the Cenozoic and Mesozoic eras are relatively thin when compared with their equivalents in south Florida. This is due to the presence of the positive structural features in the area.

PHYSIOGRAPHY
The Northern Highlands are the most prominent physiographic feature in north-central Florida. The physiographic map (Figure 2) shows that the Northern Highlands almost entirely encompass the study area. The Northern Highlands are separated from the Coastal Lowlands by what has been described as the most "persistent topographic break in the state" by Puri and Vernon (1964). This escarpment is called the Cody Scarp and extends from the eastern perimeter of Trail Ridge, through the study area, and across northern Florida into Alabama. Within the Upper Suwannee River Basin the crest of the scarp approximately correlates with the 11 0-foot topographic contour; and its continuity is broken by the Suwannee, Withlacoochee, and Alapaha rivers.
The Lake City Ridge (Figure 2) is a geomorphic feature associated with the Northern Highlands. It was recognized by Pirkle (1972) as the more southerly of two prominent ridges which intersect the Trail Ridge in southeastern Georgia and northern Florida. Elevations on the Lake City Ridge vary from 150 to 215 feet and are generally about the same as the elevations on Trail Ridge. Pirkle described the Lake City Ridge as extending from Lake City, Florida, to a point six or seven miles west of Macclenny, Florida, where it turns north to meet Trail Ridge at the St. Marys River. Knapp (1979) showed an area west of Lake City to have a lithology, configuration, and topography similar to this easterly ridge. This area, lying directly east of Live Oak and southwest of White Springs, is here included as part of the Lake City Ridge.
There are three marine terraces or elevation zones recognized within !he Upper Suwannee River Basin. These are the Wicomico (70' to 100' elevation), the Okefenokee (100' to 170' elevation), and the Coharie (170' to 21 5' elevation) (Healy, 1975). The Wicomico Terrace extends t p all of the major river valleys and is part of the Gulf Coastal Lowlands. he Okefenokee Terrace forms the higher elevations surrounding these
ver valleys, and the Coharie Terrace is represented by the Lake City .idge.
The Gulf Coastal Lowlands extend into the southwestern segment
f the study area (Figure 2). The Suwannee, Alapaha, and Withlacoochee i ver valley lowlands are present in the study area. All of these river valley I )wlands extend into the Northern Highlands but are still considered part 'f the Gulf Coastal Lowlands division. The Suwannee River Valley







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R i0

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dw

M A 1 8 0N C 0 T 1 8





o
L___ 0

1 0 3 6 mi. Oak S 024 68 Km. G)0


- Cody Scarp T I


Figure 2. Physiographic features.






REPORT OF INVESTIGATION NO. 87


.owlands are larger and more distinctive than the other river valley wlands in the study area.
The change in course of the Suwannee River at White Springs from i, north-south to an east-west direction is to a large degree the result of the stratigraphy and structure of the study area. Above White Springs, the Suwannee River bed is entrenched in the Miocene Hawthorn Fornation; and downstream from this point the Oligocene Suwannee Limestone forms the walls and bed of the river channel to Ellaville. The change in lithology between these two formations is influential in the course of the Suwannee River.
The lithology of the beds associated with the Hawthorn Formation and exposed in the river channel varies from a weakly cemented, argillaceous, phosphatic sandstone to a well-indurated, phosphatic dolomite with interbedded clayey sands and sandy clays (Appendix A-2). The more resistant and stratigraphically lower beds of this formation, which are dolomitized and/or silicified, are most apparent east and northeast of White Springs where they are influential in turning the river to the west. The durability of these bends to fluvial processes is exemplified by the numerous overhanging dolomite ledges and the abundance of silicified materials along the shoal areas. A relatively thin (less than 8 '), green, clayey sand bed or, less commonly, a calcareous clay bed separates the dolomitic beds from the top of the Suwannee Limestone. When the river channel intersects the Suwannee Limestone, it aligns its course parallel to the major fracture patterns in the study area and assumes a northwesterly course (Vernon, 1951). Downstream from the confluence of the Withlacoochee River, the course of the Suwannee River follows the regional topography and flows in a predominantly southerly direction to the Gulf of Mexico.



GEOLOGIC STRUCTURE

The Peninsular Arch is the dominant subsurface structure in the Forida Peninsula (Figure 3). Applin (1951) used the name "Peninsular / rch" to describe "the anticlinal fold, or arch, which is approximately 275 miles long, trends south-southeastward, and forms the axis of the F orida Peninsula as far south as the latitude of Lake Okeechobee." / pplin (1951) concluded that the Peninsular Arch had been a dominant s ibsurface structure since Paleozoic time and owes its present configurat )n to regional movements during the Mesozoic and Cenozoic. The Upper jwannee River Basin lies west of the crest of the Arch, which is in the cinity of Union and Bradford counties, Florida, and is at a depth of 2600 t: 3000 feet below sea level (Applin and Applin, 1967). The pre. 'esozoic rocks that form the crest of the Arch are described as having , en topographically high during Early Cretaceous time (Puri and Vernon,








BUREAU OF GEOLOGY


-


1

iv


Suwannee


Embaymei


10 0 s0 100 Mi.
I ! 0I I K m a 50 100 180 Km.


Ob C 0'


Figure 3. Major structural features of North Central Florida and South Georgia.






REPORT OF INVESTIGATION NO. 87


1964) and were not completely covered by sediments until Late Cretaceous time.
The term "Ocala Uplift" was first used by O.B. Hopkins in the USGS press release in 1920. It was documented and described by Vernon (1951) as "an anticline that developed in Tertiary sediments as a gentle flexure, approximately 230 miles long, and about 70 miles wide where exposed in central peninsular Florida." He showed the structure to have been active from Late Eocene to Early Miocene time. Despite the development of this feature along the flanks of the Peninsular Arch, it does not appear to reflect any structural association with that feature. This conclusion was reached by Vernon (1951) because wells drilled on the crest of the Ocala Uplift in eastern Citrus and Levy counties penetrated the Peninsular Arch well down on its flanks after encountering relatively thick sequences of Mesozoic strata. Chen (1965), in studying the regional Paleocene and Eocene stratigraphy of Florida, reported the Ocala Uplift to have formed in "post-Oligocene or Lower Miocene" time. In later work, Winston (1976) proposed that the Ocala Uplift was not really an anticline but had resulted from the anomalous thickening of the Lake City Formation and the eastward tilting of the Florida Peninsula.
The Southeast Georgia Embayment (Toulmin, 1955), also termed the Okefenokee Embayment (Pressler, 1947), is a negative feature which lies to the northeast of the study area (Figure 3). This basin plunges in an easterly direction beneath southeast Georgia, northeast Florida, and the adjacent continental shelf. Murray (1961) expanded the area encompassed by the embayment and referred to it as the Savannah (Southeast Georgia) Basin. He felt that this larger feature may have been active as early as the Paleozoic Era. Herrick and Vorhis (1963) proposed the term "Atlantic Embayment of Georgia" for a major structural feature in southeastern Georgia. They thought that the basin originated in Middle Eocene time and was active intermittently through Middle Miocene time. Determining when deposition began in this basin appears to be a question of defining the geographic limits of the embayment. For the area referred to by Pressler (1947) and Toulmin (1955), deposition was most active curing Paleocene-Eocene time (Chen, 1965) and progressed interriittently through Middle Miocene time.
The Suwannee Strait lies directly adjacent to, and partly within, the LUpper Suwannee River Basin (Figure 3). The term "Suwannee Straits" kas first used by Dall and Harris (1892) to define an area "which s aparated the continental border from the Eocene and Miocene Island" \('here Hawthorn sediments were deposited. Hull (1962) described the uwannee Strait as being more than 200 miles long and 20 to 30 miles \'ide with up to 800 feet of relief developed on top of the Cretaceous r )cks. The origin of the Strait is quite debatable. Jordan (1954) attributed i* to regional movements at the close of the Cretaceous, causing a c iannel to be formed along the transition zone between the clastic and c-irbonate facies of the Cretaceous. Hull (1962) considered it to be a r arrow area of nondeposition due to the effects of oceanic currents






BUREAU OF GEOLOGY


similar to the present-day Gulf Stream. Chen (1965) used the tern "Suwannee Channel" and described it as "the site of relatively thi, accumulation of very fine sands, silts, clays, and limestones at leas, during the time from late Upper Cretaceous to Lower Eocene." He fel that slower Paleocene-Eocene accumulation of sediment within the channel rather than differential erosion was responsible for the feature. Applin and Applin (1967) used the term "Suwannee Saddle" and designated it as "a subsurface syncline that extends about 200 miles in a broad arc from southeastern Georgia to Jefferson, Leon, and Wakulla counties in north-central Florida, bordering the Peninsular Arch on the north and northwest." They interpreted the feature as an upwarped barrier during Late Cretaceous time and concluded that widespread tectonic movements in the Tertiary in the Coastal Plain of Georgia and the Florida Peninsula resulted in the relative depression of the upwarped feature due to uplift of the areas north and south.



STRATIGRAPHY
Table 1 shows the stratigraphic units which exist in the Upper Suwannee River Basin. The outcropping formations range in age from Oligocene to Recent. From oldest to youngest they are: the Suwannee Limestone, the St. Marks Formation, the Hawthorn Formation, and the undifferrentiated Marine Terrace Deposits. The Eocene and older stratigraphic units are restricted to the subsurface. Figure 4 is a cross section showing the shallow stratigraphy of the study area.


Paleozoic Erathem
Within the study area there have been three wells drilled deep enough to penetrate pre-Mesozoic sediments. Applin (1951) described and interpreted these wells and referred the lowermost beds to the Paleozoic Erathem. Well number 1 548 in Suwannee County (T2S,R1 51, Sec. 28, Figure 5) encountered a black shale at an elevation of -333.3 msl and -3165 msl, respectively. Berdan and Bridge (in Vernon, 1951) examined these shales and concluded from faunal evidence that the., were of "Upper Silurian or Lower Devonian" age. In Well 1789 (T1iL R17E, Sec. 22);'Applin (1951) also listed six intrusions of diabase an I amygdaloidal basalt sills within the black shales. He assigned these intr sions to the Triassic Period. Other deep wells bordering the study are i have revealed the presence of quartzitic sandstones believed to L Ordovician in age.







REPORT OF INVESTIGATION NO. 87 15

Table 1. Stratigraphic nomenclature for geologic formations
in the upper Suwannee River Basin.



ERATHEM SYSTEM SERIES STAGE FORMATIONS

? Recent
E Pleistocene Unnamed Marine Terrace Deposits


Pliocene Undifferentiated Marine Terrace Deposits

Miocene Alum Bluff Hawthorn Formation

__ Tampa St. Marks Formation
N 0
z Oligocene Vicksburg Suwannee Limestone
w o
Crystal River Formation 0- Cl t=o to o.
Williston/Inglis
Formation
Eocene

Claiborne Avon Park Limestone

Wilcox Lake City Limestone

Paleocene Midway Cedar Keys Formation

Navarro Beds of Navarro Age Taylor Beds of Taylor Age Gulf Austin Beds of Austin Age . Woodbine- Atkinson Formation
o Eagleford
N 0
V) Comanche Unnamed red and variegated sand


Unnamed intrusions of diabase and amygdalar basalt skills

o c
cc Unnamed micaceous shale
N
0
Lu Unnamed quartzitic sandstone
0-.. __ _ _ _ _ _=_ _ __ _ _ _ _














East


150 W 1oo



.50 0


.5oo
-100.

*150.

-200

-250.

-300

-350



.365o
-400

-460


-50






-700-


Fine to Mediun Sand

Phosphatic Sand Medium Grained Linestone (Calcarenite) Calcareous and Dolomitic Clay and Silt Micrilic and Coquinoid Limestone Calcareous Sandstone Higly Recrystallized Dolomitic Limestone Very Fine Grained Limestone Highly Recrystallized Dolomite Figure 4. Geologic cross section.


0 2 4 6 8 KLOITERS


West


ISO

100 50 0

-50





.200 -250 ..300

-350 -400

-450

-500


-550




--700




R if Vr


Well Locations (Wells with cuttings taken, well data in appendix A-I) Auger Sample Locations


Figure 5. Stratigraphic data points.


S3 E 0 R G
S P4AMI T R C5E E O ILT] N CO0 AHAMI . f


MAD


T2N


T I S
0


M






M
0

0
on

m G),


0I

0 %J


T3S


._





BUREAU OF GEOLOGY


Mesozoic Erathem

Cretaceous System
The Paleozoic sediments are overlain unconformably by rocks of Early Cretaceous age. These sediments have been assigned to tile Comanche Series by Applin (1951). They are described as consisting predominantly of red and variegated sand that tends to be conglomeratic at the base. The Comanche Series is overlain by the Upper Cretaceous Gulf Series. The Gulf series consists of beds that are equivalent to the Woodbine, Eagle Ford, Austin, Taylor, and Navarro stages of the Gulf Coast. The basal Woodbine and Eagle ford equivalent beds are sandy, calcareous, glauconitic, and shaly with a distinct microfauna. The Austin, Taylor, and Navarro equivalent beds are composed of marine limestones, dolomites, and chalks.

Cenozoic Erathem

Paleocene Series
The Paleocene Series within the study area unconformably overlies the Gulf Series and is represented by sediments belonging to the Cedar Keys Formation. The term "Cedar Keys Formation" was proposed by Cole (1944) and "designed to cover the rocks encountered in wells in peninsular and northern Florida from the first appearance of the Borelis fauna to the top of the Upper Cretaceous." Cole also determined the Cedar Keys Formation to be the stratigraphic equivalent of the Midway Formation of the Gulf Coast area. Applin and Applin (1944) described this formation as a "gray and cream-colored to white limestone, commonly having a distinctive spotted appearance." Within the study area, the Cedar Keys Formation occurs as a slightly gypsiferous dolomite containing the foraminifer Bore/is.

Eocene Series
The Oldsmar Limestone overlies the Cedar Keys Formation witilin the Upper Suwannee River Basin. The term "Oldsmar Limestone" v.,as originally used by Applin and Applin (1944) to denote the nonclastic ro:ks of Early Eocene age in Peninsular and northern Florida. This unit is mar:.ed at the top by abundant specimens of the foraminifer Helicostegina gyr, !is. Chen (1965) recognized a conformable relationship between this ( nit and the overlying beds. Within the study area, the Oldsmar Limest( ne is essentially composed of dolomite and limestone with evapor; es (gypsum and anhydrite) and glauconite being minor accessory miner Is.
The Lake City Limestone overlies the Oldsmar Limestone through ut the study area. Applin and Applin (1944) first used the term "Lake ( tY Limestone" for rocks of early Middle Eocene age and described this -it as a dark brown and chalky limestone in northern and peninsular Flori !a.






REPORT OF INVESTIGATION NO. 87


T' ie Applins established the top of the Lake City as the highest appearai ce of the foraminifer Dictyoconus americanus. Within the study area, the Lake City Limestone is predominantly a gray-brown, dense, mcrocrystalline dolomite with occasional thin beds of limestone, chert, and carbonaceous material. Commonly, this unit is impregnated with gypsum and anhydrite.
It is difficult to lithologically differentiate this unit from the underlying Oldsmar Limestone in this area of Florida. The lithologies of the two are markedly similar and differences in microfauna are the major criteria for formation separations. The Oldsmar Limestone, Lake City Limestone, and possibly the Avon Park Limestone in this area could easily be referred to as one formation and divided into several biostratigraphic zones.
The Avon Park Limestone overlies the Lake City Limestone throughout the study area. The term "Avon Park Limestone" was proposed by Applin and Applin (1944) for sediments of late Middle Eocene age in Florida. Vernon (1951) described three different lithologies within this unit where it crops out in Citrus and Levy counties, Florida. In general, these lithologies are a very fossiliferous limestone, a fossiliferous, peatflecked limestone, and a very crystalline dolomite. The Avon Park Limestone within the study area occurs predominantly as a dolomite with numerous molds and casts of foraminifera, especially Dictyoconus cookei.
The Ocala Group overlies the Avon Park Limestone throughout the study area. The term "Ocala Limestone" was first used by Dali and Harris (1892). This unit is named after the city of Ocala, Marion County, Florida, where it has been quarried for many years. Cooke (1915) established the Ocala Limestone as Eocene in age and proved that its fauna is essentially identical to that of the Jackson Stage. Applin and Applin (1944) showed that the Ocala Limestone could be divided into an upper and a lower member. Puri (1953) followed Vernon (1951) in recognizing three distinct units that he believed were present within the strata of the "Ocala Limestone." He propospid for his units the natties Crystal River Formation, Williston Formation, and Inglis Formation "in descending order and depth" and suggested that the new formations should be included in the Ocala Group. This usage is followed in this report.
The Ocala Group does not crop out within the Upper Suwannee River Ba ,in. It is, however, ubiquitous in the subsurface, being overlain un "onformably by the Suwannee Limestone or Hawthorn Formation and un lerlain unconformably by the Avon Park Limestone. The structural top of the Ocala Group is depicted in Figure 6. Lithologically, in this area thi Ocala can be separated into two formations. The upper unit (Crystal Ri\ er Formation) is a very pale orange tb very light gray, moderately inc urated, biogenic, and very micritic limestone containing many larger foi iminif era. The lower unit-Williston Formation-is a very pale orange to tery light gray, moderately indurated, biogenic, and medium-grained lirt astone (calcarenite) containing many smaller foraminifera especially Ar lphistegina pinarensis cosdent). The boundary between these two foi -nations is conformable and gradational.


















































Fiaure 6. Structural top of Ocala Group.


" LO 11 -10R1 G E 0 R G I
12-150 R 17 E -200 R1

i�HAMI H AM I LTON C 0T.
T2N







a A
0

0 gO 25





� 1-150

o 10






REPORT OF INVESTIGATION NO. 87


Oligocene Series
The term "Suwannee Limestone" was established by Cooke and M-insfield (1936) for limestone exposures along the Suwannee River from White Springs to the confluence with the Withlacoochee River containing the echinoid Rhyncholampas (cassidulus) gouldii. In the period before 1936 the characteristic Suwannee Limestone beds were placed in various other formations. Matson and Clapp (1909) placed them in the Hawthorn Formation; Mossom (1926) referred them to the Glendon Formation; and Cooke and Mossom (1929) put them in the Tampa Limestone. Cooke (1945) described the lithology and fauna of the Suwannee Limestone regionally. Pur and Vernon (1964) summarized various other authors, presented several measured sections, and listed associated fossils. Colton (1978) studied the lithostratigraphy and depositonal history of this formation in detail in Hamilton County.
The Suwannee Limestone crops out along the Withlacoochee River from near the Florida and Georgia border to the confluence with the Suwannee River and along the Suwannee River from White Springs to the confluence with the Withlacoochee River. The structural top of the Suwannee Limestone is depicted in Figure 7. The Suwannee is normally found as a very pale orange, moderately indurated, very porous calcarenite with numerous foraminifera, mollusks, and echinoids present. It is unconformably overlain by either the St. Marks or Hawthorn formations. Colton (1978) recognized another major lithology within the Suwannee Limestone and described it as "a dense, hard resonant limestone composed of foraminiferal tests completely embedded in dense crystalline calcite." Other minor lithologies associated with this formation include silicified limestone, dolomite, and lithographic limestone. The Suwannee Limestone can be differentiated from the overlying St. Marks Formation by its lack of sand, more granular texture, and characteristic faunal content (Appendix A-3). The underlying Crystal River Formation is much more micritic and has a distinctive fauna.

Miocene Series
The sediments now assigned to the Tampa Stage (Lower Miocene) ha ,e been subdivided and redefined may times. Finch (1923) referred to 1he limestone at St. Marks in his description of mollusks from Wakulla Co inty, Florida. The name "Tampa Formation" was applied to the lir 3stone outcrops near Ballast Point in Hillsborough County, Florida, by L.C. Johnson in 1888. Dall and Harris (1892) included the Tampa, Ch-pola, and Alum Bluff beds in the Tampa Group. Matson and Clapp (1 ,09) put the Tampa Formation in the base of the Apalachicola-Group an I restricted it to south Florida. Cooke and Mossom (1929) changed thE name "Tampa Formation" to "Tampa Limestone" and redefined it to nclude the Chattahoochee Formation. Vernon (1942) used the term "T impa Formation" to include "all sediments lying above the Suwannee Lir estone and below the Alum Bluff Group." Puri (1954) erected the


















7 50 1 2 5

00

\'1 o0




25 5-a)
-1)0





______ Cotu onteUpe ufc
50 0M





of~~ht uane Lietnei)ee S
25 50i Sp--0
Ct Itv 2

1 0 3S 6uMc 75 5
I I'1 I 1 I 1- 0
0 2 4 6 8 Km. 8 U W A N N E

o Well Locations
S Limit of Occurrence of -75
Suwannee Limestone

75 Contour on the Upper Surface
of Suwannee Limestone in Feet MSL
(Dashed Where Eroded)
Contour Interval 25 Feet
Figure 7. Structural top of Suwannee Limestone.







REPORT OF INVESTIGATION NO. 87


I impa Stage in his study on the Miocene of the Florida Panhandle and ii cluded in it "all Miocene sediments lying between the Oligocene Series aid the Alum Bluff Stage." Within the Tampa Stage he recognized two d fferent lithofacies-an updip, silty, and clayey lithology (Chattahoochee Ficies) and a downdip, calcareous lithology (St. Marks Facies). Puri and Vernon (1964) described the Chattahoochee and St. Marks formations as comprising the Tampa Stage (Lower Miocene). They established a type locality for the St. Marks Formation in Wakulla County, Florida. Yon (1966) adhered to the nomenclature presented by Puri and Vernon and described the St. Marks Formation in Jefferson County as "a white to very pale orange, finely crystalline, sandy, silty, clayey limestone (calcilutite)." Within the study area, the St. Marks Formation is a very pale orange, sandy, silty, occasionally fossiliferous, and micritic limestone. It occurs infrequently along the northern Withlacoochee River and in deep sinkholes in western Hamilton county. This formation is thin, discontinuous, and only occurs as erosional remnants east of the Alapaha River.
The Hawthorn Formation is named after the town of Hawthorne located in Alachua County, Florida. Dall and Harris (1892) were the first authors to use the term "Hawthorne Beds" when referring to phosphatic limestone they saw being quarried and ground for fertilizer near the town of Hawthorne, Florida. Dall also cited some measured geologic sections by L.C. Johnson. Matson and Clapp (1909) designated these beds the Hawthorne Formation. They described the formation as consisting of clays, sands, and phosphatic limestone and lying stratigraphically between the limestones of the Vicksburg Group and the Alum Bluff Formation. Vaughn and Cooke (1914) showed that the Hawthorn Formation is almost synonymous with the Alum Bluff Formation as defined by Matson and Clapp (1909) and recommended that the name "Hawthorn" be discarded. Gardner (1926) raised the Alum Bluff deposits to the rank of group including the Chipola Formation (at base), the Oak Grove Sand, and the Shoal River Formation (at top). Cooke and Mossom (1929) restored the name "Hawthorn Formation" by fitting it into the Alum Bluff Group. They referred to the Hawthorn Formation as being different from other formations in the group, containing some fossils that ar) of Chipola Age, and excluding the "Cassidulus-bearing" limestone (S jwannee Limestone) which is older. Cooke (1945) described outcrops of the Hawthorn Formation along the Suwannee River and in Columbia C( unty. Puri and Vernon (1964) erected the Alum Bluff state and included th: Hawthorn Formation within it. They also examined Hawthorn outcr )ps in the Upper Suwannee River Basin and concluded that this unit in -his area presented the most diversified lithofacies of the Hawthorn. W ler (1978a) in his description of geologic and geophysical logs from tF , Osceola National Forest area identified five lithologic units within tF.L Hawthorn (Table 2).
The Hawthorn Formation is exposed continually in the banks of the S wannee River from the Florida-Georgia border to White Springs and






BUREAU OF GEOLOGY


Table 2. Relationship of lithologic and geologic units
in Osceola National Forest (from Miller, 1978a).


GEOLOGIC THICKNESS
Unit Age (feet) Lithology
Unnamed Post- 6-54 Medium-grained sand and blue-gray Miocene sandy clay. Lacal peat layers.
A 15-102 Brown phosphate sand, yellow-brown to blue-gray clay, gray phosphatic
shell limestone. Limestone more proc minent in western part of forest.
B .0 13-70 Green to greenish-gray massive clay.
co Often fractured. Black clay prominent.
C E ( 13-58 Green to greenish-gray, fine- to
o
LL ( medium-grained sand. Contains clay
c 0J
0 and limestone to east of forest.
- 5-43 Complexly interbedded shell
3.- limestone, clay, clayey sand, and
co fine-grained sandstone.
E 14-73 Brown sandstone, tan to dark-brown limestone, dolomite, and argillaceous
limestone. Fossiliferous, well
indurated.
Ocala * 102 + White calcarenite at top, containing
Lime- Eocene some green clay. Gray hard fractured
stone limestone below. Penetrated 102 feet.
*The Suwannee Limestone of Oligocene age, which is part of the Floridan Aquifer in places, was not found in the Osceola National Forest.

intermittently from White Springs to the confluence of the Alapaha River (Figure 8). The top of the Hawthorn Formation normally occurs as phosphatic clayey sands and pale blue-green, phosphatic clays. The unit as a whole is characteristically phosphatic, dolomitic, calcareous, clayey, and heterogenous throughout. The lower section is dominated by sancy, phosphatic dolomites and limestones. The St. Marks Formation aid Suwannee Limestone underlie the Hawthorn Formation in the study arva. The absence of phosphorite and lower percentages of quartz sand in tie St. Marks Formation and Suwannee Limestone are the major distinctic is between them and the Hawthorn Formation. East of a line drawn fr rn Live Oak, Florida, to Jasper, Florida, and within the Upper Suwann .e River Basin, the top of Hawthorn Formation gently slopes down to t ie northeast (Figure 9). The structural highs near Lake City, Florida, aId Township 3 South, Range 15 East are due to uneroded, thicker accumu ations of the Hawthorn in these area. In parts of the study area, tie Hawthorn Formation is either absent or has been greatly modified :Y post-depositional erosion.


24





ii ~ W-13 GE 0 ~G IA


LEGEND-______ _SAND
CLAY
SANDY CLAY
CLAYEY SAND z
PHOSPHATIC CLAYEY SAND ILko CALCAREOUS SANDSTONE 2 City
PHOSPHATIC CALCAREOUS SANDSTONE VERTICAL SCALE
SHELL BED OR MARL (FEET)
LI MESTONE 0
SANDY LIMESTONE
CHERTY UMESTONE 1i
SHELLY UMESTONE
DOLOMITIC LIMESTONE
DOLOMITE
SANDY DOLOMITE * DATA POINT
PHOSPHATIC SANDY DOLOMITE A = ALAPAHA 5
LIMESTONE RUBBLE S = SUWANNEE [4,,
SILTSTONE W - WITHLACOOCHEE
Figure 8. Location and lithology of surface


0

o
outcrops.


10 MI. 10 Km.


___. . E W-13


(3EO0R G IA










?VV !8 18, u e G E 0 R r ON ,,,/12N 0
-poll II 2 5 1 2
75 ~ ~ 15 aEI




on .. ... o n U r f o1 100


Contour iera 2 Feet







Wtho Foationa
76~~ 1 Conou onteUprSraeo --'------I Motu InerA 26 Fee 6 o




o aWll r L o nation s en 7l


III Ir . ........ ... sit" ed "







REPORT OF INVESTIGATION NO. 87


The name "Alachua Clays" was first used by Dali and Harris (1892) ir a reported memorandum they submitted to the Director of the USGS ir 1885. They described the clays as being "of a bluish or grayish color and extremely tenacious" and containing a mammalian fauna. The IViocene Alachua Formation was reported by Cooke (1945) to exist in Hamilton County west of the Alapaha River, although no details were available. Puri and Vernon (1964) described this formation as being terrestrial and, in part, possibly lacustrine and fluviatile. Lithologically, it is quite diverse, being a mixture of interbedded sand, clayey sand, and sandy clay. Within the Upper Suwannee River Basin it is not possible to lithologically differentiate the Alachua Formation from the Hawthorn Formation and the Undifferentiated Marine Terrace Deposits, either in outcrop or in the subsurface. In observations of outcrops within the study area, a few localities were found where mammalian fauna was preserved in clays and sandy clays. However, the occurrence of these deposits are infrequent and lateral correlation between them is not apparent. The Alachua Formation is not recognized as a geologic formation in this report.

Plio-Pleistocene Series
The term "Undifferentiated Marine Terrace Deposits" is here used for the clastic materials which lie above the Hawthorn Formation. These deposits are normally fine-to medium-grained quartz sand with minor amounts of organic material, clays, and heavy minerals. They are virtually ubiquitous in the Upper Suwannee River Basin and are only absent where they have been eroded by streams or rivers. These terrace deposits owe their origin to Plio-Pleistocene eustatic sea level fluctuation. Figure 10 depicts the total thickness of Hawthorn sediments plus these undifferentiated sediments.










13E GE O R G I A
- - --- - .R1 E 17


T2N


TiS
0
300


275

250
228
200 T3 S


* Well Locations A Auger Samples
75o Line of Equal Thickness In Feet 0015
g75 100 12s 1o
Figure 10. isopach of combined Hawthorn Formation and Plioplistocene deposits.






REPORT OF INVESTIGATION NO. 87


HYDROGEOLOGY

HYDROGEOLOGIC OVERVIEW
There are three aquifer systems within the Upper Suwannee River Basin (Figure 11). A perched, surficial (water table) aquifer mantles the Northern Highlands. Areas where the surficial aquifer exist are usually underlain by a secondary artesian (Hawthorn) aquifer that is wholly confined by low permeability units within the Hawthorn Formation. The Floridan Aquifer displays two distinct characteristics. It is artesian where it underlies the secondary artesian aquifer; it is nonarteasian in areas where the Hawthorn Formation is thin or nonexistent.
The unconfined surficial aquifer, consisting of Miocene and younger sands, maintains the highest water levels relative to mean sea level. The secondary artesian aquifer, comprised of sands and carbonates of the Miocene Hawthorn Formation, has water levels at altitudes between those of the surficial aquifer and the Floridan Aquifer. The potentiometric surface of the artesian portion of the Floridan Aquifer is higher than the potentiometric surface where the Floridan is unconfined; therefore, water within the Floridan Aquifer flows from the artesian to the nonartesian portion. The portion of the Floridan Aquifer that contains potable water consists of carbonates that range from early Miocene to middle Eocene in age.
These aquifer systems can be differentiated by water chemistry as well as by stratigraphic position, lithology, and hydraulic heads. Groundwater samples from the study area were analyzed for the following variables; pH, specific conductance, alkalinity, chloride, flouride, sulfate, orthophosphate, nitrate, calcium, magnesium, sodium, and potassium (Appendix B-2). These variables tend to be correlated; that is, an increase or decrease in one variable may be accompanied by a predictable change in another variable. The mutual variablility or covariance of a pair of prop.rties is the joint variation of two variables about their common mean. Ir order to estimate the degree of interrelation between variables, the correlation coefficient is used. Correlation is the ratio of the covariance o two variables to the product of their standard deviations (Davis, 1973). P !arson Product Moment correlation coefficients of the variables sampled ft r this study are shown in Appendix B-3. The correlation coefficient i, used as a similarity measure. Two variables are connected that have t' a mutually highest correlations with each other.
A cluster diagram constructed from the mutually highest correlat in coefficients is shown in Figure 12. This diagram shows the relations ip among variables. A" + " indicates a strong correlation between the t to variables (r is ) + 0.3). A "( + )" indicates a weak correlation between t e two variables (r is between + 0.135 and + 0.03). For a sample size c 370, a correlation coefficient of )0. 135 is significant (Rohlf and Sokol, 1 -69). The three cluster relations in Figure 12 represent chemical pro-







GENERAL NORTHERN HIGHLANDS HYDROGEOLOGY confined (artesian) Floridan Aquifer

LITHOLOGY IISAND GULF COASTAL LOWLANDS CLAY unconfined (non-artesian) %9S0 Floridan Aquifer
1 LIMESTONE


FORMATION FORMATION
BOUNDARY
EJ POST MIOCENE A

HAWTHORN Spring
3 FORMATION MEMBER B &BASAL UNIT are members " ' .. within HAWTHORN FORMATION i I

SUWANNEE
FORMATION E OCALA
GROUP


Figure 11. General hydrogeology.


Cl S0 >0.
.00
M
"I






REPORT OF INVESTIGATION NO. 87


cesses that reflect water in contact with different lithologies. Each lithology is associated with a different hydrogeologic horizon.
The variables in Cluster 1 are associated with the dissolution of calcium and magnesium carbonates. This is the lithology that comprises the Floridan Aquifer. Therefore, Floridan waters are typically characterized by higher relative values for calcium, magnesium, alkalinity, pH, and specific conductance, which reflect the amount of bicarbonate in the water. Sulfate values are relatively higher in the Floridan Aquifer due to oxidation of sulfides or dissolution of evaporites in ground water at depth.



pH SC Al k S04 Ca Mg Cl Na K N03 F O-P04


+ Strong Correlation (r > .300)
(+) Weak Correlation (r = .135 to .300)
Significance Level for 370 Samples = 0.135 (Rohlf and Sokol, 1969)



Figure 12. Cluster analysis of water quality parameters.
The variables in Cluster 2 are associated with marine aerosols. The ominant lithology containing surficial aquifer water is sand that does ot readily react with water. The water in the surficial aquifer is essenally rainwater that is relatively higher in sodium, chloride, and potassium 'ian water from the lower aquifers. The higher relative values for nitrate ,re man-induced.






BUREAU OF GEOLOGY


The variables in Cluster 3 are associated with the dissolution of fluorapatite. The Hawthorn Formation contains abundant flourapatite. The secondary artesian aquifer is entirely within the Hawthorn and is characterized by water that has higher relative concentrations for orthophosphate and fluoride than the other aquifers.
An aquifer test at Occidential Chemical Company in Hamilton County indicates that the cofficient of transmissivity is about 190,000 ft2/day; and the coefficient of storage is about 0.001 for the confined artesian portion of the Floridan Aquifer.

Table 3. Water Use in the Suwannee River
Above the Withlacoochee and the Alapaha Subbasins in Florida.

Water
Consumed
Pumpage (MGD) (MGD) Ground Surface
Water Water
Public Supply 2.61 0 0.56 Industrial 28.81 0 4.40 Rural (Domestic) 0.70 0 0.26 Rural (Livestock) 0.22 0.15 0.28 Irrigation (Average) 1.62 0.29 1.88
TOTAL 33.96 0.44 7.38


Within the study area, Lake City, White Springs, Jasper, Jennings, and Wellborn have public supply wells. Total industrial use is accounted for by Occidental Chemical Company's phosphate mine and chemical plant in Hamilton County. Irrigation use is seasonal, but in Table 3 irrigation is averaged daily over the entire year. Most irrigation takes place during the spring, and a maxium 24.5 million gallons per day (mgd) is used for this purpose during the peak irrigation period.

SURFICIAL AQUIFER

Configuration and Extent
An unconfined, surficial aquifer (also referred to as the water table aquifer) exists in the Upper Suwannee Basin (Figure 13). This aquifer consists of Miocene and younger sands and clayey sands that blankel the area and range in thickness from 20 feet to 150 feet. In the Osceolz National Forest in Columbia County, Miller, et al. (1978b) divided the Hawthorn Formation into five mappable lithologic units that he assignec informal letter designations (Table 2). The massive clays of Member E retard or restrict downward percolation and are the base of the surficia
















































Figure 13. Extent of surficial aquifer.


T2N


TiS


T3 S






34 BUREAU OF GEOLOGY

aquifer throughout the Upper Suwannee Basin. Member B is the same unit referred to as Bed A in strata of the Alapaha River Basin (Ceryak, 1977). Member A (Miller, et al., 1978b) of the Hawthorn is entirely within the surficial aquifer as are the overlying Pliocene, Pleistocene, and Recent sands. The areal extent of the surficial aquifer coincides with the elevation of two prominent ancient marine terraces within the Northern Highlands. The Okefenokee Terrace exists between elevations of 100 to 170 feet. Portions of Suwannee and Columbia counties also display remnants of the Coharie Terrace at elevations between 170 to 215 feet.


Water Level Relationships and Fluctuations
Water levels within the surficial aquifer are at or near land surface and often coincide with surfacewater levels observed in swamps, lakes, and ponds. The water table is a subdued replica of the topography and ranges in altitude from about 100 to 200 feet above msl. The surficial aquifer is recharged directly by rainfall that migrates vertically downward to the water table. Mean annual rainfall in the study area is 54 inches per year.
Water level fluctuations in the surficial aquifer are in direct response to the amount of rainfall. Rainfall events cause sharp rises in surficial aquifer levels, while lack of precipitation causes a gradual decline. Normal annual fluctuation is a few feet as shown in hydrographs of wells completed into this aquifer (Figure 14).
0 141
S140 Lu
< 2 11139
,, USGS WELL 7B
CC 3 , , , 138w


0
A A
2 P_____4 USGS WELL 10B JUNE JUL.Y ! AUG ISENT I OCT 1 ,,r JcAN FEB Ij MAR
1976 1977


Figure 14. Hydrographs of wells that tap the surficial aquifer in
Osceola National Forest.


183 182 181 180 179 178







REPORT OF INVESTIGATION NO. 87


Of the 54 inches of available rainfall per year, approximately 42 inches per year is lost to evaportranspiration (ET) (Fisk, 1977). Discharge from the surficial aquifer is mostly downward to the underlying aquifers and is greatest where Hawthorn Member B is breached, discontinuous, or permeable. There is also lateral discharge along the Cody Scarp and into topographically low areas-lakes, swamps, and streams. A minimal amount of water from the surficial aquifer is consumed by rural domestic use.

Aquifer Properties
In western Hamilton County, the average hydraulic conductance reported for clayey sands of the water table aquifer (Reynolds, Smith, and Hills, 1974) was 3.0 x 10-4 ft/min. An aquifer test on the water table aquifer at the Swift Creek Chemical Complex site in Hamilton County yielded a storage coefficient of 7.5 x 10-4 and a transmissivity of approximately 500 ft2/day (U.S. EPA, 1978).

Groundwater Development
Most shallow wells completed into the surficial aquifer are driven or jetted; a few are dug.
Shallow wells usually consist of one 20-foot section of 1 1/2-inch or 2-inch diameter pipe. Well screens are not commonly used. A typical well has a 1/2 to 1 horsepower (hp) jet pump and yields between 4 and 10 gallons per minute (gpm).

Water Chemistry
Surficial aquifer water is characterized by high relative values for sodium, chloride, potassium, and nitrate. These parameters are strongly correlated in Cluster 2 in Figure 12. Figure 15 shows the range of values for each aquifer water type. The ranges extend two standard deviations From the mean, which accounts for 95% of the variability of the values. The purpose is to show, along with trilinear and cluster diagrams, distinct lifferences in parameter values that define the water types. Figure 15, ike Figure 12, reveals the relatively high values for the constituents ,haracteristic of surficial aquifer water.
The relatively high sodium and chloride values are apparently deived from precipitation of marine aerosols (ocean-derived moisture) Ceryak, 1977). This is especially true in the summer in peninsular Florida !vhen ocean-derived moisture accumulates daily as afternoon thunder;howers. The CI:Na ratio in seawater is 1.8:1 and, similarly, averages 2:1 in the 61 surficial aquifer water samples that were analyzed. Sodium s the most abundant cation in seawater, while chloride is the most ibundant anion. Potassium is a very soluble cation found in water and easily recombines with clay minerals. Figure 15 shows the effect of clays n the secondary artesian aquifer on potassium correlation, but this ion







BUREAU OF GEOLOGY


Chemical Parameters


I . . .PH Unitn a
IH 11 1"1"t I1 HIt
4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 C. micromhos-cm
id. OEI I
0 so 100 150 200 250 300 350 400 450 500
1k === 1 mm.== I m/"

3 40 8 1210 180 200 240 280 1 0 380 400


3 � 5 8 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28


F . .8 I


S Q 4 "n I I
0 3 6 9 12 15 18 21 24 27 30 33 38 39 42 45 48 51 54 57 60 63 66 69 72 75

O-PO4 1i 1 1�1 1 1, mg
0 .09 .18 .27 .36 .45 .54 .63 .72 .91 1.0 1.09 1.18 1.27 1.38 1.45 1.54 1.63

N03 10mR OU,, Rmg/I
0 1 2 3 4 5 6 7 8 9 10

Ca " I l """I' ' "' " " w mnt
0 10 20 30 40 50 80 70 80 90 100
Mg. ... . I I' I I m

0 3 8 9 12 15 18 21 24 27 3r

Na all 111111 M1
0 1 2 3 4 5 8 7 8 9 10 11 12 13 14 15 18 17 18 19 20 21 22 23 24 2 K !h� mg/i.

0 1 2 3 4 5 6 7 a
Surficial Aquifer (61 Samples) Secondary Artesian Aquifer (7 Samples) Floridan (Non-Artesian) Aquifer iRsoumuummuuns (43 Samples) Floridan (Artesian) Aquifer (23 Samples)
Mean (Example) I
(This Data Represents 2 Standard Deviations on Each Side of Mean)


Figure 15. Means and ranges of parameter values.


F

Spe Cor


A







REPORT OF INVESTIGATION NO. 87


is also present in relatively high values in the surficial aquifer where clays are not as abundant. High potassium concentrations in the surficial aquifer are the probable result of marine aerosols.
High nitrate concentrations in the surficial aquifer appear to be maninduced. Natural nitrate values can be as high as 5 milligrams per liter (mg/I) but are often less than 1 mg/I (Hem, 1959). Factors that contribute to high nitrate values in the surficial aquifer are barnyard animal excrement, chicken and hog barns, chemical fertilizers, septic tanks, outhouses, and, to a lesser degree, plants that fix nitrate-nitrogen in the soil. These factors are all common in a predominantly rural area such as that where the shallow aquifer occurs.
Contrasting these high values, pH, specific conductance, alkalinity, calcium, and magnesium exhibit relatively low values when compared with water from the secondary artesian and Floridan Aquifers (Figure 15). Once the cation-anion balance of the variables was determined (Fred Lawrence, SRWMD, Live Oak, FL, unpublished computer program, 1978), the results were plotted on a Piper Trilinear Diagram (Figure 16). This is a useful graphical 'method to show sources of, and chemical relationships between, different groundwater types in the study area. The trilinear plots help to further distinguish the basin's aquifer types. Piper Trilinear Diagrams treat ground water as though it contains three cation constituents (Mg, Na + K, Ca) and three anion cnstituents (CI, S04, CO3 + HCO). Figure 16 shows the distinction between surf icial aquifer water and the deeper aquifer water types on a trilinear diagram. Surficial water contains a high relative percentage of sodium and potassium cations and a low relative percentage of calcium cations. The anion balance reveals relatively high values for chloride and low values for carbonate plus bicarbonate. The resultant plot on the diamond-shaped field classifies surficial water as a type where strong acids exceed weak acids compared to the remaining water types that fall in the category of carbonate hardness "secondary alkalinity", where chemical properties of the water are dominated by alkaline earths and weak acids (Walton, 1970).
Chapter 17-3 of the Rules of the Department of Enviromental RegulaJion of the State of Florida lists water quality standards for Class I-B waterss (Florida Administrative Code, 1977), potable and agricultural vater supplies, and storage (ground water). Of the parameters sampled or this study, fluoride and nitrate have criteria standards. Fluoride shall lot exceed 1.5 mg/I, and nitrate shall not exceed 10 mg/l. Secondary tandards for chlorides and sulfates limit their concentration to 250 mg/l. ,ontaminated wells in the surficial aquifer display nitrate values as high 's 24t6 mg/l. Values of 114.1 mg/I of chlorides, 89.1 mg/I of sodium, ind 14.32 mg/I of potassium have been reported. Standards have not ,een set for sodium and potassium, but these values are high when ,ompared to the mean for surf icial aquifer waters and are obviously the esult of point source pollution to the aquifer. High values for the above )arameters result in specific conductances as high as 600 micromhos umhos/cm), whereas the mean is 70 umhos/cm and the standard leviation is 35.8.








38 BUREAU OF GEOLOGY


WATER TYPE Floridan (Non-Artesian) Aquifer
Floridan (Artesian) Aquifer O Secondary Artesian Aquifer Surficial Aquifer
- Surficial Aquifer
Secondary Concentration


CATONS


Figure 16. Piper trilinear diagram-ground water.


ANIONS






REPORT OF INVESTIGATION NO. 87


SECONDARY ARTESIAN AQUIFER

Configuration and Extent
The secondary artesian aquifer system underlies most of the Northern Highlands (elevations higher than 110 feet msl) in the study area. Where the surficial aquifer exists (Figure 13), the secondary artesian aquifer usually underlies it. The secondary artesian aquifer system is comprised of phosphatic sands, clays, and carbonates (Members C, D, and E) of the middle Miocene Hawthorn Formation. Permeable beds within the aquifer system vary in depth and thickness throughout its extent. Water-bearing Hawthorn sediments in the study area range from around 80 feet to 234 feet in thickness; the entire unit thickens considerably from the west to the northeast. The massive clays of Member B act as the upper confining bed for the secondary artesian aquifer (Table 4). Beneath Osceola National Forest, the E member contains well-indurated sandstone and dolomitized limestone that acts as a very tight semipermeable unit and forms the lower confining bed for the secondary aquifer system and the upper confining bed for the Floridan Aquifer.
Six sets of observation wells penetrate the secondary aquifer system in eastern Hamilton County at OXY's Suwannee River Mine (U.S. EPA, 1978). The A and B Hawthorn members are definable, but the lower Hawthorn section has not been differentiated into lithologic zones. As the Hawthorn thins to the west, the depositional environment changes from marine to deltaic. The lower section becomes a conglomeration of sediment types, and, therefore, is difficult to differentiate into lithologic zones. No single lower confining bed for the secondary aquifer system has been described in this area, but a thin sand below Member B is lithologically similar to Member C in the Osceola National Forest. Variations in lithology in the lower parts of the Hawthorn create variations in permeability. For the most part, the basal Hawthorn in Hamilton County can be considered a confining bed separating local permeable Hawthorn beds from the underlying Floridan Aquifer.

Water Level Relationships and Fluctuations
Water levels in the secondary artesian aquifers are lower in altitude t ian surf icial aquifer levels throughout the study area. In Osceola National Forest, in two wells completed into the Hawthorn C member, the water I,:vels (approximately 100' above msl) lie 40 feet below surficial aquifer Ivels. Secondary artesian aquifer water levels at the Suwannee River r line (approximately 60' to 75' above msl) are also intermediate bet ieen surficial aquifer and Floridan Aquifer water levels but are lower i, i altitude than in Osceola National Forest. These water levels from wells r enetrating permeable fine sands below Member B lie 50 to 60 feet below t ie water table and 10 to 20 feet above Floridan water levels. The smaller [-ad difference between the secondary and Floridan Aquifers in the OXY vells is probably due to a greater amount of hydraulic connection be-







Table 4. Generalized description of hydrogeologic units in Osceola National Forest (Modified from Miller, et al., 1978b).
HYDROGEOLOGIC GEOLOGIC THICKNESS
UNIT WATER-BEARING PROPERTIES UNIT AGE (feet) LITHOLOGY
Water unconfined. Readily absorbs and Post- 6-54 Medium-grained sand and bluestores precipitation until water table rises to Unnamed Miocene gray, sandy clay. Local peat
Surficial land surface. Principal source of baseflow to layers.
Aquifer streams draining forest. Uppermost member A 15-102 Brown phosphatic sand, yellowof Hawthorn Formation is hydraulically con- brown to blue-gray clay, gray
tinuous with surficial deposits and forms phosphatic shell limestone. Limelower part of surficial aquifer. stone more prominent in western ....__part of forest.
Because of comparatively low permeability, B 13-70 Green to greenish-gray massive most of unit acts to retard the downward o clay. Often fractured. black clay
Hawthorn movement of waterfrom the surficial aquifer . prominent.
confining to the Floridan Aquifer. Member C yields C C 13-58 Green to greenish-gray, fine- to o0
unit small quantities of water under confined U. medium-grained sand. Contains
(Secondary conditions. Basal limestone beds are not E clay and limestone to east of
0
Artesian considered part of the Floridan Aquifer in Z Forest
Aquifer) Forest. D C 5-43 Complexly interbedded shell limeI stone, clay, clayey sand, and finegrained sandstone.
E 14-73 Brown sandstone, tan to darkbrown limestone, dolomite, and
argillaceous limestone.
. .. .......__Fossiliderous, well indurated.
Floridan Yields large quantities of water under Ocala" Eocene 102 + White calcarenite at top containing
Aquifer confined conditions everywhere under Lime- some green clay. Gray, hard
Osceola National Forest. fractured limestone below. pene__ I_ 1_ _1 _ 1-trated 102 feet.
"Thp ,11%,kP= I nqtnne rf n.m~en age, which is part of the Floridan Aquifer in places, was not found in the Osceola National Forest.






REPORT OF INVESTIGATION NO. 87 41

tween the two units there than exists in the Osceola National Forest. The E member at OXY is thinner and probably more permeable than to the east. High rates of pumping from the Floridan Aquifer by OXY (28.8 mgd) may also contribute to secondary aquifer drawdown in the area.
Figure 17 compares secondary aquifer potentiometric surface fluctuations with Floridan fluctuations in Osceola National Forest wells. The pattern of fluctuation is similar, but the range of fluctuation in the secondary aquifer well is one-third the range of the Floridan Aquifer. Secondary aquifer fluctuations respond to the same changes in storage that affect the Floridan Aquifer, but the lesser degree.
Feet Above
Mean Sea Level
102
Secondary
Artealan ,
Aquifer 100
98

64
62
60
Floridan
Aquifer .58 U53 U IA U005 *-A




52
50 J ,, J_1A1-S1 0 'N )11 F M


Io 1 I Ims - l: L I W7

Figure 17. Relationship of secondary artesian water levels to Floridan Aquifer water levels in Osceola National Forest (Modified from Miller).
In the OXY area, secondary aquifer water levels fluctuate as much as, or more than, Floridan Aquifer water levels (Figure 18). The basal Hawthorn confining beds (E member ) apparently are more permeable at OXY than in Osceola National Forest, accounting for lower secondary iead pressures and a more direct correlation with Floridan Aquifer ootentiometric surface fluctuations.
The secondary aquifer system is recharged from the overlying ;urficial aquifer wherever Member B is discontinous and leaky. Due to !ack of data, it is difficult to pinpoint exact locations of recharge to the secondary aquifer. The secondary aquifer discharges vertically ,downward to the Floridan Aquifer where confining beds separating the two are breached through karst activity or are permeable. Some discharge occurs laterally along the Cody Scarp and anywhere streams have cut through the upper confining bed (Member B).







BUREAU OF GEOLOGY


Water Level in Feet Above Mean Sea Level 80 'r1111-


6 0
-011500 -0115020 18





II I
- 0 1 15 0 2 0 1 4 " ",






-011501001 -;1;5r02018
II I I I! - I , - .
-011511001

t' I' II = ,

-011436001

501''









40 5 10 15 20 25 5 10 15 20 25 5 10 15 20 25 5 10 15 20 25 5 10 15 20 25
JANUARY FEBRUARY MARCH APRIL MAY 1978
-0 11502009 SRWMD Well Site Identification Number
* Secondary Artesian Wells
* Floridan Artesian Wells



Figure 18. Relationship of secondary artesian water levels to FMorid nl
Aquifer water levels at Occidental Chemical Company.






REPORT OF INVESTIGATION NO. 87


Aquifer Properties
In 1977 the USGS conducted an aquifer test on the C member of the Hawthorn in Osceola National Forest. The unit was pumped at 3.2 gpm for 336 hours. Effects of pumping were felt in the C and D members of the Hawthorn. Analysis of the data by the Hantush Method resulted in a low transmissivitv of 15 ft2/day and a storage coefficient of 0.00012 (1.2x10-4) (Miller, et al., 1978b).

Groundwater Development
Wells tapping the secondary aquifer system are not common in the Upper Suwannee River Basin. Where the secondary aquifer exists, there is an overlying surficial aquifer that yields as much or more than the secondary aquifer. If there is a need for a larger supply (irrigation, public supply, industry), a deeper Floridan Aquifer well is usually drilled.

Water Chemistry
Secondary aquifer water chemistry is not as well defined as surficial or Floridan Aquifer chemistry due to the small number of wells completed into the aquifer (15 in the study area) available for sampling and the lack of areal Hawthorn Formation stratigraphic data. In northern Columbia County there are five Hawthorn members (Miller, et al., 1978b). The lower three-C, D, and E-are permeable enough to contain water, while C is the most productive. In eastern Hamilton County, Members D and E appear to be absent or discontinuous, while in Suwannee County there are no data. Facies changes are common throughout the Hawthorn Formation, and the lithology varies from sand to clay to carbonate in all manner of proportions. This causes difficulties in attempting to characterize the water.
Secondary artesian water is characterized by high relative values for fluoride and orthophosphate. These parameters are strongly correlated in Cluster 3 in Figure 12. The high values for fluoride and orthophosphate (Figure 15) are a result of dissolution of fluorapatite, the most abundant phosphate mineral present in the Hawthorn Formation (Lawrence and Upchurch, 1976). Figure 15 also reveals that secondary artesian water has high relative values for the parameters potassium, sodium, and pH. Montmorillonite clays within the Hawthorn readily sorb
-otassium and sodium ions, and weathering those clays can release the sodium and potassium into solution (Garrels and Christ, 1965). The pH nay be high because of high sodium and orthophosphate values that promote a higher pH due to hydrolysis reactions influenced by )hosphates and carbonate salts (Hem, 1959).
Trilinear plots of secondary aquifer ion ratios (Figure 16) show that 3s far as the major anions and cations are concerned, secondary artesian water is nearly identical to the calcium-magnesium-bicarbonate 'loridan artesian water. These ratios are relative percentages and the





BUREAU OF GEOLOGY


stoichiometric equations are for the same reactions so the relative percentages of ions for the two types should be the same (Robert Hull, USGS, Tallahassee, FL, personal communication, 1980). In the adjacent Santa Fe River Basin, secondary artesian water from the Hawthorn Formation is of the calcium-magnesium-bicarbonate type (J.D. Hunn, USGS, Tallahassee, FL, written communication, 1980). In the Upper Suwannee Basin the secondary artesian aquifer is always underlain by the artesian portion of the Floridan Aquifer, and there are varying degrees of hydraulic conductivity between the two.

FLORIDAN AQUIFER

Configuration and Extent
In north central Florida the potable water-bearing portion of the Floridan Aquifer is comprised of carbonates deposited during the Tertiary Period. The portion of this aquifer that extends into Georgia is named the principal artesian aquifer. The base of potable water in the Floridan Aquifer is estimated to range from approximately 1000 feet below land surface (-900 feet msl) in the southern part of the study area to more than 1250 feet below land surface (-1150 feet msl) in the northern part (Klein, 1975) (Figure 19). These depths are generalized from widely scattered data, and test wells need to be drilled to verify the base of potable water. Krause (1979) reports highly mineralized, nonpotable water in the Valdosta, Georgia, area as shallow as -330 feet msl.
The deepest (oldest) formation in the area that contains potable water is the Lake City Limestone (Eocene). Water from the lower portions of the Lake City contains high sulfate concentrations. From oldest to youngest, the other carbonate units containing potable water are the Avon Park and Ocala Group (Eocene), the Suwannee Limestone (Oligocene), and the St. Marks Formation (Miocene). Together these units comprise the Floridan Aquifer. Even though they may be hydraulically connected to the older carbonates, basal Hawthorn carbonates are not considered to be a part of the Floridan Aquifer in this area because of differences in water chemistry, potentiometric heads, and transmissivities. Most of the domestic Floridan wells in Hamilton and northern Suwannee counties tap the Suwannee Limestone for water. In northern Columbia County the Suwannee is thin or absent, and most Floridan wells are completed into the Ocala Limestone. A few municipal and industrial wells penetrate rocks older than the Ocala in the study area.
Most of the groundwater circulation takes place in the upper 200 to 300 feet of saturated limestone (J.D. Hunn, USGS, Tallahassee, Florida, written communication, 1980). Suwannee River Water Management District geophysical and drillers' logs were examined to locate cavity zones in the Floridan Aquifer. Data revealed that of all reported cavities in the study area, nearly two-thirds occurred at formational contacts. Most occurred at the contact between the Suwannee


44





C,


/. -A K E ~ DUVAL

loop -- "" ,I COLUMBIA P1
SUWANNEE "-a-" ".

750 -- ,,
T AY LO0R U N IcN C L A Y LAFA E 0 ERADFOR
"00


m -,--.. Line Showing Inferred Depth A " 250
In the Floridan Aquifer 111250

Contour Interval 250 Feet .1 n H
Datum is Land Surface 250 -- A U A
(Modified from Klein, 1975) x I E . ..PUTNAM 0


N c

\ L E V Y %-4
ONOIrUE 4 LATITUO E
r"--"1 M A R ION


250500:
SOURCE DATA
EF S Ol[P? OF INTERIOR q ,
a toLOGICAL SURyy
STATt a? PEONo A VAP 111117
01
Figure 19. Inferred depth to base of potable water in Floridan Aquifer.





BUREAU OF GEOLOGY


Limestone and the overlying Hawthorn, but the Ocala Group-Suwannee Limestone contact is also a major cavity zone. Area springs exhibit extensive horizontal cave systems at these contacts (Fisk and Exley, 1977). These systems are known to extend for miles, and velocities within the conduits commonly reach five feet per second (Dave Fisk, SRWMD, personal communication, 1979).
The upper one-half of the Suwannee Limestone also contains significant cavity zones. A high degree of secondary porosity has developed in the upper Suwannee since it is, generally, the first major carbonate unit encountered by the downward percolating acidic ground water, especially where the aquifer is in a leaky artesian or nonartesian condition. The upper portion of the Suwannee Formation is also a former erosional surface, is not as lithified as the lower Suwannee because of less compaction in early diagenesis, and probably developed a degree of secondary porosity during this weathering period.
In the areas south and east of White Springs, the Suwannee Limestone is relatively thin (less than 20 feet thick). Where this situation exists, the entire Suwannee and Upper Ocala are potentially cavernous. Cavity zones up to 25 feet thick are common. The limestone along the rivers has developed high secondary porosity partially due to dissolution by acidic river waters. During flood stages, a large volume of river water recharges the Floridan Aquifer along the river corridor. In areas that are nonartesian now, or have been in the geologic past, solution cavity development takes place at the water table and within the zone of water table fluctuation. Where the aquifer is artesian, most solution takes place at the contact of the saturated carbonates with the overlying confining bed.
The upper surface of the carbonate rock that comprises the Floridan Aquifer is depicted in Figure 20. The highest elevation of limestone is approximately 100 feet above msl in the Live Oak area. Limestone is at land surface here and is quarried. The carbonates form a domal feature that underlies most of Suwannee and western Columbia counties. From the dome the rock surface drops at a steep gradient (400 feet over 30 miles) to the east-northeast to more than 200 feet below msl within the study area.
The Floridan Aquifer has been described extensively in the literature. Miller, et al. (1978b, p. 28) sum it up very well:
It consists of a thick and areally extensive sequence of interbedded limestones and dolomites of Paleocene to middle Miocene age. Although these carbonate rocks differ vertically and horizontally in texture, porosity, and permeability, they can be treated as a single hydrologic unit in that, overall, their internal hydrologic dissimilarities are minor compared with dissimilarities between them and other units. Groundwater storage and movement in the Floridan takes place through a complex admixture of intergranular
openings, cavities, and solution cavities.




11 ...


0 0 25 0


M A' Dy 1
25 25 50

. 50
1 0 3 6 Mi.
0 2 4 6 8 Km. 75
75 - Contour on the Upper Surface of the
Carbonate Rock That Comprises the Floridan Aquifer In Feet MSL
(Dashed Where Eroded) Contour Interval 25 Feet


II w1


St. Marks Formation Suwannee Limestone


Ocala Group


G E O R G I A
-25 1 _ 0s o -75-o0-125-15o-175-9


F" ,
25


Figure 20. Structural top of Floridan Aquifer.


T2N


-200 T IS
-175
-150

-125
-100
-75
-50
T3S
-25






BUREAU OF GEOLOGY


Areas of Artesian and Nonartesian Conditions
Two types of hydrologic conditions exist in the Floridan Aquifer. Artesian conditions prevail beneath the Northern Highlands (Figure 21). Where the Floridan is confined on top by relatively impermeable strata of the Hawthorn Formation, it is under artesian pressure. Under artesian conditions, water levels in tightly cased wells penetrating the aquifer will rise above the altitude of the saturated carbonates.
Nonartesian conditions prevail in the Coastal Lowlands. The Floridan is not confined on top, and the saturated zone of the aquifer is at atmospheric pressure. Water levels fluctuate from below the upper surface of limestone to above it into the overlying sands, depending on the amount of water in storage. The potentiometric surface of the Floridan is higher where the aquifer is in an artesian condition; therefore, groundwater flow in the Floridan Aquifer is from the artesian to the nonartesian portion.
The artesian-nonartesian boundary in Figure 21 was described by superimposing potentiometric surfaces onto the structural top of the Floridan Aquifer map (Figure 20). Along the boundary line, the highest limestone encountered is the Suwannee Limestone. There is a small area in the northwest portion of the study area where the St. Marks Formation is the highest limestone encountered. Artesian areas are defined where the potentiometric surface is above the top of the limestone. Nonartesian areas are defined where the potentiometric surface is below the top of the limestone. The transition zone between the artesian and nonartesian portions migrates as water levels fluctuate. During periods of recharge to the aquifer, the potentiometric surface rises. This results in an areal increase of artesian conditions. The increase is greatest in the Alapaha Subbasin where groundwater fluctuation is greatest.
The artesian-nonartesian transition zone during high water levels (maximum artesian area) generally concides with the crest of the Cody Scarp which follows the 100- to 110-foot msl surface contour lines. These contours also separate the Northern Highlands from the Gulf Coastal Lowlands as seen in Figure 21. Along the Cody Scarp there is a high degree of physical and chemical weathering. Mature karst develop ment is evidenced by deep, steep-sided sinkholes, dolines, sinking; streams, and, at the base of the scarp, artesian springs. The artesiarnonartesian boundary also generally coincides with the 40- to 50-foo: msl contour lines on the top of the Floridan Aquifer (Figure 22). Artesian conditions prevail wherever the top of the limestone is less tha, 40 feet above msl. Since the transition zone generally follows th 110-foot msl surface contour, the Hawthorn has been eroded to a 5C to 70-foot thickness along this boundary (Figure 23). It becomes apparer that thickness of the overlying, confining Hawthorn strata is related t, artesian conditions. Less than 50 to 70 feet of basal Hawthorn does no appear to constitute a good confining bed. Where the Hawthorn has beei eroded to a thickness of less than 70 feet, it has become solution-riddle(: and is leaky and discontinuous. Along the transition zone, up to 50 fee


-A8





Ru 11


G E


T2 N

Lm

00
-I
100
0 "







m0
1+ o 3 6MI.r . Z 02468K. 0 00
Cody Scarp

Northern Highlands " Lowlands Arteslan-Nonarteslan Transition Zone


Figure 21. Artesian-Nonartesian transition zone superimposed on the physiographic map.









50 H I L T:.:S~ T 2 N


7 5




9m
00OF0

so 0 00
M o A D .� 11 8, ",0 N T 1 S ,


25 25 50 T3Se


75 Contour on the Upper Surface of th' r eg
~~-125;abnt



CroaeRock That Comprises the
Fioridan Aquifer in Feet MSL_____(Dashed Where Eroded) 7
Contour Interval 25 Feet
I Artesian-Nonartesian Transition Zone 2 50
.,,, , A .,, ,&, ' +! transition zone superimposed on the structural top of the Floricfan ., fr




75
5RuE100 128


I G E 0R G I &


MAD


Line of Equal Thickness of Hawthorn Formation in Feet Contour Interval 25 Feet


Figure 23. Artesian-Nonartesian transition zone superimposed on the isopach of the Hawthorn Formation.


5075100






BUREAU OF GEOLOGY


of basal Hawthorn can be carbonate rock that directly overlies Floridan carbonates. The Hawthorn carbonates have varying degrees of hydraulic connection with the underlying Floridan. They constitute a separate aquifer from the Floridan, however, since they exhibit different hydraulic heads and different water types.

Potentiometric Surface Fluctuations
River basin boundaries for the Suwannee River above the Withlacoochee River, Alapaha River, and Withlacoochee River subbasins are shown in Figure 24. Oligocene and Eocene carbonates that comprise Georgia's principal artesian aquifer (equivalent to the Floridan Aquifer) outcrop in the northwest. This aquifer dips southeast beneath Upper Miocene and younger coastal plain sediments and underlies all of the coastal plain of Florida. The aquifer is recharged generally in the outcrop area and locally wherever the overlying sediments are thin, discontinuous, removed, or leaky. Since 94 percent of the Alapaha and 69 percent of the Suwannee River above the Withlacoochee subbasins lie in Georgia, precipitation in the outcrop area and in the upper river basin area is the major source of recharge to the artesian portions of these basins of Florida.
Georgia has two climatolotical regions in the area of concern - the South-Central Divsion and the Southeast Division (NOAA, B, 1949-1978) (Figure 24). Precipitation data from these two divisions (Table 5) were correlated with fluctuations in the potentiometric surfaces in the Alapaha and Suwannee Basins in Florida. The South-Central Division encompasses all of the Alapaha and Withlacoochee subbasins in Georgia and approximately two-thirds of the Suwannee River above the Withlacoochee River Subbasin in Georgia. The eastern one-third of the Suwannee above the Withlacoochee Subbasin is within the Southeast Division.


Table 5. Mean monthly rainfall in inches. Georgia- 1977 through 1978.

May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr
a 2.25 3.79 5.82 6.66 5.20 1.13 4.19 5.11 6.33 2.96 4.10 3.20
b 2.40 2.72 5.01 6.77 7.82 1.08 4.19 5.89 4.15 2.91 3.19 2.55
a = South-Central Division
b = Southeast Division

Generally, the potentiometric highs in the aquifer outcrop area ir Georgia are the controlling factors responsible for the pressure head ir the principal artesian aquifer in Georgia and part of the Floridan Aquife in extreme north Florida (Figure 25). The potentiometric high (approx imately 100 feet above msl) in Brooks and Lowndes counties, Georgia,









REPORT OF INVESTIGATION NO. 87


Climatological Region Boundary River Subbasin Boundary Outcrop Area of Principal Artesian Aquifer (From Lawton 1977) Wells with Continuous Recorders









---h

'1
S o u h e a s t
R E





E 01VER
C cHA L T 0N
IT E;....." o







HE

ON 0~
,, 0 A K E











0 c 20 3 o ......,0


Figure 24. River basin and climatological region boundaries for the
Suwannee River above the Withlacoochee, Alapha, and Withlacoochee River subbasins.







BUREAU OF GEOLOGY


Pttatric SLrface in Feet "
aboe Mean Sea Level
Cantous kterval 10 and 20 Feet.
(Modifted from Laugh 1976, Rosenau and '-0 2. *Y� 4Q KI
Meadows 1977, Fisk and Rosenau 1977 b, unpubllshed
USGS 1976 Water Level Data Jacksonve, FL)


Figure 25. Potentiometric surface of principal artesian-Floridan
Aquifer in south-central Georgia and north-central Florida.




6fl~


T2N


MI
45 0
IfI
0
40 25.
M I
ii
35302530 WhteXv
S Springs 0

00
Km.1 0 3 2 Mi. 1A

0. 22 m




0 Data Points
60 - Contour Line - Potentiometric Surface
In Feet above Mean Sea Level 30 mm 7111111 IN erred
~ inferred30 35 40 45 50 0
Contour Interval 6 Feet 0 4 5
Figure 26. Potentiometric surface of the Floridan Aquifer in north-central Florida, August 1977.






BUREAU OF GEOLOGY


is the source of the pressure head that moves ground water southward across the state line into Madison, Hamilton, and Columbia counties, Florida. The high in the area around Valdosta is created by a high rate of recharge that occurs primarily as flow from the Withlaroochee River and other streams enters the principal artesian aquifer via sinkholes and solution cavities. Groundwater also enters the study area from the east and northeast. A hydrologic divide extends southeast from Echols County, Georgia, to Putnam County, Florida. Ground water moves southeasterly from this divide into Nassau, Duval, Clay, and Putnam counties and westerly into the Suwannee River Basin (Figure 25).
Drought conditions existing in north-central Florida in the summer and fall of 1977 (Musgrove and Shoemyen, 1979). In August 1977 the potentiometric surface of the Floridan Aquifer approached record low levels (Figure 26). Total precipitation for the three-month period prior to this August measurement was below normal. Total rainfall in Georgia's South-Central Division was 11.86 inches, 2.69 inches below the 30-year mean; rainfall in the Southeast Division was 10.13 inches, 6.05 inches below the mean (NOAA, 1949-1978 B). Low rainfall and high ET account for the low potentiometric conditions in the Floridan Aquifer in north-central Florida in August 1977.
The lowest groundwater levels in the study area in August 1977 occurred at the confluence of the Suwannee and Withlacoochee rivers. At this point, the Suwannee River exits the upper basin. Water levels of 25 feet msl were measured here, 127 miles from the river mouth. Levels as low as 40 feet above msl extended to the Georgia-Florida line. The area within the 45-foot contour in the western portion of the study area indicates a zone of major geological structural weakness extending north through the Alapaha Subbasin. This could result in high transmissivities in this area due to high secondary porosity which may produce conduit flow in the subsurface. Approximately 50 percent of the time the Alapaha River disappears underground for 17 miles in this area. Minor geological structural control extends eastward toward White Springs. Localized highs ()50 feet above msl) extend westward through Lake City toward Live Oak. Other potentiometric highs are in the northwest and northeast corners of Hamilton County. These potentiometri6" highs coincide with areas of relatively high surface elevations and thick sequences of Hawthorn strata. As the 50-foot contour continue; southeast through Hamilton County, it exhibits an eastward extendin. 1 lobe that encircles White Springs and extends into Columbia Countv. This configuration appears repeatedly on water level maps and is signif, cant because it coincides with the first outcrop of the Suwannet, Limestone along the river. This is the first point of interconnection when. water may be exchanged between the Floridan Aquifer and the Suwan nee River depending on river stage and aquifer head. The outcropping limestone occurs at 50 feet above msl; and, at low river flow, artesiar springs appear along both sides of the river as the aquifer discharge! directly into the river.









T2 N


0 0

45I
0






MI <








-' nf e 30354 45r Oak1 30 354 45 50 8





Contour Interval 5 Feet Figure 27. Potentiometric surface of the Floridan Aquifer in north-central Florida, November 1977.







+1 to +2 R ~ I IE


GEORGIA


SA10T2N

C. I



MAION) E E C 0






Area' :of Not Change In WatereLevels
within th Flria Aqie InFe
5 0 r
o .t:. � ,0

I T3 S



* Data Points ., SArea of Net Change In Water Levels
within the Fioridan Aquifer in Feet 0


Figure 28. Net change in the potentiometric surface in Floridan
A ,- , 0 f a - r i r n i - ..Ir,- r r el r l A i t - i t 1 0 7 7 + e -% - - I- ,







REPORT OF INVESTIGATION NO. 87


From August to November 1977, total precipitation for south-central 3eorgia was about 12.99 inches, 1.31 inches above the mean. Precipitaion for southeast Georgia was 15.67 inches, 0.11 inches above the nean. Since water level conditions were already near record lows and :he rivers were at very low flow, water levels continued to decline over
-nost of the area in spite of average rainfall. The November 1977 poten.iometric map (Figure 27) is quite similar to the August 1977 map (Figure 26). Net groundwater level fluctuation-mostly decline-from August to November is shown in Figure 28. Water levels declined over most of the study area. The shaded areas exhibit the greatest fluctuations. The three linear northwest-southeast trending areas are coincident with postulated linear trends of subsurface fracture systems (zones of structural weakness inferred to have high secondary porosity). A linear trend of sinkholes in the area of maximuim fluctuation near Lake City may represent the surface expression of a subsurface fracture system (Lawrence and Upchurch, 1976). The area of high fluctuation coincidental with the Suwannee River is an area where the Suwannee Limestone outcrops. The river here flows along the same northwest-southeast linear trend of subsurface fracture systems. The northwest-southeast trending reach of the Alapaha, southeast of Jennings, contains dozens of sinkholes through which the Alapaha River disappears underground much of the time. This is the most dynamic area in the SRWMD, and water levels fluctuate up to 30 feet. All three of these areas exhibit higher transmissivities because of higher secondary porosity and permeability.
From November 1977 through January 1978, south-central Georgia received 15.63 inches of rainfall, 6.19 inches greater than the mean. The Southeast Division received 14.23 inches, 6.18 inches greater than the mean. Wide areal winter precipitation combined with low ET rates to replenish the aquifer. In the Alapaha Subbasin the resulting potentiometric surface was highest in the Alapaha River corridor, and contour lines indicate that river waters flowed laterally as well as downstream (Figure 29). River water at this time was recharging the aquifer vertically and laterally and was mixing extensively with Floridan Aquifer waters (Ceryak, 1977). Water levels rose as much as 29 feet during this threeF!onth period (Figure 30). The area of least fluctuation on Figure 30 is i1 the confined area where the Floridan Aquifer underlies the Northern lighlands in eastern Hamilton and Northern Columbia counties-the area 3rthest away from areas of recharge. Large increases in groundwater torage occurred in the Suwannee River corridor because increased .recipitation created high river stages. Along the river where limestone rops out and springs appear, high river stage caused the springs to averse flow; and the river water was directly recharged into the aquifer.
By May 1978 the potentiometric surface (Figure 31) declined to a onfiguration similar to that which it had exhibited in the summer and all of 1977 (compare Figures 26 and 31). Total rainfall for Georgia's .outh-Central Division in the three-month period preceding May 1978 'as 10.26 inches, 2.74 inches below the mean. The Southeast Division






60 BUREAU OF GEOLOGY

received 8.65 inches, 2.21 inches below the mean. The area of the most dramatic decline again was along the Alapaha River where water level3 dropped as much as 18 feet (Figure 32). The Suwannee River corridor also experienced a relatively large water level decline, while again the least fluctuation occurred beneath the confined highlands in eastern Hamilton and northern Columbia counties. The river corridors experience the widest range of water level fluctuations. Considerable amounts of water move into bank storage during high river stages and slowly drains back as the stage declines. Transmissivities along the river corridors are probably higher because the rivers are thought to occupy zones of weakness (i.e., faulting and jointing) where secondary porosity has increased due to greater groundwater dissolution of the limestone. Appearances of lineaments confirm the coincidence of the river paths and zones of weakness (Beatty, 1978; Vernon, 1951).








T2N


0 0 m
0


0; 00 I S

., < .otoo ,-to , ,0 .,

0i


100.1
1 ,0 a aM mi 60 I C'O 0 r iA CD " � i n I ! I ' I f I .... I r A
0. 20 m
UN A_ N2EC





* Data Points355 SContour Line - Potentiometric Surface 3 In Feet above Mean Sea Level
Contour Interval 5 Feet 303540 45 50 0 Figure 29. Potentiometric surface of the Floridan Aquifer in north-central Florida, February 1978.










GE ORG IA

o115 +10+15+20 R 13 E +20 +15 +10 R 1 5 e +5 R 17 E R 9E

C tm Iou It Tc 0 r T ee


tp

#AA+ 1 0 ; . r













F~gure suhil e afte F o~ f
30. N A N e E etri
0 D a t P o int u w N ~


5,mo Line Of Equal Rise in Water Levels �
within the Floridn Aquifer In Feet 0o 0
o n t o u r in t e r v a ls 5 F e e t u f c f t e F ~ l a FijgUre 30 Net htangeintepetlmris




-T a -6 o- - . G 3 .


T2 N


50 rm � 0
4 5 o 0

T I S I

40 35 36 40 NO 0--,"I' , . m �0o 0*j



Lv 0


* Data Points 4,1
50" Contour Line - Potentionietrio Surfa:ce 3
in Fee ao Min Ca 0LeUvel1




" " ' " I n f e r r e d
Contour Interval 6 Feet 35 0
Figure 31. Potentiometric surface of the Floridan Aquifer in north-central Florida, May 1978.








0


T2N







o0 co~ 0'" " C r
C


00
Mi.;- C. A ,LR .
0

0 2 4 8Km.SUWA EEC0
I~~~~ T ,3 8eM.'I

� � T35

Data Points L a � Line of Equal Decline in Water Levels 0 0 within the Floridan Aquifer In Feet Contour Interval 5 Feet
0;

Figure 32. Net change in the potentiometric surface of the Floridan Aquifer in north-central Florida, February to May 1978.






REPORT OF INVESTIGATION NO. 87


Water Level Relationships
The potentiometric high in Brooks and Lowndes.counties, Georgia, cefines a recharge area. Groundwater within the Floridan Aquifer flows from this area into the Northern Highland areas of Hamilton, northern Columbia, Baker, and eastern Suwannee counties, Florida (Figure 25). Seasonal fluctuations in precipitation and ET cause corresponding changes in streamflow stages and in the groundwater levels of the principal artesian or Floridan Aquifer. Areas with relatively high water levels tend to be recharge areas. The area around Valdosta, Georgia, is a recharge area. A portion of the flow of the Withlacoochee River (up to 112 cfs) directly recharges the Floridan Aquifer through sinkholes in the river bed (Krause, 1979). The potentiometric surface fluctuates more than 20 feet (between 73 and 100 feet above msl). The structual top of the Floridan Aquifer near Valdosta is around 20 feet above msl; and there is a thickness of greater than 100 feet of overlying Hawthorn, so groundwater conditions in this area are always artesian. Figure 33 depicts the mean monthly rainfall for the South-Central Division of the Georgia climatological region (30-year mean). Precipitation normally is highest in midsummer, July and August, when convectional afternoon thunderstorms are the typical rainfall event. The other peak rainfall period is in March, culminating a relatively high midwinter rainfall. October and November usually have the lowest amounts of precipitation, resulting in low streamflow and groundwater levels at this time.
Figure 34 depicts the seasonal relation of precipitation, pan evaporation, streamflow, and groundwater levels for the Valdosta area. Precipitation for this station is nearly identical to the regional pattern displayed in Figure 33. Streamflow responds to the winter rains and increases through April, only to begin decreasing as pan evaporation begins to increase. Pan evaporation is beginning to peak by April, resulting in ET being a major factor causing streamflow to decline in the summer months. Streamflow decreases as bank storage is depleted. Groundwater ;evels decline in the summer and usually continue to drop into November, the month that commonly displays the lowest groundwater levels and lowest river stages. Stream and groundwater levels rise in December when the winter frontal systems begin. The long-term relationship betveen precipitation, streamflow, and ground water levels for the Valdosta area also emphasizes a direct correlation between these three v-iriables (Figure 35).
For the year 1977 a comparison was made between daily groundv ater levels, stream discharge, and precipitation for Valdosta (Figure 3). During the winter months, each rainfall event is followed _by an ir mediate rise in the level of ground water in the principal artesian a iuifer. The water level peak occurs within two days and often within c ie day of the rainfall event. Water levels then decline until the next n infall event. When summer rains begin in late May, ground water levels s ill respond within two days of the precipitation; however, due to higher E . rates, the magnitude of water-level rises is lower than in the winter






BUREAU OF GEOLOGY


LU







___ F M T M *,I ,, A S~ 02 N.J... D...L Months
Figure 33. Mean monthly rainfall for the south-central Georgia
climatological region (30-year mean).
months. Barometric pressure changes cause fluctuations in groundwater levels in confined aquifers. Frontal systems moving through the area cause fluctuations of around one foot every three to seven days in August and September.
Streamflow also corresponds directly with rainfall in the winter months; streamflow usually is very low in summer and shows little response to the summer rainfall since ET rates are highest and runoff in the upper basin is minimal. Streamflow response to rainfall is again more direct at the end of summer when ET rates begin to drop. Throughout the year a one-inch rainfall event can cause groundwater levels to rise two feet or more. One to two inches of rainfall usuall, causes a two- to five-foot positive response in water levels. This respons&, is slightly greater in winter than in summer. There is nearly 20 feet c a yearly fluctuation in USGS Well 304949083165301 in Valdosta Georgia. This high degree of groundwater fluctuation is typical c* recharge areas. Also common in recharge areas is a water level rise fror' mid- to late summer in response to the convectional rains. Over th, 10-year period from 1968-1977, Valdosta water levels experienced summer rise of nine for those years. Rises ranged from one to eight fee:








REPORT OF INVESTIGATION NO. 87


3000


2000


1000 -


90 -


U Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec





Figure 34. Seasonal relation of mean monthly precipitation, evaporation, streamf low, and groundwater level, Valdosta area.


PRECIPITATION Valdosta 4 NW







oI I I e S o i





I I I I I I I I I I



T.f.o.Exprimenal.Satio


Z
0
c

LiO.
W



LL (L






_TW

wU
<


~STREAMFLOW








l i I I I I I I I I t I


GROUND-WATER LEVELii..
Well 185-7






BUREAU OF GEOLOGY


PRECIPITATION Valdosta 4 NW




I


i SREM I F W
K UavI I I I I I I I InIi l l |








i I p i l I p


1960 1965 1970 1975


Figure 35. Long-term relation of precipitation, streamf low, and
groundwater level, Valdosta area, 1957-1975.


,, 80
-,
(n s

LE 70
z

g 60 a

o 50 a
< 40
z
z
30


3i a 3000




2el00
0 Z



<- 0
00


90 851


Rfl


GROUND-WATER LEVEL
Well 185-7


I , I I . IIIIIIIi I I I


1967


I I I I I I I I I I I I I I. . . . .































ai r M A M I J A 5 U N D
m Water Level In Feet Below Land Surface
Stream Discharge, CFS PrecIpitatIon In Inches

Figure 36. Daily groundwater levels, stream discharge and precipitation for Valdosta, Georgia.





BUREAU OF GEOLOGY


100


YEAR
Figure 37. Groundwater level fluctuation, Valdosta, Georgia, and
Jennings, Florida, 1968-1977.






REPORT OF INVESTIGATION NO. 87


with an average of 3.3 feet. Levels do not usually attain the altitudes of February and March, but a five-foot rise is common (Figure 37).
Jennings, Florida, (SRWMD Well + 021202001) in the Alapaha Subbasin (Figure 24) is 20 miles southeast of, and down the potentiometric gradient from, Valdosta. Groundwater levels at Jennings fluctuate from 35 to 68 feet above msl, a 33-foot fluctuation. The top of the Floridan Aquifer is at 50 feet above msl; and there is nearly 100 feet of overlying, confining Hawthorn sediments. This well is on the artesiannonartesian boundary and can be either, depending on the water level. This area exhibits mature karst development and is also a recharge point. Nearby, the entire Alapaha River flows underground about 50 percent of the time through numerous streamsinks (Ceryak, 1977). These streamsinks have been known to accept 770 cfs of the river's flow and contribute to more than 30 feet of fluctuation in water levels in the underlying Floridan Aquifer. Figure 37 compares water level fluctuations in Valdosta with Jennings. The hydrographs are nearly identical in times of high and low water level peaks. They differ only in amount of fluctuation. Total yearly fluctuation at Valdosta can be 20 feet, whereas in Jennings it is around 30 feet. For 16 years of record at Jennings (1962 to 1977) there was a midsummer water level rise for 12 of those years, ranging from a 1- to 19-foot rise with an average rise of 4.7 feet.
Jasper, Florida, (SRWMD Well + 011407001) is located 12 miles southeast of Jennings, 30 miles southeast of Valdosta (Figure 24), and down the potentiometric gradient from Jennings. Water levels fluctuate from 30 to 55 feet above msl, a 24-foot fluctuation. The top of the Floridan Aquifer at Jasper is at 50 feet above msl. Conditions are nonartesian most of the time and only become artesian during times of extremely high water levels. There are 60 to 70 feet of confining Hawthorn, and the confining bed is leaky due to karst development in the area. Jasper is on the topographic divide between the Alapaha and Suwannee River above the Withlacoochee Subbasins and is also in a recharge area.
The Valdosta monitor well is three miles from the Withlacoochee Fiver and less than six miles in a direct line from a streamsink area. The Jennings well is one mile from the Alapaha River and less than two miles f:om the nearest streamsink. The Jasper well is five miles from the t lapaha and seven miles from a streamsink area. The Jennings well protably has the greatest water level fluctuations because it is only one r. ile from the river, is influenced by bank storage, and is reflecting large r ,ovements of water in and out of the aquifer (Dick Johnston, USGS, tlanta, Georgia, written communication, 1980). The sinks at Jennings
_3ve been known to accept 770 cfs of Alapaha River water (Ceryak,
977), while the sinks in the Withlacoochee River near Valdosta have
,en known to accept 112 cfs (Krause, 1979).
In Figure 38 daily water level fluctuations at Jasper are compared
* those at Valdosta for the period June 1976 to November 1977. aasonal fluctuations are slightly greater at Jasper than Valdosta. ummer groundwater levels fluctuate more in Valdosta because the well






BUREAU OF GEOLOGY


100

95


1976


1977


Figure 38. Daily groundwater level fluctuation, Valdosta, Georgia, ant
Jasper, Florida, June 1976 through November 1977.







REPORT OF INVESTIGATION NO. 87


ts closer to the point of recharge from the Withlacoochee River and is also subject to bank storage effect in summer. The Alapaha River flow is minimal and entirely underground at Jasper in the summer. In winter, however, when the Alapaha River flows above ground also, river water is recharged laterally into the Floridan Aquifer; and the Jasper well responds in less than 24 hours to fluctuations in the Alapaha River (Figure 39). Under these conditions, Jasper water levels fluctuate up to 10 feet higher than those in Valdosta.


90--



UAlapaha River at Jennings, FL
M70 - -


L60--C" Groundwater Level at Jasper, FL (SRWMD 4011407001)
> 50- --30A 8 N 0- F M A M J J A 8 0
1976 1977


Figure 39. Daily groundwater level fluctuation at Jasper, Florida,
compared with daily stage of Alapaha River near Jennings, Florida, July 1976 through October 1977.
USGS test well OK 8 IWell 304943082213701) is located east of :ephen C. Foster State Park on the western edge of the Okefenokee CNamp. This area is 50 miles due east of the Valdosta recharge area. V.'ithin the Suwannee River above the Withlacoochee Subbasin in Georgia (I igure 24) and down the potentiometric gradient from Valdosta, the p, tentiometric surface of the principal artesian aquifer fluctuates 10 feet fi -m 48 to 58 feet above msl. The limestone aquifer underlying the site d ps to the northwest, and the top of rock is approximately -350 feet n sl. There are more than 400 feet of confining Hawthorn Formation. Ie water level fluctuation at this site is typical of a deeply buried artesian a juifer away from the recharge area (Figure 40). Total fluctuation for 1 -177 was only four feet compared to 21 feet at Valdosta, 26 feet at J .sper, and 38 feet at Jennings. Water level response in well OK 8 lags fim 5 to 20 days behind water level fluctuations in the Valdosta well,






BUREAU OF GEOLOGY


100 1 1 1 Valdosta, GA k(USGS 304949083165301) 95


90


CI 85


80 ----"L75 - __ __ __J70


3 65



Fargo, GA
(USGS OK8 304943082213701)
55
Osceola Nat.
Forest. FL .
(USGS ONF6 302251082194901? "
50 1 ' a t " '
SF M A M J J A S O N D

1977




Figure 40. Daily groundwater level fluctuation at Valdosta, Georgi h;
Fargo, Georgia; and Osceola National Forest, Florida, 1977.






REPORT OF INVESTIGATION NO. 87


,ssuming no recharge between the sites. It is common for OK 8 to lag 0 to 13 days behind. Mean monthly comparisons $how OK 8 lagging up to one month behind Valdosta. About 50 percent of the time OK 8 Sioes have a summer peak although the highest in ten years was one and one-half feet. Barometric pressure changes that result from frontal systems crossing the area affect the water levels most dramatically in August and September. Valdosta water levels have gradually risen nearly ten feet over the past ten years (Figure 37). During this same period, there has also been more than 26 inches of total rainfall above the norm in this climatological region. The Stephen C. Foster Park water levels have declined three feet over the same period. This apparent decline is probably due to regional water level decline caused by increased pumpage and drawdown in the Fernandina, Florida; Jacksonville, Florida; and Brunswick, Georgia, area about 50 miles east of the study area (Dick Johnston, USGS, Atlanta, GA, written communication, 1980).
USGS test well ONF 6 (Well 302251082194901) in the Osceola National Forest is 30 miles south of OK 8 and approximately 55 miles southeast of the Valdosta well (Figure 24). At this site the Floridan Aquifer is always under artesian conditions as the top of rock is at -192 feet msl; and there is 286 feet of overlying, confining Hawthorn, typical of the deeply buried, artesian Floridan Aquifer far from the recharge area. Water levels in this well have only fluctuated five feet, from 51 to 56 feet msl, over the period of record (August 1976 to June 1978) (Figure 40). This well has the least amount of fluctuation in the study area. This is to be expected. This area is in the center of the flat saddle between the potentiometric highs in Brooks and Lowndes counties, Georgia, and Putnam, Bradford, and Alachua counties, Florida (Figure 25). In this saddle the potentiometric surface is relatively flat over an area greater than 250 square miles. The resultant groundwater flow is eventually to the east-northeast to the Atlantic Ocean and to the west-southwest into the Upper Suwannee River Basin in Florida.
The structural top of the Floridan Aquifer at well OK 8 is more than 150 feet deeper than at well ONF 6; and, therefore, approximately 150 more feet of overlying Hawthorn occurs there. Otherwise, hydrogeologic conditions are similar under the Okefenokee Swamp and Osceola National Forest. Water level hydrographs for the two wells for 1977 are narly identical (Figure 40). Daily peaks lag a few days behind in ONF & as it is slightly farther from the Valdosta Recharge area. The Osceola l' :tional Forest area may receive some recharge from the southeast, but t .e potentiometric surface gradient is steeper from the direction of V ildosta, so the majority of groundwater inflow is probably from the r )rthwest. ONF 6 responds to the winter rainfall in the recharge area. F uctuations due to barometric pressure changes are more pronounced i, mid- to late summer; but in 1977, as in OK 8, water levels continued t decline through the periods of summer rainfall. Miller, et al. (1 978b) c )mpared the stage of the Suwannee River at White Springs to water 4 vels in wells tapping the Floridan Aquifer in Osceola National Forest.


75





BUREAU OF GEOLOGY


The direct correlation between precipitation and streamflow in the recharge area has.been shown in Figure 36. Miller states:
Wells 1A, 3A, and 6A are located progressively farther eastward from the river. The magnitude of groundwater rise at times of high stream stage decreases progressively
eastward away from the river.
See Figure 41. Well 6A is well ONF 6. This figure once again demonstrates that groundwater fluctuations decrease with distance from the source of recharge.
High river stage at White Springs causes White Sulphur Spring and other down-river springs to reverse flow. Potentiometric maps (Figures 26, 27, 29, 31) reveal that in the White Springs area groundwater flow is toward the river. Just as these maps and others (Miller, et al., 1 978b) reveal isolated potentiometric highs in the surrounding aquifer, the river can have periods of high stage also; but these localized river stage highs do not reverse the regional groundwater flow entering the Suwannee Basin from the east-northeast.
Lake City, Florida, (USGS Well 301031082381001, SRWMD
-041705001) is 20 miles southwest of, and down the potentiometric gradient from, ONF 6 (Figure 24). At Lake City there are 72 feet of confining Hawthorn, and the top of the Floridan Aquifer is 50 feet above msl. Groundwater levels have fluctuated up to 18 feet in the past but since 1950 have only fluctuated 10 feet, from 47 to 57 feet above msl (Figure 42). Water levels at Lake City are influenced by sinking streams and lakes in the area that occasionally drain underground. Most of the major water level fluctuations in the Lake City area are the result of variations in rainfall. Minor fluctuations are caused by changes in atmospheric pressure and by earth tides in the more confined portion of the aquifer. Finally, large fluctuations in the potentiometric surface of the Floridan Aquifer are related to stream stage where the aquifer is directly connected to a stream (Miller, et al., 1978b).


Aquifer Properties
Transmissivity (T) is the rate at which water of the prevailing kinematic viscosity is transmitted through a unit width of the aquifer under a unit hydraulic gradient. It is a property of the confined liquid as well as the aquifer. T in ft2/day equals Kb, where K is the hydrauli; conductivity in ft/day and b is the thickness of the aquifer in fee. Hydraulic conductivity is the volume of water at the existing kinemati; viscosity (temperature dependent) that will move in a unit time undEr a unit hydraulic gradient through a unit area measured at right angles to the direction of flow [K(LT-1)] and measured in ft/day (Lohman, 1972, p. 30).
Storage coefficient (S) is the volume of water an aquifer release; from or takes into storage per unit surface area of the aquifer per unit





_J
C0,
75


>m
0 70

4- 0 065 0
n)

0
. 60


>~
I)
0 55
"- 50.2
45 MAY I JUNE IJULY I AUG I SEPT ,OCT INOV IDEC JAN FEB MAR P 1976 1977 0o

-- Stage of Suwannee River at White Springs Well (USGS IA ONF1 302243082360201) Well (USGS 3A ONF3 302052082312401)
Well (USGS 6A ONF6 302251082194901) %4 Figure 41. Comparison of stage of Suwannee River with water levels in three wells tapping the Floridan Aquifer in Osceola National Forest.




















70


- 6 SRWMD -041705001 60 USGS 301031082381001

> . 4) "
So 55 - --- -- - -

C)50- - - - --- -._ 40 -35 1 -


1950


1955


1960


1965


1970


1975


Figure 42. Long term groundwater level fluctuation, Lake City, Florida, 1948-1979.





REPORT OF INVESTIGATION NO. 87


change in head (dimensionless). Confined (artesian) aquifers have storage coefficients that range from 10-5 to 10-3, while most unconfined (nonartesian) aquifers range from 0.1 to 0.3 (Lohman, 1972, p. 8).
Leakance (K '/b') is the ratio of the vertical hydraulic conductivity of the confining bed (K') to its thickness (b '). This is a property of the aquifer and not of the confining bed even though it is referred to in terms of the confining bed. Units of measurement are in days-1.
To determines the T, S, and K '/b' of the (confined) Floridan artesian aquifer in the Upper Suwannee River Basin, an aquifer test was conducted. On December 27, 1978, an 800' production well at OXY's Swift Creek Chemical Complex was pumped at 6928 gpm for 18.5 hours. A second 800' deep production well and three shallower wells were used for observation wells. Well data and configurations are shown in Figure 43. Of the four observation wells, two were used in the aquifer analysis. SCD #2 is completed into the Hawthorn Formation, did not display any drawdown, and was not used in the analysis. SC #1 is an 800' production well, cased and completed to the same depth as the pumped well. Drawdown in SC #1 was not as great as drawdown in SCD #3 which is 2660' further from the pumped well. This may indicate a more direct connection between SC #1 and SCD #3 through fractures or cavities. Less drawdown resulted in higher calculated T's for well SC #1 that are incompatible with the rest of the data.
Assumptions are necessarily made when Theis curve matching techniques are applied to this data. The Floridan Aquifer is considered homogeneous and isotropic while being bounded above and below by impermeable beds. The well is also considered to be fully penetrating and flow to the well bore is assumed uniform. Studies by Bentley (1977) indicate that transmissivities increase with thickness penetrated in partially penetrating wells in the Florida Aquifer. Hydraulic conductivity and therefore transmissivity does vary horizontally and vertically in this aquifer. The presence of fractures, interconnecting cavities, and varying degrees of secondary porosity all influence the application of Theis curve matching techniques to this data.
Distance-drawdown curves for the pumped well and the observation wells are shown in Figure 44. Drawdown in the pumped well reached steady state by the end of the test. The Theis composite curve matching techniques matches s versus r /t (s = drawdown, r = radius, t = time) curves to the Theis family of type curves (Hantush, 1961) and yields .he match in Figure 45. This match results in a T of 190,000 ft2/day
-and an S of 1.0 x 10-3. Lohman (1972, p.8) states that a storage coeffi,ient of a confined aquifer is about 1 x 10-6 per foot of thickness. In zhis area the Floridan Aquifer is estimated to be about 1000-feet thick. Vhis would estimate the S to be 1 x 10-3. This figure matches the ;alculated value of 1 x 10-3 which is a good representative value.
A leakance K 'Ib' between 2.6 x 10-4 days and 5.4 x
10-4 days was determined from K 'Ib' = 4 Tv2/r2 (Lohman, 1972, Plate 3) for a T of 190,000 ft2/day. The values for






BUREAU OF GEOLOGY


fl)
2000


3000 4000


-140
-100


-MSL


-100
Co,

-200 (D
U.

-300 s


-400

-500 600 700


Figure 43. Generalized geology, well construction, and static water levels at aquifer test site.


SC03*
267'




a 0 .000 ..
0 too a 27 SC l



EXPLANATION
0 Production Wen S Observation We SCI Well Name 80 Total Depth 5


Distance from Pumped Well In Feet





5CD1 543-


sCI*
Ti--60-'


ouu 1000 1500
O I IDrawdown after 40 Minutes Distance from
* Drawdown after 18.5 Hours Q=6928 GPM Steady Pumping Rate
*Data Points from Well SCI Were Anomalous and Not Used


2000 2 Pumped Well in Feet


500


3000


Figure 44. Distance versus drawdown at Aquifer test site.


8C2
Pumped Well


SCD8


3500


C
1



4-d
5-




6
7
8



11
12
I , 14 , .
15'"


v





BUREAU OF GEOLOGY


10.0




10 L.
C
C
0
3
m 0.1


SCO1I r=543


CI- - MatCh 0 0020 gpm r 1100 * ... 7,50100

-Z IIb.u Poin
U~~ v~- I

(15141 1 )
hg t of wc






fiigbd is abou 75'. Th auaecaaei then
t. Ti I / Y a1,4 1 70"'j







ca.34 lculatdt. e 539x10' 009f/ 2 0e 10 e lr 0th 100 1 r t



Figure 45. Theis composite curve matching method.
K'/b' seem like small numbers, but when you test them for reasonableness, it becomes apparent that they are too high. The amount of water that can leak through the confining beds and into the aquifer is equal to the head difference across the confining bed multiplied by K '/b' . The natural (unstressed) head difference across the confining bed is about 75'. The natural recharge rate is then calculated to be: 75(3.9 x 10-4) =0.029 ft/d = 128 inches/year. This is more than twice the annual rainfall. The problem, I believe, is this. Though the pumped well and the deepest observation well are the same depth (800 feet), their driller's logs indicate they might be producing Most of their water from entirely different levels. For example, the pumped well has a 5' cavity at about 540', whereas the observation well has a 3' cavity at about 756'. Both wells are cased to about 250' and have specific capacities of about 700 (gal/min)/ft. It is possible that the pumped well.derives most of its water from the cavity at 540' . During the aquifer test, this would lower the head in the upper part of the aquifer, but due to the effects of vertical anisotropy, the head in the lower part would tend to remain higher, at least for a time. Now, if the observation well






REPORT OF INVESTIGATION NO. 87 83

(when pumped) produces most of its water from the cavity at 756' , the lowering of the head in the upper zone by the pumped well would cause water to migrate up the borehole of the observation well and move out into the upper zone. This would not only attenuate the drawdown in the observation well itself, it would cause the observation well to act as a recharging well for the upper zone. This would have the effect of attenuating the drawdown in the other (shallower) observation wells tool The weakness with this discussion is that we really don't know where the main producing intervals are. A caliper log and a flowmeter survey could best define the producing intervals. The amount of water moving up into the upper zone might ap= proximately be equal to the drawdown in the observation well multiplied by its specific capacity 1.5' x 700 (gal/min)/ft = 1050 gal/min. This is about 15 percent of that produced by the pumped well during the test and is significant. (Charles Tibbals, USGS, Orlando, FL, written
communication, 1980.)
The specific capacity of a well is the rate of discharge of that well per unit of drawdown, commonly expressed in gallons per minute per foot of drawdown. A direct relationship exits between specific capacities and transmissivities in.the confined region of the Upper Suwannee River Basin. The graph in Figure 46 depicts the range of T's for specific capa= city values in the confined Upper Suwannee River Basin. 700


600
0
V

600
0
0
0 U.
( 400 .5

C300

N
W

06 100
0


0 25,000 50,000 75,000 100,000 12,000 O,o 175,000 200,000 22,uuu 20.uuuu Transmlsslvlty In FT
DAY
Figure 46. Transmissivity versus specific capacity in the Floridan
Aquifer in north-central Florida.


RWMo 401 1436001




0Tranomissivity values calculated from aquifer tests
U M23These data points fit to a linear regression line where-37.9 Is the intercept and .0028 is the slope

UoS,2 30 22i
.. . . . . . . . . . . . .. . . ..r . .





BUREAU OF GEOLOGY


Groundwater Development
A typical domestic Floridan well in the Upper Suwannee Basin is a four-inch diameter well, cased between 60 and 160 feet with 10 to 50 feet of open borehole penetrating the aquifer. Water levels range from 30 to 120 feet below land surface, and a one horsepower submersible pump yields 15 to 22 gpm with little or no drawdown.
Large irrigation systems pump up to 1000 gpm from 12-inch diameter wells with only a few feet of drawdown.
Large industrial use wells, cased 200 feet from land surface, with a 26-inch diameter open borehole penetrate the aquifer for 600 feet below the bottom of the casing. These wells can yield more than 6000 gpm with up to 15 feet of drawdown.

Water Chemistry
The solution of limestone (CaCO3) or dolomite
(CaMg(C03)2) by natural waters in the presence of carbon dioxide (C02)is probably the largest single factor responsible for the quality of ground water in Florida. While limestone and dolomite are only slightly soluble in pure water, their solubility increases in natural water that contains carbon dioxide derived from the atmosphere and, to a much larger extent, soil air as the water percolates through the soil and the unsaturated zone above the water table. (Larry Slack,
USGS, Tallahassee, FL, written communication, 1980)
Floridan Aquifer water is characterized by high relative values for specific conductance, calcium, alkalinity, magnesium, pH, and sulfate. These parameters are strongly correlated in Cluster 1 in Figure 12. This cluster represents water of the calcium-bicarbonate type where the typical constituents result from the dissolution of limestone, which is essentially a massive deposit of calcium carbonate (Hem, 1959).
All limestones contain magnesium contained in the magnesium carbonate common in carbonate rocks. The high relative values for pH correspond with the high relative alkalinity values. High specific conductivity is in response to the high number of calcium, magnesium, and carbonate ions in solution.
Artesian Floridan water displays high relative values for sulfate (Figure 15). Hamilton and northern Columbia counties have always been known to have "sulfur water" at depth. The taste and odor associated with "sulfur water" is imparted by hydrogen sulfide gas. Hydrogen sulfide is formed in two ways - the decomposition and reduction of organic matter in water or the reduction of sulfate in ground water. The former is usually associated with swampy areas with abundant vegetative matter; while in north-central Florida, the latter can be associated with the dissolution of gypsum and anhydrite within the carbonates of the Floridan Aquifer. Previous investigators (Meyer, 1962;






REPORT OF INVESTIGATION NO. 87


Krause, 1976, 1979) attribute hydrogen sulfide in the Floridan Aquifer to the reduction of sulfate in ground water at depth. Meyer associated hydrogen sulfide with the Floridan artesian areas, overlain by a thick sequence of confining Hawthorn.
Krause's investigation (1979) yielded significant data and conclusions concerning sulfate and total dissolved solids in groundwater. Concentrations of these parameters generally increased with depth in the Valdosta area, and a zone of high concentration occurred at -330 feet msl. Sulfate concentration increased two orders of magnitude from 23 mg/I to 2,400 mg/I, while dissolved solids increased from 114 mg/I to 3,300 mg/I in a zone from 400 to 550 feet below land surface (Figure 47). Values for calcium, magnesium, calcium-magnesium hardness, iron, fluoride, and strontium also increased in the same interval (Figure 47). In Valdosta, these concentrations occur in the lower portion of the Suwannee Limestone. High sulfate concentrations are due to intergranular gypsum occurring as cement. In this gypsiferous interval, a 10-foot section may contain 25 percent to 30 percent gypsum, Whereas a 100-foot to 150-foot section may contain 5 percent to 10 percent gypsum (Dwayne Jorgensen, U.S. Gypsum, Saltville, VA, personal communication, 1980).
In the Wellborn, Florida, area (Township 3 South, Range 15 East, Section 16), nonpotable, highly mineralized water appears at -710 feet msl. From -630 feet msl to -710 feet msl sulfate concentrations increase from 41.2 mg/I to 896 mg/l. In the same interval, calcium increased from 103 mg/I to 494 mg/I; magnesium increased from 7 mg/I to 242 mg/I; and the resulting specific conductance increased from 950 to 1725 micromhos per centimeter.
In north-central Florida, gypsum has previously been associated with the Lake City Limestone which is deeper in the section than the Suwannee Limestone. The structural top of the Lake City ranges from
-300 feet to -550 feet in the study area. Klein (Figure 19) has estimated the base of the potable aquifer to be from -1000 feet to -1300 feet msl in the study area.
Deep industrial and municipal wells (total depth -670 feet msl or 800 ,eet below land surface) exhibit relatively high sulfate values (up to 65 rig/I). There is up to 600 feet of open borehole in these wells. The maority of groundwater flow to these wells is probably in the cavernous .ones in the fresher upper few hundred feet. Data indicate a zone of non-otable sulfate and dissolved solid-rich water 500 or 600 feet shallower fhan Klein predicted. It is possible that there is a zone of high sulfates md dissolved solids at depth, mixing with fresher water in the more proJuctive upper zones of the Floridan, resulting in a relatively high sulfate !alue at the pump at land surface. Water samples from deep wells in he Valdosta area yield sulfate values from 24 mg/I to 310 mg/l. Chapter 17-22 of the Rules of the Florida Department of Environmental Regula:ion limits sulfate concentrations in public supply wells to 250 mg/I and total dissolved solids to 500 mg/l. A public water supply system is any







BUREAU OF GEOLOGY


U 200
U

300

z
< 400


0 500 LU
600
Lu
U
_ 700
-r
800
I.
0 oo
0.
U 1000

1100




100


I i p I I I I
0 500 1000 1500 2000 2500 3000 3500 4000 4500
CONCENTRATION IN MILLIGRAMS PER LITER Relation of magnesium, calcium, sulfate, dissolved solids, and calcium, magnesium hardness with depth

I III 1


200 Explanation
JC - PACKER-SAMPLE INTERVAL 300 t Pattern reverses to show co overlap of 'Intervals

Z400 (

": 1 Maximum concentration of iron and fluoride o 500 recommended for drinking water
_j50
-4
ut




02 y
1600
LU
LU
700 2




0 o0 irFluoride
'-Iron

0 1000


110 0 2 4 6 8 10 12 CONCENTRATION, IN MILLIGRAMS PER LITER Relation of Iron, fluoride, end strontium with depth


Figure 47. Relation of parameters with depth, Test Well 1,

Valdosta, Georgia.


Explanation PACKER-SAMPLE INTERVAL Pattern reverses to show overlap of Intervals Maximum concentration of sulfate and dissolved
solids recommended for drinking water



N,





k\ Dissolved solids

I Calcium Sulfate

; Calcium,
Magnesium magnesium hardness


ut]


IO






REPORT OF INVESTIGATION NO. 87


system serving more than 25 persons or otherwise making water available to public grouping or the public in general. Gypsum has been identified in Florida Bureau of Geology well cuttings as shallow as -690 feet msl at White Springs in Hamilton County (W-7053). Further study needs to be done in this area to locate the base of the potable aquifer and to prevent possible upconing of high density, nonpotable waters rich in sulfate and dissolved solids.
An attempt was made to differentiate between Floridan artesian and Floridan nonartesian water types. Eighty-four water'samples were taken from the Floridan Aquifer, and parameter values in Figure 15 reveal that the artesian Floridan has higher values for all parameters except nitrate and calcium. These high values are probably approaching equilibrium with the aquifer rock and have had a longer residence time within the strata (Lawrence and Upchurch, 1976). The nonartesian Floridan is unconfined on top; therefore, higher values for man-induced nitrates are expected since this represents an area with high agriculture land use; and animal wastes, septic tank wastes, and chemical fertilizers are easily leached downward to the Floridan water table. The unconfined Floridan has higher secondary porosity due to rapid downward percolation of acid rainwater. This may result in more calcium ions in solution in the nonartesian Floridan.
The trilinear plot in Figure 16 is a method that can be used to differentiate the two aquifers, especially the cation balance. In the cation field, artesian Floridan always displays higher magnesium, sodium, and potassium, and lower calcium proportions than nonartesian Floridan water. Floridan nonartesian water is always confined to the calcium bicarbonate water type on the Piper Trilinear Diagram.






BUREAU OF GEOLOGY


HYDROLOGY


HYDROLOGIC OVERVIEW
The Okefenokee Swamp is the headwaters of the Suwannee and St. Mary's rivers. The upper Suwannee River watershed above the USGS gaging station at Ellaville, Florida, including the major tributary subbasins. (Alapaha and Withlacoochee), is approximately 6970 square miles (Figure 1). The Suwannee River above the Withlacoochee Subbasin in Florida (excluding the Alapaha and Withlacoochee subbasins) is approximately 855 square miles. Surface water and rainfall stations are shown in Figure 48. Upstream from White Springs, Florida, the Suwannee River is superimposed on as much as 300 feet of sandy clays, clayey sands, sandstone, and limestone overlying the Floridan Aquifer. Flow for this portion of the river is essentially dependent on surface runoff from tributaries draining the numerous swamps, bays, marshes, flatwoods, lakes and ponds and seepage from the surficial aquifier. Beginning at White Springs and continuing downstream, the Suwannee River is incised into the carbonate rock of the Floridan Aquifer. During times of low river stage, groundwater inflow from Floridan Aquifer springs and seeps in the river corridor supplements surface runoff in the reach downstream from White Springs.
In Hamilton County, mining and processing of phosphate has altered natural drainage patterns and affected water quality in some Suwannee River tributaries. The amount of surface area created by mining and beneficiation of phosphate is on the order of 10 square miles (Miller, et al., 1978b). Lake Louise in Suwannee County (Figure 49 and Table 6), about 104 acres in size, is the largest lake in the Upper Suwannee River Basin in Florida. Most lakes and ponds in the Upper Basin generally cover less than 20 acres in surface area.
There are 14 known springs of third magnitude (1-10 cfs) or larger in the study area. Nine of these are in the Suwannee River above the Withlacoochee Subbasin (Figure 49 and Table 7). Alapaha Rise, a first magnitude spring (greater than 100 cfs), has the highest discharge. The measured range is from 294 to 1043 cfs.
Local Floridan Aquifer fluctuations (Figures 28,30, and 32) and stage fluctuations on the Alapaha River near Jennings, Florida, (Figure 39) generally correspond. Hydrographs of the Alapaha River near Jennings and Alapaha Rise are also correlative (Figure 50). The apparent discrepancy or lag time of one month at Alapaha Rise during winter 1977-78 is due to backwater from the Suwannee River. The Alapaha Rise is approximately 22 miles downstream from the station near Jennings. The response time between stage fluctuations and well level fluctuations in a Floridan well approximately 12 miles to the southeast is usually less than 12 hours. While it has not been shown conclusively, Alapaha Rise












RI4E R ISE


O 10 Kin.

Rainfall Stations Streamflow Stations M Jasper ( Fargo M Folkston T Benton [ Uve Oak (DWhte Springs M Lake City Q) Suwannee Springs


G E C


Figure 48. Location map, study area, surfacewater and rainfall stations.


2 ~0n


2Ii
M



0 0







LAKE

Alapaha Rise @)Statenville �)Aepaha R. near Jennings
() Einseta @ Ellaville C




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