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Core drilling and analysis
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 Material Information
Title: Core drilling and analysis city of Sarasota, downtown well field
Series Title: Open file report - Florida Geological Survey ; 62
Physical Description: 16 p. : ill., maps ; 28 cm.
Language: English
Creator: Campbell, Kenneth M. ( Kenneth Mark ), 1949-
Scott, Thomas M.
Green, Richard C.
Donor: unknown ( endowment ) ( endowment )
Publisher: Florida Geological Survey
Place of Publication: Tallahassee, Fla.
Publication Date: 1995
Copyright Date: 1995
Edition: Rev.
 Subjects
Subjects / Keywords: Geology -- Florida -- Sarasota County   ( lcsh )
Genre: bibliography   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 16).
General Note: Cover title.
Statement of Responsibility: K.M. Campbell, T.M. Scott, and R.C. Green.
 Record Information
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier: alephbibnum - 002295488
oclc - 37045261
notis - ALP8707
issn - 1058-1391 ;
System ID: UF00094046:00001

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STATE OF FLORIDA
DEPARTMENT OF ENVIRONMENTAL PROTECTION
Virginia B. Wetherell, Secretary



DIVISION OF ADMINISTRATIVE AND TECHNICAL SERVICES
Nevin G. Smith, Director



FLORIDA GEOLOGICAL SURVEY
Walter Schmidt, State Geologist and Chief





OPEN FILE REPORT 62





CORE DRILLING AND ANALYSIS:
CITY OF SARASOTA, DOWNTOWN WELL FIELD
(revised)

by


K.M. Campbell, P.G. 192, T.M. Scott
and R.C. Green


FLORIDA GEOLOGICAL SURVEY



Tallahassee, Florida
1995


ISSN 1058-1391







Core Drilling and Analysis:
City of Sarasota, Downtown Well Field

by
K.M. Campbell, P.G. 192, T.M. Scott, P.G. 99 and R.C. Green
1994

Introduction

The Florida Geological Survey (FGS), in cooperation with the U.S. Geological
Survey (USGS) and the city of Sarasota, drilled and analyzed a deep core hole located
at the Sarasota Downtown Well Field (SDWF). The investigation focused on the
Neogene and Paleogene lithostratigraphy and the Floridan aquifer system. The
corehole was drilled into the top of the Middle Eocene Avon Park Formation and
terminated at a total depth of 1101 feet below land surface (bls). The core obtained
in this study is cataloged as well W-16999 and is stored in the FGS core repository.
Funding was provided by the Florida Geological Survey and the City of Sarasota.
The SDWF draws water from both the intermediate and Floridan aquifer
systems. The intermediate aquifer system and confining units consist of Neogene and
Paleogene Hawthorn Group sediments. The Floridan aquifer system is composed of
latest Paleogene sediments of the Hawthorn Group, and Paleogene sediments of the
Suwannee and Ocala Limestones and the Avon Park Formation.
The corehole site is located within the City of Sarasota at the SDWF (SE, SE,
SW, section 18, Township 36 S, Range 18 E, elevation 18 feet), northwest of the
intersection of 10th St. and Orange Ave (Figure 1). The well was drilled utilizing the
FGS Failing 1500 drill rig. Core samples were collected from the land surface to 1101
feet bls. A four-inch diameter monitor well was constructed after coring was
completed. The FGS installed casing from the land surface to 353 feet bls and
plugged the corehole with neat cement from 590 to 1101 feet bls creating a monitor
zone from 353 to 590 feet.
A lithologic description for the core (Appendix 1) was generated by R.C.Green
utilizing a binocular microscope. The description was recorded in the standard FGS
format and entered into the FGS data base via WELL LOG DATA SYSTEM software
(Geosys Inc., 1992). A stratigraphic column was also generated from the lithologic
log.

Structure

The broad Florida Platform extends southward from the North American
continent, separating the Gulf of Mexico from the Atlantic Ocean. The exposed
portion of the platform forms the peninsula of Florida, with the present-day western
coast of peninsular Florida lying approximately on the axis of the Florida Platform.
Sarasota County, located in the southwestern portion of the Florida peninsula, lies
near the center of the southern half of the platform. The main structural features that
affected Cenozoic deposition in the study area include the Sarasota Arch, South
Florida Basin, Ocala Platform and Okeechobee Basin. The Sarasota Arch and the South




















R 17 E R 18 E I 19 E I 20 E I R 21 E R 22 E



w 16999 ug a
SARASOTA DOWNTOWN WUELW cor


SARASOTA
COUNTY


-N-





VENICE \x

t CM


o 6 MILI
SCALE
SWELL LOCATION




FOS060194


Figure 1. Location Map







Florida Basin influenced deposition during the Paleogene, while the Ocala Platform and
the Okeechobee Basin affected deposition during the Neogene. Subsurface
investigations in southwestern Florida have encountered complex geologic conditions
in the Paleogene and Neogene section. Some researchers have delineated faults
disrupting the strata, complicating the lithostratigraphic and hydrostratigraphic
interpretations (Sproul et al., 1972; Hutchinson, 1991). Other investigators
recognized folding in seismic reflection surveys run parallel to the coastline and up the
Caloosahatchee River (Missimer and Gardner, 1976). This has led to speculation that
deep-seated faulting was responsible for near- surface structures. Interesting new
data acquired during recent seismic surveys off the southwestern coast of the state
have revealed that the reflectors in the mid-Eocene section are essentially flat lying,
while reflectors in the Mio-Pliocene section appear folded (Missimer, personal
communication, 1993). Evans and Hine (1988) discussed the existence of a number
of small basins, erosional features and deltas. Samples from wells penetrating these
features can provide a very confusing picture of the stratigraphy. The very limited
information obtained from well cuttings has led to complex interpretations that include
significant faulting (Sproul et al., 1972).

Lithostratigraphy

This investigation focused on the lithostratigraphy of the Neogene and
Paleogene section in the SDWF corehole drilled for this study (FGS W-16999). This
core penetrated the top of the Middle Eocene Avon Park Formation at 1028.5 feet
bls.
The Avon Park Formation in this core consists of interbedded limestones and
dolostones (Figures 2 and 3). The dolostones are grayish brown to dark yellowish
brown, fine grained, well indurated, variably porous and recrystallized. Benthic
foraminifera, echinoids and fossil molds are the most common fossils present.
Limestones present are very light orange, fine- to medium-grained, moderately- to well-
indurated packstones. Fossils present are similar to those in the dolostones. Both
lithologies may contain small quantities of organic material. The Avon Park is overlain
by the Ocala Limestone. The contact in the northern portion of the peninsula is
unconformable, however, in southern Florida the contact may be conformable.
The Upper Eocene Ocala Limestone occurs from 781 to 1028.5 feet bls in the
SDWF core. The Ocala consists primarily of limestone (781-961 feet) with a limited
amount of dolostone (961-1028.5 feet). The limestones are very light orange,
microcrystalline- to medium-grained, fossiliferous, moderately indurated grainstones
and packstones with calcilutite matrix. Fossils consist primarily of benthic
foraminifera, bryozoans, echinoids and mollusks. Dolostones are grayish brown, fine
grained, well indurated, highly recrystallized, sucrosic and may contain trace quantities
of organic material. Fossils and fossil molds are common, primarily species of the
large benthic foraminifers Operculinoides, Nummulites, and Leoidocvclina. The Ocala
Limestone in this core and others in the area, appears to be gradationally overlain by
the Suwannee Limestone.
The Lower Oligocene Suwannee Limestone occurs from 549 to 781 feet bls
in the SDWF core. The limestones encountered are white to very light orange,

























EXPLANATION



HATCHING PATTERNS





GRAVEL FINE MEDIUM COARSE
LIMESTONE




SAND FINE MEDIUM COARSE
DOLOSTONE


Ia I I I1

SILT FINE MEDIUM COARSE
INTERBEDDED LIMESTONE AND DOLOSTONE




CLAY CHERT SHELL BED NO SAMPLE






COMMENTS

M MICRITE T SILT
S SAND C CLAY
P PHOSPHATE GRAVEL Sh SHELL
p PHOSPHATE SAND D DOLDSTONE
D ORGANIC L LIMESTONE
R SPAR H HEAVY MINERALS
I IRON STAIN NO SPL NO SAMPLE
O QUARTZ G GYPSUM
A ANHYDRITE Py PYRITE
Ch CHERT FGS060294




Figure 2. Stratigraphic column legend











V-16999
CITY OF SARASOTA CORE
T.D.= 1101'

FEErT TCRS UNDIFFERENTIATED
o -- 014- r SAND AND CLAY
p,c,

- 5so 0-- s .ccry
pPy,Ch
ppy


- 40
-150 -
C.SPy; o

.. Do pyr UNDIFFERENTIATED
-2w0 "-, pp. *
oac. ARCADIA FORMATION




-a so





-4o
-50 -


-55R



- -- soa -


- son -







FIr
AR


-I-0


-ar, - D SUWANNEE

A LIMESTONE
-700 ARAI FORMAOChN




~s -:

M


-7WI -K4, -e J


-9on OCALA
-ee LIMESTONE


R
_1 -10 R
- an


--mo - -se


mp, AVON PARK
-oo rAo FORMATION
--wo FGSO60394B

Figure 3. Stratigraphic column of W-16999







predominantly moderately- to well-indurated, fine- to medium-grained, fossiliferous
packstones to grainstones. Matrix material consists of calcilutite and to a lesser
extent, sparry calcite. Foraminifera, including characteristic miliolid forms are the most
common faunal constituent followed by mollusk fragments and molds.
The Suwannee Limestone is overlain by the Arcadia Formation of the Hawthorn
Group. The contact in some areas of the state appears to be disconformable while in
other areas it appears to be gradational and conformable. The unconformity is often
difficult to recognize due to similarities in lithologies between the top of the Suwannee
Limestone and the basal Tampa Member or undifferentiated Arcadia Formation. The
occasional difficulty in recognizing the disconformity spawned the humorous term
"Suwa-Tampa-Haw" to describe the unit. This difficulty is predominantly related to
lithologic descriptions and formational picks made from well cuttings. Close
examination of high-quality core samples often allows the unconformity to be
recognized.
The Hawthorn Group, in the SDWF core, consists of the Arcadia Formation with
its component Tampa Member (Scott, 1988). The Arcadia Formation is found from
6.8 feet to 548.5 feet bls. The Tampa Member is found from 376-548.5 feet bls.
The upper Hawthorn Group Peace River Formation is absent due to erosion. The
absence of the Peace River Formation in this core is not unusual for this area (Scott,
1988).
The Lower Oligocene to Middle Miocene undifferentiated Arcadia Formation
contains a wide variety of lithologies. In general, carbonates dominate the section
with siliciclastic beds being less abundant (Figures 2 and 3). Dolostone tends to
dominate the carbonate lithologies of the Arcadia Formation in this region. Limestone
becomes more common within this section to the south and southeast.
Dolostones in the core are generally yellowish gray, light olive gray and white,
moderately- to well-indurated, fine- or very fine-grained, quartz sandy and clayey.
Phosphate is ubiquitous in these sediments, although economic concentrations are not
present. The concentration of phosphate particles varies considerably, from less than
one to more than 20 percent of the sample, generally varying from approximately
three to 10 percent.
The Upper Oligocene to Lower Miocene Tampa Member of the Arcadia
Formation was identified in the SDWF core from 376 to 548.5 feet bls. The Tampa
Member consists predominantly of light- to yellowish-gray, slightly- to non-phosphatic,
quartz sandy and occasionally clayey limestones. Dolostones are found from 475 to
501 and from 537.5 to 540 feet bls in this core. These dolostones are light gray to
yellowish gray, predominantly very fine-grained, and moderately- to well-indurated.
The Tampa Member is fossiliferous, with mollusk fragments and molds, benthic
foraminifera and corals being common.
One of the units of primary interest in this study is the Venice clay member
(Joyner and Sutcliffe, 1976), an informal unit originally identified as a lower member
of the Tamiami Formation. Upon investigating the Carlton Reserve core (W-16782)
(Campbell, et al., 1993), characteristic Arcadia Formation sediments were found
superimposed on the clays referred to the Venice clay member. The implication is that
either the Arcadia sediments were reworked locally during the Pliocene and
redeposited on the Venice clay member, or the Venice clay member is part of the






Arcadia Formation. Microfossils recovered from the Venice clay member in the USGS
Walton core, suggested an Early to Middle Miocene age (L. Edwards, USGS, personal
communication, 1992) which is compatible with the age range of the Arcadia
Formation. Following this lead, the Venice clay member has been recognized in the
Arcadia Formation in other cores on file at the FGS. Scott (1992) suggested the
informal placement of the Venice clay member in the Arcadia Formation based on the
subjacent and suprajacent lithologies and preliminary fossil evidence.
The Venice clay member is recognized in the SDWF core, occurring between 19
and 41.3 feet bls, and is generally, a variably dolomitic, gray-green clay with minor
amounts of quartz sand and silt. Phosphate is rarely present in identifiable quantities.
It becomes more silty (quartz and/or dolomite) toward the upper and lower contacts.
Fossils were not noted in the Venice clay member, although microfossils are present
in the unit in other cores.
Sediments immediately above and below the Venice clay member may be very
clayey "dolosilts." These beds are not included in the Venice clay member as defined
in this report. The SDWF core reveals that a thin (five feet) carbonate bed occurs
between two clay units that make up the Venice clay member, which is included in
the unit. It is possible that, upon further study, the clay- and dolomite-rich zones that
overlie or underlie the Venice clay member may be included in the informal unit.
The gamma-ray signature of the Venice clay member consists of a zone of low
gamma-ray intensity falling between two zones of more intense gamma-ray activity.
The overall pattern of gamma-ray activity surrounding the Venice clay member is quite
characteristic of the Arcadia Formation in southwestern peninsular Florida (Scott,
1988).
The erosional disconformity forming the upper surface of the Hawthorn Group
cuts across a variety of units depending on the location within southwest Florida. In
the Tampa area, most of the Arcadia Formation is missing leaving the Tampa Member
at or near the surface. The Hawthorn Group sediments thicken to the south as the axis
of the platform dips in that direction, forming a more complete section.
A thin Pleistocene section (0-6.8 feet bls) overlies the eroded surface of the
Arcadia Formation. These materials consist of light gray and olive gray, medium-
grained quartz sands with minor clay and calcilutite matrix and some weathered shells.

Paleontology

A paleontological reconnaissance based on calcareous nannofossils and diatoms
was conducted by FGS paleontologists. Unfortunately, the samples are virtually barren
of both nannofossils and diatoms. There are no indications that these microfossils
were previously present. Analysis for dinoflagellates was not conducted.

Hydrostratigraphy

The potable water resources in the Sarasota area are contained primarily in the
intermediate aquifer system, with limited quantities coming from the surficial aquifer
system. The Floridan aquifer system underlies the entire area but does not contain
potable water.
The Floridan aquifer system consists of the carbonates of the Avon Park








Formation, Ocala Limestone, Suwannee Limestone and the lower portion of the Tampa
Member of the Arcadia Formation. The top of the Floridan aquifer system occurs at
approximately 507 feet bls in the lower portion of the Tampa Member (Barr, personal
communication, 1994). The Floridan aquifer system in the Sarasota area is used
principally for irrigation, to supply saline water for reverse osmosis desalinization and
the injection of waste water.
The Arcadia Formation comprises the entire intermediate aquifer system and
confining unit in this portion of Sarasota County. There are two major permeable
zones and several confining zones recognized in the intermediate aquifer system in this
area (Barr, personal communication, 1994). The Venice clay forms part of the upper
confining zone in the SDWF core. The intermediate aquifer system extends from
approximately seven feet bls to 507 feet bls.
The surficial aquifer system is poorly developed in this core. It consists of a
seven foot thickness of undifferentiated sands disconformably overlying the Arcadia
Formation.

Hydraulic Conductivity

Falling head permeameters (Figure 4) were utilized to measure the hydraulic
conductivity of 26 core samples. Thirteen sample intervals were analyzed for both
vertical and horizontal hydraulic conductivity. One-inch diameter core plugs were
taken adjacent to the vertical permeability samples to determine horizontal hydraulic
conductivity. The following procedure is summarized from FGS permeability lab
procedures.
Indurated core samples were prepared for hydraulic conductivity testing by
cutting the sample on a trim saw and encasing the sample in an epoxy resin within a
larger diameter plastic tube. Liquid rubber and wax were placed on the ends of the
core sample to ensure that the liquid resin did not block the ends of the sample during
pouring and curing. After the epoxy hardened, the wax and liquid rubber layers were
removed to allow fluid flow through the core. Rubber-ring gaskets were then placed
on each end of the plastic tube containing the sample and the entire assembly was
clamped in the permeameter. The assembled permeameter is placed on a stand and
connected to a buret filled with de-ionized water to a level simulating one meter of
hydraulic head. The stopcock on the buret is opened and the permeameter is
monitored until flow has been achieved through the sample, at which time the
stopcock is closed and the buret refilled. The fluid level is measured from the upper
drain port to the top of the buret fluid level. This figure is recorded as the initial head.
The time is noted and the stopcock opened. After sufficient head drop (usually 10
centimeters or more) the stopcock is closed and the time is recorded as the end of the
test. Tests are conducted in triplicate except where saturation is not achieved.
Samples that do not reach saturation after 31 days are removed. After testing of a
sample is complete, the hydraulic conductivity is calculated by PERMCAL (software
by Jon Arthur, FGS).
Ten samples (6 horizontal, 4 vertical) did not saturate during the test period











METER STICK


LOWER RETAINING
SCREEN


PLEXIGLAS
-TOP
PLATE


STOPCOCK


PLASTIC
TUBING


QUICK


4ECT FITTING

o- WATER FLOW DIRECTION


Figure 2: Falling head permeameter (Green, et al., 1989).




/yIPY


(over 31 days in each case). Hydraulic conductivity of these samples should be
considered only in a qualitative sense and are best described as having very low
permeability. One sample (316 feet bis) was destroyed by slaking while saturating.
The range of average hydraulic conductivities determined for those samples
which did flow is from 1.65E-03 to 3.80E-09 centimeters/second (4.69E+00 to
1.08E-05 feet/day). In general, vertical hydraulic conductivity was less than the
horizontal, although there were exceptions. For three of the sample intervals (316,
465 and 1095 feet bls), neither sample achieved saturation. Hydraulic conductivity
data is presented in Tables 1-3.

Effective porosity

The samples cut for vertical hydraulic conductivity were also utilized for
effective porosity determination. Samples were rinsed in distilled water after being cut
on a trim saw, then oven dried at 500C. When dry, the samples were removed and
allowed to cool and equilibrate with the lab air, then were weighed. Following
weighing, each sample was placed in distilled water and allowed to saturate overnight.
Samples were then removed from the water, lightly blotted and immediately weighed.
Following weighing, the saturated sample was placed in a beaker with a known
volume of water to determine the saturated sample volume. Porosity was then
calculated.
In order to obtain a porosity figure for the 316 foot sample which was
destroyed by slaking, a second method was utilized. The shape volume of the dried
sample was obtained by averaging several measurements of the core diameter and
core height. The sample was then saturated in a known volume of distilled water in
a graduated cylinder. Sample porosity was calculated utilizing the difference between
the shape volume of the sample and the increase in volume (known volume of water
and saturated sample) to get volume of pore spaces, which is then converted to
percent porosity. To ensure that the results of this process are comparable to the
previous method, several samples were run with both methods. Although the second
process is less precise, the porosity values obtained are similar to the previous
method. Effective porosity of the selected samples ranges from over 32 percent to
less than one percent (Table 4).

Acknowledgments

A number of people provided assistance with different aspects of this project.
Alex Howell prepared microfossil samples and conducted hydraulic conductivity
analyses. Frank Rupert examined microfossil samples. Jon Arthur, Jim Balsillie, Joel
Duncan, Ron Hoenstine, Steve Spencer and Frank Rupert of the FGS edited the text.





Table 1

Vertical Hydraulic Conductivity Analysis of Selected
Samples: Downtown Wellfield Core (W-16999)

Depth Hydraulic Conductivity (K)
(Ft) cm/s cm/s
ft/day ft/day
Run 1 Run 2 Run 3 Mean (K)

316 Sample destroyed by slaking during saturation.

465 Sample did not reach saturation after 31 days. Hydraulic conductivity
can best be described as very low.

495 9.22E-08 1.13E-07 8.64E-08 9.72E-08
2.62E-04 3.20E-04 2.45E-04 2.76E-04

756 Sample did not reach saturation after 31 days. Hydraulic conductivity
can best be described as very low.

779 5.12E-06 3.96E-06 3.09E-06 4.05E-06
1.45E-02 1.12E-02 8.76E-02 1.15E-02

807 Sample did not reach saturation after 31 days. Hydraulic conductivity
can best be described as very low.

847 Sample did not reach saturation after 31 days. Hydraulic conductivity
can best be described as very low.

895 5.18E-06 4.94E-06 4.49E-06 4.87E-06
1.47E-02 1.40E-02 1.27E-02 1.38E-02

953 4.00E-09 4.00E-09 3.40E-09 3.80E-09
1.13E-05 1.13E-05 9.65E-06 1.08E-05

980.5 1.66E-03 1.70E-03 1.60E-03 1.65E-03
4.72E+00 4.81E+00 4.53E+00 4.69E+00

1025 2.76E-07 3.01 E-07 3.28E-07 3.02E-07
7.82E-04 8.55E-04 9.29E-04 8.55E-04

1035 4.39E-05 5.01E-05 3.59E-05 4.33E-05
1.25E-01 1.42E-01 1.02E-01 1.23E-01

1095 Sample did not reach saturation after 31 days. Hydraulic conductivity
can best be described as very low.





Table 2


Lateral Hydraulic Conductivity Analysis of Selected
Samples: Downtown Wellfield Core (W-16999)


Hydraulic Conductivity (K)
cm/s cm/s
ft/day ft/day
Run 2 Run 3 Mean (K)


Sample did not reach saturation after 31 days. Hydraulic conductivity
can best be described as very low.

Sample did not reach saturation after 31 days. Hydraulic conductivity
can best be described as very low.


316


465


495


756


779


807


847


895


953


3.26E-07
9.23E-04

2.68E-03
7.60E+00

1.69E-05
4.79E-02

6.72E-06
1.90E-02

3.81E-05
1.08E-01

2.44E-04
6.91 E-01


1.80E-07
5.11E-04

2.79E-03
7.90E+00

8.10E-06
2.30E-02

8.97E-06
2.54E-02

6.78E-05
1.92E-01

2.30E-04
6.52E-01


3.10E-07
8.79E-04

2.76E-03
7.82E + 00

1.34E-05
3.81E-02

7.38E-06
2.09E-02

4.92E-05
1.39E-01

2.39E-04
6.78E-01


Sample did not reach saturation after 31 days. Hydraulic conductivity
can best be described as very low.


6.10E-07
1.73E-03

2.09E-03
5.93E+00


4.12E-07
1.17E-03

3.80E-03
1.08E+01


1.15E-06
3.26E-03

3.63E-03
1.03E+01


Sample did not reach saturation after
can best be described as very low.

Sample did not reach saturation after
can best be described as very low.


7.24E-07
2.05E-03

3.18E-03
9.00E+00


31 days. Hydraulic conductivity


31 days. Hydraulic conductivity


Depth
(Ft)


Run 1


4.24E-07
1.20E-03

2.80E-03
7.95E+00

1.53E-05
4.33E-02

6.46E-06
1.83E-02

4.16E-05
1.18E-01

2.43E-04
6.90E-01


980.5


1025


1035


1095





Table 3

Hydraulic Conductivity: Comparison of Lateral
and Vertical Conductivity


Mean Hydraulic Conductivity
Vertical Horizontal
cm/s, ft/day cm/s, ft/day


Sample destroyed by slaking

Sample did not saturate

9.72E-08, 2.76E-04

Sample did not saturate

4.05E-06, 1.15E-02

Sample did not saturate

Sample did not saturate

4.87E-06, 1.38E-02

3.80E-09, 1.08E-05

1.65E-03, 4.69E+00

3.02E-07, 8.55E-04

4.33E-05, 1.23E-01

Sample did not saturate


Sample did not saturate

Sample did not saturate

3.10E-07, 8.79E-04

2.76E-03, 7.82E+00

1.34E-05, 3.81E-02

7.38E-06, 2.09E-02

4.92E-05, 1.39E-01

2.39E-04, 6.78E-01

Sample did not saturate

7.24E-07, 2.05E-03

3.18E-03, 9.00E+00

Sample did not saturate

SSample did not saturate


Depth
(Ft)


316

465

495

756


779

807

847

895

953

980.5

1025

1035

1095





Table 4


Effective Porosity of Selected Samples:
Downtown Wellfield Core (W-16999)


Depth (Ft)
316*
465
495
756
779
807
847


Porosity (%)
32.5
12.2
23.0
9.4
19.7
29.8
31.2


Depth (Ft)
895
953
980.5
1025
1035
1095


Porosity %
30.6
17.7
12.6
9.3
8.8
0.8


*Original sample destroyed by slaking during saturation; porosity figure determined by
alternate method described in text.








References


Campbell, K.M., Scott, T.M., Green, R.C. and Evans, W.L. III, 1993, Sarasota County
Intermediate aquifer system core drilling and analysis: Florida Geological Survey Open
File Report 56, 21 p.

Evans, M.W., and Hine, A.C., 1988, Late Miocene to Quaternary seismic and
lithologic sequence stratigraphy of the Charlotte Harbor area: Southwest Florida: Final
report to the South Florida Water Management District, 90 p.

GeoSys, Inc., 1992, The Well Log Data System, version 3.0, Gainesville Fl, 43 p.

Green, R., Duncan, J., Seal, T., Weinberg, J.M., and Rupert, F., 1989,
Characterization of the sediments overlying the Floridan aquifer system in Alachua
County, Florida: Florida Geological Survey Open File Report 29, 80 p.

Hutchinson, C.B., 1991, Assessment of hydrogeologic conditions with emphasis on
water quality and wastewater injection, southwest Sarasota and west Charlotte
Counties, Florida: United States Geological Survey Open-file Report 90-709, 101 p.

Joyner, B.F. and Sutcliffe, H., Jr., 1976, Water resources of the Myakka River Basin
area, southwest Florida: United States Geological Survey Water Resources
Investigation 76-58, 87 p.

Miller, J. A., 1986, Hydrogeologic framework of the Floridan aquifer system in Florida
and parts of Georgia, Alabama and South Carolina: United States Geological Survey
Professional Paper 1403-B, 91 p.

Missimer, T.M., and Gardner, R.A., 1976, High-resolution seismic reflection profiling
for mapping shallow aquifers in Lee County, Florida: U.S. Geological Survey Water
Resources Investigations IN-TIS, WRI 76d-45, 30 p.

Scott, T.M., 1988, The lithostratigraphy of the Hawthorn Group (Miocene) of Florida:
Florida Geological Survey Bulletin 59,
148 p.

1992, Neogene lithostratigraphy of the Florida peninsula-problems and
prospects: in Abstract volume, the third Bald Head Island Conference on Coastal
Plains Geology, p. 34-35.

Sproul, C.R., Boggess, D.H., and Woodard, H.J., 1972, Saline-water intrusion from
deep artesian sources in the McGregor Isles area of Lee County, Florida: Florida
Bureau of Geology Information Circular 75, 30 p.2.