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Neutron log signature of the Pliocene Tamiami formation in Brevard and Indian River Counties, east-central peninsular Fl...
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 Material Information
Title: Neutron log signature of the Pliocene Tamiami formation in Brevard and Indian River Counties, east-central peninsular Florida /
Physical Description: 22 p. : ill. ; 28 cm.
Language: English
Creator: Johnson, Richard A ( Richard Alan ), 1949-
Publisher: Florida Geological Survey
Place of Publication: Tallahassee, Fla.
Publication Date: 1993
 Subjects
Subjects / Keywords: Geology -- Florida -- Brevard County   ( lcsh )
Geology -- Florida -- Indian River County   ( lcsh )
Genre: bibliography   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by Richard A. Johnson.
Bibliography: Includes bibliographical references (p. 20).
General Note: Florida Geological Survey open file report number 55
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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: oclc - 36880545
System ID: UF00099433:00001

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Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Title Page
        Title Page 1
        Title Page 2
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
    References
        Page 20
    Appendix
        Page 21
        Page 22
    Back Cover
        Page 23
        Page 24
Full Text









STATE OF FLORIDA
DEPARTMENT OF NATURAL RESOURCES
Don E. Duden, Acting Executive Director





DIVISION OF RESOURCE MANAGEMENT
Jeremy A. Craft, Director





FLORIDA GEOLOGICAL SURVEY
Walter Schmidt, State Geologist and Chief





OPEN FILE REPORT 55

NEUTRON LOG SIGNATURE OF THE PLIOCENE TAMIAMI FORMATION IN BREVARD
AND INDIAN RIVER COUNTIES, EAST-CENTRAL PENINSULAR FLORIDA

BY

Richard A. Johnson, P.G. #60












FLORIDA GEOLOGICAL SURVEY
Tallahassee
1993





UNIVERSITY OF FLORIDA LIBRARIES
























SCIENCE
LIBRARY









NEUTRON LOG SIGNATURE OF THE PLIOCENE TAMIAJI FORMATION IN BREVARD
AND INDIAN RIVER COUNTIES, EAST-CENTRAL PENINSULAR FLORIDA

by
Richard A. Johnson, P.G. #60*










ABSTRACT
In eastern (coastal) Brevard and Indian River Counties, east-central
peninsular Florida, the Pliocene Tamiami Formation can be differentiated
from the subjacent Miocene to Lower Pliocene Hawthorn Group and the superja-
cent Pleistocene Caloosahatchee Formation using neutron and electric-resist-
ivity borehole geophysical logs. The carbonate-rich Tamiami Formation is
recorded as a well-defined, higher intensity, single-, double-, triple-,
or quadruple-peak on the logs, whereas the underlying and overlying more-
siliciclastic units are recorded as much lower intensity (and resistivity).
The Tamiami attains maximum known thickness in the study area in a well in
Cocoa Beach (38 feet), east-central Brevard County, and thins (to generally
10- to 20-feet thick) to the west, north and south of this location. The
thickest occurrence detected in Indian River County is an anomalous 27-feet
thickness in a well in Wabasso (northeastern portion of the county).









ACKNOWLEDGMENTS
The author wishes to thank J. Arthur, P. Bond, K. Campbell, J. Lloyd,
F. Rupert, and T. Scott of the Florida Geological Survey for reviews of this
paper. I would also like to thank J. Frazee and D. Toth of the St. Johns
River Water Management District, and former SJRWMD employee K. Rohrer for
allowing access to the shallow-rock aquifer and other test wells drilled
for their projects in Indian River and Brevard Counties.



*Independent Professional Geologist, P.O. Box 3560, Tallahassee, FL 32315.










INTRODUCTION
The purposes of this study are to identify the Pliocene, carbonate-rich,
Tamiami Formation in the subsurface of Brevard and Indian River Counties,
east-central peninsular Florida, and to trace the thickness trends of the
Tamiami in this area using borehole neutron logs. The study area is shown
in Figure 1.
The author believes that the stratigraphic interval which is the subject
of this paper represents the Pliocene Tamiami Formation and is lithologically
correlative with type Tamiami in southern peninsular Florida; other workers
refer to this interval as "Tamiami equivalent" (T.M. Scott, Florida Geological
Survey, personal communication, 1992).
TYPE AREA, LITHOLOGY AND STRATIGRAPHY
The type area of the Tamiami Formation occurs in the banks of the Tamiami
Canal along U.S. Highway 41, the Tamiami Trail, between Ochopee and Monroe
Station, southeastern Collier County, in southern peninsular Florida (Mans-
field, 1939). In this area, the Tamiami consists of two carbonate-rich lith-
ologies: the first, found in the banks of the Tamiami Canal, is a white to
tan, very hard and massive, variably molluskan moldic, variably quarts-sandy
(trace-20%), very finely recrystallized limestone which contains traces of
very fine phosphate sand and scattered to common large unaltered oysters,
pectens and echinoids. The second lithofacies, also found in the banks of
the Tamiami Canal, consists of tan to gray to white, soft, moderately quarts-
sandy (10-40%), unfossiliferous calcilutite, also with a trace of very fine
phosphate grains. A third and less common lithofacies which occurs in northern
Collier County (and to the north) consists of green-gray, poorly-consolidated,
sparsely fossiliferous, somewhat phosphatic (trace-3%), very fine quartz
sand.
In Brevard and Indian River Counties, the Tamiami Formation also consists
of two carbonate-rich faces: gray to tan, moderately indurated, slightly
phosphatic (1-2%), quarts-sandy (1-15%), partially recrystallized biogenic
calcarenite with approximately 10-30 percent calcilutite cement. The second
lithology is composed of white to gray, well-indurated, slightly phosphatic
(1-2%), quarts-sandy (5-25%), variably molluskan moldic, very finely recrys-
tallised micrite with scattered unaltered pelecypods. Both of these litho-
facies occur throughout Brevard and Indian River Counties, and also throughout
the total thickness of the Tamiami in these areas. Toward the west on the










Voluala
County




Merritt Island



\ / .. j Cape Canaveral


7 I Cocoa Beach
R ockledge
sola L
tyt

Melbourne Nth

Micco
2 \ LoedweNorth


SSebastian Inlet
i*.3
2


ceechobee 1 Vero Beach
Dunty St. Lucie
/ County

S EXHAMTION

7 City or town


2 O Logged well with number

Mile. 0 5 10 15 20 30 40

Kilometers 0 10 20 40 60


Figure 1. Location of study area and locations of the nine wells from which
logs are analysed in this paper.










mainland and to the south in St. Lucie County, the Tamiami becomes less re-
crystallized, consisting predominantly of an unconsolidated to moderately
well-cemented mixture of abundant unaltered mollusks and fragments, some
very fine to very coarse quartz sand, and scattered very fine to very coarse
phosphate grains.
Stratigraphically, the Tamiami Formation overlies the Lower Miocene
to Lower Pliocene Hawthorn Group (Scott, 1988). The upper portion of the
Hawthorn consists of green to green-brown, silt-sised-dolomite-cemented,
microfossiliferous, phosphatic (up to 8%), very fine quartz sand and silt
which varies to soft, very quartz-sandy silt-sized dolomite.
The Tamiami Formation is overlain by the Pleistocene Caloosahatchee
Formation. The Caloosahatchee consists of mollusk-rich quartz sand; quartz-
sandy, mollusk shell beds; and thin, discontinuous, partially recrystallized
limestone beds (molluskan calcarenite to calcirudite), all of which are
slightly (up to 2%) phosphatic.
METHODS AND EQUIPMENT
Forty-seven water wells in Brevard and Indian River Counties were geo-
physically logged by the author while employed at the St. Johns River Water
Management District (SJRWMD). The Appendix gives a complete list of these
wells with location and other information for each borehole. Neutron logs
were obtained from all of these wells. The process of neutron logging involves
moving an electronic probe which contains a relatively strong neutron source
within an open or cased borehole. A variable amount of the neutrons are ab-
sorbed by the lithologies in the borehole walls, depending upon the total
water (hydrogen) content of each lithology (which is related to total porosi-
ty)(Schlumberger, 1972). A neutron detector in the probe at a fixed spacing
above the source measures the neutron intensity or number of neutrons remain-
ing after absorption by the materials in the borehole walls. This value is
then sent through a cable to surface electronics, processed, and plotted
as a graph on chart paper, producing a neutron log, recorded in counts-per-
second intensity (cps).
The uncompenated neutron probe used in the geophysical logging for
this study was 1-11/16 inches in outside diameter and utilized a 3 curie
aearcism-beryllin neutron source spaced 14 inches below a single helium-
filed detector tube. Higher intensity generally indicates lower porosity
and locally, lower permeability (Schlumberger, 1972); however, in the present

A







study, the logs are used qualitatively only, with emphasis on curve shape
(peaks and valleys). The nature of this neutron logging system (i.e., uncom-
pensated, with only one detector) precludes the quantitative use of these
logs.
In most wells, a suite of logs, consisting of caliper, natural gamma-ray,
and electric-resistivity, was obtained. Nine SJRWMD-drilled small-diameter
"shallow-rock aquifer" test and observation wells were logged in Indian River
County and three in Brevard County. These wells provided the nearly-ideal
logging conditions (open hole and small diameter) required for the geophysical
detection and analysis of the post-Hawthorn Group sediments in peninsular
Florida. Sets of well-cuttings were available for all of these wells and,
where possible, were correlated with the logs. In addition, partial cores
were obtained from a few of the wells, and these were especially valuable
in identification of the Tamiami Formation. Several very old and very short-
cased small-diameter (3"-4" outside diameter, o.d.) wells also provided
well-defined logs. Copies of all logs are available from the SJRWMD and
several are on file at the Florida Geological Survey (FGS).
The Tamiami Formation section of an FGS core (W-13958) in east-central
Indian River County was also examined for this paper. A portion of the core
is described in detail and the electric-resistivity log of the Tamiami Forma-
tion is presented and discussed. Generally, resistivity logs of the Tamiami
are similar to neutron logs, but most wells are cased through all or part
of the unit and the electric log can not be obtained. The Tamiami Formation
is identified in this core and the geophysical signature on the electric
log is correlated with electric and neutron logs from nearby wells. Finally,
the Tamiami is traced to the north into Brevard County through correlation
with neutron logs from additional wells.
RESULTS
It was found that the Tamiami Formation is readily distinguishable on
geophysical logs obtained from wells in Brevard and Indian River Counties.
The Tamiami is best defined on neutron logs, recorded as a well-defined higher
intensity single-, double-, triple-, or quadruple-peak with underlying and
overlying conspicuously lower intensity valleys (representing uppermost Haw-
thorn Group and basal Caloosahatchee Formation, respectively).
The Tamiami Formation occurs in the subsurface along the Atlantic Coast
of Brevard and Indian River Counties, attaining maximum known thickness in










the study area beneath the barrier island at Cocoa Beach (38 feet) and central
Merritt Island (34 feet) in Brevard County. The unit thins to the west, north
and south of Cocoa Beach, displaying an average thickness of 10-20 feet.
The maximum thickness encountered in Indian River County was an anomalously
thick 27 feet (in one well). Table 1 below lists the nine wells from which
neutron and resistivity logs are analyzed in this paper, and gives additional
information for each borehole. The wells are listed from south (Well 1, FGS
corehole) to north (Well 9, northern Merritt Island).

TABLE 1
WELLS FROM WHICH LOGS ARE ANALYZED

Well Number, Florida Geo- Latitude/Longitude Elevation Depth to To Thickness
Name and logil Survey (feet of Tamiami of Tamio i
Location Lo Number above Mean (feet below (feet)
Sea Level) land surface)

ndIan River Cety
1 core W-1395B IR-46 2741'50'N/80O28'09"W 23 121 8
2 Wabasso S0 IR-6B 27T44'14"N/Bo2B'50o"W 20 117 8
3 Wabasso IR-69 27-45'l7"N/90B2B'1B"U 12 98 27

B9zeard Cousty
4 Micco West 27'51'58'N/80O37'21" 28 109 12
5 Sebastian Inlet 27052'09"N/80n2722"W 1 88 22
6 Cocoa Beach 2B18'45"N/80'36'34"W 12 74 3B
7 Rockledge 28019'04"N/BO43'35"W 30 92 25
8 Merritt Island BR-221 28o27'55"N/8041 'OB" 4 75 34
9 N. Merritt Isl. BR-229 28o39'44"N/B0D46'33"W 0 98 11

Table 2 (page 8) presents a lithologic description of the Tamiami Forma-
tion and adjacent beds obtained from FGS core W-13958, Well 1, in east-central
Indian River County.
The electric-resistivity (16" normal) log (Figure 2) obtained from this
corehole (Well 1, Figure 1; Township 32 south, Range 39 east, Section 16)
records the Tamiami Formation between approximately 121 feet and 129 feet
below land surface (ble) as a well-defined higher intensity peak occurring
between underlying and overlying conspicuously lower intensity valleys (repre-
senting uppermost Hawthorn Group and basal Caloosahatchee Formation, respect-
ively). Thus, the Tamiami.is only 8-feet thick at this location.
The following figures (3-10) display two sets of resistivity and neutron
logs obtained from small-diameter wells (4" o.d.) in east-central Indian
River County, and six additional neutron logs (no electric logs were obtained)

6















Depth Below
Land Surface
Caloosahatchee
Formation 120'
TAMIA-MI
FORMATION

130'
Hawthorn
Group






increasing resistivity -













Figure 2. Electric-resistivity log from Well 1, FGS corehole W-13958, east-cen-
tral Indian River County.










from equally small-diameter wells in Brevard County (Table 1, Figure 1).
These logs are correlated with the resistivity log of the corehole (Well
1), and are used to trace the Tamiami Formation toward the north into northern
Brevard County. They were selected from the 47 neutron-logged wells in the
two counties and represent the logs on which the Tamiami is best defined.

TABLE 2
LITHOLOGIC DESCRIPTION OF FGS CORE W-13958 (by R. Johnson)

Depth Range Litholocic Description
of Bed
(feet below
land surface)

Top of Core Section Described
-CALOOSAHATCHEE FORMATION-
112-115 Sand, gray-green, quartz, very fine to medium, modes very fine, angular to rounded,
common to abundant very fine spheroidal to ellipsoidel very weathered biogenic
fragments (or very weathered small foramdnifera), asme very fine black phosphate
grains, very scattered whole large (pebble size) unaltered mollusks, very scattered
fine unaltered faraminifera.

115-120.5 Sand, green-gray, quartz, very fine to fine, scattered medium, very scattered
coarse, modes very fine, common white shell fragments (very fine sand size to cobble
size, modes very fine), scattered unaltered foraminifera, ery scattered very fine
black phosphate grains, poorly-consolidated by low content of calcilutite cement.

-TAMIAMI FORMATION-
120.5-128.5 Limestone, white to very light gray, partially recrystallized biogenic calcarenite,
composed of abundant very fine send size to pebble size partially recrystallized
to recrystallized (to scattered unaltered) biogenic and mollusk fragments, scattered
whole unaltered mollusks, some very fine to very coarse quartz sand (modes medium),
scattered very fine to very coarse black phosphate grains; some cobble size zones
of hard, tan, very well-cemented, homogeneous, unfossiliferous, completely recryst-
allized micrite.

-HAWTHORN GROUP-
128.5-137+ Sand and silt, green, quartz and phosphate, silt size to very fine sand size, modez
very fine, poorly-consolidated by very low carbonate cement content, very scattered
small unaltered foraminifera.
Bas of Core Section Described

Figure 3 depicts the neutron log and the Tamiami Formation portion of
the electric-resistivity (16 e normal) log obtained from a SJRWMD-drilled
shallow-rock test and observation well (2) located in east-central Indian
River County (Township 31 south, Range 39 east, Section 32; Figure 1), approx-
imately 3.5 miles north-northwest of Well 1. The Tamiami is recorded as an
extremely well-defined, very thin, sharp peak on the neutron log between

8










- -i -- 4- t





T ,


4-- ,
i- increas.n resistivity









TAMIAMI ORMRATIO Elcti-resistivity


Hawthorn Group


Figure 3. Neutron and electric-resistivity logs from Well 2, east-central Indian
River County near Well 1.


I


U^^^


--.>










approximately 117 feet and 125 feet bis, and also as a single peak on the
resistivity log. This log trace pattern (a single thin peak) of the Tamiami
is common in eastern Indian River County and correlates very well with the
resistivity log from Well 1. The Tamiami remains only 8-feet thick at this
location.
The neutron and electric-resistivity (16" normal) logs obtained from
Well 3, a SJRWMD-drilled shallow-rock test and observation well located ap-
proximately 1.5 miles northeast of Well 2 in northeastern Indian River County
in Wabasso (Township 31 south, Range 39 east, Section 28; Figure 1), are
shown in Figure 4. In this well, the Tamiami is anomalously thick (27 feet),
and is recorded on the neutron log between 98 feet and 125 feet bis as a
double-peak. The lower intensity Hawthorn Group underlies the Tamiami below
125 feet bls, and the basal lower intensity of the Caloosahatchee overlies
the Tamiami. The resistivity log records the Tamiami as a single, albeit
very thick, peak.
Figure 5 depicts the neutron log obtained from Well 4, a shallow-rock
SJRWMD test and observation well located in southern Brevard County (Township
30 south, Range 37 east, Section 22; Figure 1) approximately 20 miles north-
west of Well 3. In this well, the Tamiami Formation extends from 109 feet
to 121 feet bls and is again recorded as a single peak. The development of
a second peak can also be seen on this trace. The top of the Hawthorn Group
is very well-defined as an abrupt stepdown in intensity marking the base
of the Tamiami at 121 feet bls. The lower portion of the overlying Caloosa-
hatchee Formation consists of partially reerystallized, mollusk-rich thin-
ly-bedded limestone, recorded on the log as a series of low peaks between
60 feet and 106 feet bis. The Tamiami attains a thickness of 12 feet in this
well.
Figure 6 shows the neutron log obtained from Well 5, an uncased SJRWMD
test well (Toth, 1985) approximately one mile north of Sebastian Inlet in
extreme southeastern Brevard County (Township 30 south, Range, 39 east,
Section 17; Figure 1) located 11 miles east of Well 4. This log again records
the Tamiami Formation as a single, albeit relatively thick, higher intensity
peak between 88 feet and 110 feet bls. The lower intensity valley directly
below the Tamiami peak represents the top of the more-siliciclastic Hawthorn
Group. The overlying thick broad valley of lower intensity between 42 feet
and 88 feet bls represents the siliciclastic Caloosahatchee Formation which,










Neutrn


.I .inc g neutron intenalty---

At i I -' -I-



I +L
K4 ~-Ii~~~~l:~It~ .I :::~


I7Zf-


4jj. Cf loo.Inhtchee


----- Inceasing resistiv ty-






SMBMO



TAHAMI FDRRATION Eletnie-msistivity


Figure 4. Neutron and electric-resistivity logs from Well 3 in Wabasso, northeastern
Indian Biver County.


.NI--











inozeasing neutron intensity -


-T ... .. ..-l --


HH !


r


Caloosa-
Shatchee
-Fonnation


S' TAMIAMI
120' FORMATION


~'T"';F--'---;-i------

Hawthorn Group



Figure 5. Neutron log from Well 4, southern Brevard County, northwest of Well 3.


~-FflGWf~--


1111111114-


- --.. -.


HM-+C 1 1 '-+ 14 1 i ---I


*HL-LLL-LI-


SI ;j 7 14 1


Hl











increasing neutron intensity -

0'




20,





4 0





60'





Shatchee
Formation



100'





120' FORMATION

Hawthorn Group






Figure 6. Neutzon log from Well 5 at Sebastian Inlet, southern Brevazd County.





13









on the barrier island in much of Brevard County, contains no partially recrys-
tallized limestone beds. At this location and to the north, the top of the
Tamiami Formation is significantly shallower below land surface than to the
south in Indian River County and to the west in south-central (mainland)
Brevard County. In this well, the Tamiami is 22-feet thick, whereas 11 miles
to the west in Well 4, the thickness is only 12 feet, illustrating that the
formation generally thins toward the west from the immediate vicinity of
the Atlantic coast.
Well 6 is located in Cocoa Beach, extreme east-central Brevard County
(Township 25 south, Range 37 east, Section 15; Figure 1), approximately 35
miles north-northwest of Well 5. The neutron log (Figure 7) depicts a quadru-
ple-peak or zone of higher intensity between 74 feet and 112 feet bls corres-
ponding to the Tamiami Formation. The uppermost Hawthorn Group below 112
feet ble is recorded on the log as lower intensity. Above the Tamiami, the
Caloosahatchee Formation is also recorded as lower intensity. The Tamiami
is 38-feet thick in this well, representing the thickest occurrence found
in the study area.
Well 7 is located in Rockledge, east-central Brevard County (Township
25 south, Range 36 east, Section 15; Figure 1), approximately 15 miles direct-
ly west of Well 6 in Cocoa Beach. This borehole represents a shallow-rock
aquifer test and observation well drilled by the SJRWMD. The neutron log
(Figure 8) shows a well-defined higher intensity double-peak (Tamamii Forma-
tion) extending from 92 to 117 feet ble, situated between underlying (Hawthorn
Group) and overlying (Caloosahatchee Formation) lower intensity zones. The
total thickness of the Tamiami at this location is 25 feet, again illustrating
that the formation generally thins toward the west inland from the immediate
vicinity of the Atlantic coast (Cocoa Beach: 38 feet, Rockledge: 25 feet).
Well 8 is located on central Merritt Island one mile southeast of the
south gate of the Kennedy Space Center, east-central Brevard County (Town-
ship 23 south, Range 36 east, Section 24; Figure 1), approximately 11 miles
north-northeast of Well 7. The neutron log (Figure 9) records the Tamiami
Formation as a well-defined triple-peak between 75 feet and 109 feet bls.
Again, the top of the underlying Hawthorn Group is recorded as markedly lower
intensity (below 109 feet bls), as is the entire Caloosahatchee Formation
which overlies the Tamiami above 75 feet his. The total thickness of the
Tamiami Formation at this location is 34 feet, the second-thickest occurrence

14

















































Hawthorn Group


Figure 7. Neutron log from Well 6 in Cocoa Beach, east-central Brevard County.






15













increasing neutron intensity----


20'





40-





60'





80'

S aloosahatcl
Formation


100'





120'
TAMIAMI
FORMATION

Hawthorn Group




Figure 8. Neutron log from Well 7 in Rockledge, east-central Brevard County.









increasing neutron intensity -


Figure 9. Neutron log from Well 8 on Merritt Island, east-central Brevard
County.



17









of Tamiami identified in the study area.
The thinning of the Tamiami Formation toward the north in northeastern
Brevard County is indicated on the neutron log obtained from Well 9 and
illustrated on Figure 10. This well is located on northern Merritt Island
in the Merritt Island National Wildlife Refuge (Township 21 south, Range
35 east, Section 13; Figure 1), approximately 15 miles north-northwest of
Well 8. As in southern Brevard County and most of Indian River County, the
Tamiami Formation is here recorded as a single peak (between 98 feet and
109 feet bls). Log suites obtained from additional wells in northern Merritt
Island indicate that the Hawthorn Group varies considerably in thickness
(<5-30 feet). On the present neutron log, the very thin valley of lower inten-
sity immediately below the Tamiami probably records this highly variable
Hawthorn Group. Above the Tamiami, the Caloosahatchee Formation is recorded
as a series of low peaks indicative of thinly-interbedded, partially recryst-
allized limestone, and siliciclastics (above 98 feet bls). The Tamiami Forma-
tion is only 11-feet thick in this well.
SUIMARY
In eastern or coastal Brevard and Indian River Counties, the Pliocene
Tamiami Formation is best defined and most easily identified on neutron logs.
Electric-resistivity logs, when available, also may be used to identify the
Tamiami. The carbonate-rich formation is recorded as a prominent single-,
double-, triple-, or quadruple-peak underlain (upper Hawthorn Group) and
overlain (basal Caloosahatchee Formation) by markedly lower intensity zones
indicative of siliclastics. In the study area, the Tamiami is thickest
beneath Cocoa Beach and central Merritt Island (38 feet and 34 feet, respec-
tively). The Tamiami thins to the south into southern Brevard and eastern
Indian River Counties as well as to the north into northern Brevard County.
The Tamiami also generally thins inland toward the west from the immediate
vicinity of the Atlantic coast. The thickest occurrence of Tamiami found
in Indian River County is an anomalous 27 feet in Wabasso in the northeastern
portion of the county. In the remainder of eastern Indian River County, and
in northern and southern Brevard County the Tamiami averages 10-20 feet or
less in thickness, but remains well-defined on neutron and electric-resistiv-
ity logs.










increasing neutron intensity -- -


Figure 10. Neutron log from Well 9 on northern Merritt Island, northeastern
Brevard County.


19









REFERENCES


Mansfield, W.C., 1939, Notes on the Upper Tertiary and Pleisto-
cene mollusks of peninsular Florida: Florida Geological
Survey Bulletin 18, 75 p.


Schlumberger Limited, 1972, Log interpretation, Volume 1, Prin-
ciples: Schlumberger Limited, New York, 113 p.


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


Toth, D.J., 1985, Test drilling report for observation wells
at Sebastian Inlet State Park, Brevard County, Florida:
St. Johns River Water Management District Technical Publi-
cation 85-6, 22 p.











APPENDIX

LIST OF ALL WELLS NEUTRON-LOGGEO IN THE STUDY AREA

Note: Since these wells were logged by the S3RWI, their SJRWM1 access numbers (Latitude/Longi-
tude) are used to identify and locate the wells.


Well Name


de


I
B
S
C


BREVARD
injection test-Brevard Waste Water Treatment Plant
ethesda Baptist Retirement Home-very old oil test
ebastian Inlet Proj (parameters for finished well)
ouch Pumps North well-Grant


Latitude/Lonqitud


282533N/804223W
280138N/B03515W
275210N/902722W
275550N/803137W
27575SV/803033W
280007N/804337?
275926N/8041469l
275459N/B04011W
279530N/8040504
275W48N/804135W
282033N/804634W
275546N/804145W
281653N/804028W
2B0234N/a03502W
282205N/804156W
283414N/803912W
282755N/BD4106W
283944N/804633W
282756N/BO4108W
282757/a04117W
282304N/BO4213W
275340N/803951W
282B07N/804220W
280634N/803859i
27515BN/BO3721W
281904N/804335W
281845N/803634W


273427N/B01956W
273615N/8028356
274837N/802935W
273821N/802739W
274123N/80294391
274455 /802637W
274522N/603D431I
273548N/102039W
27353?N/8020091
273348N/801930l
274002N/a02619W
274240N/802532W
273607N/802328B
NA
274603N/803457W


TDL* Casing/Size" Depth'


12 130
10/8 398
4 560
8 159


Floridana Beach-Oceanuay-Public Supply 556
General Development Corp (GDC)-Port Malabar-5 349
GDC Port Malabar-6 347
GDC Port talabar-1 336
GDC Port Malabar-4 335
GDC Port Malabar-2 316
Weber Ranch-Rockledge West 300
GDC Port Malabar-3 299
Crooked Mile Road-southern Merritt Island 248
Castaway Point-Palm Bay 245
Westwood Drive-central Merritt Island 242
Kennedy Space Center-in bldg-northern Merritt Island 225
Foosaner 1-central Merritt Island 212
Merritt Island National Wildlife Refuge 204
Foosaner 2-central Merritt Island-Si 202
Foosaner 3-central Merritt Island-NW 183
Merritt Crossing Shopping Center 182
Blackhaik Quarry-south county 139
Crisafolli-central Merritt Island 135
Melbourne Airport-SJRIID shallow rock test well 133
Fellsmere Joint Venture-S3RiPD shallow rock test well 130
Rockledge-SJRiPD shallow rock test well 122
Cocoa Beach-Third Street South 117

INDIAN RIVER
Seminole Shores-south barrier island 943
Jackson Brothers Groves 860
Sebastian Country Club 840
CR 505A and SR 60-Holt-iest of Vero Beach 746
Takaho Groaes-northwest of Vero Beach 676
Johns Island-Wabasso 558
Vero Beach Farns-uest of Wabasso 465
The Moorings 2-south barrier island 456
The Moorings 1-south barrier island 436
Round Island Park SJRW3 D shallow rock test well 192
South Gifford SJRUPD shallow rock test well 150
Winter Beach SJ3RWD shallow rock test well 144
South Canal SJFR shallow rock test well 143
Vera Beach public supply #28-Vero Beach High School 141
Fellsmere STJRi shallow rock test well 140


----------------------------------












APPENDIX continued

Latitude/Longitude Well Name TlL* Casing Size" Depth'

274948N/802916W Roseland SJfRD shallow rock test well 135 4 105
274517N/802618W Wabasso School SJRUPD shallow rock test well 132 4 85
274414N/802B55W SW Wabasso 5JRWMI shallow rck test well 128 4 88
NA Vero Beach public supply well 123 126 12 NA
273732N/802410W Vero Beach Elem School SJRIPD shallow rock test well 123 4 108


NOTES
*= Total depth logged by neutron probe in feet below land surface
"= Casing outside diameter in inches
= Bottom of casing (depth) in feet below land surface
NA= data not available