Sand, gravel and heavy-mineral resources potential of surficial sediments offshore of Cape Canaveral, Florida ( FGS: Open file report 35 )

State of Florida
Department of Natural Resources
Tom Gardner, Executive Director

Division of Resource Management
Jeremy Craft, Director

Florida Geological Survey
Walt Schmidt, State Geologist and Chief

Open File Report 35

Sand, Gravel and Heavy-Mineral Resources
Potential of Surficial Sediments Offshore
of Cape Canaveral, Florida

by

Bruce, W. Nocita, Pramuam Kohpina, Larry W. Papetti,
Mary M. Olivier, Andrew E. Grosz, Steve Snyder,
Kenneth M. Campbell, Richard C. Green and Thomas M. Scott

Florida Geological Survey
Tallahassee, Florida
1990

~'1;~1ICc

22

L '3R

SAND, GRAVEL AND HEAVY-MINERAL RESOURCES
POTENTIAL OF SURFICIAL SEDIMENTS
OFFSHORE OF CAPE CANAVERAL, FLORIDA

Phase II and Final Report

Cooperative Agreement 14-12-0001-30387

Bruce W. Nocita, Pramuan Kohpina, Larry W. Papetti,
and Mary M. Olivier
Department of Geology
University of South Florida
Tampa, Florida 33620-5200

Andrew E. Grosz
U.S. Geological Survey
Reston VA 22092

Steve Snyder
North Carolina State University
Raleigh, NC 27695-8208

Kenneth M. Campbell, Richard C. Green and Thomas M. Scott
Florida Geological Survey
903 E. Tennessee Street
Tallahassee, Florida 32304-7795

Table of Contents
Page

Introduction 1
Previous Work 1
Methods 3
Vibracores 4
Heavy Minerals 7
Hydrodynamic separation 7
Heavy-liquid separation 8
Magnetic separation 8
Mineral identification 9
Sediment analysis 9
Sand and Gravel 10
Surface samples 11
Seismic survey 11
Results 12
Sand and Gravel 12
Surface samples 24
Sand 24
Gravel 24
Mud 26
Vibracore sections 26
Sand upper core section -26
Gravel upper core section 26
Mud upper core section 32
Sand lower core section 32
Gravel lower core section 32
Mud lower core section 32
Heavy Minerals 38
Discussion 38
Sand and Gravel 38
Seismic Survey 42
Heavy Minerals 46
Economic heavy minerals 48
Conclusions 51
Acknowledgments 53
References 54

FIGURES

Page

Fig. 1: Location map showing major shoal bodies and 2
bathymetry.

Fig. 2: Vibracore location map. 5

Fig. 3: Surface sample location map. 6

Fig. 4: General distribution of sand-rich surficial 25
sediment.

Fig. 5: General distribution of shell-gravel-rich 27
surficial sediment.

Fig. 6: General distribution of mud-rich surficial 28
sediment.

Fig. 7: General distribution of sand-rich sediment 29
in upper section of vibracores.

Fig. 8: Distribution of mean grain size (phi) for 30
the upper section of vibracore.

Fig. 9: General distribution of shell-gravel-rich 31
sediment for the upper section of vibracores.

Fig. 10: General distribution of mud-rich sediment of 33
the upper section of vibracores.

Fig. 11: General distribution of sand-rich sediment in 34
the lower section of vibracores.

Fig. 12: Distribution of mean grain size (phi) for the 35
lower section of vibracores.

Fig. 13: General distribution of shell-gravel-rich 36
sediment for the lower section of vibracores.

Fig. 14: General distribution of mud-rich sediment for 37
the lower section of vibracores.

Fig. 15: Plotted track lines for seismic survey. 43
Locations of seismic sections in Figures 16,
17 and 18 shown.

Fig. 16: Seismic profile of a portion of a sand shoal 44
showing a sub-bottom channel, a shallow sub-
bottom unconformity and the bubble pulse. Note
the deformed Ocala Group carbonates at the
bottom of the section.

iii

Fig. 17:

Seismic profile of a portion of a sand shoal,
interpreted section on bottom. Note the
emergence of the unconformity on the sea floor.

Fig. 18: Seismic profile of a portion of a sand shoal.
Inset shows small, active bedforms on top of
older, possibly inactive shoal bodies.

TABLES

Page

Table 1:

Table 2:

Table 3:

Table 4:

Table 5:

Table 6:

Table 7:

Sand, shell-gravel and mud weight percent for
vibracore samples.

Granulometric data for vibracore samples
(carbonate included) Phase 1 samples (sieve
data) indicated by asterisk.

Sand, shell-gravel and mud weight percent for
surface samples.

Granulometric data for sand fraction of surface
samples.

Weight percent carbonate of the sand-sized
fraction for selected (whole core) repository
samples from Phase 1.

Heavy mineral (>2.96 specific gravity) content
of 84 samples from offshore of Cape Canaveral,
Florida.

Data for total heavy minerals (THM) and recovered
heavy minerals (RHM) tabulated for all vibracore
samples, in the upper 1.5m sections and the lower
1.5m sections.

INTRODUCTION

The Florida Geological Survey, in cooperation with the

United States Minerals Management Service, the University of

Texas at Austin, the United States Geological Survey and the

University of South Florida, has continued the investigation of

continental shelf sediments offshore of Cape Canaveral, Florida,

under cooperative agreement number 14-12-0001-30387. This study

(Phase II) was funded from June, 1988 to December, 1989 and

followed the Phase I project (cooperative agreement number 14-12-

0001-30316) (Nocita et al., 1989a). Phase I plus Phase II

complete the study of the Cape Canaveral area.

Much of the Inner Continental Shelf offshore of Cape

Canaveral is mantled by an extensive set of sand shoals. These

shoals (Figure 1) may be potential sources of sediment for beach

nourishment and also for a variety of strategic and critical

heavy-mineral species including ilmenite, rutile, zircon and

monazite. Other heavy minerals of less economic importance such

as garnet, staurolite, aluminosilicates (sillimanite/

kyanite/andalusite), and phosphate are also present. This report

summarizes the results of the Phase I and Phase II studies in the

Cape Canaveral area.

PREVIOUS WORK

The inner contineiAcal shelf region offsl-ore Cape Canaveral

has been the subject of a variety of different types of studies.

The work of Field and Duane (1974) examined the geomorphology and

sediment characteristics in the area. Their data base consisted

80.500

Shoal

0 3NM
0 3km

a

/ B tr Contor ( )
-0 Blhymetrio Contour (fet)

Fig. 1: Location map showing major shoal bodies and bathymetry.

of vibracore samples and high-resolution seismic lines. Sediment

analysis was from plugs taken from the vibracore samples. The

coverage of seismic profiles excluded most of the major sand-

shoal body which is attached to the Cape. This was presumably

due to the shallow water depths.

Evolution of the inner shelf sediments, including the shoal

bodies has been discussed by Duane et al. (1972) and Field

(1974). Field (1974) documented the occurrence and location of

buried strandline deposits on the basis of accumulation of an

intertidal clam, Donax variabilis. Duane et al. (1972) discussed

shoreface-connected and isolated linear shoals associated with

the Cape, and concluded that they formed by coastal-retreat

processes.

Heavy-mineral studies in the Cape Canaveral area are those

related to the current-project. Preliminary results have been

presented by Nocita et al. (1989a, 1989b) and Grosz et al.

(1989a).

METHODS

The data base for Phase II is derived from two sets of

sediment samples. One set is made up of vibracores and the other

is surface grab samples. The vibracores were part of a larger

repository of U.S. east coast samples that were initially

collected by the U.S. Army Corps of Engineers Coastal Engineering

Research Center (CERC) as part of a sand and gravel inventory

program on the U.S. Atlantic Shelf (Field and Duane, 1974).

Vibracores from offshore Florida's east coast originally were

archived by The U.S. Geological Survey in Reston, Virginia, and

now reside at the Florida Institute of Technology in Melbourne,

Florida. Surface samples were collected and high-resolution

seismic lines were run in July, 1989 as part of the Phase II

study.

Phase II comprised a total of 79 samples derived from 44

vibracores. Added to the Phase I data base, this brings the

total number of vibracores and samples for the Cape Canaveral

area to 84 and 140 respectively (Figure 2). A total of 93

surface samples was collected, mostly in the shoal areas (Figure

3).

Vibracores

The methodology for initial preparation and sample analysis

of the vibracores is the same for Phase II samples as for Phase I

samples. Samples were processed for information on grain-size

distribution, composition, heavy-mineral content, and mineralogy

of the heavy-mineral assemblage. Cores were split lengthwise,

described, photographed, and divided into approximately 1.5 m

sections on the basis of lithology and/or section length if the

lithology was consistent throughout. Repository samples of

approximately 300-500 grams were collected from each section.

Samples were weighed on a dry-weight basis; weights ranged from

about 4 to 18 kilograms (kg), averaging approximately 9 kg.

Samples were then sieved to separate the gravel fraction (>-1

phi) from which a weight-percent gravel was calculated.

of vibracore samples and high-resolution seismic lines. Sediment

analysis was from plugs taken from the vibracore samples. The

coverage of seismic profiles excluded most of the major sand-

shoal body which is attached to the Cape. This was presumably

due to the shallow water depths.

Evolution of the inner shelf sediments, including the shoal

bodies has been discussed by Duane et al. (1972) and Field

(1974). Field (1974) documented the occurrence and location of

buried strandline deposits on the basis of accumulation of an

intertidal clam, Donax variabilis. Duane et al. (1972) discussed

shoreface-connected and isolated linear shoals associated with

the Cape, and concluded that they formed by coastal-retreat

processes.

Heavy-mineral studies in the Cape Canaveral area are those

related to the current-project. Preliminary results have been

presented by Nocita et al. (1989a, 1989b) and Grosz et al.

(1989a).

METHODS

The data base for Phase II is derived from two sets of

sediment samples. One set is made up of vibracores and the other

is surface grab samples. The vibracores were part of a larger

repository of U.S. east coast samples that were initially

collected by the U.S. Army Corps of Engineers Coastal Engineering

Research Center (CERC) as part of a sand and gravel inventory

program on the U.S. Atlantic Shelf (Field and Duane, 1974).

Vibracores from offshore Florida's east coast originally were

80.50

Fig. 2: Vibracore location map.

80.33'

80.500

7.

7,371

0 3 NM
0 3km
6-A--6-

S"

- Surface Sample Location

- Bathymetrlc Contour (feet)

Fig. 3: Surface sample location map.

28.66

Heavy Minerals

Most previous studies of heavy minerals in recent marine

sediments used initial samples of relatively small mass,

typically in the range of 100 to 200 g, usually collected from

the sea floor as grab samples. The heavy-mineral concentrate

from these small samples commonly amounted to less than 1 g.

Clifton et al. (1967) have shown that low concentrations of

grains result in a "particle-sparsity-effect", which leads to

inaccurate quantitative analysis of mineral species that occur in

very small abundances. In order to compensate for this bias,

large volumes of sediment, averaging approximately 9 kg, were

processed for their heavy-mineral content.

Two different processes were used to produce a final heavy-

mineral concentrate. Initially, the sediment was

hydrodynamically separated, producing a 500 to 1,000 g sample

enriched in heavy minerals. The second step utilized

high-density liquids to remove the remaining "light" fraction.

Magnetic fractionation produced subsamples that were then

visually examined in order to estimate abundances.

Hvdrodvnamic Separation

The -10 mesh (<-1 phi) (sand, silt, clay) fraction was

processed by use of a three-turn sampling spiral to produce a

heavy-mineral concentrate (spiral heavies) averaging about 500 g

in weight. After the initial processing on the spiral, the

spiral-lights fraction (material rejected by the spiral) was

processed in the spiral again, and the concentrate from these two

runs was processed at least one more time. The spiral heavies

(concentrate) and a split (200-300 g) of the spiral lights were

dried and weighed.

Heavv-liauid Separation

A purified heavy-mineral concentrate was produced from both

the spiral lights and spiral heavies by use of tetrabromoethane

having a specific gravity of 2.96. Weight-percent heavy minerals

was calculated on the basis of heavy minerals recovered (RHM) by

the spiral concentrator. The total heavy-mineral concentration

(THM) in a sample was calculated by summing the RHM with the

calculated percentage of heavy minerals found in the spiral

lights (calculated as a percent of heavy minerals in the

spiral-light subsample multiplied by the weight of the total

spiral-light material). This estimate of total heavy minerals is

an underestimate because some heavy minerals contained in the mud

fraction of the spiral lights were lost through elutriation. The

RHM fractions for each sample were further split (utilizing a

microsplitter) into repository (12.5 volume percent), chemical

analysis (12.5 volume percent), and magnetic separation (75

volume percent) samples.

Magnetic Separation

Six magnetic fractions were derived from the 75 percentile

split of each sample by use of a Frantz Laboratory Magnetic

Barrier Separator. This procedure reduced the number of

variables (mineral species) in each magnetic fraction thereby

facilitating the mineral identification/quantification process.

The Cape Canaveral samples contain essentially no magnetite;

initial separation of ferromagnetic minerals, therefore, was not

necessary and the Barrier Separator was used for the entire

sample fractionation.

Mineral Identification

Each of the six magnetic fractions was examined by use of a

binocular microscope in order to estimate mineral abundances.

Comparison charts for visual estimation of percentage composition

(Terry and Chilingar, 1955) were used for this purpose along with

a modified point-counting method. Petrographic examination and

X-ray diffraction analysis were used to aid and verify the

identification of non-opaque minerals. The composition of the

magnetic fractions was quantified using the following guidelines:

<0.01% = Present (P); 0.0% = Not determined (N). An "others"

category was also estimated, and included those grains which

could not be identified or were present in minute quantities.

The identification of zircon and monazite was aided by the use of

long- and short-wave (respectively) ultraviolet illumination.

Sediment Analysis

Each of the 140 bulk samples had the gravel fraction removed

by use of a 10 mesh (-1 phi) U.S. Standard stainless steel sieve

by wet sieving. Gravel portions were dried, weighed and stored

for later description. Repository samples were used for the

calculation of sand and mud percentages and for grain-size

analysis of the sand fraction.

Sand and Gravel

Samples were wet sieved to separate the gravel and mud

fractions from the sand. Mud-weight percent was calculated from

this separation and no further analyses were done on the mud

fraction.

Grain-size analysis of the sand fraction (with carbonate)

was done by either sieving (1/2 phi intervals) or by use of the

Rapid Sediment Analyses (RSA; settling tube). Phase I samples

were analyzed by the Florida Geological Survey and by the

University of South Florida using sieve techniques (no RSA was

available). Phase II samples were analyzed on the RSA at the

Florida Institute of Technology. Raw data was run through

grain-size analysis computer programs which calculated the first

four moment m.,-asures (mean, standard deviation, skewness and

kurtosis). This data is not intended for detailed, quantitative

grain-size analysis.

Several authors have indicated that there are significant

differences in the way grain size distributions are perceived by

sieving and settling processes. Bergmann (1982), notes that the

settling tube sees fine grain sizes coarser than they actually

are and coarse grain sizes finer than they actually are,

resulting in a "compression" of the distribution. Relative to

sieving, settling mean grain sizes were not significantly

different, standard deviation values in almost all cases were

smaller. The settling process is very poor at detecting minor

changes in sediment distribution that are reflected in skewness

and kurtosis values (Bergmann, 1982).

A number of samples from Phase I do not have grain-size

data. This is due to one of several reasons, including lack of

enough sand-sized sediment because of the fine-grained nature of

the sample; initial mass of repository too small for sieving; and

operator error. Weight-percent carbonate of the sand fraction

was calculated by acid digestion methods for a portion of the

Phase I samples.

Surface Samples

A total of 93 surface samples were collected in July, 1989.

Samples were collected by means of an "underway sampler". This

device, consisting of a metal cylinder with a bag clamped to one

end, is lowered to the sea floor while the ship is underway.

Sediment is channeled down the tube and fills the sample bag. It

was determined that little mud was lost during this procedure and

that the sample is a good representative of sea-floor sediment.

All surface samples were analyzed for gravel, sand and mud

content by wet-sieve techniques. Grain-size analysis was done on

the sand fraction by use of sieves and computer programs.

Seismic Survey

High-resolution seismic data were collected using an EG&G

UNIBOOM profiling system. This system emits a broad spectrum of

high frequencies (400 HZ to 14 kHZ). Peak frequency is 600-800

Hz which renders a working vertical resolution of less than one

meter. The UNIBOOM was fired 3 times per second using a spark-

gap source box. This particular source produces a large post-

cursor and pre-cursor pulse, resulting in a significant bubble

pulse. The seismic signal was collected on an 8-element

hydrophone, and recorded both graphically and on a stereo VCR

(analog, magnetic tape as an archive).

The data are single-channel, analog data. No digital

processing was performed. Instead, the raw seismic data were

photocopied, studied and interpreted. Real reflecting horizons

were discriminated from multiples and highlighted. Equipment

failure about one third of the way through the cruise limited the

seismic coverage mainly to the Southeast Shoal off Cape

Canaveral.

RESULTS

Sand and Gravel

Percentages of gravel, sand and mud were plotted on maps of

the offshore Cape Canaveral area in order to show the

distribution of sediment, especially that which might be

desirable for the purpose of beach nourishment. Maps were made

for surface samples, upper core sections and lower core sections.

Gravel, sand, and mud percentages, along with grain-size analysis

data are listed in Tables 1 and 2 for vibracore samples and in

Tables 3 and 4 for surface samples. Weight percent carbonate of

the sand sized fraction for a portion of the Phase I samples is

shown in Table 5.

Because of the distinct geologic differences between the

Table 1

Sand, shell-gravel and mud weight percent for vibracore samples

U.S.G.S. Shell-
Sample No. Gravel Sand Mud
1-1 23.31 68.36 8.33
1-2 12.21 -
2-1 13.78
2-2 23.79- -
3 10.39 76.62 12.99
4-1 1.73 76.19 22.08
4-2 18.55 5.75 94.25
5-1 6.94 83.82 9.25
5-2 20.53 73.18 6.29
6-1 22.60 66.56 10.84
6-2 6.36 86.40 7.24
7-1 8.32 -
7-2 18.30 81.27 0.43
9-1 1.32 45.70 52.98
9-2 4.82 28.17 67.01
10 2.59 -
11-1 4.61 68.42 26.97
11-2 4.76 58.93 36.31
12-1 1.89 75.38 22.73
12-2 .75 85.34 13.91
13-1 2.85 62.91 34.25
13-2 1.66 67.98 30.36
14 9.62 64.57 25.82
15 8.91 82.88 8.21
16-1 2.49
16-2 10.72 -
17-1 2.37 94.47 3.16
17-2 4.31 90.15 5.54
18-1 3.16 95.49 1.35
18-2 5.30 -
19-1 21.33
19-2 3.45 -
20-1 12.79 80.31 6.90
20-2 8.04 87.77 4.19
21-1 2.35 96.64 1.01
21-2 1.72 80.26 18.03
22-1 12.85 81.84 5.31
22-2 5.46 78.84 15.70
24 8.70 89.13 2.17
25-1 5.86 84.26 9.88
25-2 26.72 64.02 9.26
26-1 8.23 88.31 3.46
26-2 20.97 72.58 6.45
27-1 32.74 63.69 3.57
27-2 36.88 48.74 14.57

Table 1

U.S.G.S. Shell-
Sample No. Gravel Sand Mud
28-1 28.85 67.31 3.85
28-2 11.28 82.56 6.15
30-1 30.00 62.37 7.63
30-2 16.28 76.74 6.98
31-1 1.66 70.62 27.73
31-2 14.86 71.03 14.11
32 19.79 76.30 3.91
33 4.64 93.57 1.79
34-1 1.80 96.70 1.50
34-2 9.20 87.60 3.20
35-1 3.57 -
35-2 21.69 -
36-1 2.55 95.99 1.46
36-2 8.77 -
37-1 1.45 97.27 1.28
38-1 14.93 73.88 11.19
38-2 7.93 84.14 7.93
39-1 9.40 78.06 12.54
39-2 9.45 71.65 18.90
40 3.55 77.23 19.22
42-1 8.30 85.16 6.10
42-2 7.73 69.98 22.29
43 12.24 75.53 12.24
44-1 19.22 68.63 12.16
45-1 6.08 79.47 14.45
45-2 13.27 60.20 26.53
46-1 0.68 63.04 36.28
46-2 3.87 -
47-1 13.45 80.86 5.69
47-2 33.10 43.55 23.35
48-1 -
48-2 3.57 92.43 4.00
49-1 5.32 76.53 18.15
49-2 4.97 81.42 13.61
50 0.46 98.17 1.37
51-1 2.45 96.57 0.98
51-2 2.02 96.51 1.47
52 7.94 90.48 1.59
53 20.73 75.13 4.15
54-1 15.6 80.38 2.46
54-2 20.56 72.98 6.45
57-1 1.04 87.57 11.38
57-2 10.64 76.91 12.45
58-1 7.45 90.59 1.96
59-1 10.77 86.15 3.08
59-2 5.60 ".90O 3.60
60-1 7.00 89.21 3.79
61 29.11 65.19 5.70
62 15.85 81.13 3.02
63-1 1.77 82.07 16.16

Table 1

U.S.G.S. Shell-
Sample No. Gravel Sand Mud
63-2 18.39 52.91 28.70
64-1 13.77 75.30 10.93
64-2 19.62 -
65 10.48 87.83 1.69
66-1 3.4 -
66-2 11.15 -
69-1 8.41 88.32 3.27
69-2 18.24 78.12 3.65
70 11.17 83.78 5.05
72-1 32.19 65.24 2.58
72-2 21.89 71.30 6.80
73 10.50 82.65 6.85
74-1 19.16 72.08 8.77
74-2 27.32 68.85 3.83
75-1 19.48 76.62 3.90
76-1 3.96 95.12 0.92
76-2 3.61 94.54 1.85
77-1 3.62 95.65 0.73
77-2 4.40 93.20 2.40
78-1 30.04 66.52 3.43
78-2 37.93 57.47 4.60
79-1 10.03 85.07 4.9
79-2 16.68 -
80-1 3.84 84.51 11.65
80-2 2.90 -
81-1 3.47 93.30 3.22
81-2 34.63 58.10 7.27
82-1 11.28 86.01 2.71
82-2 4.24 -
83-1 6.30 91.45 2.25
83-2 28.42 66.51 5.07
84-1 48.28 -
84-2 29.51 -
85 13.06 85.04 1.9
87-1 33.75 -
87-2 31.06 -
88-1 34.68 60.36 4.95
88-2 11.27 85.45 3.29
89-1 33.69 -
89-2 18.54 77.57 3.89
90 24.14 70.13 5.73
91-1 -
91-2 5.08 89.77 5.15
92-1 38.37 56.59 5.04
92-2 79.86 16.25 3.89
93 13.22 84.3 2.48
95 0.85 -

Table 2

Granulometric data for vibracore samples (carbonate included).
Phase 1 samples indicated by asterisk.

U.S.G.S.
Sample No.
1-1 *
1-2 *
2-1 *
2-2 *
3
4-1
4-2
5-1
5-2
6-1
6-2
7-1 *
7-2 *
9-1 *
9-2 *
10
11-1
11-2
12-1
12-2
13-1 *
13-2 *
14
15
16-1 *
16-2 *
17-1
17-2
18-1 *
18-2 *
19-1 *
19-2
20-1
20-2
21-1
21-2
22-1
22-2
24
25-1
25-2
26-1
26-2
27-1
27-2
28-1
28-2
30-1

Mean grain
size (phi)

1.55

2.54
2.55
2.98
2.64
2.24
2.10
2.19

3.19
2.09
3.09
3.05

2.77

3.61
1.60
2.16
1.98
1.57
1.48
1.45
1.76
1.43
1.15
2.03
2.88
1.62
2.83
1.J9
1.69
1.73
1.73
1.45
1.23
1.28
1.29
1.30
0.70

Standard
Deviation

1.10

2.55
2.13
2.02
2.87
3.47
2.49
2.32

1.82
3.17
1.58
1.76

1.31

0.70
1.34
2.21
1.89
0.66
0.76
0.95
0.76
1.02
0.94
1.20
1.69
2.32
1.59
1.75
1.53
1.90
1.46
1.61
1.69
2.13
1.88
1.75
1.74

Skewness

-0.02

0.49
0.12
2.30
2.27
4.93
0.11
2.85

3.08
0.48
1.27
1.40

-1.16

-1.73
0.46
2.05
0.84
-0.89
-0.50
-0.52
-0.74
0.02
0.51
-2.52
0.60
-0.09
0.94
-0.35
-1.30
-0.75
-0.48
-0.15
-0.25
-0.63
-1.03
-0.50
-1.78

Kurtosis

2.99
-
1
14.17
14.06
16.14
24.55
47.92
9.93
30.40

24.02
14.07
11.77
10.3

3.43
-
6.07
2.23
26.69
15.30
4.62
4.03
3.38
4.77
3.00
3.62
22.13
13.08
13.34
16.00
14.11
10.40
10.93
11.65
11.02
14.43
7.93
15.76
8.45
14.27

Table 2

U.S.G.S. Mean grain
Sample No. size (phi)

30-2 1.37
31-1 1.54
31-2 2.87
32 1.94
33 1.68
34-1 1.71
34-2 1.84
35-1 1.94
35-2 *
36-1 1.35
36-2 1.06
37-1 1.34
38-1 1.66
38-2 0.98
39-1 2.75
39-2 2.94
40 3.09
42-1 3.19
42-2 *
43 2.66
44-1 2.51
45-1 1.66
45-2 2.02
46-1 *
46-2 *
47-1 2.96
47-2 *
48-1 1.45
48-2 1.80
49-1 2.42
49-2 2.36
50 2.04
51-1 1.25
51-2 2.01
52 0.71
53 1.66
54-1 0.81
54-2 1.93
57-1 2.77
57-2 *
58-1 1.80
59-1 1.45
59-2 2.15
60-1 1.94
61 1.40
62 1.70
63-1 2.18
63-2 2.49
64-1 *

Standard
Deviation

1.52
2.33
4.13
2.65
1.49
1.10
1.07
0.85

0.81
0.85
0.67
1.97
1.82
1.96
1.53
0.96
1.03

2.39
2.55
2.68
2.93

0.99

0.76
0.85
1.18
1.26
0.59
0.74
0.56
1.66
1.63
1.56
2.49
0.75

1.23
1.64
2.00
1.40
1.80
1.45
2.18
1.95

Skewness

-1.05
-0.25
6.60
2.93
-0.48
0.34
0.44
-0.61

-0.50
-0.06
-0.22
-0.84
-1.53
0.93
1.37
-2.24
-1.73

0.07
0.58
-0.06
-0.20

-0.85

-0.28
-0.08
-0.64
-0.61
-0.78
-0.33
1.02
1.06
-0.30
-1.81
0.44
-1.21

-0.90
-0.65
3.19
-0.12
-0.71
0.71
-1.82
0.72

Kurtosis
9.28
9.95
62.43
30.45
12.45
17.78
14.30
4.37

3.76
3.19
5.07
9.44
12.19
11.68
12.28
8.08
5.31

13.12
8.91
9.32
8.72

3.27

3.44
4.02
2.58
2.40
7.63
3.67
6.80
11.47
9.06
13.30
9.23
6.14

17.78
17.70
29.86
8.14
9.16
10.41
14.22
11.67

U.S.G.S. Mean grain
Sample No. size (phi)

64-2 *
65 *
66-1 *
66-2 *
69-1
69-2
70
72-1
72-2 *
73
74-1
74-2
75-1
76-1 *
76-2 *
77-1 *
77-2 *
78-1
78-2
79-1 *
79-2 *
80-1 *
80-2 *
81-1 *
81-2 *
82-1 *
82-2 *
83-1 *
83-2 *
84-1 *
84-2 *
85 *
87-1 *
87-2 *
88-1
88-2
89-1
89-2
90
91-1
91-2
92-1
92-2
93
95 *

2.09
1.95
1.14
1.13
1.42
1.27
1.47
0.45
1.47

1.48
1.43
1.79
1.70
2.48
1.48
1.49
0.40
0.56
2.34
2.35
2.66
2.71
2.29

1.39
2.00
1.85
1.62
0.87
-

0.68
1.04
0.90
1.56
0.87
1.44
2.03
1.68
1.57
1.24
1.34
2.13

Table 2
Standard
Deviation

1.31
0.78
0.66
0.75
1.47
1.93
1.84
1.48
1.59

1.86
1.50
1.80
0.70
0.86
0.71
0.78
1.48
1.43
0.89
0.82
0.93
1.40
0.91

0.96
0.90
0.74
1.43
1.33

1.06
1.14
2.17
1.44
1.10
1.09
1.30
0.92
1.09
1.75
2.00
1.76

Skewness

-0.34
0.19
-0.11
-0.11
0.90
-0.02
-0.12
-2.80
-0.30

-0.63
0.17
-0.58
0.01
0.10
-0.38
0.21
-3.27
-1.97
0.14
0.56
-1.22
-0.29
0.62

-0.06
-0.05
-1.28
0.74
0.72

0.75
0.87
-1.52
0.08
0.27
0.15
0.27
0.87
0.29
-0.88
-1.16
2.11

Kurtosis

2.24
4.23
4.68
3.90
15.20
11.89
11.12
16.96
11.92
-
11.76
10.57
8.41
6.88
2.40
5.19
4.70
17.15'
13.92
3.20
3.18
4.94
1.49
2.14

3.22
4.15
5.48
2.23
2.80

3.60
3.51
13.00
12.41
2.49
3.00
1.97
4.08
2.66
8.70
10.25
21.59

Table 3

Sand, shell-gravel and mud weight percent for surface samples

Sample no.

S-1
S-2
S-3
S-4
S-5
S-6
S-7
S-8
S-9
S-10
S-11
S-12
S-13
S-14 Nc
S-15
S-16
S-17
S-18
S-19
S-20
S-21
S-22
S-23
S-24
S-25
S-26
S-27
S-28
S-29
S-30
S-31
S-32
S-33
S-34
S-35
S-36
S-37
S-38
S-39
S-40
S-41
S-42

Sample

Shell-
Gravel
0.00
0.12
1.42
0.01
3.27
0.18
4.68
15.19
1.11
6.36
20.77
2.77
0.08

0.08
13.88
0.48
0.88
1.67
1.67
.0.61
1.08
23.60
0.31
0.11
0.06
0.24
3.42
0.00
5.66
3.58
0.26
9.15
3.78
1.39
1.95
2.55
5.64
0.31
0.00
0.05
4.38

Sand

99.84
99.75
98.53
96.31
96.63
99.37
95.03
83.01
87.66
93.59
78.06
96.94
73.83

65.42
85.75
99.05
90.00
97.94
98.16
99.25
98.72
75.26
99.17
95.92
93.11
91.52
73.54
96.17
94.07
96.34
99.45
76.33
58.26
98.37
61.29
65.60
85.76
97.68
99.23
99.37
95.50

Mud

0.16
0.13
0.05
3.68
0.10
0.45
0.29
1.80
11.23
0.05
1.17
0.29
26.09

34.50
0.37
0.47
9.12
0.39
0.17
0.14
0.12
1.14
0.52
3.97
6.83
8.24
23.04
3.83
0.27
0.08
0.29
14.52
37.96
0.24
36.76
31.85
8.60
2.01
0.77
0.58
0.12

Table 3

Shell-
Sample No. Gravel Sand Mud

S-43 0.08 99.59 0.33
S-44 0.15 99.44' 0.41
S-45 13.82 85.38 0.80
S-46 0.18 96.55 3.27
S-47 0.04 97.62 2.34
S-48 5.85 93.78 0.37
S-49 33.96 65.80 0.24
S-50 67.41 31.60 0.99
S-51 14.80 83.82 1.38
S-52 24.87 73.73 1.40
S-53 1.97 96.29 1.74
S-54 3.54 95.97 0.49
S-55 1.46 97.59 0.95
S-56 0.00 98.82 1.18
S-57 38.77 60.69 0.54
S-58 39.38 60.16 0.46
S-59 31.21 68.50 0.29
S-60 61.55 38.35 0.10
S-61 67.17 32.76 0.07
S-62 8.89 90.85 0.26
S-63 25.15 73.90 0.95
S-64 0.07 98.66 1.27
S-65 55.61 44.10 0.29
S-66 7.05 92.65 0.30
S-67 15.02 84.56 0.42
S-68 0.01 98.45 1.54
S-69 0.37 99.24 0.39
S-70 5.87 93.45 0.68
S-71 1.35 98.43 0.22
S-72 8.56 91.36 0.08
S-73 3.11 96.67 0.22
S-74 21.62 78.27 0.11
S-75 11.63 88.25 0.12
S-76 9.27 90.58 0.15
S-77 0.71 99.11 0.18
S-78 0.18 99.82 0.00
S-79 0.33 99.52 0.15
S-80 62.49 37.40 0.11
S-81 45.25 54.66 0.09
S-82 1.30 98.56 0.14
S-83 0.37 99.28 0.35
S-84 0.35 99.48 0.17
S-85 .47 99.31 0.22
S-86 10.46 89.42 0.12
S-87 50.00 49.67 0.33
S-88 48.41 51.39 0.20
S-89 3.56 96.05 0.39
S-90 1.76 63.75 34.49
S-91 57.38 40.89 1.73
S-92 0.07 98.07 1.86
S-93 5.37 94.51 0.12
S-94 2.9 96.59 0.51

meter. The UNIBOOM was fired 3 times per second using a spark-

gap source box. This particular source produces a large post-

cursor and pre-cursor pulse, resulting in a significant bubble

pulse. The seismic signal was collected on an 8-element

hydrophone, and recorded both graphically and on a stereo VCR

(analog, magnetic tape as an archive).

The data are single-channel, analog data. No digital

processing was performed. Instead, the raw seismic data were

photocopied, studied and interpreted. Real reflecting horizons

were discriminated from multiples and highlighted. Equipment

failure about one third of the way through the cruise limited the

seismic coverage mainly to the Southeast Shoal off Cape

Canaveral.

RESULTS

Sand and Gravel

Percentages of gravel, sand and mud were plotted on maps of

the offshore Cape Canaveral area in order to show the

distribution of sediment, especially that which might be

desirable for the purpose of beach nourishment. Maps were made

for surface samples, upper core sections and lower core sections.

Gravel, sand, and mud percentages, along with grain-size analysis

data are listed in Tables 1 and 2 for vibracore samples and in

Tables 3 and 4 for surface samples. Weight percent carbonate of

the sand sized fraction for a portion of the Phase I samples is

shown in Table 5.

Because of the distinct geologic differences between the

Table 4

Granulometric data for sand fraction of surface samples

Sample No.

S- 1
S- 2
S- 3
S- 4
S- 5
S- 6
S- 7
S- 8
S- 9
S-10
S-11
S-12
S-13
S-15
S-16
S-17
S-18
S-19
S-20
S-21
S-22
S-23
S-24
5-25
S-26
S-27
S-28
S-29
S-30
S-31
S-32
S-33
S-34
S-35
S-36
5-37
S-38
S-39
S-40
S-41
S-42
S-43
S-44
S-45
S-46
S-47

Mean grain
size (phi)

1.71
1.25
1.46
3.32
1.65
1.85
1.45
1.60
3.69
1.39
1.31
1.26
3.38
3.16
0.89
1.53
3.12
1.58
1.16
1.48
1.33
0.85
1.93
3.42
3.59
3.66
3.62
3.52
1.05
1.78
2.13
3.17
3.52
1.78
3.20
3.49
3.49
3.52
3.25
2.38
1.33
1.29
1.61
1.24
3.51
3.46

Standard
Deviation

0.34
0.55
0.50
0.58
0.61
0.54
0.56
0.77
0.38
0.61
0.84
0.76
0.54
0.63
0.75
0.67
0.77
0.63
0.64
0.56
0.55
0.83
0.55
0.50
0.46
0.38
0.52
0.37
0.83
0.62
0.73
0.95
0.79
0.69
1.21
0.82
0.50
0.41
0.59
0.41
0.82
0.48
0.53
1.10
0.46
0.40

Skewness

-0.96
-0.32
-1.02
-1.19
-0.78
-0.88
-0.94
-0.12
-3.99
-1.09
0.09
-0.38
-1.83
-1.57
0.01
-0.33
-1.42
-0.72
-0.56
-0.99
-0.86
0.16
-0.80
-1.31
-3.21
-3.12
-4.19
-2.26
0.05
-0.98
-0.38
-1.87
-3.37
-0.28
-2.12
-2.99
-3.95
-2.69
-1.04
-0.11
-0.36
-0.48
-0.69
0.57
-2.55
-2.74

Kurtosis

6.35
4.01
5.05
5.15
4.13
6.33
4.82
3.97
34.54
4.32
3.42
3.16
10.29
7.41
3.18
4.08
5.88
3.92
3.10
4.64
4.37
2.72
5.85
5.75
20.52
22.46
28.36
17.27
2.78
5.43
4.12
6.49
15.17
4.22
6.36
12.78
27.23
20.17
4.33
8.81
2.55
5.22
4.86
3.25
15.12
19.59

7 r

Table 4

Sample No.
S-48
S-49
S-50
S-51
S-52
S-53
S-54
S-55
S-56
S-57
S-58
S-59
S-60
S-61
S-62
5-63
S-64
S-65
S-66
S-67
S-68
S-69
S-70
S-71
S-72
S-73
S-74
S-75
S-76
S-77
S-78
S-79
S-80
5-81
5-82
S-83
S-84
S-85
S-86
S-87
S-88
S-89
S-90
S-91
S-92
S-93
S-94

Mean grain
size (phi)
0.89
0.80
1.34
0.85
1.50
1.77
1.23
1.10
3.26
0.96
0.61
1.05
-0.09
-0.06
0.37
1.84
2.84
0.59
1.06
0.96
3.47
2.02
1.72
1.71
1.14
1.36
0.82
0.99
0.97
1.64
1.38
1.33
0.22
0.21
1.51
1.56
1.75
1.89
1.21
0.63
0.15
1.36
1.25
1.01
1.26
1.45
1.58

Standard
Deviation
0.54
0.69
1.53
0.96
1.26
1.21
0.70
0.81
0.38
0.70
0.83
0.95
0.50
0.53
0.55
1.43
0.73
0.73
0.76
0.76
0.51
0.46
0.79
0.59
0.75
0.68
0.75
0.85
0.82
0.59
0.48
0.51
0.64
0.68
0.57
0.68
0.50
0.54
0.76
0.76
0.55
0.55
0.75
1.35
0.57
0.79
0.65

Skewness
0.14
-0.62
0.34
1.08
0.43
0.60
0.60
1.31
-2.83
0.97
1.03
1.09
1.67
1.22
3.41
0.39
-0.98
0.40
-0.23
-0.33
-3.95
-1.42
-1.09
-1.38
-0.43
-0.82
-0.23
-0.16
-0.11
-1.05
-0.79
-0.78
0.49
0.98
-0.70
-0.40
-1.31
-1.00
-0.67
0.23
0.48
-0.89
0.47
0.93
-1.72
-0.36
-0.87

Kurtosis
6.22
2.94
1.77
4.93
2.22
2.12
5.79
6.27
20.32
6.63
5.20
4.01
11.51
7.01
20.57
1.64
3.77
4.11
2.54
2.50
25.15
7.53
4.03
5.75
2.71
3.48
2.28
2.04
2.29
4.63
4.59
4.44
3.33
5.24
4.77
3.61
6.05
5.53
2.74
3.58
3.90
5.08
5.40
2.95
8.53
2.76
4.19

Table 5

Weight percent carbonate of the sand-sized fraction for
selected (whole core) repository samples from Phase I.

U.S.G.S. Weight %
Sample No. CaL,

1-2 46.27
9-1 7.87
14 14.40
18-1 36.32
19-1 32.45
20-1 39.55
20-2 39.36
35-1 32.90
36-1 38.89
37-1 39.96
40 5.39
46-1 10.38
48-1 27.64
48-2 29.40
49-1 22.38
49-2 31.85
50 27.15
51-1 41.38
57-1 28.87
66-1 50.54
76-1 27.03
77-1 26.94
77-2 32.32
80-1 24.42
82-1 36.91
82-2 33.23
83-1 36.24
89-2 39.70
91-2 46.60
95 42.02

surface and vibracore samples, each is treated separately in

discussing sediment characteristics. The surface samples

represent only the upper few centimeters of sediment and

therefore are in equilibrium with modern shelf processes. The

vibracore samples, on the other hand, are up to 1.5 m in length

and thus represent a range of geologic time and depositional

environments.

Surface Samples

The 93 surface samples collected are predominantly sand and

gravel rich. Twenty samples have greater than 15% shell gravel,

12 of which are greater than 30%. Thirteen samples have greater

than 5% mud.

Sand

Sand-rich areas (Figure 4) correspond roughly to the shoal

areas. Virtually all of Southeast Shoal, with water depths less

than 30 feet, is >90% sand. Most samples from this shoal have

greater than 95% sand. Chester Shoal, the shore-attached shoal

to the north of the cape, as well as several isolated, offshore

shoals are also sand-rich. Figure 4 emphasizes the wide

distribution of sediment with >90% sand. Virtually the entire

sample area has >70% sand.

Gravel

The most extensive shell-gravel rich zones of surface

samples are found close to shore, generally north of the cape

(Figure 5). Minor concentrations of shell material are

S 3 NM
0 3km
6_-_A 1

'"S B >90% Sand

Bathymetric Contour (feet)

Fig. 4: General distribution of sand-rich surficial sediment.

associated with some of the offshore shoals.

Mud

On the whole, the surface samples have small percentages of

mud. The only area of significant size that has >5% mud is

located along the southern flank of Southeast Shoal (Figure 6).

Regions with less than 5% mud correspond roughly to the two main

shore-attached shoal bodies where sand percentages are high.

Vibracore Sections

Sediment distribution for the core samples has been analyzed

for the upper vs. the lower 1.5 m core sections. In this manner,

a regional picture of sediment distribution with depth can be

developed.

Sand Uoper Core Section

Sand distribution for the upper core-section samples is

divided into two categories; >90% sand, and 70- 90% sand (Figure

7). Much of the top meter and a.half of sediment in the study

area is characterized by sandy sediment, with significant areas

on several shoals having >90% sand. The grain size distribution

for the upper core sections is shown in Figure 8.

Gravel Upper Core Section

The highest percentages (>30%) of shell-gravel in the upper

core sections are found parallelling the shore off of False Cape

to the north of the true cape (Figure 9). Surface samples in

this same area are also gravel rich.

28.66

0 3 NM
0 3km
6-&--L-

a

U"'" >30% Gravel 15-30% Gravel

Bathymetric Contour (feet)

Fig. 5: General distribution of shell-gravel-rich surficial
sediment.

27

Fig. 6: General distribution of mud-rich surficial sediment.

Fig. 7: General distribution of sand-rich sediment in upper
section of vibracores.

29

Fig. 8: Distribution of mean grain size (phi) for the upper
section of vibracores.

30

Fig. 9: General distribution of shell-gravel-rich sediment for
the upper section of vibracores.

31

Mud Upper Core Section

Figure 10 shows areas with >5% mud. It can be seen that the

major areas with muddy sediment lie primarily in deep (>30 ft.)

water down drift of Chester Shoal and downdrift of, and along the

flanks of Southeast Shoal.

Sand Lower Core Section

Areas with >90% sand are still associated with shoal bodies,

but are not as regionally extensive as those of the upper core

sections (Figure 11). Overall, the Southeast Shoal appears to

have the greatest quantity of sand-rich sediment, with a minimum

3 m mantle of sediment covering much of the shoal that is at

least 70% sand, and much of it >90% sand. The grain-size

distribution for these samples is shown in Figure 12.

Gravel Lower Core Section

The main shell-gravel-rich zone is a band which parallels

the coastline offshore of False Cape (Figure 13). This same area

is also gravel-rich in the upper core sections and in the surface

samples, suggesting a long-term accumulation of shell gravel.

Mud Lower Core Section

Both Southeast Shoal and Chester Shoal are associated with

regions which have >5% mud (Figure 14). As.with the upper core

sections, this corresponds to areas in relatively deep water,

down drift of Chester Shoal and along the flank of Southeast

Shoal. Overall, sediments are slightly more muddy in the lower

Fig. 10: General distribution of mud-rich sediment for the
upper section of vibracores.

S>90% Sand 70-90% Sand

/ Bathymetric Contour (feet)
Fig. 11: General distribution of sand-rich sediment in the
lower section of vibracores.

Fig. 12: Distribution uf mean grain size (phi) for the
lower section of vibracores.

35

Fig. 13: General distribution of shell-gravel-rich sediment
for the lower section of vibracores.

36

Fig. 14: General distribution of mud-rich sediment for the
lower section of vibracores.

37

core sections than in the upper.

Heavy Minerals

The results of the heavy-mineral analysis are detailed in

Table 6.

DISCUSSION

Sand and Gravel

It can be seen from a comparison of the sediment

distribution maps that some areas show relatively constant trends

with sediment depth. Sand distribution between upper and lower

core sections (Figures 7, 11) shows part of Chester and Southeast

Shoals to contain very sandy (>90%) sediments to a depth of at

least 3 m. Overall, the upper 1.5 m of sediment in the Cape

Canaveral is more sand-rich than the lower 1.5 m of sediment.

The gravel portion of all samples is dominated by shell

material. It consists of both whole and broken shells, along

with minor amounts of lithic fragments (limestone and phosphate).

The gravel fraction ranges between approximately 1 and 60 weight

percent of the samples analyzed, averaging approximately 13.5

weight percent (Tables 1 and 3).

Gravel distribution is quite similar between the upper and

lower cores (Figures 9, 13). There is apparently a zone of very

shell-gravel-rich sediment running shore-parallel for about 10 km

just offshore of 2alse Cape.

Mud-rich zones occupy non-shoal areas in both upper and

lower core sections (Figures 10, 14). The area between Chester

and Southeast Shoals is mud-rich, as is an area farther offshore.

TABLE 6

Heavy mineral (>2.96 specific gravity) content of 84 core samples

from offshore of Cape Canaveral, Florida (P, present but less

than .01%; N, none determined; THM, total heavy minerals; RHM,

recovered heavy minerals).

Footnotes:

1: includes leucoxene (altered ilmenite)

2: aluminosilicates (may include sillimanite, kyanite,

andalusite)

3: may include magnetite, phosphorite, sulfides, unidentified

grains, coated grains, spinel, quartz, etc.

4: sum of economically valuable heavy minerals (ilmenite,

rutile, zircon and monazite)

8ULK
DEGREES DEGREES CORE SPI.MPE MEIGN
LOiOITUDE LATITUDE LENGTH EIGHT PERCENT
UNEST) NORTH) (cH) (g) ORAVEL

IUSS CERC
CUME CORE

-00.33040
-00.36950
-*.47730
-00.57010
-30.5412W
-80.51000
-0.5F700
-00.54300
-90.55390
-B0.55390
-60.52590

-10.44750

-90.44550

-40.4102

-80.4210
-30.4P0M

-00.36630
-0.319410

-0.37950
-80.34900
-90.3350

-W.433630

-00.46050
-30.40240
-10.51410
-1.52300
-W.51410

-00.45120

-:0.53380
-0.503590
-00.41320
-80.4570w

16502
10725
4313
3405
7491
9000
24976
15425
7710
12031
12485
lam2
13099
7996
t165
17252
250BM
24323
23633
14902
12939

10669
13047
14753
11004
14755

998
19295
16452

13299
17252
17252
11319
19305

12252
15697
17627
23105
1737

17.01
18.78
14.30
16.39
16.70
19.65
12.59
3.35
2.59
7.74
3.39
2.26
6.72
0.52
6.7?
4.24
4.63
12.69
14.29
3.74
0.60
10.41
16.41
19.47
20.20
26.65
32.92
16.45
14.24
5.41
2.25
12.69
6.93
1.74
14.34
19.57
7.01
0.06
11.53
6.09
35,16
2.19
10.97
3.29
S. 76

EIGHT PERCENT
HEWN HINERRLS
TOrl. RECOVERED
(

0.12
0.17
0.30
0.23
0.25
0.22
0.14
0.34
0.14
0.10
0.5
0.96
0.52
0.16
0.36
0.20
0.11
0.13
0.15
0.22
0.36
0.07
0.22
0.10
0.06
0.05
0.05
0.42
0.20
0.07
0.21
0.24
0.13
0.12
0.22
0.19
6.30
0.98
0.67
0.16
0.19
0.47
0.53
0.20
1.06

0.11
0.14
0.09
0.12
0.22
0.13
O.06
0.24
0.09
S0.10
0.21
0.50
0.34
0.15
0.20
0.16
0.10
0.12
0.13
0.16
0.15
0.05
0.11
0.09
0.05
0.04
0.04
0.40
0.23
0.04
0.14
0.17
0.09
0.00
0.10
0.16
2.09
0.73
0.1
0.10
6.14
9.25
6.39
0.18
0.49

PERCENT PERCENT PERCENT PERCENa PERCENT PERCENr PERCENT
EPIDOrE GtIMEf PYRBOLES ILIENIrE1 rOURRLINE STAUIOLITE ALSII2

37.0 3.0
35.7 35.8
22.' 27.5
29.9 31.6
24.7 25.0
27.9 27.9
41.6 41.9
31.4 31.3
23.2 23.5
21.S 22.2
20.0 20.4
32.2 31.0
31.6 31.8
35.2 35.3
27.0 26.6
21.3 21.0
40.6 40.8
37.9 30.0
26.9 26.5
22.5 22.6
24.6 25.5
32.2 32.3
23.4 23.4
27.9 28.0
33.7 34.0
29.7 30.2
26.6 27.3
1.1 I1I.1
21.6 21.4
19.3 20.0
22.1 21.9
32.6 32.7
20.0 1.95
31.2 31.4
20.6 20.?
10.1 10.1
4.9 34.6
20.5 20.5
16.6 17.2
19.6 19.0
20.2 20.4
32.0 32.0
32.0 31.9
23.6 23.8
30.5 29.9

28.370%
28.35790
20.35630
28.35630
28.36130
28.37050
20.30500
20.39288
20.41635
20.43635
20.41434
20.40066
20.36515
28.37344
20.37920
20.38537
28.40561
20.40561
28.4499
20.42395
28.43034
20.40007
20.44750
28.4057
20.39993
20.42940
28.47903
20.46304
28.44071
20.50503
28.50534
20.51752
20.51423
20.40936
28.48004
20.48624
20.49930
21.50300
20.51109
29.51550
28.52759
20.S4242
29.53741
29.$3331

3.0 3.0
3.2 3.1
2.1 2.6
3.7 2.6
2.7 2.6
3.4 2.0
2.4 2.3
1.5 1.6
3.2 3.3
1.9 2.0
3.9 4.1
2.1 2.2
2.1 2.1
3.7 3.6
2.7 2.7
6.6 6.7
4.0 3.0
3.2 3.1
2.9 2.0
4.0 4.0
1.5 1.5
5.3 5.3
6.1 6.3
4.6 4.6
6.0 6.0
6.2 6.1
3.2 3.0
3.7 3.7
6.4 6.5
12.5 12.5
6.7 6.5
3.0 3.0
S.1 4.9
6.0 6.7
6.4 6.3
3.3 9.4
1.0 1.0
1.0 1.1

3.9 4.4
3.6 3.0
5.0 5.0
0.7 0.7
2.0 2.9
5.2 5.1
2.9 3.0

PERCENT PERCENT PERCENT
ZIRCON RUTILE IIOIRZITE

rM Rm rim lm RIM 1M RIM OM rim Ri TM R II tW mi TI Mrl TlI RI Tim M TMI mRI

10.5 10.4 6.5 6.5
13.0 13.0 5.3 5.3
26.2 17.4 5.4 6.7
12.9 10.0 0.2 0.6
10.5 9.0 7.9 7.9
9.1 7.9 6.1 6.2
5.? 5.6 0.1 0.0
16.9 17.0 5.4 5.4
10. 5.? 10.6 10.7
14.9 12.3 7.6 0.0
11.3 0.0 10.2 10.4
12.9 12.9 6.5 6.5
13.2 13.3 7.2 7.2
12.6 12.7 4.1 4.1
10.4 10.7 0.3 0.4
6.6 6.2 12.9 12.9
11.3 11.2 5.3 5.3
13.6 13.5 6.1 6.1
9.9 9.8 10.0 10.1
13.0 12.5 0.1 8.2
16.5 14.4 0.0 0.6
7.6 7.6 9.2 9.3
9.1 7.5 9.1 9.2
7.7 7.5 0.4 0.5
0.1 7.4 6.0 6.0
9.4 9.0 7.9 8.0
0.0 7.0 7.2 7.3
6.0 5.9 8.1 0.1
0.5 0.1 11.7 11.8
9.6 0.8 7.6 7.7
11.0 II.n 6.0 6.0
9.1 9.1 4.7 0.7
5.4 5.4 9.2 9.2
6.0 5.7 4.0 4.8
12.9 12.4 7.0 7.0
10.2 10.0 11.0 11.0
7.0 7.9 0.6 0.6
10.5 10.5 12.6 12.6
10.3 13.6 9.4 10.5
tO.6 0.3 .10.1 0.2
11.4 10.9 10.7 10.6
9.3 9.3 3.9 9.0
3.9 0.0 0.5 0.9
7.6 7.S 11.7 tl.9
11.6 12.0 9.4 9.6

PERCENT PERCENT
OTFIERS l EMH4

.;;;;;:ss; = --=-======5=f=l======S SU U =5 =5 = == 5g=S == S

4.6 4.6 21.1 21.2
6.5 6.4 24.1 24.4
3.9 3.1 23.6 29.7
6.2 6.2 20.5 22.9
7.2 7.3 29.0 30.2
5.7 6.0 22.4 23.9
12.4 11.6 15.6 16.2
13.7 13.5 24.2 24.5
4.4 4.4 20.1 20.6
10.9 II.2 26.3 27.7
7.5 7.6 26.7 20.2
10.4 9.6 29.7 30.7
5.9 S. 29.5 29.0
3.9 3.9 25.6 25.7
4.1 3.2 29.6 30.5
2.0 1.5 25.6 26.4
3.9 3.9 19.3 19.9
3.0 3.0 22.4 22.5
3.0 3.0 7.5 27.7
4.9 5.0 23.3 23.6
5.5 5.1 2.5 30.7
1.3 3.3 10.6 19.0
2.0 2.0 26.5 20.2
3.5 3.5 25.0 25.2
4.6 4.6 16.5 16.7
2.1 2.2 21.3 21.3
22. .0 21.8 22.3
5.5 5.S 36. 36.7
2.0 2.0 27.1 27.6
4.3 4.3 20.0 20.3
4.0 4.9 21.9 22.3
5.0 7.0 25.5 26.9
2.5 2.5 28.4 2.7
5.1 5.2 1.5 15.7
1.7 1.7 25.4 25.6
7.0 7.0 25.4 25.6
7.6 7.3 30.7 31.0
1.5 6.3 31.9 32.2
5.2 5.5 21.3 24.4
S.5 S., 25.5 26.2
2.0 2.9 31.0 31.6
10.3 9.9 20.6 29.2
11.2 10.9 24.5 24.9
3.3 3.3 23.5 20.7
7.2 5.6 27.2 20.8

I

I

-----------

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

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

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

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

--

TIN Ri
zzriMmmmnmz
5.7 5.S
4.5 4.3
5.2 5.3
2.6 2.9
0.8 0.7
2.4 2.3
3.0 3.0
2.6 2.S
3.0 2.9
2.1 2.6
3.4 3.4
2.4 2.4
1.7 1.6
4.0 3.9
3.2 3.1
3.7 3.6
3.4 3.2
2.7 2.6
4.4 4.3
3.2 3.2
3.0 3.6
4.1 3.6
4.0 4.0
5.5 5.4
0.3 0.2
10.2 9.6
12.0 12.0
2.1 2.1
I.5 1.5
5.4 5.2
5.2 5.2
4.2 4.0
4.5 4.3
6.5 6.2
3.0 3.0
5.9 5.9
2.8 2.7
3.9 3.1
4.4 4.7
7.6 7.4
2.6 2.1
6.1 5.6
4.6 4.6
3.3 3.3
4.4 4.1

PULAK

0.04 34.0
0.06 39.3
0.0S SO.0
0.04 35.0
0.10 43.9
0.05 3.4
0.0 27.4
0.11 3.5
0.04 41.5
0.04 42.2
0.09 40.4
0.23 45.6
0.16 46.
O.06 41.6
0.10 52.7
0.06 3.6
0.03 34.2
0.05 35.1
0.05 3.?
0.06 39.?
0.07 40.9
0.02 36.
0.04 41.0
0.03 37.5
0.01 92.2
0.01 35.5
0.01 35.6
0.31 44.5
0.10 40.
0.01 32.2
O.06 39.2
0.06 30.2
0.04 41.4
0.02 25.6
0.00 45.
0.6 38.2
0.4 42.2
0.35 45.2
0.07 40.7
0.94 36.9
6.07 40.2
0.10 40.4
0.14 36.2
.07 40.5
0.21 43.0

__+

2.4 P P
2.0 P P
2.9 N N
2.1 P P
3.5 0.41 0.42
6.4 0.07 0.07
1.6 P P
1.9 P P
3.2 N N
2.2 P P
3.4 P P
2.2 P P
3.5 P P
3.4 P P
3.5 0.01 0.01
6.0 P P
3.2 P P
3.6 P P
2.2 P P
3.4 0.p1 0.20
3.0 N N
9.0 P P
5.3 0.06 0.06
4.0 P P
5.1 P P
4.7 P P
5.5 N N
1.9 P P
5.2 N N
3.0 0.12 0.13
6.0 P P
2.2 P P
7.3 P P
4.2 P P
7.7 P P
2.6 P P
3.2 P P
2.5 P P
2.7 P P
3.9 P P
5.5 P P
1.9 P P
2.5 P P
4.3 P P
2.3 P P

US65 CERC DEGREES
CORE CORE LONGITUDE
NUIIIR NUHIER ( .... L-n=sms== ====
50 175 -80.44670
51 150 -00.42160
52 151 -00.42540
53 174 -90.44230
54 152 -80.43060
57 120 -80.33330
58 142 -80.33260
59 131 -80.34060
60 143 -80.34630
61 144 -00.38360
62 148 -80.38360
63 127 -60.54420
64 147 -60.39410
65 146 -80.40004
66 139 -80.4204
69 171 -80.46990
70 172 -00.45830
72 153 -90.44110
73 173 -80.44650
74 167 -80.48900
75 168 -80.49520
76 165 -80.51280
77 166 -80.53220
70 128 -80.55530
79 159 -80.52430
80 169 -00.51400
81 151 -80.33040
82 157 -80.52740
83 156 -80.52300
4 170 -80.49440
85 155 -80.47290
87 138 -80.44920
w8 137 -80.44290
89 136 -80.44770
90 135 -0.42580
91 134 -90.39890
92 133 -80.30210
93 1328 -80.33620
95 132 -90.33400

BULK
DEGREES CORE SAMPLE EIGHT
LATIrTUDE LENGTH UEGiIGH PERCENT
NORTHI) cn>) (9) GRA EL

28.53719
20.53574
20.54766
28.55765
28.56209
28.55056
28.50720
28.61090
20.62227
28.63447
28.59251
28.55093
28.61413
28.62803
28.61087
28.62639
28.60067
28.59197
28.57220
28.59234
20.59682
20.56380
20.56517
28.58314
28.59793
28.61995
20.37096
20.63113
20.64940
20.66197
20.65940
28.65493
20.67430
20.68740
20.67579
20.69793
28.72486
20.71490
20.71640

9424
15217
6810
6810
12031
17037
10215
17933
5448
10215
9307
12939
22978
8031
20981
13847
10442
14755
4313
7264
6356
25691
29376
16344
23188
19105
19733
20500
23518
19618
14927
26303
21330
23640
13004
26301
13166
0393
2928

0.89
3.90
0.24
16.87
16.39
5.65
10.23
8.64
8.41
28.04
6.29
7.23
17.57
14.26
7.15
12.39
14.46
22.74
17.97
18.79
23.13
3.58
4.52
34.32
12.69
12.12
16.00
9.10
19.00
37.34
14.65
32.39
17.00
24.34
26.51
11.05
30.14
6.10
0.85

UEIOHr PERCENT
HERUW HIIERALS
TOTAL RECOVERED
(cH) (cRm)

PERCENT PERCENT PERCENT PERCENT PIERCE PER CENT PERCETRCENr PERC PERCENT PERCENT PERCE EENT
EPIDOTE GARNET PVROOOLES ILEMNITE1 TOURIIALINE STRUROLITE ALSIL2 ZIRCON RUTILE IONZITE OTHERS EnM4

rm Rim rnil m ru RiM Tim RIii rTi RIm I r TM r RI rm R Rm
. . . . . . . . . . . . .

flu. -1-1 S ~l-=1- ==

28.1 28-3
19.7 19.7
20.7 20.7
25.1 24.9
31.6 19.0
33.8 33.9
24.7 24.4
24.4 24.5
24.9 25.1
23.4 23.6
21.6 21.6
22.9 22.9
28.5 28.5
32.2 32.3
15.4 15.4
24.4 24.5
26.8 26.9
17.4 17.6
21.5 21.7
16.6 16.9
23.3 23.6
23.1 23.0
17.0 17.0
16.6 16.9
27.0 27.0
26.1 25.9
31.0 31.1
32.1 32.3
20.2 20.3
32.0 32.6
31.7 31.8
30.0 31.1
23.7 23.8
34.5 34.6
33.1 33.2
35.9 36.1
28.3 29.0
24.7 25.2
34.0 34.2

2.0 8.4
5.3 3.5
5.9 1.4
2.3 3.4
9.7 1.1
1.0 12.6
4.0 4.6
5.6 4.0
3.9 9.0
3.6 4.6
2.7 2.1
4.5 3.4
2.0 7.7
3.5 4.6
9.0 2.1
7.4 4:4
3.7 2.5
8.5 2.4
4.1 2.3
10.9 1.0
9.3 5.9
2.1 3.2
5.4 2.5
14.1 3.0
2.5 3.5
2.4 4.3
1.5 7.3
3.0 5.6
8.3 3.0
4.4 5.0
4.9 6.5
5.0 3.5
7.6 2.2
5.5 5.7
6.2 4.6
6.5 6.0
3.5 0.6
5.9 2.9
2.5 13.0

23.0 23.1
23.8 23.9
17.8 18.0
26.0 26.8
26.3 26.9
25.4 25.7
19.8 20.0
21.1 21.6
21.7 21.9
17.0 10.0
26.2 26.2
33.2 33.5
27.6 27.0
25.5 25.7
23.8 23.0
20.4 20.5
23.8 24.0
23.9 24.6
22.1 22.3
21.3 21.9
19.6 19.9
29.3 29.7
29.1 29.2
22.2 22.6
33.8 33.8
31.5 31.9
30.8 31.3
24.4 24.5
35.5 35.0
27.6 28.1
23.8 23.9
24.4 24.0
26.7 27.0
23.2 23.3
24.4 24.9
20.4 20.7
17.1 17.5
25.0 25.0
22.3 23.0

5.3 5.3
7.0 7.0
14.0 14.4
7.2 .7.2
7.3 7.2
1.1 1.1
0.2 0.0
7.3 7.2
7.5 7.5
11.2 11.2
0.2 8.2
3.9 3.9
3.6 3.7
3.8 3.8
7.6 7.6
9.1 9.1
0.1 8.0
11.1 10.9
11.2 11.2
9.1 9.2
10.2 10.3
4.5 4.4
5.6 5.5
6.4 8.5
3.4 3.4
2.1 2.1
2.2 2.2
4.6 4.5
5.4 5.2
3.6 3.4
3.2 3.2
3.7 3.5
4.5 4.4
3.5 3.5
3.5 3.4
2.8 2.6
S.S 5.3
5.9 5.8
3.6 3.2

0.4 8.0 9.3 9.3
11.0 10.0 7.3 7.3
7.4 7.5 5.5 5.5
15.2 14.4 9.4 8.7
6.1 5.1 12.2 12.3
9.1 9.2 9.1 9.1
0.0 0.1 1u.4 10.5
0.5 0.1 '..0 9.1
10.0 9.8 d.6 8.7
11.0 10.5 7.0 7.9
15.0 15.0 6.0 6.0
11.2 10.9 7.2 7.2
11.1 11.2 8.4 0.4
10.3 10.3 7.0 7.0
7.2 7.1 5.0 5.0
5.9 5.5 0.6 0.6
6:4 6.2 9.3 9.3
10.0 9.2 7.6 7.7
8.5 0.1 0.7 0.8
11.5 10.1 5.0 4.9
11.1 10.2 4.7 4.7
8.7 0.7 14.1 14.2
0.1 0.1 11.2 11.3
6.5 7.5 6.7 6.7
8.1 8.1 10.6 10.6
9.0 9.0 13.2 13.3
11.0 10.0 7.9 0.0
10.7 10.7 8.0 8.1
7.2 7.2 4.0 4.0
6.8 6.9 10.0 10.1
10.2 10.1 6.8 6.0
9.6 0.6 12.0 12.0
9.1 8.9 7.9 7.9
7.7 7.6 9.0 9.0
8.0 0.0 10.1 10.2
10.8 10.8 6.1 6.1
4.3 3.4 10.4 10.5
7.2 5.9 11.9 12.3
8.6 8.5 7.5 7.6

rHn RHri THI RHM rmH ROM

3.7 P P
5.0 P P
7.5 0.19 0.19
2.1 N N
6.5 P P
2.3 P P
4.0 N N
5.7 N N
3.6 P P
3.5 N N
4.2 N N
4.7 P P
2.4 P P
3.0 P P
7.2 P P
5.4 2.54 2.56
5.9 N N
4.7 P P
6.0 P P
6.1 1.94 2.00
2.9 0.04 0.04
3.4 P P
7.1 0.02 0.02
9.0 0.07 0.07
4.0 0.02 0.02
3.2 P P
2.6 P P
2.8 P P
3.5 0.05 0.05
2.6 P P
2.9 P P
2.9 P P
7.5 P P
2.4 P P
2.5 P P
2.6 P P
6.7 P P
7.0 N N
2.5 P P

BULK RHI
mmumu====
0.08 34.0
0.06 39.7
0.02 33.2
0.02 43.3
0.04 30.5
0.14 37.2
0.01 32.9
0.02 35.4
0.03 35.3
0.04 32.0
0.04 45.4
0.08 49.0
0.10 41.4
0.05 39.0 -
0.04 38.1
0.03 34.0
0.04 36.1
0.01 38.4
D.02 37.3
0.05 40.1
0.06 33.0
0.11 41.9
0.11 44.4
0.02 39.1
0.18 45.9
0.13 44.1
0.09 44.?
0.06 37.9
0.37 46.6
0.04 37.6
0.05 36.9
0.02 36.3
0.05 43.4
0.04 33.3
0.03 35.2
0.03 34.1
0.06 27.6
0.02 38.?
0.05 33.9

POPULATION STATISriCS
illNIIUnl
RVERnGE

STD DEV

2928 0.05
14850 13.29
29011 37.34
6561 0.75

0.05 0.03
0.26 0. 1
1.38 1.09
0.25 0.17

11.1 11.1
26.4 26.6
41.6 41.9
6.3 6.3

0.7 0.? 0.6
5.2 5.3 5.0
21.4 21.S 13.?
3.2 3.3 2.9

15.5 15.7
24.9 25.5
36.5 36.7
4.3 4.4

0.7 0.7
5.0 5.O
.14.0 14.4
2.8 2.8

1.0 1.0
6.2 6.2
14.9 15.0
3.5 3.6

4.3 3.4 4.1
10.2 9.6 0.4
26.2 10.7 14.1
3.3 2.0 2.2

1.6 <.01 <.01
4.1 <.01 <.01
9.8 2.54 2.56
1.8 <.01 <.01

0.01 25.6
0.07 39.2
0.46 52.7
0.08 5.2

=========== m

" ^ ^

" ^

-- --

+

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

The region of muddy sediment seen to the south of Southeast Shoal

for upper core sections (Figure 10) is probably also mud-rich for

the lower core sections but most of the cores in that area did

not have a lower section.

Seismic Survey

A total of 174 km of high resolution seismic lines were run

offshore of Cape Canaveral, mostly across the Southeast Shoal

area (Figure 15). Four significant stratigraphic relationships

were revealed by the seismic survey. They are:

(1) The Hawthorn Group (Miocene) lies within 20 meters of

the sea-floor throughout the study area (Figure 16).

(2) Reflectors within the carbonates of the Ocala Group

show significant deformation (below about 80MS; Figure 16).

(3) An unconformity of unknown age is found as an undulate

boundary at a depth of about 18-22 m below sea-level (i.e. just

below the 20 millisecond time-line in Figure 17). More

importantly, this unconformity crops out directly on the sea-

floor throughout much of the survey area not covered by shoal

sands (Figure 17).

(4) The large sand bodies forming the shoals offshore of

Cape Canaveral appear to be relict features. They may even be

composed of older (Pleistocene) stratigraphic sections.

The Hawthorn Group is easily identified by a very strong

reflector at about minus 40 milliseconds (about 35 m) (Figures 16

and 17). It appears throughout the survey area. The internal

stratigraphy within the Ocala Group displays numerous folds

Fig. 15: Plotted track lines for seismic survey. Locations
of seismic sections in Figures 16, 17 and 18 shown.

43

NORTHEAST

I0

50 eo *ao ,, *",' '-." -.,-J, t.
4. *.. .

A r val cale

RFlletlors within the Ocala Group carbonatei
Kilomners

Fig. 16: Seismic profile of a portion of a sand shoal
showing a sub-bottom channel, a shallow sub-bottom
unconformity and the bubble pulse. Note the deformed
Ocala Group carbonates at the bottom of the section.

SOUTHWEST

Sca-Level

Kilomeimr

Fig. 17: Seismic profile of a portion of a sand shoal,
interpreted section on bottom. Note the emergence of
the unconformity on the sea floor.

EAST
0 is

WEST

0 mR

Alppoximale Vcallcal Scalc
in mIulas
using 1700U mnlcartcond

indicating that this section has experienced dissolution and

concomitant collapse (i.e., solution-tectonics). The section

overlying these Eocene carbonates is undeformed (Figures 16 and

17). This implies that the dissolution events primarily occurred

prior to deposition of the overlying sequences.

The unconformity found to crop out on the seafloor is

characterized by several channels (Figure 17), which are probably

fluvial in origin. This interpretation is based on the

geometries exhibited in the subbottom data and size-similarity to

modern coastal fluvial systems. The age of the unit underlying

this unconformity is unknown. A portion of the heavy minerals

present may be due to reworking of this stratigraphic unit.

The internal stratigraphy of the large sand bodies was

masked by the large bubble pulse throughout the survey. No

significant reflectors were identified within these features

(Figures 16 and 17). They appear to be relict features because

small sand waves were found on top of the large sand bodies

(Figure 18). This implies that active sand transport in the form

of migrating sand waves occurs over the large sand bodies, and

that the large features are either dormant sand bodies or

coherent Pleistocene stratigraphic sections which have escaped

shoreface erosion. Unfortunately, the seismic data were not able

to differentiate which scenario is more probable.

Heavy Mine:-als

The average total heavy-mineral (THM) content of the 140

samples from offshore of Cape Canaveral is 0.26 weight percent;

the recovered heavy-mineral (RHM) content averages 0.18 weight

SOUTH
20 ms

40il

60 111S

s

M MN;-.A I Mit2
J'ske^it a... ^^^^^Bottom S

Approximaic Veical Scale
in mclus
using 1700 mncrcsccond
subbontom velocity

Fig. 18: Seismic profile of a portion of
shows small, active bedforms on
inactive shoal bodies.

a sand shoal.
top of older,

Relict Bedforms

NORTH

40ms

some

Kilometers

Inset
possibly

!

Bubble ulse

smie

percent (minimum, average, maximum and standard deviation values

are given in Table 6 Population Statistics). About 75 percent,

on the average, of the THM was recovered by the methods described

in an earlier section. Individual samples were more (or less)

susceptible to the recovery of their heavy-mineral content by our

methods of recovery: some heavy-mineral species, specifically

the aluminosilicates, were less likely to be recovered by the

spiral concentrator because of their poor hydrodynamic shape.

Data for individual mineral species expressed as percentages of

the RHM and THM are given in Table 6. Table 7 summarizes values

for THM and RHM for all samples and also according to depth

interval (either upper or lower 1.5 m section). The data for

individual sections for the Phase I study are given in Nocita et

al. (1989a) Grosz et al. (1989a), and Kohpina (1989). The data

and population statistics included in this report for the entire

sample population are on a whole core basis (Table 6). The

heavy-mineral species present in these samples, in decreasing

order of abundance are epidote, ilmenite, aluminosilicates,

zircon, pyroxene/amphibole, staurolite, garnet, tourmaline,

rutile, monazite, and others (including magnetite, phosphorite,

sulfides, unidentified opaques, non-opaques, quartz, coated

grains, etc.)

Economic Heavy Minerals

The minerals rcf highest economic importance that are present

in the Cape Canaveral offshore area include ilmenite, rutile,

zircon and monazite. Monazite is present in only minute

quantities and so does not figure in calculations of economic

TABLE 7

Data for Total heavy minerals (THM) and Recovered heavy minerals
(RHM) tabulated for all samples, in the upper 1.5 m sections
and the lower 1.5 m sections.

ALL SAMPLES UPPER 1.5 m SAMPLES LOUER 1.5 m SAMPLES
(N0140) (N=84) (N?56)
VARIABLE M MAX STD MIN AVG MAX SD IN AVG MAX STD

WtX RHM 0.01 0.18 1.10 0.18 0.01 0.19 1.09 0.18 0.02 0.18 1.10 0.18

WtX THM 0.02 0.27 1.48 0.26 0.02 0.26 1.38 0.26 0.03 0.27 1.48 0.28

heavy-mineral (EHM) abundances. There is the possibility that

some monazite is being overlooked, perhaps being mistaken for

epidote. This is based on preliminary geochemical analyses which

show elevated quantities of certain elements common to monazite

(A. Grosz, unpub. data). However, at this time, the available

data indicate average quantities of monazite of significantly

less than 1 weight percent of the RHM.

Ilmenite averages 26.7 weight percent of the RHM fraction.

This is second only to epidote in absolute abundance and is the

highest value for any of the EHM fraction. An examination of the

spiral lights (material rejected by the spiral) shows virtually

no ilmenite. This suggests that the weight percent RHM value

closely represents the THM value.

Zircon averages 9 weight percent of the RHM fraction and is

second to ilmenite in EHM abundance. The spiral-light estimates

for zircon were almost all less than 10 weight percent, most

being less than 5 weight percent. This suggests efficient

recovery of zircon by the spiral concentrator.

Rutile is the third most abundant economic heavy mineral,

averaging about 4.2 weight percent of the RHM fraction. Recovery

of rutile by the spiral concentrator appears to have been

inconsistent amongst samples. Although most of the spiral-light

values for rutile are quite low (<5%), there are some that are 20

or 30 weight percent.

A recent study by Kohpina (1989) showed that there is no

appreciable fractionation of either economic or non-economic

heavy minerals with core section (upper vs. lower). This same

conclusion was reached during the first phase of the Cape

Canaveral project (Nocita et al., 1989a) but Kohpina's

conclusions are based not just on semi-quantitative weight

percent but also detailed statistical analysis. Kohpina (1989)

also showed statistically through factor analysis that certain

groups of heavy minerals are commonly found in abundance

together. This is due to consideration mainly of grain size and

specific weight of the heavy minerals. The average EHM content

for these samples is 39.2 weight percent of the RHM; .07 weight

percent of the bulk sample.

CONCLUSIONS

The heavy-mineral assemblage offshore of Cape Canaveral

consists dominantly of epidote, ilmenite, aluminosilicates,

pyroxene/amphibole, and zircon. The assemblage is qualitatively

and quantitatively different than those found offshore of

Virginia (Grosz and Escowitz, 1983; Berquist and Hobbs, 1988) and

off shore of New York (Grosz, et al., 1988), but is qualitatively

similar to suites found offshore of Jacksonville, Florida and

South Carolina (Grosz and Escowitz, 1983).

Although the heavy-mineral species which occur offshore of

Cape Canaveral are similar to those found in onshore economic

deposits such as Trail Ridge and Green Cove Springs, absolute

abundances and concentrations appear to be almost ar order of

magnitude lower on the average for the offshore deposits.

The results of the analyses show a very low potential for

detrital heavy-mineral resources in sediments offshore of Cape

core sections than in the upper.

Heavy Minerals

The results of the heavy-mineral analysis are detailed in

Table 6.

DISCUSSION

Sand and Gravel

It can be seen from a comparison of the sediment

distribution maps that some areas show relatively constant trends

with sediment depth. Sand distribution between upper and lower

core sections (Figures 7, 11) shows part of Chester and Southeast

Shoals to contain very sandy (>90%) sediments to a depth of at

least 3 m. Overall, the upper 1.5 m of sediment in the Cape

Canaveral is more sand-rich than the lower 1.5 m of sediment.

The gravel portion of all samples is dominated by shell

material. It consists of both whole and broken shells, along

with minor amounts of lithic fragments (limestone and phosphate).

The gravel fraction ranges between approximately 1 and 60 weight

percent of the samples analyzed, averaging approximately 13.5

weight percent (Tables 1 and 3).

Gravel distribution is quite similar between the upper and

lower cores (Figures 9, 13). There is apparently a zone of very

shell-gravel-rich sediment running shore-parallel for about 10 km

just offshore of 2alse Cape.

Mud-rich zones occupy non-shoal areas in both upper and

lower core sections (Figures 10, 14). The area between Chester

and Southeast Shoals is mud-rich, as is an area farther offshore.

Canaveral. Values for the economically important heavy-mineral

species (ilmenite, rutile, zircon and monazite) calculated as

percentages of the heavy-mineral concentrates and of bulk

sediment samples are below values for sediments from other areas

on the Atlantic Inner Continental Shelf (Grosz and Nelson, 1989;

Grosz et al., 1989b; Grosz and Escowitz, 1983; Grosz, 1987;

Luepke and Grosz, 1986).

Sand and gravel deposits on the shore attached shoal bodies

are mud-poor, sand-rich, and over a wide area maintain these

characteristics to a depth of at least 3 meters. Without deeper

core data it is not possible to say how thick the desirable

sediments are. It is not uncommon for nearshore dredging of

beach nourishment sand to extend down to a sediment depth of 6 m

or more.

conclusion was reached during the first phase of the Cape

Canaveral project (Nocita et al., 1989a) but Kohpina's

conclusions are based not just on semi-quantitative weight

percent but also detailed statistical analysis. Kohpina (1989)

also showed statistically through factor analysis that certain

groups of heavy minerals are commonly found in abundance

together. This is due to consideration mainly of grain size and

specific weight of the heavy minerals. The average EHM content

for these samples is 39.2 weight percent of the RHM; .07 weight

percent of the bulk sample.

CONCLUSIONS

The heavy-mineral assemblage offshore of Cape Canaveral

consists dominantly of epidote, ilmenite, aluminosilicates,

pyroxene/amphibole, and zircon. The assemblage is qualitatively

and quantitatively different than those found offshore of

Virginia (Grosz and Escowitz, 1983; Berquist and Hobbs, 1988) and

off shore of New York (Grosz, et al., 1988), but is qualitatively

similar to suites found offshore of Jacksonville, Florida and

South Carolina (Grosz and Escowitz, 1983).

Although the heavy-mineral species which occur offshore of

Cape Canaveral are similar to those found in onshore economic

deposits such as Trail Ridge and Green Cove Springs, absolute

abundances and concentrations appear to be almost ar order of

magnitude lower on the average for the offshore deposits.

The results of the analyses show a very low potential for

detrital heavy-mineral resources in sediments offshore of Cape

ACKNOWLEDGMENTS

This study has benefitted from the input of many

individuals. At the University of South Florida, Robert Hogue

helped greatly with manipulation of the spreadsheet data and also

provided a grain-size analysis program. Gary Zarillo, Maryann

Civil and Tania Bacchus provided the spiral separates and grain

size analyses for the Phase II samples. Fred Pirkle of DuPont

continued to provide financial assistance for the project.

REFERENCES

Bergmann, P. C., 1982, Comparison of sieving, settling and
microscope determination of sand grain size: Unpub. M.S.
Thesis, Florida State University, 178 p.

Berquist, C.R., Jr. and Hobbs, C.H. III, 1988. Reconnaissance of
economic heavy minerals of the Virginia Inner Continental
Shelf: Contrib. No. 1425, Virginia Institute of Marine
Sciences, College of William and Mary, 69 p.

Clifton, H.E., Hubert, A. and Phillips, R.L., 1967. Sediment
sample preparation for analysis for low-concentrations of
detrital gold: U.S. Geological Survey Circular 545, 11 p.

Duane, D.B., Field, M.E., Meisburger, E.P., Swift, D.J.P. and
Williams, S.J., 1972. Linear shoals on the Atlantic Inner
Continental Shelf, Florida to Long Island: In: Swift,
D.J.P. et al., (eds.), Shelf Sediment Transport, Dowden,
Hutchinson and Ross, p. 447-498.

Field, M.E., 1974. Buried strandline deposits on the central
Florida inner continental shelf: Geol. Soc. Amer. Bull., v.
85, p. 57-60.

Field, M.E. and Duane, D.B., 1974. Geomorphology and sediments
of the Inner Continental Shelf, Cape Canaveral, Florida:
U.S. Army, Corps of Engineers Technical Memorandum No. 42,
87 p.

Grosz, A.E., 1987. Nature and distribution of potential heavy-
mineral resources offshore of the Atlantic coast of the
United States: Marine Mining, v. 6, p. 339-357.

Grosz, A.E., and Escowitz, E.C., 1983. Economic heavy minerals
of the U.S. Atlantic Continental Shelf: In: Tanner, W.F.,
(ed.), Proceedings of the Sixth Symposium on Coastal
Sedimentology, Florida State University, Tallahassee, FL, p.
231-242.

Grosz, A.E., Lopez, R., Aparisi, M., Albanese, J.R., Kelly, W.M.,
Berquist, R., Nelson, D.D., Nocita, B.W., Scott, T.M. and
Burbanck, G.P., 1988. Recent developments: U.S. Atlantic
shelf marine mineral surveys: Abstract with Program, 19th
Annual Underwater Mining Institute, Oct. 2-5, 1988, Woods
Hole, MA, 4 p.

Grosz, A.E., and Nelson, D.D., 1989. Textural and mineral.-:'c
analyses of surficial sediments offshore of Myrtle Beach,
South Carolina: United States Geological Survey Open-File
Report 89-168, 23 p.

Grosz, A.E., Nocita, B.W., Kohpina, P., Olivier, M.M. and Scott,
T.M., 1989a. Preliminary grain-size and mineralogic
analyses of vibracore samples from the Inner Continental
Shelf offshore of Cape Canaveral, Florida: U.S. Geological
Survey, Open-File Rpt. 89-18. 22 p.

Grosz, A.E., Muller, F.L., Uptegrove, J., Farnsworth, J., Bell
C.,'Maharaj, S.V., Muessig, K. and Hathaway, J.C., 1989b.
Textural, physiographic, bathymetric, and geologic factors
controlling economic heavy minerals distribution in
surficial sediments on the Atlantic Continental Shelf
offshore of New Jersey: United States Geological Survey
Open-File Report 89-683, 32 p.

Kohpina, P., 1989. Heavy Minerals in Sediments of the Inner
Continental Shelf, Cape Canaveral, Florida: Unpub. MS
thesis, University of South Florida, 153 p.

Luepke, G. and Grosz, A.E., 1986. Distribution of economic heavy
minerals in sediments of Saco Bay, Maine: United States
Geological Survey Bulletin 1681, 18 p.

Nocita, B.W., Kohpina, P., Olivier, M.M., Campbell, K. M., Green,
R.C. and Scott, T.M., 1989a. Results of a Preliminary
Reconnaissance Study of the Sand, Gravel and Heavy-mineral
Resources Potential of Sediments Offshore of Cape Canaveral,
Florida Phase I, an Interim Report: Cooperative Agreement
14-12-0001-30316, Florida Geological Survey, 42 p.

Nocita, B.W., Kohpina, P., Olivier, M.M. and Grosz, A.E., 1989b.
Economic heavy minerals offshore of Cape Canaveral, Florida:
Geol. Soc. Amer. Annual Meeting, Abstr. Prog. v. 21, p.
A174.

Terry, R.D, and Chilingar, G.V., 1955. Summary of "Concerning
some additional aids in studying sedimentary formations: by
M.S. Shvetsov: Journal of Sedimentary Petrology, v. 25, p.
229-234.

FLRD GEOLOSk ( IC SUfRiW

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	Front Cover
	Title Page
	Table of Contents
	List of Figures
	List of Tables
	Introduction
	Methods
	Results
	Discussion
	Conclusions
	Acknowledgments
	References