CORE 4A:
Core 4A was taken at a water depth of 5m (16.3ft) (Table 1) and had a total length of 280cm (110.2in) (Figures 23-26). A total
of 16 grain size samples were taken at depths of 1-10cm (0.4-3.9in), 11-20cm (4.3-7.9in), 41-50cm (16.1-19.7in), 61-70cm (24-
27.6in), 71-80cm (28-31.5in), 101-110cm (39.8-43.3in), 111-120cm (43.7-47.2in), 141-150cm (55.5-59.1in), 171-180cm (67.3-
70.9in), 181-190cm (71.3-74.8in), 211-220cm (83-86.6in), 221-230cm (87-90.6in), 231-240cm (90.9-94.5in), 241-250cm (94.9-
98.4in), 251-260cm (98.8-102.4in) and 271-280cm(106.7-110.2in). From the top of the core to a depth of 220cm (86.6in), percent
sand remained above 79% and had a mean grain size between 0.116mm (3.1phi) and 0.094mm (3.4phi). From 220cm (86.6in) to
230cm (90.6in) percent sand decreased from 89 to 39%.From 230cm (90.6in) to the bottom of the core, percent sand ranged from 39
to 57% and mean grain size was less that 0.0799mm (3.6 phi).
Sand and shell weights are shown in Table 17. Percent sand, silt and clay are shown in Table 18. Median grain size, mean
grain size, skewness and sorting index are shown in Table 21. Graphs of the results are located in Figures 27-30.
It was determined that core 4A had approximately 225cm (88.5in) of sediment contained at least 50% sand, of which 100cm
(39.4in) was located shallower than 1m (39.4in) depth.
0m
0.5m
1.0m
1.5m
2.0m
2.5m
4A
0m
0.5m
1.0m
1.5m
2.0m
2.5m
4B
0m
0.5m
1.0m
1.5m
2.0m
4C
Core ID
Sample Depth (cm)
shell weight (g)
200+ weight (g)
200-230 weight (g)
overall sand weight (g)
4A
1-10
5.15
110.39
3.58
110.39
4A
11-20
10.53
88.14
2.35
88.14
4A
41-50
3.32
91.21
3.21
91.21
4A
61-70
13.92
84.62
2.72
84.62
4A
71-80
4.07
83.45
4.62
83.45
4A
101-110
1.40
91.20
4.70
91.20
4A
111-120
1.91
88.80
3.37
88.80
4A
141-150
0.34
83.53
5.42
83.53
4A
171-180
0.72
78.41
6.85
78.41
4A
181-190
0.78
89.85
3.93
89.85
4A
211-220
0.35
93.48
2.55
93.48
4A
221-230
0.02
22.68
2.64
22.68
4A
231-240
0.33
43.83
10.80
43.83
4A
241-250
0.46
40.33
15.30
40.33
4A
251-260
0.10
20.81
5.41
20.81
4A
271-280
0.10
22.58
3.62
22.58
Table 1: Shell and Sand weights for core 4A
Core ID
Sample Depth (cm)
% shell
% sand
%silt
%clay
4A
1-10
4.12
88.29
4.38
3.21
4A
11-20
9.91
82.94
3.66
3.50
4A
41-50
3.09
84.88
5.72
6.31
4A
61-70
12.98
78.88
4.63
3.51
4A
71-80
4.08
83.75
7.69
4.47
4A
101-110
1.35
87.68
8.37
2.60
4A
111-120
1.92
89.45
5.90
2.72
4A
141-150
0.35
87.02
9.61
3.02
4A
171-180
0.74
80.65
15.30
3.31
4A
181-190
0.74
85.49
8.69
5.08
4A
211-220
0.33
89.12
6.37
4.18
4A
221-230
0.03
39.15
33.73
27.08
4A
231-240
0.43
57.01
33.11
9.44
4A
241-250
0.50
44.00
38.85
16.64
4A
251-260
0.16
34.03
38.27
27.54
4A
271-280
0.22
49.69
32.64
17.45
Table 2: Percent Shell, Sand, Silt and Clay for core 4A
Core ID
Sample
Depth
(cm)
N10/
2.0mm
Screen
Sample
Weight
(g)
N14/
1.40mm
Screen
Sample
Weight
(g)
N18/
1.00mm
Screen
Sample
Weight
(g)
N25/
710μm
Screen
Sample
Weight
(g)
N35/
500μm
Screen
Sample
Weight
(g)
N45/
355μm
Screen
Sample
Weight
(g)
N60/
250μm
Screen
Sample
Weight
(g)
N80/
180μm
Screen
Sample
Weight
(g)
N125/
125μm
Screen
Sample
Weight
(g)
N170/
90μm
Screen
Sample
Weight
(g)
N200/
75μm
Screen
Sample
Weight
(g)
N230/
63μm
Screen
Sample
Weight
(g)
CATCH
Pan
4A
1-10
1.81
1.30
0.92
0.64
0.28
0.20
0.25
0.80
22.34
73.32
13.68
3.58
0.81
4A
11-20
4.23
2.49
1.74
1.15
0.61
0.31
0.40
0.74
24.83
55.73
6.44
2.35
0.79
4A
41-50
1.49
0.74
0.47
0.30
0.17
0.15
0.23
0.70
12.37
64.29
13.62
3.21
0.81
4A
61-70
5.73
3.65
2.08
1.34
0.73
0.39
0.60
0.92
18.71
57.12
7.27
2.72
0.77
4A
71-80
1.63
0.99
0.65
0.38
0.24
0.18
0.33
0.66
27.35
46.10
9.01
4.62
1.78
4A
101-110
0.43
0.36
0.20
0.18
0.12
0.11
0.33
0.75
20.04
60.52
9.56
4.70
1.82
4A
111-120
0.72
0.44
0.30
0.22
0.13
0.10
0.17
0.68
16.41
59.50
12.04
3.37
1.05
4A
141-150
0.08
0.09
0.06
0.02
0.03
0.06
0.08
0.40
13.43
54.60
15.02
5.42
1.96
4A
171-180
0.26
0.16
0.06
0.09
0.06
0.09
0.14
0.57
9.83
51.94
15.93
6.85
3.56
4A
181-190
0.21
0.17
0.11
0.08
0.10
0.11
0.22
0.74
68.60
17.61
2.68
3.93
3.44
4A
211-220
0.10
0.02
0.05
0.06
0.07
0.05
0.16
1.43
33.52
51.30
7.07
2.55
1.60
4A
221-230
0.02
22.68
2.64
1.33
4A
231-240
0.06
0.06
0.05
0.04
0.04
0.08
0.23
0.42
6.47
27.98
8.73
10.80
9.30
4A
241-250
0.05
0.12
0.11
0.06
0.05
0.07
0.07
0.32
5.38
22.97
11.59
15.30
9.70
4A
251-260
0.10
20.81
5.41
5.11
4A
271-280
0.10
22.58
3.62
1.86
Table 3: RO-TAP data for core 4A
ASTM
Classification
coarse
sand
medium
sand
medium
sand
medium
sand
medium
sand
fine sand
fine
sand
fine
sand
fine sand
fine sand
fine
sand
silt
Wentworth
Classification
granule
very
coarse
sand
very
coarse
sand
coarse
sand
coarse
sand
medium
sand
fine
sand
fine
sand
fine sand
very fine
sand
very fine
sand
very
fine
silt
Core ID
Sample
Depth
(cm)
% finer
than
N10/
2.0mm/
-1.0Φ
Screen
% finer
than
N14/
1.40mm
/ -0.5Φ
Screen
% finer
than
N18/
1.00mm/
0.0Φ
Screen
% finer
than
N25/
710μm
/ 0.5Φ
Screen
% finer
than
N35/
500μm/
1.0Φ
Screen
% finer
than
N45/
355μm /
1.5Φ
Screen
% finer
than
N60/
250μm
2.0Φ
Screen
% finer
than
N80/
180μm/
2.5 Φ
Screen
% finer
than
N125/
125μm/
3.0Φ
Screen
% finer
than
N170/
90μm /
3.5Φ
Screen
% finer
than
N200/
75μm /
4.0Φ
Screen
%
finer
than
4μm/
8Φ
Observed
Contents of
the sample
shell
only
shell
only
shell
only
shell
only
shell
only
shell
only
shell
only
sand
sand
sand
sand
silt
4A
1-10
98.6
97.5
96.8
96.3
96.0
95.9
95.7
95.0
77.2
18.5
7.6
3.2
4A
11-20
96.0
93.7
92.0
91.0
90.4
90.1
89.7
89.0
65.7
13.2
7.2
3.5
4A
41-50
98.6
97.9
97.5
97.2
97.1
96.9
96.7
96.0
84.5
24.7
12.0
6.3
4A
61-70
94.7
91.3
89.3
88.1
87.4
87.0
86.5
85.6
68.2
14.9
8.1
3.5
4A
71-80
98.4
97.4
96.7
96.3
96.1
95.9
95.6
94.9
67.5
21.2
12.2
4.5
4A
101-110
99.6
99.2
99.0
98.9
98.8
98.7
98.3
97.6
78.3
20.2
11.0
2.6
4A
111-120
99.3
98.8
98.5
98.3
98.2
98.1
97.9
97.2
80.7
20.8
8.6
2.7
4A
141-150
99.9
99.8
99.8
99.7
99.7
99.6
99.6
99.1
85.2
28.3
12.6
3.0
4A
171-180
99.7
99.6
99.5
99.4
99.4
99.3
99.1
98.5
88.4
35.0
18.6
3.3
4A
181-190
99.8
99.6
99.5
99.5
99.4
99.3
99.0
98.3
33.1
16.3
13.8
5.1
4A
211-220
99.9
99.9
99.8
99.8
99.7
99.7
99.5
98.2
66.2
17.3
10.5
4.2
4A
221-230
100.0
60.8
27.1
4A
231-240
99.9
