CORE 4B:

CORE 4B:

Core 4B was taken at a water depth of 6.1m (20ft) (Table1) and had a total length of 314cm (123.6in) (Figures 23 & 31-34). A

total of 14 grain size samples were taken at depths of 1-10cm (0.4-3.9in), 31-40cm (12.2-15.8in), 61-70cm (24-27.6in), 91-100cm

(35.8-39.4in), 101-110cm (39.8-43.3in), 131-140cm (51.6-55.1in), 141-150cm (55.5-59.1in), 161-170cm (63.4-66.9in), 201-210cm

(79.1-82.7in), 211-220cm (83-86.6in), 221-230cm (87-90.6in), 251-260cm (98.8-102.4in), 291-300cm (114.6-118.1in) and 301-

310cm (118.5-122in). The top of this core down to approximately 80cm (31.5in) contained a percent sand decreasing from 87% to

38%, and a mean grain size ranging from 0.1149mm (3.1phi) to 0.1003mm (3.3phi). From depth 80cm (35.1in) to 100cm (39.4in)

percent sand remained below 40%. From the depth of 100cm (29.4in) to 140cm (55.1in) there was an increase in percent sand from

40 to 84% with mean grain size ranging from 0.0867mm (3.5phi) to 0.0968mm (3.4phi). There was a decrease in percent sand from

84% to 21% between the depths of 140 to 260cm (55.1 to 102.4in) and a decrease in mean grain size ranging from 0.0968mm (3.4phi)

to 0.0217mm (5.5phi). From 260cm (102.4in) to the bottom of the core percent sand remained below 30%.

Sand and shell weights are shown in Table 22. Percent sand, silt and clay are shown in Table 23. Median grain size, mean

grain size, skewness and sorting index are shown in Table 26. Graphs of the results are located in Figures 35-38.

It was determined that core 4B had approximately 193cm (76in) of sediment contained at least 50% sand, of which 72cm

(28.3in) was located shallower than 1m (39.4in) depth.

0.5m

1.0m

1.5m

2.0m

2.5m

0.5m

1.0m

1.5m

2.0m

2.5m

0.5m

1.0m

1.5m

2.0m

Core ID

Sample Depth (cm)

shell weight (g)

200+ weight (g)

200-230 weight (g)

overall sand weight (g)

1-10

3.14

87.44

2.56

87.44

31-40

7.45

94.12

2.69

94.12

61-70

9.57

97.40

4.80

97.40

71-80

1.41

33.96

4.73

33.96

91-100

0.13

24.08

3.86

24.08

101-110

0.19

74.51

7.26

74.51

131-140

0.36

77.84

5.88

77.84

161-170

0.86

96.67

5.69

96.67

201-210

0.65

97.71

7.10

97.71

211-220

0.34

78.54

6.20

78.54

221-230

0.01

28.27

3.85

28.27

251-260

0.02

9.84

2.47

9.84

291-300

0.06

14.70

4.63

14.70

301-310

0.01

14.02

1.52

14.02

Table 1: Sand and Shell weights for core 4B

Core ID

Sample Depth (cm)

% shell

% sand

%silt

%clay

1-10

3.13

87.21

6.84

2.82

31-40

6.68

84.44

4.41

4.46

61-70

7.53

76.65

9.57

6.25

71-80

1.56

37.62

25.06

35.76

91-100

0.21

38.65

26.20

34.94

101-110

0.19

75.32

18.83

5.66

131-140

0.39

84.22

11.79

3.60

161-170

0.68

76.33

17.41

5.58

201-210

0.47

71.03

15.42

13.08

211-220

0.27

61.25

19.53

18.95

221-230

0.02

48.21

26.43

25.33

251-260

0.04

21.38

38.43

40.15

291-300

0.12

28.23

42.22

29.43

301-310

0.02

30.59

30.38

39.01

Table 2: Percent Shell, Sand, Silt and Clay for core 4B

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

1-10

0.81

0.69

0.61

0.28

0.14

0.16

0.96

16.73

58.75

10.84

2.56

0.52

31-40

2.5

2.18

1.37

0.80

0.40

0.20

0.44

0.93

31.33

54.56

6.86

2.69

0.75

61-70

5.3

2.01

1.13

0.65

0.28

0.20

0.24

0.65

16.43

67.27

12.81

4.80

2.72

71-80

1.41

33.96

4.73

2.13

91-100

0.13

24.08

3.86

2.59

101-110

0.04

0.02

0.03

0.08

0.12

0.38

6.00

52.64

15.37

7.26

5.15

131-140

0.15

0.07

0.05

0.03

0.01

0.05

0.09

0.33

11.22

52.98

13.22

5.88

1.95

161-170

0.09

0.05

0.15

0.13

0.17

0.27

0.35

0.93

22.21

62.07

11.11

5.69

4.45

201-210

0.01

0.10

0.06

0.09

0.12

0.27

0.52

0.76

27.51

60.44

8.48

7.10

7.05

211-220

0.03

0.02

0.04

0.03

0.05

0.17

0.22

0.44

8.21

53.73

15.94

6.20

3.39

221-230

0.01

28.27

3.85

1.82

251-260

0.02

9.84

2.47

1.49

291-300

0.06

14.70

4.63

2.58

301-310

0.01

14.02

1.52

1.23

Table 3: RO-TAP data for core 4B

ASTM

Classification

coarse

sand

medium

sand

medium

sand

medium

sand

medium

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

silt

1-10

99.2

98.5

97.9

97.3

97.0

96.9

96.7

95.8

79.1

20.5

9.7

2.8

31-40

97.8

95.8

94.6

93.9

93.5

93.3

92.9

92.1

64.0

15.0

8.9

4.5

61-70

95.8

94.2

93.4

92.8

92.6

92.5

92.3

91.8

78.8

25.9

15.8

6.2

71-80

98.4

60.8

35.8

91-100

99.8

61.1

34.9

101-110

100.0

99.9

99.8

99.7

99.3

93.2

40.0

24.5

5.7

131-140

99.8

99.7

99.6

99.5

99.2

87.0

29.7

15.4

3.6

161-170

99.9

99.8

99.7

99.5

99.3

99.0

98.3

80.8

31.8

23.0

5.6

201-210

100.0

99.9

99.8

99.7

99.5

99.1

98.6

78.6

34.7

28.5

13.1

211-220

100.0