17
    Figure 1: Core Photograph of 8D
    8D
    0cm
    50cm
    100cm
    150cm
    200cm
    250cm
    300cm
    5
    CORE 8D
    :
    Core 8D was taken at water depth of water depth of 9.7m (31ft) (Table1) and had
    a total length of 332cm (131in) (Figures 2-5). A total of 8 grain size samples were taken
    at depths of 1-10cm (0.4-3.9in), 51-60cm (20-23.6in), 101-110cm (39.3-49.8in), 150-
    160cm (59.4-63in), 200-210cm (78.7-82.7in), 240-250 (94.5-98.4in), 250-260cm (98.4-
    102.4in), and 300-310cm (118.1-122in). This revealed that the upper 60cm (23.6in)
    increased from 7 to 41% sand and had a mean grain size ranging from 0.009mm (6.8phi)
    to 0.06mm (4.1phi). Depths of 61 to 160cm (24 to 63) contained sand ranging from 41 to
    26% and a mean grain size ranging from 0.006mm (4.1phi) to 0.015mm (6.0phi). From
    depths of 160 to 210cm (63 to 82.7in) there is an increase in sand percentages from 26%
    to 75% and a change in mean grain size from 0.015mm (6.0phi) to 0.088mm (3.5phi).
    From depths of 210cm to 250cm (82.7 to 98.4in) there is a decrease in the percent sand
    from 75% to 5% and then an increase in percent sand from 250cm (98.4in) to the bottom
    of the core, from 5% to 17% sand (Tables 5&6). Sand and shell weights are shown in
    Table 4. Percent shell, sand, silt and clay are shown in Table 5. Median grain size, mean
    grain size, skewness and sorting index are shown in Table 6. Graphs of the results are
    located in figures 8-11.
    It was determined that core 8D had approximately 45cm (17.7in) of sediment that
    contained at least 50% sand, none of which was located at less than 1m (3.28ft). The
    average grain size in the upper 1m (3.28ft) was determined to be 0.0339mm (4.9phi).
    18
    Figure 2: Core Log of 8D for 0-150cm
    Figure 3: Core Log of 8D for 150-300cm
    19
    Figure 4: Core Log for 8D for depths 300-332cm
    Figure 5: Computerized core log for 8D
    20
    Core
    ID
    Sample
    Depth
    (cm)
    #10/
    2.0mm
    Screen
    Sample
    Weight
    (g)
    #14/
    1.40mm
    Screen
    Sample
    Weight
    (g)
    #18/
    1.00mm
    Screen
    Sample
    Weight
    (g)
    #25/
    710μm
    Screen
    Sample
    Weight
    (g)
    #35/
    500μm
    Screen
    Sample
    Weight
    (g)
    #45/
    355μm
    Screen
    Sample
    Weight
    (g)
    #60/
    250μm
    Screen
    Sample
    Weight
    (g)
    #80/
    180μm
    Screen
    Sample
    Weight
    (g)
    #125/
    125μm
    Screen
    Sample
    Weight
    (g)
    #170/
    90μm
    Screen
    Sample
    Weight
    (g)
    #200/
    75μm
    Screen
    Sample
    Weight
    (g)
    #230/
    63μm
    Screen
    Sample
    Weight
    (g)
    8D
    1-10
    6.46
    7.68
    8D
    51-60
    16.81
    7.52
    8D
    101-110
    19.11
    7.15
    8D
    150-160
    10.79
    4.41
    8D 200-210
    0.01
    0.06
    0.05 0.06 0.05 0.06 0.12 0.22 2.33 54.37 15.24 10.34
    8D
    240-250
    2.20
    1.75
    8D
    250-260
    3.18
    1.78
    8D
    300-310
    6.19
    2.96
    Table 2: RO-TAP data for core 8D
    21
    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
    8D
    1-10
    83.2
    20.6
    8D
    51-60
    58.7
    14.8
    8D
    101-110
    70.7
    24.0
    8D
    150-160
    74.1
    23.6
    8D
    200-210
    100.0
    99.9
    99.9 99.8 99.8 99.7 99.6 99.3
    96.9 40.4 24.6
    3.1
    8D
    240-250
    95.4
    30.5
    8D
    250-260
    91.3
    35.6
    8D
    300-310
    82.6
    29.7
    Table 3: Percent Finer table for core 8D
    22
    Core ID
    Sample Depth (cm)
    shell weight
    200+ weight
    200-230 weight
    sand + shell
    8D 1-10
    6.46
    7.68
    6.46
    8D 51-60
    16.81
    7.52
    16.81
    8D 101-110
    19.11
    7.15
    19.11
    8D 150-160
    10.79
    4.41
    10.79
    8D 200-210
    0.29
    72.28
    10.34
    72.57
    8D 240-250
    2.20
    1.75
    2.20
    8D 250-260
    3.18
    1.78
    3.18
    8D 300-310
    6.19
    2.96
    6.19
    Table 4: Shell and Sand weights for core 8D
    Core ID
    sample id
    mid sample
    depth
    % shell
    % sand
    %silt
    %clay
    total %
    CC8D 1-10 5.5 16.8 62.6 20.6 100
    CC8D 51-60 55.5 41.3 43.9 14.8 100
    CC8D 101-110 105.5 29.3 46.7 24.0 100
    CC8D 150-160 155.5 25.9 50.5 23.6 100
    CC8D 200-210 205.5 0.3 75.1 21.5 3.1 100
    CC8D 240-250 245.5 4.6 64.9 30.5 100
    CC8D 250-260 255.5 8.7 55.7 35.6 100
    CC8D 300-310 305.5 17.4 53.0 29.7 100
    Table 5: Percent Shell, Sand, Silt and Clay for core 8D
    23
    Station ID
    Average Depth
    Median Grain Size
    Median Grain
    Size Mean Grain Size
    Mean Grain