Fróðskaparrit - 01.01.2009, Blaðsíða 166

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CHEMICAL SEDIMENT VARIABLES FROM THE FAROE AREA:
ORCANIC CONTENT, NITROGEN, PHOSPHORUS, ZINC, AND COPPER
Sediment LOI % Total-N g/kg Total-P g/kg Total-N/LOI g/g Total-P/LOI g/g Zinc mg/kg Copper mg/kg Zinc/LOI mg/g Copper/LOI mg/g
Clay
Min 0.5 0.77 0.60 0.077 0.070 29 38 0.5 0.5
Max 11.1 3.20 1.62 0.324 0.170 96 120 8.6 12.0
Mean 6.2 1.64 0.97 0.046 0.027 55 66 1.0 1.3
Std. dev. 2.0 0.63 0.30 0.074 0.039 14 76 7.0 7.4
n 78 16 16 76 76 70 77 70 77
Mixed clay
Min 3.0 0.49 0.6 7 0.073 0.077 34 35 0.5 0.6
Max 8.8 2.00 7.19 0.036 0.026 65 99 7.6 7.9
Mean 5.7 7.47 0.83 0.027 0.076 57 60 1.0 7.7
Std. dev. 7.7 0.47 0.77 0.006 0.004 70 78 0.3 0.4
n 20 70 10 70 70 20 20 20 20
Gravelly sand
Min 1.4 0.79 0.49 0.007 0.071 72 19 0.3 0.4
Max 77.7 2.37 2.02 0.058 0.059 82 110 6.0 7.3
Mean 4.6 1.27 0.89 0.029 0.023 51 67 7.2 7.5
Std. dev. 1.6 0.68 0.33 0.013 0.073 72 76 0.7 0.9
n 80 22 22 22 22 74 74 74 74
Sand
Min 2.2 0.22 0.65 0.070 0.023 35 14 0.6 0.4
Max 6.2 0.79 0.97 0.020 0.029 54 50 1.6 7.4
Mean 4.6 0.57 0.78 0.075 0.026 43 34 7.1 0.8
Std. dev. 1.6 0.40 0.18 0.007 0.005 9 73 0.4 0.4
n 5 2 2 2 2 5 5 5 5
Mixed sand
Min 1.5 0.14 0.43 0.003 0.002 35 36 0.5 0.6
Max 72.7 4.07 7.63 0.047 0.043 82 83 3.9 3.7
Mean 5.6 7.54 0.93 0.027 0.078 53 54 7.7 7.7
Std. dev. 2.7 0.86 0.25 0.009 0.007 73 72 0.6 0.6
n 35 34 34 34 34 35 35 35 35
No info. on sediment Min 3.7 7.03 0.66 0.012 0.007 38 39 0.4 0.3
Max 73.0 7.50 7.30 0.029 0.026 98 77 7.9 7.7
Mean 5.8 7.37 7.04 0.023 0.079 57 58 7.7 7.2
Std. dev. 2.6 0.22 0.20 0.006 0.006 77 73 0.5 0.4
n 77 7 7 7 7 70 70 70 70
All samples
Min 0.5 0.74 0.43 0.007 0.007 12 14 0.3 0.3
Max 13.0 4.01 2.02 0.324 0.170 98 720 8.6 12.0
Mean S.4 1.49 0.92 0.031 0.021 53 61 7.7 1.3
Std. dev. 2.0 0.70 0.27 0.032 0.078 73 77 0.8 7.0
n 229 97 97 97 97 274 275 274 275
Table 2. Loss on ignition (LOI), total nitrogen (Total-N), total phosphorus (Total-P), zinc and copper organized
by sediment types. A total of 229 samples were analyzed. n = number of samples.
found was 98 mg/kg dry matter and the low-
est value 12 mg/kg. When total mean zinc
values are compared to depth, there is a
small decrease in zinc concentration with
depth (Fig. 3.e). When total mean zinc is cal-
culated against LOI and compared to depth,
there is also a small decrease (Fig. 3.f). Mean
value of zinc calculated against LOI is 1.1