Table 2 Porewater trace- and major-elements extracted from Seaplane Lagoon core SC4 (July 10, 1998). Calcium, iron, potassium, magnesium, manganese, sodium, and silica were measured by ICP-AES. Aluminium, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc were measured by ICP-MS. Uncertainty for potassium was not reported

SC4-1

1.5

327 ± 1

2.20 ± 0.01

318

1017 ± 2

0.366 ± 0.002

7870 ± 20

14.4 ± 0.0

SC4-2

4.5

355 ± 1

0.20 ± 0.01

340

1133 ± 2

0.195 ± 0.003

8440 ± 20

20.9 ± 0.0

SC4-3

7.5

350 ± 2

<0.2

346

1192 ± 2

0.182 ± 0.004

8600 ± 30

22.4 ± 0.1

SC4-4

10.5

388 ± 1

<0.2

374

1368 ± 3

0.275 ± 0.002

9540 ± 20

23.0 ± 0.1

SC4-5

13.5

390 ± 1

<0.2

398

1414 ± 4

0.375 ± 0.001

9800 ± 40

21.3 ± 0.1

SC4-6

16.5

410 ± 2

<0.2

435

1493 ± 3

0.431 ± 0.001

10400 ± 200

20.9 ± 0.0

SC4-7

19.5

430 ± 2

<0.2

474

1546 ± 5

0.271 ± 0.002

10900 ± 100

21.3 ± 0.1

SC4-8

22.5

444 ± 2

0.69 ± 0.00

487

1620 ± 6

0.173 ± 0.001

11500 ± 100

21.4 ± 0.1

SC4-9

25.5

438 ± 1

<0.2

496

1604 ± 4

<0.1

11400 ± 100

21.6 ± 0.1

SC4-10

28.5

434 ± 2

<0.2

560

1633 ± 4

<0.1

11700 ± 0

21.2 ± 0.1

SC4-11

31.5

436 ± 3

<0.2

461

1639 ± 3

<0.1

11800 ± 0

21.7 ± 0.0

SC4-12

34.5

427 ± 2

<0.2

509

1640 ± 5

<0.1

11800 ± 100

21.9 ± 0.1

ICP-MS

Sample ID

Depth/cm

Al (ppb)

Cd (ppb)

Cr (ppb)

Cu (ppb)

Fe (ppb)

Mn (ppb)

Ni (ppb)

Pb (ppb)

Zn (ppb)

SC4-1

1.5

2.4 ± 0.2

0.19 ± 0.02

0.53 ± 0.06

0.52 ± 0.09

3000 ± 60

395 ± 4.0

2.00 ± 0.24

0.19 ± 0.02

4.12 ± 0.70

SC4-2

4.5

6.2 ± 0.1

0.14 ± 0.02

1.89 ± 0 23

0.46 ± 0.08

1400 ± 70

165 ± 1.7

1.38 ± 0.17

0.43 ± 0.05

4.00 ± 0.68

SC4-3

7.5

2.6 ± 0.1

0.80 ± 0.10

2.35 ± 0.28

0.35 ± 0.06

1000 ± 70

175 ± 3.5

.34 ± 0.16

0.30 ± 0.04

2.82 ± 0.48

SC4-4

10.5

6.6 ± 0.1

0.12 ± 0.01

2.80 ± 0 34

0.55 ± 0.09

500 ± 25

263 ± 5.3

.37 ± 0.16

0.46 ± 0.06

3.21 ± 0.55

SC4-5

13.5

2.2 ± 0.1

0.20 ± 0.02

2.91 ± 0 35

0.92 ± 0.16

<110

462 ± 9.2

.25 ± 0.15

0.38 ± 0.05

5.61 ± 0.95

SC4-6

16.5

3.8 ± 0.3

0.08 ± 0.01

4.19 ± 0 50

1.00 ± 0.17

<110

536 ± 10.7

.23 ± 0.15

0.86 ± 0.10

6.83 ± 1.16

SC4-7

19.5

5.3 ± 0.2

0.12 ± 0.01

5.40 ± 0.65

0.76 ± 0.13

<110

304 ± 3.0

.18 ± 0.14

1.06 ± 0.13

7.36 ± 1.25

SC4-8

22.5

3.5 ± 0.2

0.25 ± 0.03

5.74 ± 0.69

2.67 ± 0.45

<110

188 ± 1.9

.19 ± 0.14

1.05 ± 0.13

9.45 ± 1.61

SC4-9

25.5

8.2 ± 0.3

<0.06

6.04 ± 0 72

1.97 ± 0.33

<110

52 ± 0.5

<0.2

0.67 ± 0.08

6.28 ± 1.07

SC4-10

28.5

38.4 ± 0.8

0.29 ± 0.03

7.51 ± 0.90

1.08 ± 0.18

<110

10 ± 0.3

.20 ± 0.14

1.58 ± 0.19

5.04 ± 0.86

SC4-11

31.5

4.4 ± 0.2

0.24 ± 0.03

9.61 ± 1 15

0.69 ± 0.12

<110

2 ± 0.1

.00 ± 0.12

1.65 ± 0.20

6.88 ± 1.17

SC4-12

34.5

8.3 + 0.2

0.63 ± 0.08

15.38 ± 1.85

0.94 ± 0.16

<110

<1

0.97 ± 0.12

4.07 ± 0.49

8.64 ± 1.47