Table 5 Bulk sediment chemistry from Seaplane Lagoon cores SC2, SC3, SC4, Cl, C2 and C3 reported as the average ( ± uncertainty) of 2–4 replicate analyses multiplied by 1.47 to correct for solution viscosity

SC2-1

1.5

41700 ± 4900

11000 ± 900

11.0 ± 2.0

22.2 ± 2.9

230 ± 24

98 ± 7

41300 ± 4700

7350

382 ± 36

108 ± 12

183 ± 21

9950

240 ± 22

SC2-2

4.5

45300 ± 4200

9840 ± 200

12.7 ± 0.4

24.6 ± 0.1

248 ± 7

108 ± 2

48700 ± 1600

9180

447 ± 8

125 ± 2

200 ± 21

13400

268 ± 31

SC2-3

7.5

46300 ± 4000

8510 ± 330

18.8 ± 0.2

24.7 ± 0.8

284 ± 14

129 ± 3

51800 ± 1700

9840

456 ± 17

136 ± 1

240 ± 43

15800

298 ± 28

SC2-4

10.5

49000 ± 3400

8820 ± 410

28.1 ± 1.8

29.3 ± 0.5

355 ± 21

157 ± 8

53700 ± 2600

10300

467 ± 24

148 ± 9

365 ± 27

16600

357 ± 29

SC2-5

13.5

48400 ± 3900

8730 ± 530

32.7 ± 2.9

31.0 ± 2.8

385 ± 32

164 ± 11

53400 ± 3900

10300

459 ± 33

147 ± 11

415 ± 28

16600

395 ± 25

SC2-6

16.5

45100 ± 3200

8510 ± 410

30.4 ± 0.8

28.1 ± 0.5

386 ± 20

163 ± 5

50400 ± 1400

9890

424 ± 16

139 ± 2

387 ± 46

15800

369 ± 36

SC2-7

19.5

45500 ± 4800

20900 ± 600

33.1 ± 1.9

26.91.7 ±

392 ± 20

174 ± 6

49000 ± 3200

9440

402 ± 19

138 ± 8

414 ± 44

14200

373 ± 41

SC2-8

22.5

44200 ± 4000

7770 ± 210

38.9 ± 0.9

30.2 ± 1.1

425 ± 18

168 ± 4

47000 ± 1600

9400

386 ± 12

137 ± 3

453 ± 36

13900

373 ± 39

SC2-9

25.5

45800 ± 4300

8040 ± 220

53.4 ± 1.1

50.6 ± 2.4

494 ± 27

163 ± 5

48000 ± 2800

9790

384 ± 17

146 ± 4

568 ± 42

13200

389 ± 39

Core SC3

SC3-1

1.5

41600 ± 4300

9280 ± 216

17 ± 1

23 ± 0

248 ± 8

106 ± 4

43700 ± 1400

9420 ± 2910

384 ± 7

112 ± 3

210 ± 26

10700

257 ± 30

SC3-2

4.5

42800 ± 3800

10300 ± 428

16 ± 1

21 ± 2

240 ± 12

107 ± 1

43800 ± 1600

10100 ± 2900

392 ± 16

112 ± 4

210 ± 6

12300

251 ± 23

SC3-3

7.5

42900 ± 4500

13200 ± 289

13 ± 0

27 ± 1

242 ± 8

107 ± 3

46800 ± 1600

10900 ± 3300

425 ± 11

117 ± 1

199 ± 15

13400

256 ± 29

SC3-6

16.5

41100 ± 3400

10100 ± 387

46 ± 1

43 ± 2

419 ± 16

149 ± 5

45100 ± 900

11100 ± 3400

371 ± 10

147 ± 1

516 ± 47

13700

354 ± 41

SC3-7

19.5

44500 ± 5100

9110 ± 555

84 ± 5

69 ± 5

550 ± 51

199 ± 14

49400 ± 4600

12300 ± 3300

382 ± 32

186 ± 10

898 ± 70

14100

445 ± 40

SC3-8

22.5

45800 ± 6600

9330 ± 1100

81 ± 12

33 ± 3

481 ± 68

162 ± 17

56200 ± 8400

13400 ± 3500

436 ± 60

163 ± 23

676 ± 103

16400

377 ± 40

SC3-9

25.5

33500 ± 3100

10000 ± 335

347 ± 14

26 ± 2

876 ± 57

216 ± 9

47700 ± 2900

12400 ± 3600

440 ± 24

147 ± 7

955 ± 63

13700

386 ± 38

SC3-10

28.5

38200 ± 4300

9970 ± 45

285 ± 8

20 ± 0

865 ± 33

207 ± 4

49200 ± 2500

12500 ± 4000

429 ± 12

119 ± 6

1120 ± 129

17800

525 ± 70

SC3-11

31.5

37400 ± 4000

11200 ± 573

358 ± 24

22 ± 2

1150 ± 100

236 ± 10

52800 ± 4400

12400 ± 3500

399 ± 28

150 ± 10

1130 ± 111

20900

631 ± 62

SC3-12

34.5

34600 ± 5100

14100 ± 1110

316 ± 33

19 ± 2

830 ± 74

241 ± 18

48800 ± 6000

11100 ± 3600

364 ± 34

137 ± 16

1230 ± 188

18900

481 ± 72

SC3-13

37.5

35400 ± 4900

10400 ± 660

270 ± 23

20 ± 2

691 ± 57

226 ± 13

49300 ± 5300

11400 ± 3400

385 ± 30

125 ± 12

784 ± 108

18900

475 ± 58

Core SC4

SC4-1

1.5

44300 ± 6100

11200 ± 1100

15 ± 2

24 ± 2

243 ± 23

108 ± 8

44000 ± 3900

11900 ± 3400

429 ± 40

120 ± 11

214 ± 40

10100

287 ± 52

SC4-2

4.5

46900 ± 6500

9800 ± 1100

17 ± 2

25 ± 2

275 ± 27

123 ± 15

49100 ± 4700

13600 ± 3700

443 ± 46

130 ± 15

242 ± 49

12000

322 ± 57

SC4-3

7.5

47100 ± 6100

9700 ± 1100

19 ± 2

25 ± 1

278 ± 28

131 ± 10

50700 ± 4600

14000 ± 3600

474 ± 48

132 ± 12

249 ± 45

12800

318 ± 53

SC4-4

10.5

48300 ± 6100

10200 ± 1200

15 ± 2

26 ± 1

279 ± 29

133 ± 8

52600 ± 5100

14700 ± 3600

504 ± 54

138 ± 17

242 ± 42

13300

326 ± 54

SC4-5

13.5

48900 ± 4900

10300 ± 900

21 ± 2

26 ± 2

280 ± 21

128 ± 11

51100 ± 3700

15900 ± 3100

503 ± 38

137 ± 12

251 ± 33

13200

331 ± 40

SC4-6

16.5

48500 ± 4800

10600 ± 900

39 ± 3

27 ± 2

327 ± 24

129 ± 13

51100 ± 3600

15800 ± 3200

543 ± 40

139 ± 10

338 ± 47

14700

346 ± 43

SC4-7

19.5

47800 ± 4600

9200 ± 800

38 ± 3

28 ± 2

351 ± 26

148 ± 12

50800 ± 3600

15900 ± 3200

528 ± 40

140 ± 12

393 ± 55

15200

374 ± 45

SC4-8

22.5

46800 ± 4600

9700 ± 700

56 ± 5

33 ± 2

422 ± 27

172 ± 11

49600 ± 3100

15600 ± 3200

541 ± 35

145 ± 10

593 ± 79

14900

426 ± 52

SC4-9

25.5

46900 ± 4300

8900 ± 600

66 ± 5

36 ± 2

456 ± 26

166 ± 11

49700 ± 2800

15700 ± 3100

526 ± 30

148 ± 10

562 ± 69

15300

432 ± 47

SC4-10

28.5

48200 ± 4900

9600 ± 300

78 ± 3

47 ± 1

493 ± 15

189 ± 13

53800 ± 1800

15400 ± 3800

518 ± 21

173 ± 4

831 ± 97

16600

463 ± 55

SC4-11

31.5

44700 ± 7000

14800 ± 1300

136 ± 14

27 ± 2

584 ± 38

202 ± 13

54200 ± 4800

14900 ± 4700

435 ± 35

155 ± 13

946 ± 192

16700

496 ± 90

SC4-12

34.5

46200 ± 6200

10600 ± 700

192 ± 18

31 ± 2

766 ± 45

210 ± 14

53500 ± 3900

15200 ± 4300

42230 ±

155 ± 11

1270 ± 230

17100

515 ± 84

Core C1

Cl-1

75.0

34700 ± 4400

9460 ± 350

1 ± 0

22 ± 2

159 ± 9

40 ± 4

46100 ± 4100

9670 ± 2940

952 ± 51

129 ± 7

57 ± 24

3940 ± 80

108 ± 14

Cl-2

55.0

32000 ± 3800

21900 ± 600

1220 ± 50

19 ± 1

1730 ± 90

232 ± 8

48400 ± 3600

12300 ± 3500

400 ± 18

113 ± 5

1400 ± 140

4770 ± 480

574 ± 61

Cl-3

40.0

41800 ± 5200

8680 ± 260

72 ± 4

27 ± 1

470 ± 26

165 ± 7

51600 ± 4100

13200 ± 3800

398 ± 20

1530 ± 10

645 ± 69

4550 ± 60

373 ± 42

Cl-4

30.0

44600 ± 5000

8950 ± 330

29 ± 1

34 ± 2

424 ± 25

177 ± 6

54100 ± 4300

13200 ± 3800

427 ± 23

153 ± 5

475 ± 53

4740 ± 480

399 ± 43

Cl-5

20.0

46500 ± 4800

8810 ± 200

30 ± 2

28 ± 2

346 ± 4

150 ± 4

55100 ± 3000

13200 ± 4200

479 ± 6

145 ± 5

347 ± 55

4790 ± 50

344 ± 48

Cl-6

13.5

48300 ± 4800

8930 ± 190

20 ± 1

27 ± 1

300 ± 11

137 ± 3

57600 ± 3500

13900 ± 3900

508 ± 19

145 ± 3

241 ± 27

5000 ± 400

313 ± 33

Cl-7

10.5

47800 ± 4100

8860 ± 200

15 ± 1

25 ± 1

271 ± 11

118 ± 7

56600 ± 2500

13700 ± 3800

508 ± 17

144 ± 3

195 ± 24

4900 ± 190

282 ± 27

Cl-8

7.5

48500 ± 6400

10000 ± 330

14 ± 1

25 ± 1

262 ± 12

116 ± 6

55800 ± 4100

14200 ± 4700

505 ± 25

140 ± 10

185 ± 37

4700

280 ± 44

Cl-9

4.5

48200 ± 4600

9400 ± 290

11 ± 2

27 ± 1

259 ± 16

116 ± 7

54700 ± 3000

13900 ± 4000

478 ± 29

133 ± 1

188 ± 21

4590

285 ± 31

Cl-10

1.5

47000 ± 6100

9210 ± 350

15 ± 1

26 ± 2

264 ± 9

123 ± 10

52600 ± 4500

13600 ± 4600

430 ± 23

131 ± 10

206 ± 45

4460

295 ± 51

Core C2

C2-1

1.5

44100 ± 6000

9280 ± 970

15 ± 1

27 ± 2

265 ± 24

126 ± 13

51400 ± 4600

14700 ± 4000

434 ± 41

136 ± 12

234 ± 49

11800

318 ± 55

C2-2

4.5

43800 ± 6500

9690 ± 1320

13 ± 2

27 ± 3

264 ± 32

131 ± 14

51700 ± 6000

14700 ± 4000

442 ± 56

130 ± 18

231 ± 49

13000

322 ± 61

C2-3

7.5

43800 ± 6200

8680 ± 1030

18 ± 2

28 ± 3

281 ± 30

137 ± 11

52600 ± 5400

14500 ± 4000

441 ± 49

135 ± 15

269 ± 64

13500

336 ± 61

C2-4

10.5

45000 ± 6200

9170 ± 1060

58 ± 7

28 ± 2

373 ± 37

150 ± 13

53900 ± 5100

15500 ± 4100

458 ± 47

140 ± 15

451 ± 89

14200

361 ± 62

C2-5

13.5

46100 ± 6500

9120 ± 1100

16 ± 2

27 ± 3

278 ± 29

132 ± 12

53300 ± 5400

15100 ± 4000

460 ± 52

141 ± 16

266 ± 52

14300

322 ± 57

C2-6

20.0

48400 ± 6900

9150 ± 1120

20 ± 3

28 ± 3

309 ± 33

146 ± 13

55300 ± 5500

16200 ± 4300

484 ± 53

150 ± 17

313 ± 67

14900

351 ± 62

C2-7

30.0

45000 ± 6100

9180 ± 1040

40 ± 4

44 ± 4

455 ± 44

167 ± 13

52000 ± 5000

15800 ± 4200

414 ± 41

154 ± 15

514 ± 96

14500

395 ± 68

C2-8

40.0

36000 ± 4900

9440 ± 1020

73 ± 10

157 ± 17

544 ± 51

227 ± 19

49200 ± 4900

14800 ± 4000

350 ± 35

173 ± 20

1169 ± 231

13500

518 ± 92

C2-9

55.0

33400 ± 4300

12200 ± 1300

274 ± 40

20 ± 1

774 ± 73

197 ± 14

46200 ± 4200

13500 ± 3500

406 ± 38

114 ± 12

895 ± 162

16300

492 ± 82

C2-10

75.0

31200 ± 3700

12300 ± 800

1 ± 0

14 ± 1

100 ± 6

19 ± 3

23300 ± 1600

6550 ± 1800

341 ± 24

73 ± 5

55 ± 13

6570

85 ± 14

Core C3

C3-1

1.5

46300 ± 5600

9580 ± 580

8 ± 1

26 ± 1

238 ± 14

115 ± 6

51700 ± 3100

15000 ± 4000

434 ± 28

132 ± 9

182 ± 29

9460

285 ± 42

C3-2

4.5

47900 ± 6200

10700 ± 800

10 ± 1

25 ± 1

252 ± 16

124 ± 9

55000 ± 3900

15900 ± 4300

461 ± 35

136 ± 11

201 ± 39

12300

311 ± 50

C3-3

7.5

50600 ± 6100

9320 ± 630

10 ± 1

26 ± 2

264 ± 16

121 ± 14

56900 ± 3600

16600 ± 4400

528 ± 36

146 ± 10

209 ± 38

14300

321 ± 49

C3-4

10.5

49200 ± 6700

9400 ± 830

10 ± 1

24 ± 3

262 ± 20

117 ± 12

55900 ± 4600

16400 ± 4600

518 ± 44

148 ± 15

196 ± 40

14100

297 ± 51

C3-5

13.5

51300 ± 7100

9260 ± 670

16 ± 2

28 ± 3

282 ± 15

132 ± 10

57600 ± 4200

17000 ± 5000

523 ± 34

153 ± 13

233 ± 46

14500

329 ± 54

C3-6

20.0

46900 ± 5800

9720 ± 620

18 ± 2

26 ± 2

276 ± 15

127 ± 7

53000 ± 3300

15700 ± 4200

466 ± 30

138 ± 9

276 ± 48

15000

325 ± 50

C3-7

30.0

54100 ± 15500

9840 ± 1490

28 ± 5

37 ± 7

475 ± 89

221 ± 48

58200 ± 11600

18200 ± 4300

47886 ±

176 ± 31

600 ± 124

28000

531 ± 123

C3-8

40.0

40900 ± 5300

9330 ± 540

68 ± 5

103 ± 6

511 ± 24

170 ± 8

49400 ± 3100

15100 ± 3500

364 ± 18

177 ± 10

739 ± 102

15800

426 ± 56

C3-9

55.0

39800 ± 5400

10300 ± 600

214 ± 16

28 ± 2

792 ± 34

205 ± 11

47500 ± 2900

14400 ± 3500

379 ± 19

136 ± 9

1371 ± 220

16900

486 ± 69

C3-10

75.0

31100 ± 4100

10000 ± 660

391 ± 33

18 ± 2

869 ± 43

214 ± 11

49100 ± 2700

13900 ± 3200

503 ± 30

119 ± 7

1005 ± 137

14700

428 ± 61

C3-11

95.0

41700 ± 5100

10500 ± 700

0.9 ± 0.6

24 ± 1

184 ± 9

40 ± 4

52200 ± 2900

12600 ± 2800

490 ± 23

155 ± 9

73 ± 11

10900

125 ± 17