Table 3. Mean elemental composition in mg kg-1 and standard errors (SE). The values of columns 0-1, 1-2, 2-3 and 3-4 represent the depth of the sample in mm and correspond to the soil within the reddish-yellow layer. The soil samples at 4.6, 13-15, 28-30 and 100-150 mm lay below this layer. T represents the sample of tailings in contact with the reddish-yellow layer and UCS the uncontaminated soil (0-100 mm).

 

0 - 1

1 - 2

2 - 3

3 - 4

4 - 6

13 - 15

28 - 30

100 - 150

UCS

T

 

Mean

 

S.E.

Mean

 

S.E.

Mean

 

S.E.

Mean

 

S.E.

Mean

 

S.E.

Mean

 

S.E.

Mean

 

S.E.

Mean

 

S.E.

Mean

S.E.

Mean

S.E.

Pb

1482.1

***

86.2

1168.5

**

146.4

779.7

**

94.3

470.0

**

82.2

80.0

 

12.5

114.7

 

12.4

90.0

 

7.8

98.3

 

12.3

81.6

6.1

9507.3

1047.3

Zn

6939.5

***

153.0

7527.1

***

419.1

10200.0

***

424.7

23090.0

***

461.8

6178.1

***

155.5

2043.2

***

73.7

673.5

***

35.6

294.3

**

31.9

100.4

3.0

8063.4

426.7

As

2233.7

***

97.7

1008.4

***

73.1

620.8

***

46.9

280.4

**

36.4

31.4

*

1.3

44.0

***

1.4

28.6

 

1.1

31.4

 

1.6

25.8

1.3

4094.1

165.5

Cu

3387.0

***

147.0

4557.4

***

456.5

7835.0

***

1000.3

11480.0

***

989.8

131.4

***

4.4

165.6

***

12.5

144.7

***

6.0

38.2

**

2.3

25.7

0.4

2175.8

205.6

Sb

22.9

**

2.7

10.6

***

1.0

7.2

***

0.3

6.3

***

0.4

2.8

**

0.2

4.4

***

0.3

3.4

**

0.3

3.3

**

0.2

1.9

0.1

820.1

68.8

Ba

211.4

 

17.8

209.2

 

15.1

210.0

 

48.6

218.6

 

8.7

246.4

 

12.7

255.0

 

12.6

251.3

 

29.1

273.5

 

19.7

296.3

10.7

794.3

72.8

Mn

334.2

 

7.4

359.8

 

16.2

364.0

 

4.5

648.3

 

81.2

804.8

 

67.1

756.7

 

136.3

734.2

 

55.1

789.3

 

19.6

816.3

120.5

723.8

34.2

Bi

12.7

***

1.4

7.1

***

0.5

4.4

***

0.3

2.2

***

0.2

0.5

*

0.0

0.5

 

0.0

0.4

 

0.0

0.4

 

0.0

0.4

0.0

85.9

8.1

Tl

5.9

***

0.2

4.2

***

0.1

4.4

***

0.4

4.3

***

0.1

2.6

***

0.1

1.1

***

0.0

0.8

**

0.1

0.9

**

0.1

0.4

0.0

66.8

4.7

Cr

43.0

 

3.0

44.0

 

10.1

41.7

 

7.6

41.3

 

2.4

47.7

 

3.4

48.6

 

2.7

62.0

 

6.5

41.6

 

4.1

93.4

22.7

63.4

5.4

Co

9.8

 

0.4

9.8

 

0.3

11.1

 

0.3

19.0

***

0.1

21.8

***

0.8

15.5

 

0.7

15.2

 

0.4

15.5

 

1.1

14.9

0.2

53.7

2.6

Cd

12.0

***

1.4

12.6

***

0.5

13.5

***

0.9

20.0

***

0.2

20.8

***

0.9

3.2

***

0.4

1.2

***

0.0

0.8

***

0.0

0.3

0.0

36.0

4.1

V

59.8

 

4.9

60.2

 

6.2

58.9

 

10.6

57.9

 

4.2

66.6

 

6.0

70.7

 

6.1

92.5

 

8.0

82.1

 

16.6

130.2

24.9

34.8

1.8

Ni

17.1

 

4.7

17.9

 

2.0

19.1

 

1.9

23.6

 

1.5

25.0

 

2.0

23.0

 

1.4

25.7

 

1.4

22.8

 

2.1

33.0

1.9

19.9

2.5

Mo

0.4

 

0.1

0.4

 

0.1

0.4

 

0.0

0.4

 

0.1

0.3

 

0.0

0.4

 

0.0

0.5

 

0.0

0.4

 

0.2

1.0

0.1

8.5

1.2

Sn

0.0

 

0.0

0.0

 

0.0

0.0

 

0.0

0.0

 

0.0

0.3

 

0.0

1.1

 

0.1

0.4

 

0.0

0.4

 

0.1

0.5

0.1

6.1

1.0

Se

0.0

 

0.0

0.0

 

0.0

0.0

 

0.0

0.0

 

0.0

0.0

 

0.0

0.0

 

0.0

0.0

 

0.0

0.0

 

0.0

0.2

0.2

5.3

0.5

Y

9.7

 

2.7

11.5

 

0.9

12.7

 

1.0

18.0

 

1.7

15.2

 

2.1

15.6

 

1.4

18.9

 

1.6

19.4

 

1.2

20.3

1.5

5.2

0.8

Th

6.2

 

0.4

7.2

 

0.7

6.6

 

0.7

6.8

 

0.6

8.3

 

0.9

7.9

 

0.5

9.2

 

0.2

8.2

 

0.6

9.6

0.5

3.7

0.1

In

6.5

***

0.3

5.2

***

0.2

3.0

***

0.2

1.1

**

0.2

0.1

 

0.0

0.1

 

0.1

0.1

 

0.0

0.1

 

0.0

0.1

0.0

2.9

0.1

Hg

0.5

 

0.2

0.3

 

0.1

0.2

 

0.1

0.2

 

0.1

0.1

 

0.0

0.1

 

0.0

0.3

 

0.1

0.2

 

0.0

0.4

0.1

2.6

1.0

Sc

7.0

 

0.5

7.6

 

1.5

7.5

 

1.4

7.2

 

0.5

7.0

 

0.2

7.6

 

0.5

8.3

 

1.4

7.9

 

0.9

17.6

5.0

2.2

0.3

U

1.6

 

0.3

2.2

 

0.6

3.3

 

0.3

4.0

 

0.3

1.6

 

0.1

1.5

 

0.2

1.9

 

0.2

1.6

 

0.3

1.5

0.3

2.2

0.3

Be

1.3

 

0.5

1.5

 

0.2

2.0

 

0.1

2.0

 

0.1

0.8

 

0.1

1.4

 

0.1

1.5

 

0.2

1.9

 

0.1

2.0

0.3

0.6

0.2

Au

0.1

 

0.0

0.1

 

0.1

0.2

 

0.0

0.1

 

0.0

0.0

 

0.0

0.1

 

0.0

0.2

 

0.1

0.3

 

0.1

0.2

0.1

0.2

0.1

 

*** p<0.001, **p<0.01, *p<0.05.