Table 5 Statistical range of MDI and HQ for NO₃⁻ and F⁻ in the Samalpatti-Sevathur carbonatite complexes.

MDI (NO₃⁻)

Minimum

0.24

0.22

0.21

0.20

Maximum

8.69

8.17

7.63

7.3

Mean

2.58

2.42

2.26

2.16

HQ (NO₃⁻)

Minimum

0.15

0.14

0.13

0.12

Maximum

5.43

5.10

4.77

4.56

Average

1.61

1.51

1.41

1.35

No. of samples at risk

45

43

39

38

MDI (F⁻)

Minimum

0.0083

0.0078

0.0073

0.007

Maximum

0.219

0.206

0.192

0.184

Mean

0.084

0.079

0.074

0.07

HQ (F⁻)

Minimum

0.139

0.130

0.122

0.117

Maximum

3.65

3.43

3.21

3.1

Average

1.40

1.31

1.23

1.17

No. of samples at risk

55

52

51

50