SN

Durov’s Diagram Yaoundé

No.

%

Water type and hydrogeochemical process

Wet

Dry

Wet

Dry

1

${\text{HCO}}_3^{-}$ and Ca⁺ dominant, indicates recharging waters in migmatites and gneiss.

8

19

15.6

42.2

2

This water type is dominated by Ca⁺ and ${\text{HCO}}_3^{-}$ ions. Association with dolomite is presumed if Mg⁺ is significant. However, those samples in which Na⁺ is significant, an important ion exchange is presumed

10

11

22.2

24.4

3

${\text{HCO}}_3^{-}$ and Na⁺ are dominant, normally indicates ion exchanged water, although the generation of CO₂ at depth can produce ${\text{HCO}}_3^{-}$ where Na⁺ is dominant under certain circumstances

28

11

62.2

24.4

4

${\text{SO}}_4^{2-}$ dominates, or anion discriminant and Ca⁺ dominant, Ca⁺ and ${\text{SO}}_4^{2-}$ dominant, frequently indicates recharge water in lava and gypsiferous deposits, otherwise mixed water or water exhibiting simple dissolution may be indicated.

0

2

0

4.4

5

No dominant anion or cation, indicates water exhibiting simple dissolution or mixing

0

1

0

2.2

6

${\text{SO}}_4^{2-}$ dominant or anion discriminate and Na⁺ dominant; This water type is not frequently encountered and indicates probable mixing or uncommon dissolution influences.

0

1

0

2.2