Fig. 4

Ionic relationships: (a, b) Ca²⁺/Na⁺ against both Mg²⁺/Na⁺ and HCO₃⁻/Na⁺, (c) Ca²⁺+ Mg²⁺ against SO₄²⁻+HCO₃⁻, (d) Ca²⁺⁺ against SO₄²⁻, (e) Ca²⁺+ Mg²⁺ against HCO₃⁻, (f) Na⁺ vs. Cl⁻, (g) CAI-1 vs. CAI-2, (h, i) NO₃⁻/Na⁺ against both SO₄²⁻/Na⁺ and Cl⁻/Na⁺.