Patterns of Ground‐Water Chemistry, Ross Creek Basin, Alberta, Canada

On the basis of the degree of mineralization, approximately 40 percent of the ground water in Ross Creek Basin may be considered as fresh (TDS < 2,000 ppm), and 60 percent as brackish (2,000 < TDS < 10,000 ppm). At least 70 percent of the ground water is potable within treatable limits. Major ion analyses of over 167 water samples reveal a strikingly consistent regional pattern of hydrochemistry. The hydrochemical pattern correlates with the flow pattern of ground water in the basin. Low total dissolved solids contents, high Ca²⁺:Mg²⁺ ratio, low SO₄²⁻, and high HCO₃⁻ occur in recharge areas, whereas opposite conditions are associated with discharge areas. In terms of hydrochemical facies, waters of the Ca‐Mg‐HCO₃ and Na‐HCO₃ types are dominant in recharge areas, and those of the Ca‐Mg‐SO₄‐HCO₃ and Na‐SO₄‐HCO₃ types prevail in discharge areas. The hydrochemical evolutionary trends appear to be strongly related to the flow paths.