The Saline Lakes of Saskatchewan III. Chemical Characterization

The salinity of Saskatchewan saline lakes varies up to 342%0. Highly saline lakes are widely distributed. Some reach saturation at high summer temperatures but salt precipitation occurs on cooling. Saline lakes tend to increase in salinity with time but the greatest changes occur in the shallow more saline lakes. The lakes are dominated by sodium, magnesium and sulphate. The cation sequences are dominated by sodium or magnesium while calcium and potassium are proportionally much smaller. Chloride or bicarbonate‐carbonate are secondary to sulphate among the anions. Ion sequences tend to be characteristic of certain physiographic regions. Lake types were magnesium (sodium) sulphate, sodium sulphate and sodium (magnesium) sulphate in order of abundance of lakes. Phosphorus and ammonia were high in concentration but nitrate and silica were scarce. The lakes were all alkaline between pH 7.8 and 9.8. The evolution of closed saline lakes is briefly discussed.