The Chemical Composition of some Waters from Slacks in Rameswaram Island, Madras State

Analyses of pH, total dissolved solids, CO,, HCO₃, Cl, SO₄, Ca, Mg, Na and K are presented for water samples from dune slacks in Rameswaram Island. Comparison of these analyses has been attempted with well waters from the area, sea water and world average fresh water. It is inferred that these slacks are under the influence of sea water but ion-exchange process similar to those in arid alkali soils appear to be responsible for Ca/HCO₃ ratios of less than unity and Na/Cl and Mg/Cl ratios greater than those in sea water. Exceptionally high Na₂Co₃ and NaHCO₃, contents in one of the slack waters is explained on the basis of sulphate reduction due to favourable conditions developed locally there.