Sources of Salts Strontium Isotopes

Jones et al. (1967) first reported that the average 8 Sj./86Sr ratio of 15 water samples from a depth profile of Lake Vanda is 0.7149 0.0(X)1 which is identical within analytical error to the Sr/ Sr ratio of 0.7146 0.0002 of strontium in the water of the Onyx River. On the other hand, the Sr/ Sr ratios of strontium in Lake Vanda and the Onyx River differ markedly from the average Sr/ Sr ratio of the Cenozoic basalt of the McMurdo Volcanics (0.7043) and from the average Sr/ Sr ratio of two samples of seawater from the Ross Sea (0.7094). These results indicate unequivocally that the strontium at all levels in Lake Vanda and in Onyx River did not originate from marine sources or by weathering of Cenozoic basalt or volcanic ash in Wright Valley. 

The profiles of the isotopic composition and concentration of strontium in Fig. 19.40 measured by Jones and Faure (1967) demonstrate that the Sr/ Sr ratios of the water in Lake Vanda are constant at all levels in the lake including the basal brine at 60 m, but that the concentrations vary with depth much like the concentrations of sodium in Fig. 19.34. Soil samples leached with acidified water and even a bulk sample of 

7157 (Meserve Glacier) regardless of whether the soil was leached with demineralized water or with dilute hydrochloric acid. 

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