Further Checks on Atmospheric Noble Gas Retention Warm Groundwater

5 Further Checks on Atmospheric Noble Gas Retention Warm Groundwater 

The closed system conditions seen in cold groundwater systems may be further checked in warm springs, that is, in waters that are trapped at a depth of 1-2 km and get heated by local (normal) heat gradients. The first study of this type was done on warm springs and wells (up to 60 °Q of the Jordan Rift Valley (Mazor, 1972). The isotopic compositions of the encountered dissolved Ne, Ar, Kr, and Xe were found to be atmospheric, that is, very close (in the range of the analytical accuracy) to the values given in Table 13.2. 

The atmospheric noble gases are presented in Fig. 13.5 in a fingerprint diagram. An overall similarity of the line patterns to those of air-saturated water at 15-25 °C is clear. Thus the relative abundances of the four noble 

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Example A spring emerges at 34 °C and is found to contain 3.8 x 10 4 cc STP Ar/cc water. Is it oversaturated, that is, does it contain more gas than expected from air equilibration at the emergence temperature The air-water solubility at 34 °C is seen in Fig. 13.1 to be 2.5 x 10-4 cc STP Ar/cc water. Hence, the observed value of 3.8 x 10-4 cc STP Ar/cc water is oversaturated by 

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