Water samples for Oxygen-18 and deuterium isotope determinations were stored unfiltered in 15 ml glass bottles and analyzed at the USGS laboratories in Reston, Virginia. Analysis of oxygen isotopes was according to the methods of Epstein and Mayeda [1953] with a precision of ±0.1‰, and the hydrogen isotopes were analyzed according to the method described in Kendall and Coplen [1985] and Coplen et al. [1991] with a precision of ±1.5‰. Ratios are reported relative to VSMOW. References: Coplen, T. B., J. D. Wildman, and J. Chen, Improvements in the gaseous hydrogen-water equilibration technique for hydrogen isotope ratio analysis, Anal. Chem., 63, 910– 912, 1991. doi:10.1021/ac00009a014. Epstein, S., and T. Mayeda, Variation of 18O content of waters from natural sources, Geochim. Cosmochim. Acta, 4, 213– 224, 1953, doi: 10.1016/0016-7037(53)90051-9. Kendall, C., and T. B. Coplen, Multi sample conversion of water to hydrogen by zinc for stable isotope determination, Anal. Chem., 57, 1437-1440, 1985, doi: 10.1021/ac00284a058.