Radiocarbon and stable isotopes in water and dissolved constituents, Milk River aquifer, Alberta, Canada

The Milk River aquifer contains water which is considered to be very old and beyond the limit of 14C dating. It is also an aquifer which at first glance may appear rather simple because a sandstone confined by shales is the major water-bearing zone. However, previous authors recorded significant variations in stable isotope contents. These were explained as being largely due to physico-chemical processes. Because variations might also be expected in relation to changing input conditions, it was decided to include a complete stable isotope investigation into the evolution of 14C within the IAEA co-ordinated research project on the dating of old groundwater. This paper summarizes the distribution of 2H and 18O in water, 13C and 2H in CH4, 34S and 18O in SO4, 13C and 14C in dissolved inorganic as well as dissolved organic C, and tritium. (author)