Strontium isotopic composition of some brines from the Precambrian Shield of Canada.

Groundwater samples (24) from seven operating mines at Sudbury, Yellowknife and Thompson (Ontario, North West Territories and Manitoba, respectively), all from depths >1 km and ranging in total dissolved solids 1900-250 000 mg/l, were measured for their ⁸⁷Sr/⁸⁶Sr values. Each geographic location gives a limited range in values and each location is distinct from the others. This is interpreted as the result of extensive water-rock interaction on …