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Strontium isotopic systematics of mineralized and background water samples, Montezuma Mining District, Colorado

January 1, 2017

Surface and groundwater samples within the Montezuma mining district were sampled to evaluate the use of strontium isotopic compositions as signatures of different water types. Waters draining Precambrian metamorphic units had distinctly higher 87Sr/ 86Sr values (0.72893 to 0.73833) than waters draining Tertiaryage plutonic rocks (0.71064 and 0.71114). Waters draining mine workings along Tertiary-age mineralized veins in Precambrian metamorphic units had isotopic compositions between these two endmembers such that Sr isotopic composition could not be used as a unique signature of mining-related waters.