IDENTIFICATION OF TWO METAL CONTAMINANTS IN SOLUTION WITH CU ISOTOPES IN FIRST, SECOND AND THIRD ORDER STREAMS NEAR DEXING MINE, CHINA
In the streams surrounding the Dexing mine, two different isotope values from the dissolved minerals chalcopyrite and pyrite can be differentiated. Values interpreted as being consistent with a chalcopyrite origin have values that fractionate predictably by +1.5 (per greater). Values seen as being pyrite, or from weathered tailing piles, have unique values greater than +6 ‰, and high isotope values were seen throughout the watershed. Particulate copper isotope values in the waters are complicated and vary greatly, so no clear pattern could easily be made with our understanding of it thus far. The highest copper isotope values are tied to waters closer to the tailings’ source. The tailings themselves were found in two soil samples taken near the largest tailings site, and visible sulfides were present. The sulfides from the soil produced copper isotope values that relate directly with the dissolved copper isotope values found in the waters collected downstream of the tailing sites. With thorough sampling, unique isotope values from the dissolved pyrite tailings and the primary-source chalcopyrite allow for the tracing of the metallic pollutants throughout the complicated watershed. These techniques may be applied to other contamination zones elsewhere and prove its usefulness in tracking transition metal pollutants in other industry impacted sites.