Trace Metals and Metalloids Present in Springwater of a Mining Area: Assessment Based on Chemical and Isotopic Data (δ2H, δ18O, 3H and 87Sr/86Sr)

Abstract

The Taxco mining district is a well-known international producer of silver, jewelry, and precious metal handicrafts. Inappropriate disposal wastes from anthropogenic activities have been deteriorating the hydric resources and threatening the inhabitants’ health, since they use the springwater for human consumption and domestic activities. A multi-tracer approach combining measurements of hydrochemical data, trace elements, and isotopes δ2H, δ18O, 3H, and 87Sr/86Sr ratios was undertaken for 18 springwater samples. δ18O and δ2H indicate that the springwater comes from the rain and had experienced some degree of isotopic fractionation by atmospheric evaporation in some samples at lower altitudes. 3H values on the springwater showed the existence of old and new water. Three groups of springwater were identified according to age: local flow in rhyolites, intermediate flow through red beds to the outcrop point in sandstone and shales, and deep flow in greenschist. The results of this study show the utility of 87Sr/86Sr ratios in identifying the water–rock interactions and springwater flow paths, suggesting that more widespread use of the strontium isotopic fingerprint is warranted.