Collaborative Research: Deciphering the origin and the timing of silver enrichment in high-sulfidation epithermal deposits: The case study of Filo Del Sol deposit, Argentina

About This Grant

The increasing global demand for metals is being driven by the transition to renewable energy technologies (like solar and wind) and energy storage solutions (like batteries). Mineral deposits that are acidic and sulfur rich are called “high-sulfidation epithermal deposits.” They are formed from magmatic-hydrothermal fluids and are important sources of critical and precious metals such as copper, antimony, arsenic, gold, and silver. Despite their economic significance, the geological and geochemical controls on whether these deposits are silver-rich or silver-poor are not well understood. Because silver is often recovered as a by-product in these deposits, we need to improve our ability to predict where high-grade silver zones will occur. This is essential for progressing from exploration to economic viability and meeting growing industrial demand for silver in solar panels and batteries. This team will use geochemical and age information to evaluate different models for the origin of silver-rich deposits and the timing of silver mineralization in the newly discovered world-class Filo Del Sol deposit in the San Juan province, Argentina. Their findings at Filo Del Sol have the potential to benefit mineral exploration strategies in the U.S. and globally. In addition, students will learn technical skills needed for employment in the mining sector and it will also raise awareness for professional career paths in mineral resources. Previous studies of high-sulfidation epithermal deposits have primarily focused on the physicochemical conditions responsible for Au and Cu enrichment, while relatively few have explored the origins and timing of silver enrichment in these deposits. This project addresses this knowledge gap by investigating the nature and spatiotemporal distribution of Ag-rich ore mineralogy at Filo Del Sol, Argentina. The main objectives are to (1) characterize the elemental and isotopic compositions of both silver-rich and silver-poor ore mineral assemblages and their associated hydrothermal alteration minerals, and (2) determine the relative and absolute timing of silver enrichment within the deposit. In addition to conventional methods, this study will be the first to apply in-situ sulfur isotope and trace element chemistry, collected simultaneously from sulfides, sulfosalts, and sulfates, alongside in-situ 40Ar/39Ar geochronology of alunite and other potassium-bearing minerals, in high-sulfidation epithermal deposits. Ultimately, this project aims to constrain the timing and physicochemical conditions of the hydrothermal fluids responsible for Ag enrichment in this deposit. These findings will have applicability to the numerous other high-sulfidation epithermal deposits in the U.S. and globally. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.