Distribution of critical minerals in the Mount Evelyn Pb–Zn–Ag skarn deposit, Pine Creek Orogen, Northern Territory

Emerging technologies and the increasing adoption of renewable energy have driven an increase in the demand for critical minerals. To match this demand, new sources of critical minerals need to be developed, prompting research into the critical mineral potential of mine waste, historic and existing deposits. This study assesses the distribution of critical minerals in the historic Mount Evelyn Pb–Zn–Ag skarn deposit, located in the Pine Creek Orogen (PCO), Northern Territory, Australia. Primary sulfide mineralisation at the Mount Evelyn deposit comprises sphalerite and galena with lesser arsenopyrite, pyrrhotite, stannite and tetrahedrite. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) spot analyses across the sulfide mineralogy reveal that galena is the preferred host of Se (6.73–703.84 ppm), Te (0.31–31.33 ppm) and Tl (0.42–46.07 ppm); stannite is the preferred host of Ge (12.04–22.85 ppm) and In (138–248 ppm); tetrahedrite is the preferred host of Sb (26.97–33.60 wt%); and arsenopyrite is the preferred host of As (42.51–55.05 wt%), Co (10–1401 ppm) and Ni (5–1996 ppm). SEM-based automated mineralogical mapping (AMICS) was conducted across 12 samples to quantify the sulfide mineralogy. Through the combination of AMICS and LA-ICP-MS data, this study calculates the deportment of critical minerals across the analysed sulfide mineralogy. It is shown that sphalerite is the most important carrier of the critical minerals In, Ga and Ge; galena is the most important carrier of Bi, Tl and Te; tetrahedrite is the most important carrier of Sb; pyrrhotite is the most important carrier of Ni; and arsenopyrite is the most important carrier of As and Co. These findings provide a baseline understanding of the critical mineral distribution in mineralogically similar deposits throughout the PCO and globally.