Tellurium and Selenium Systematics in Mafic VMS from Cyprus: Mineral, Mound and Regional Scale Controls

Tellurium (Te) and selenium (Se) are critical elements used in the production of photovoltaic solar cells. Their criticality is paralleled by a poor understanding of their distribution and enrichment in a range of ore forming environments. This study aims at understanding Te and Se systematics on a range of scales in mafic VMS systems. To investigate this, >20 VMS of the Troodos ophiolite have been sampled. On a mineral scale, the distribution of Te and Se is not uniform between different sulfide phases; chalcopyrite is preferentially enriched in Se, averaging 1147 ppm (n=202), whilst pyrite averages 439 ppm (n=1570). In contrast, Te is preferentially incorporated in pyrite averaging 17 ppm compared to 6 ppm in chalcopyrite. Some VMS deposits exhibit evidence of Se remobilization leading to enrichment of Se in pyrite up to 4950 ppm. This demonstrates the significance of fluctuating fluid redox in VMS mineralisation and the enrichment of Se. Additionally, on an ophiolite scale, trace element distribution demonstrates a robust link between magmatic volatile influx and Te and Se enrichment in mafic VMS deposits