Third Party Funds Group - Sub project
Start date : 01.08.2022
End date : 31.07.2024
The increasing demand of critical and energy critical elements in the high-tech industry requires a secure and steady supply of these rare commodities. Many of these metal(loid)s cannot be substituted due to their very specific application and economic grades in ore deposits exist only in a few countries, which may cause bottlenecks in the supply-chain in the near future. Hence, to secure the future supply of these strategic elements alternative sources must be explored, including those in the deep sea. Hydrothermal systems associated with subduction zone volcanism host some of the world’s most important volcanogenic massive sulphide (VMS) deposits. Many of them formed in back-arc rifts, where seafloor massive sulphides (SMS) occur as their modern analogues, some of which are characterized by high metal(loid) grades (e.g., Cu, As, Se, Ag, Sb, Au, Hg, Tl and Pb) exceeding those of deposits currently mined on land. Many of these elements have a strong affinity to volatiles derived from magmas, but it is still poorly understood how magma degassing contributes to the trace metal(loid) budget of SMS and VMS mineralizations. This project aims to quantify the geochemical fluxes in submarine back-arc hydrothermal systems from a new 3-dimensional perspective by constraining the effect (1) of magmatic volatile influx, (2) variable host rock compositions and (3) metal(loid) fractionation in the hydrothermal upflow zone on the composition of VMS and SMS mineralizations. In order to address these objectives a continuous sample spectrum from the reaction zone to the seafloor is required, which can only be fulfilled by drill cores, such as those recovered during ODP and IODP expeditions. We have identified suitable cores, which together with samples from the modern seafloor and from ancient VMS-related hydrothermal systems from the Troodos ophiolite provide a unique sample set. This approach is beyond the state of the art and requires an innovative analytical set-up combing (ultra-)trace element with Se and multiple S isotope analyses, which will allow to track the hydrothermal metal(loid) cycle through the oceanic crust, providing a new window into metal(loid) sourcing, fractionation and precipitation. This will ultimately help to develop new fundamental concepts for the economic enrichment of metal(loid)s in submarine back-arc hydrothermal systems.